SEARCH RESULT

The iron and steel (I&S) sector plays an active role in the world economy with a market share of an estimated $1,715 billion. As in other sectors, qualified production is a crucial step for international trade for I&S sector. For example; between the years 2013-2015, two major steel-producing countries of Turkey and Germany have reacted differently against the low quality steel sale from China. While the poor quality steel produced by China has no place in the German market, it has played an active role in the Turkish market. From this point of view, the effects of the accredited laboratories on the sectors they serve were examined by means of the iron and steel industry. The trend of the accredited laboratories in Turkey serving the iron and steel industry has been investigated in detail. In addition, the results were compared with Germany.

International Iron & Steel Symposium
UDCS

Betul ERCAN Yasin Akgül Alper Incesu Muzeyyen ABUNAZ Bulent AYDEMIR Murat KAVRUK

A composite surface layer of wear plate was manufactured by using centrifugal casting and M7C3 carbide particles as reinforcement. Spherical cast iron was chosen as matrix material. During casting, the machine was operated at 50-500 rpm. The samples were microstructurally characterized by optical microscopy. Energy Dispersive Spectrometer (EDS) and X-ray Diffraction (XRD) were used to determine chemical compositions of carbides and the microstructure of the composite structure. The carbide reinforcement powders were arranged in the thick composite layer of 300-1600 µm thickness on the sample surfaces by centrifugal casting. The increase of the reinforcement size, amount and revolution of the casting increased the thickness of the composite texture.

International Iron & Steel Symposium
UDCS

S. Osman YILMAZ Tanju TEKER

In this study, the work hardening amount of the work roll surface was determined via nondestructive methods. An experimental work designed to find the parameters effected to work hardening. Furthermore, a mathematical formula generated in terms of that parameters to calculate the work hardening and amount of grinding thickness.

International Iron & Steel Symposium
UDCS

Aykut BASKAYA Levent KABA

Nuclear fusion energy, as the world's primary energy source, may be among the strongest sustainable ways to replace fossil fuels. Nuclear fusion is able to supply considerable amounts of energy over millions of years. The high temperature and intensive radiation in a nuclear fusion reactor can cause damage to the structural materials. Thus, the design and structural material selection of fusion reactors are very important. Nuclear materials can be broadly categorized into nuclear fuels and structural materials. Structural materials play vital role in the economics of the nuclear power plant. Iron is obviously one of the most common elements in the structural materials in nuclear technology applications. Iron also is one of the most important materials in experimental accelerator facilities, many evaluations go beyond 20 MeV. Natural iron (natFe) and 56Fe are among the best measured materials. Many measurements exist for the natural element, as well as for the major isotopic constituent Fe-56 (91.8% of natural iron), which is the main element for steel alloys. Steel is a commonly used structural material for many nuclear applications such as reactor pressure vessels that serves as the primary containment for the nuclear fuel. We have considered minor iron isotopes Fe-54 (5.8%), Fe-57 (2.1%), and Fe-58 (0.3%). The cross sections of nuclear reactions induced by nucleons are required for the design calculations in fusion reactors and other related investigations, such as fusion, fission, accelerator-driven applications, dosimetry, and nuclear medical applications. In this study, the total cross sections values for natFe(n,tot) and 54,56-58Fe(n,tot) nuclear reactions were calculated with TALYS code and were later compared with the available experimental cross section data reported in the literature.

International Iron & Steel Symposium
UDCS

Necla Çakmak Rıdvan Baldık

The aim of this paper is to present the main concepts of advanced high strength steels (AHSS) using in the automobile industry, containing chemical composition, microstructure and mechanical properties development during production and heat treatment processing. The AHSS microstructures are obtained either appropriate cooling condition after hot rolling or by setting proper temperature cycle in the continuous annealing process of cold rolled sheets. The AHSS family can be divided into three generations. First generation of AHSS contains dual phase (DP), complex-phase (CP), ferritic-bainitic (FB), martensitic (MS), transformationinduced plasticity (TRIP) and hot-formed (HF) steels. Second generation of AHSS mainly includes twinning-induced plasticity (TWIP) steels. These 1st and 2nd generation AHSS grades are qualified to meet the performance demands of certain automobile parts. Recently there has been increased research for the development of the “3rd generation” of AHSS. 3rd generation of AHSS includes carbide-free bainitic steels, medium Mn steels and Q&P processed steels. It is aimed with the 3rd generation of AHSS to achieve improved strength-ductility combinations compared to present grades.

International Iron & Steel Symposium
UDCS

Mehmet Eroğlu

— Nowadays, the demand for energy has increased in parallel with the increasing world population and the necessity to provide diversity in energy supply has emerged. It is of great importance to ensure energy efficiency and to improve waste heat recovery applications in sectors where energy is used intensively in supplying this energy demand and supply diversity. How much more energy if the benefit is reduced to that amount of production costs and emissions, emission caused environmental problems by reducing wastes, imply avoided. In this study, the evaluation of waste heat generated by steel production with basic oxygen furnace by absorption cooling system is investigated. In this study, theoretical analysis and inference method was used. The obtained results showed that the energy thrown into the atmosphere as a waste heat is evaluated with the right methods and it contributed positively to the environment, production costs and yield.

International Iron & Steel Symposium
UDCS

Aytaç AYDIN Mustafa Karagoz Emrah Deniz

Electro-discharge process (EDM) is an important manufacturing technique for the manufacture of the hard and conductive materials. The goal of this work is to investigate the (EDM) processes using low carbon steel The work involves cutting holes by Electro discharge machine using copper electrode and using Taguchi analysis to obtain the best cut-off parameters. The impact of various parameters such as (current, pulsation on time and pulsation off time) are studied on the surface roughness, material removal rate and macro hardness. Nine samples were run by using CNC-EDM machine which used for mild carbon steel by supplied DC current values (10, 30, 50A), pulse on time (100, 150, 200µs) and pulse off time (4, 12, 25µs) uses to cut 3mm thickness of the steel utilizing the copper electrode.The result from this work is useful to be implemented in industry to reduce the time and cost. It is observed that the applied current has the most influence parameters of surface roughness, material removal rate and macro hardness while pulse on time and plus off time have less influence parameter on it. The maximum Ra, MMR and HV which are achieved was (1.813 µm, 23.523 mm3/min, 173.1), respectively. The qualitative assessment reveals that the MRR, Ra, HV were increases as the applied current increases.

International Iron & Steel Symposium
UDCS

Shukry H. Aghdeab Marwa Qasim Ibraheem Nareen Hafidh Obaeed Ali Abdul Munim Alhattab

In this study, 316L stainless steel with austenitic microstructure and low carbon S235JR quality steel material were welded. The materials were welded by cored wire-MAG welding method. In the welding process, EloxcorS309L quality rutile cored wire is used. In our study; a “Welding Method Specification (PQR)” has been followed and its standard requirements are reported. As a requirement of PQR, tensile and bending tests were carried out according to the standards. Macro images are taken from the weld region to track macro transitions that occur in the weld region. Based on mechanical values, comparisons were made with academic studies.

International Iron & Steel Symposium
UDCS

Bünyamin ÇİÇEK

Corporate social responsibility (CSR) can be as the fullfilling obligations of the individuals and areas responsible for the internal and external environment while the organizations perform their economic activities. CSR has a long history, it has changed with dynamics of society, religion and culture. This study aims to examine the perception of employees about corporate social responsibility in terms of demographic variables. Data collection method which has been chosen for this study is survey method. The data obtained through research are analyzed by using statistics hardware programme and the data is evaluated by reliability test, frequency analysis, ANOVA test, t test. The results indicate that there are significant differences in employees‟ perception of CSR according to education, occupational position and occupational experience.

International Iron & Steel Symposium
UDCS

Buket Acar

Today, parallel to the rapid development of the industry, mechanical and metallurgical properties of the steel profiles that used as structural elements for constructions need to be improved. The constructions where steel profiles are used scaling up over time, require higher strength values for the materials or larger cross-sectional areas. Larger cross-sectional area has significant disadvantages in terms of product cost due to the weight increase, and the addition of strength-enhancing microalloys has significant disadvantages in terms of raw material cost. In this study, low-carbon and non-microalloyed base quality steel profiles that neither the hard nor the very soft material structure of undesirable were subjected to quenching of the profile surface to a certain depth with the quenching method, and then tempered the cooled surface by the region which was hot in the profile center. The changes in mechanical and metallurgical properties of the materials tested as a result of the process application designed according to the steel profile quality and cross-section. According to the results obtained, it was determined that the mechanical properties of the material increased and this increment was observed by the change in the material microstructure which was caused by the applied process. As a result of the study, it has been determined that more economical solutions can be revealed with the quenching process instead of using microalloying by using rare elements in a working environment where competition is gradually increasing.

International Iron & Steel Symposium
UDCS

Mehmet Akkaş Ezgi SEVGİ Burak ÖNDER Aytaç BAŞSÜLLÜ Osman Çulha

Industry sector is a locomotive sector that provides the development of countries. Iron-steel sector is the most important part of the industrial sector. World trade has been developing due to the developments in the iron and steel industry. The demand that is affected and affected by the iron and steel sector increases the importance of the iron and steel sector with every passing day in the world conjuncture. Turkey always wants to have a say in the iron and steel industry. The idea of wanting to meet the Growing demand for the world is that Turkey is more important to the iron and steel industry. In this study, analysis of Turkey's iron and steel industry of world trade is carried out with comparative advantages in the method. As a result of the Analysis, the RCA index in the iron-steel chapters is superior to the RCA index of the iron and steel sector in Turkey's 72 and 73 chapters, in 2 parts of the foreign trade. According to RSCA index, iron and steel sector has competitive power. According to the TDI index, Turkey 72. The net importer in foreign trade in the chapter, 73 is the net exporter in the chapters. Turkey should always increase its investments in this area if it wants to take place in the world trade and continue its continuity in the iron and steel sector. Towards high technological products should feed the chapters in the industry sector sufficiently.

International Iron & Steel Symposium
UDCS

Hayrettin KESGİNGÖZ Muharrem YELDAN

In recent years, the use of Modern Maintenance Management Systems (MOBAYS) has an important place to optimize maintenance costs and increase efficiency in enterprises, factories, hospitals etc. In this study, applicability and usage performance of WEB-based MOBAYS to rail profile rolling plant was investigated. As a short brief; at the end of the usage of the MOBAYS Modern maintenance management system at the rail profile rolling plant; the rate of periodic maintenance %78.26 and the network rate %8.71 increases and in addition to this the unit stoppages %24.06 decreases, were detected.

International Iron & Steel Symposium
UDCS

Semih DOĞAN Hasan GÖKKAYA Ahmet Fatih YILMAZ

Friction welding is one of the most economical and highly productive methods in joining similar and dissimilar metals. It is widely used in the automotive and aerospace industrial applications. In the present study, the continuous drive rotary friction welding was conducted on AISI1040 and high chromium white cast iron rods under different rotational speeds (1600, 1700 and 2000 rpm). Microstructural studies were carried out by Optical Microscopy (OM), Energy Dispersive Spectrometry (EDS). The microhardness variation across the joint zone was determined. The characteristics such as hardness and microstructural changes showed by friction processed welds were compared to base materials.

International Iron & Steel Symposium
UDCS

Tanju TEKER Eyyüp Murat KARAKURT Mustafa ÖZASLAN

The Iron&Steel sector is developing day by day. In order to increase the demand for hot rolling steels, there is a need for production potential to supply this demand. For this reason, concepts such as speed, cost reduction, efficiency and quality are gaining importance in production each passing day. As in many sectors, the iron and steel sector has increased the need for advanced technology for production processes and has started the transition to automation systems. Since the systems and facilities previously operated in a manual manner do not allow for standard quality production, mass production is transited to automation systems and worked at high efficiency in production. In this study, the transition studies, parameters, measurement and recording-control phases to the automation system for the full controlled production of the products in Kardemir Haddecilik are examined and the gains of the system are explained.

International Iron & Steel Symposium
UDCS

Didem Kılıç Orhan Akyol Metehan Bacaksız

There are 4 Blast Furnaces in Iskenderun Iron and Steel Co. (ISDEMIR) and there is no system to display these furnaces during operation. Similar applications around the world were searched and samples of blast furnace imaging systems were examined. Since the types of raw materials and flammable materials used in the furnaces are unique. It has been decided to use the Infrared Camera as a suitable system. In accordance with the operating parameters of the furnace, air and water-cooling hulls were designed and it was investigated how efficient monitoring could be made in the furnace. As a result of the necessary preliminary preparation of water and nitrogen-cooled body is manufactured and assembled. In test applications, contamination was continuously detected on the camera glass, different types of nitrogen blow nozzles were manufactured to prevent contamination and different types of glass were tested. Research, development and manufacturing were carried out together with TMT Company. The benefits of the top imaging system for the Blast Furnace Process are as follows: 1. Providing operators with the opportunity to see the inside of the furnace, contributing to the improvement of the process and also reducing the maintenance costs through real-time monitoring, 2. Examining the temperature distribution diagram, 3. Operators will be able to quickly detect any abnormal condition or equipment failure in the furnace equipments. With this imaging system • Whether the flow of material is regular or irregular, • Whether there is any wear and damage in the rotary gutter, • From which area the furnace works as a result of gas permeability, • Amount of raw material powder, • How open the oven's center is, etc. provides information on issues.

International Iron & Steel Symposium
UDCS

Sertaç Kaya Cemil Bayramoğlu Ümit Gebenli

Laser ışını, malzemenin yüzeyinden daha derin noktayaa, oluşan buhar kanalı aracılığı ile ulaşır. Malzeme içine çok yoğun bir enerji taşınımı gerçekleştirildiğinden, ısı yanımı için ısıl iletkenliğinin bu aşamadaki rolü ihmal edilecek kadar az olur. Ne var ki; türbülans olayları ile ergiyik banyonun geometrisinin oluşumu ve buna bağlı olarak da elde edilen kaynak dikişinin genişliğine, ısı iletiminin etkisi büyüktür. Kaynaklı birleşmeler, oluşturulmuş ergiyik fazın katılaşması ile elde edilir. Laser ile yüksek kaynak hızlarına ulaşıldığından, katılaşma hızı da görece yüksek olmaktadır, örneğin; çelik için 103-104 K/s katılaşma hızlarına ulaşılmaktadır. Bu nedenle özellikle alaşımsız ve düşük alaşımlı çeliklerin laser kaynağında mikroyapıya ve malzemenin son özelliklerine, soğumanın etkisi büyüktür. Bu çalışmada yapı çeliğinde laser ile kaynak edilebilirlik değerlerinin deneysel sonuçları verilmiş, yapı çeliği/ soğuk iş takım çeliği, sementasyon çeliği/küresel grafitli dökme demir, krom çeliği/sıcağa dayanıklı çelik, yapı çeliği/sert metal ve yapı çeliği/alüminyum çiftlerinin laser kaynak kabiliyetleri hakkında genel değerlendirmeler yapılmıştır.

International Iron & Steel Symposium
UDCS

Ahmet Karaaslan

Vickers microhardness values depended on the load applied. Therefore, it would be beneficial to establish a relationship between the results of the study made for the same material. This relationship between the microhardness value and the applied load is expressed as the track size effect (ISE), and it is examined with ISE models and curve fitting equations. In this study, AISI 1040 steels are investigated which have been the quenched and different temperatures tempered. Load values selected for experimental studies are total 7 values from 50 gram to 2000 gram. The experimental results were compared with HaysKendall and MPSR models. The results showed that both ISE models were compatible with similar sensitivity with the experimental results. However, a correlation was found between the Hays-Kendall model coefficients and the Vickers hardness values. From this relationship, equations were obtained which may be useful in comparing a hardness value measured using any microhardness load with the results of different microhardness loads.

International Iron & Steel Symposium
UDCS

Erdal Karadeniz

In the packaging industry, double-reduced (DR) tin plate materials are produced by the deep drawing process and are mostly used in the production of twist-off cap. However, one of the most common problems in the deep drawing process is the earing. This problem increases the cost of scrap cutting and therefore decreases the production efficiency. In this study, texture analysis were carried out by using electron backscatter diffraction (EBSD) technique to clarify formation of earing. The earing test, optic microscope (OM) examination and EBSD technique were performed to material, which has same chemical composition but three different thicknesses (0.14 mm, 0.17 mm and 0.19 mm) in order to characterize the earing behavior. It was determined that the earing value decreased with the increase in thickness. In addition, it was confirmed that the earing were related to <111> // ND fiber intensity, gamma (γ) fiber distribution and grain size.

International Iron & Steel Symposium
UDCS

Ramazan UZUN Umran BASKAYA Yasemin KILIC Kemal DAVUT

Material scientists have developed a variety of synthesizing approaches and methods for synthesizing new families of materials called advanced or “high-tech” materials that exhibit exceptional and superior chemical, physical and mechanical properties. Metal matrix composites reinforced with nano particles are very promising materials, suitable for a wide range of applications. In this study, nano Al2O3 was reinforced in micro sized iron powders. Al2O3 nano powder was added to iron powder at rates of 1, 2, 3, 4 and 5 wt%. The samples were prepared by mechanical alloying, pellet pressing and sintering processes. Grinding and polishing processes were applied on the sample surfaces at various levels for metallographic investigations. The densities of the samples decreased with increasing in additives amount, but it was an important result of reaching 77% ratio of the theoretical density of the measured density in dry pressing. The hardness values increased linear with the increase in the amount of additives. The highest hardness value of 121,33 HV1 was reached with at the rate of 5 wt%.

International Iron & Steel Symposium
UDCS

Açıkgöz A Aktaş B Demircan G Amasyalı F Akdemir F

Production lines in factories are producing not only the products but by products and wastes. Steel machining plants are producing steel parts with steel chips and oxidized metal scale. Pipe production lines uses steel strips to produce steel pipes. In pipe producing process, pipes are machined to cut welding bent, welded pipes are shot blasted with steel granulates and oxidized metal scale is broken in shaping processes. All these production steps are producing oily sludge of pipe production lines. Machining operation cooling and greasing oils causes sludge to be oily. This oily sludge is considered to be a hazardous waste and sent to be treated in waste treatment centers. In this study oily sludge is characterized in order to understand characteristics of oily sludge and develop possible recycle technologies.

International Iron & Steel Symposium
UDCS

Samet Ballı Yeşiltepe Yeşiltepe Mustafa Kelami Şeşen

Corrax steel belong to the PH martensitic stainlesssteel family and it’s mechanical specifications and chemical composition are similar with PH 13-8 Mo. PH steels offer to the users high strength and hardness through precipitation hardening. The high specifications and high ductility of this steel make it hard to machine. Especially high ductility causes lamellar and continuous chip formation in machining. This type of chips coils up to the workpiece and cause surface defections on the workpiece surface. This study investigated the different chip formations in orthogonal machining of Corrax Steel. Results shows the high cutting speeds and high feed rates breakes the chips instead of low cutting speeds and low feed rates.

International Iron & Steel Symposium
UDCS

Ahmet Serdar Güldibi Halil DEMİR

In the automobile and steel industry, zinc-based electrogalvanized coatings have an increasing interest as they have excellent resistance to corrosion and mechanical properties. In the literature, however, there is insufficient research into the application of conversion coating to electrolytic zinc-coated steels and corrosion behavior. In this study, the corrosion behaviour of free cutting (Ç-1113) steel in different thickness of electrolytic zinc plating was investigated using electrochemical methods. In these methods, potential ve time change, AC impedance and current – potential curves were taken into account respectively. Corrosion potential (Ecor), corrosion current (icor) and other corrosion parameters were determined from current-potential curves. Steel samples coated in cyanide baths were obtained in thicknesses of 10 µ and 20 µ. Two different processing times were used for this. The basic cyanide zinc coating bath was prepared by adding (1 gram per liter of zinc (Zn (CN)2) zinc cyanide, 85 grams (NaOH) sodium hydroxide, 40 grams (NaCN) sodium cyanide and 5 grams zinc brightener (patent)). After this coating, samples were passivated by immersion solution in % 20 CrO3 +% 3 H2S04 +% 3 HNO3 for 60 seconds. After the current-potential curves of the coated steel samples were taken in aqueous medium, the change in the composition of the surface was investigated by SEM / EDS and XRD analyzes. The corrosion behaviour and corrosion rates of coated steel samples in aqueous medium were determined by three different methods. As a result, it was shown that the corrosion of 20 µ zinc coated steel samples in neutral environment decreased by 91% after the passivation process.

International Iron & Steel Symposium
UDCS

Şengül Danışman Mustafa Maşlak

Corrosion is an important problem encountered in metals and alloys.One of the effective solutions to protect against atmospheric corrosion is the electrolytic zinc coating. In this study, the corrosion behaviour of free cutting (Ç-1080) steel in different thickness of electrolytic zinc plating was investigated using electrochemical methods. In these methods, potential ve time change, AC impedance and current – potential curves were taken into account respectively. Corrosion potential (Ecor), corrosion current (icor) and other corrosion parameters were determined from current-potential curves. Steel samples coated in cyanide baths were obtained in thicknesses of 10 µ and 20 µ. Two different processing times were used for this. The basic cyanide zinc coating bath was prepared by adding (1 gram per liter of zinc (Zn (CN)2) zinc cyanide, 85 grams (NaOH) sodium hydroxide, 40 grams (NaCN) sodium cyanide and 5 grams zinc brightener (patent)). After this coating, samples were passivated by immersion in solution % 20 CrO3 +% 3 H2S04 +% 3 HNO3 for 60 seconds. After the current-potential curves of the coated steel samples were taken in aqueous medium, the change in the composition of the surface was investigated by SEM / EDS and XRD analyzes. The corrosion behaviour and corrosion rates of coated steel samples in aqueous medium were determined by three different methods. As a result, it was shown that the corrosion of 20 µ zinc coated steel samples in neutral environment decreased by 93% after the passivation process.

International Iron & Steel Symposium
UDCS

Şengül Danışman Mustafa Maşlak

During the life of a coke oven many types of damage can appear which affect the productivity of the process and production. To keep coke oven batteries in service for many years, various methods of repair (gunning, ceramic welding etc.) applies in different periods. Erdemir Coke Oven Plant Batteries has repaired via fused silica modular bricks since 2009. Each step of hot repair has been improved in cooperation with repair company. The Fused silica modular brick method using less than 10% of conventional shapes, has enabled rapid push to charge down times. By using zero expansion brick after repair work it doesn’t needed complex heating regime and long heating time. During repair time, less production loss, less manpower needed are biggest advantages of this method. At last repair, before charging of repaired oven, oven sole repair has done first time by using self-leveling material. Self-leveling repair method is rapid, smooth and easy way of the oven sole repair.

International Iron & Steel Symposium
UDCS

Bülent ÖZTÜRK Adnan NEHROZOĞLU Murat YAMAN Ozan TURHAN

The values of the Grubel-Lloyd, Vollrath and CEP indices are important indices used to show the countries' competitiveness levels. Turkey wants to prove and maintain its presence in the iron and steel sector, which has been the locomotive sector of industrialization for years. Turkey's iron and steel industry competitiveness, to a comparative analysis with countries Grubel-Lloyd, Vollrath and CEP indices were calculated for the years 2001-2017. As a result of analysis, Turkey; It operates in-industry trade against the USA. In Addition, it has a comparative advantage in the field of iron and steel and its competitiveness is quite high. The country where we have the highest competitive power and export share is USA, considering the intra-industry trade values. In industrial trade, which is the feature of Industrialised Country, Turkey sells significant amounts of iron-steel out and also buys it from outside. Considering these analyses; In the iron and steel sector, which is a capital-intensive sector, iron-steel sector investments should be encouraged in order to maintain the increase continue in competitiveness observed against the USA and increase its competitiveness. For This, financial arrangements such as the necessary infrastructure investments and tax incentives appear to be a viable policy.

International Iron & Steel Symposium
UDCS

Hayrettin KESGİNGÖZ Muharrem YELDAN

Bending fatigue lives of resistance spot welded (RSW) joints using commercial DP600 and DP1000 advanced high strength automotive sheets were compared in this study. Advanced high strength steels, especially DP600 and DP1000 steels which are used in this study, are the most important metal materials in which today's automotive body and attachment parts are produced. The materials used for the manufacture of the vehicle under dynamic conditions need to be identified of their all features are vey important. The literature has mainly focused on axial fatigue. Fatigue lives of base material and resistance spot welded joints obtained from different welding parameters were investigated by using two different high strength dual phase steel. It was seen that as the welding current increased and the electrode pressure increased up to a certain value as in the axial fatigue, the bending fatigue life was increased from the results of this study. Direct proportional relationship was obtained between the weld nugget size and fatigue life. 7 kA-4 bar (DP600) and 7 kA-3 bar (DP1000) welding parameters yielded better fatigue life. DP1000 and DP600 steel sheet samples have similar fatigue life values in low cycle fatigue. It was also seen that DP600 steel had better fatigue life than DP1000 in high cycle fatigue.

International Iron & Steel Symposium
UDCS

Muhammed Elitaş Bilge Demir

In this study, effect of air cooling from intercritical austenitizing temperatures on microstructure and hardness in GGG70 grade ductile cast irons. For this aim, ductile cast iron specimens air cooled from intercritical austenitizing temperatures at 780°C, 790°C, 800 °C, 810 °C, 820 °C, and 830 °C for 30 minutes. Experimental results showed that, pearlite volume fraction and hardness increased with increasing intercritical austenitizing temperatures. It can be produced ductile cast irons which has different pearlite volume fraction by controlling intercritically austenitizating in same chemical composition GGG70 grade ductile cast iron.

International Iron & Steel Symposium
UDCS

Mehmet Uğur Söğüt Serdar Uğurlu Volkan Kılıçlı

— In present study, the morphology, structure and corrosion properties of electroless NiP/NiB duplex composite coatings on ferrous powder metal (PM) compacts were investigated. Some of the coated samples were heat treated at 400 °C for 1 hour. The morphology, structure and chemical composition of the coatings were analyzed by SEM, XRD and EDX. The corrosion resistance of PM compact and the coatings in 3.5% NaCl solution was assessed by polarization studies. The corrosion potential (Ecorr) and corrosion current density (icorr) were determined using the Tafel extrapolation method. The NiP/NiB duplex coating results in a significant increase in the corrosion resistance of the PM compacts. However, the applied heat treatment affects corrosion resistance of the coatings negatively.

International Iron & Steel Symposium
UDCS

Ulaş MATİK

-In this study, Cr, Mn, Fe, Co, Ni and Al elements using vacuum arc Melting production method with high entropy (CrMnFeCoNiAl) alloy (YEA) was produced. Valence Electron Concentration (VEC Value) of the high entropy alloy produced was calculated as 7.67. The dendritic and interdentritic structures of high entropy alloy microstructures were observed. In the SEM mapping studies, it was observed that the distribution of the elements was homogeneous. The hardness value was measured as 46.95 HRA. The results are discussed by comparing.

International Iron & Steel Symposium
UDCS

Yusuf Karaca Cemal ÇARBOĞA Bülent KURT

The Charpy impact test is a well-known material testing method used to determine the amount of the energy absorbed by the material during fracture and to investigate the material behavior at high strain-rate during impact. Nowadays, it is widely used in many industries to determine appropriate material and design in engineering applications such as pressure vessels, bolts, and bridges. Although it consists of straightforward components, in order to obtain accurate results, it is crucial to perform the tests under standardized conditions and a user-friendly environment. Thus, the aim of this work is to design and manufacture a cost-effective, user-friendly, in-house Charpy impact tester using Arduino. A Charpy tester with a maximum capacity of 48 J was designed in a CAD environment and its each component were manufactured and assembled into a solid body. In addition, to prevent plastic deformation during the fracture, the hammer was heat-treated. For a user-friendly control panel, a LCD screen was mounted to display all experimental data including the impact energy for each sample. The data acquisition was realised using an Arduino UNO microcontroller board equipped with a SD card module. The system enables the saving of measurement sets in separate .csv files (comma separated files), an open and widely accessible format. The system can be used in two different modes: display only mode (when no SD card inserted) or display and save mode (when an SD card is detected). Another advantage of the system is the possibility to simulate the integration of the different modules thanks to the Arduino platform. The calibration of the device was realized according to international standards. The obtained Charpy impact tester, thus can be used confidently for future planned investigations and the described procedure can be implemented for different material testing equipment to achieve cost-effective and user-friendly designs.

International Iron & Steel Symposium
UDCS

Necati Uçak Görkem Ünlü Mustafa Yediparmak Serife Akkoyun Anıl Kurt Mehmet O. Şahin Ömer T. Dolanbay Adem Çiçek

This study includes device design and design for determining the performance of rigid round thin wires under a bending rotating fatig load over a given lifetime. Small diameter wires are thin wires with a diameter equal to or greater than 1.60 mm (0.63 inch). Bending rotating fatig tester ensures that the wire is rotated at constant speed and subjected to constant amplitude bending deformation. For this purpose, the wire retaining pliers are parallel to each other and the wire between the pliers is 180° paralel. After the speed is entered to the driver, the AC motor power is started by means of the belt-pulley and then transferred to the gears with the help of the cardan shaft. The number of cycles is transmitted to the counter by the encoder and recorded. The number of cycles can be generated in response to the bending deformation applied. The test device was reproducible and healthy.

International Iron & Steel Symposium
UDCS

Emre Demirci Hayrettin Ahlatçı Yavuz Sun Yunus Türen Hüseyin Koymatcık

By rolling the materials between two rollers with a cylindrical shape rotating around their axes, the forming process is called rolling.Rolling systems in the rolling mill sizes are much higher than the weight of the produced part.The rollers are subject to sudden cooling and wetting conditions in hot environment during operation.In such cases, the life of the rollers should monitor and the roller must be re-heat treated without any errors.In our study, it was aim to remove the microstructure map of the roller by taking image replica with non-destructive examination method on the roller.With this process, an instant check will make without disassembling and damaging the roller.The images obtained by the replica method will be determined using the Deep Learning method in computer systems.The images will be compare to the actual images by this modelling and the crack tendency will be estimate.

International Iron & Steel Symposium
UDCS

Selim Özdem İlhami Muharrem ORAK Bünyamin ÇİÇEK

The use of advanced high strength steels in industrial applications has been gradually increasing. In bending operations, it is extremely important to obtain parts at accurate dimensions. Depending on the properties of the material and operation used, bending process results with springback. In this study, the effects of punch radius, sheet material thickness, and material type on springback in U-bending operations were investigated. Springback values of the materials were determined by analyzes using Deform software. DP600, DP1000 and JAC270 sheet materials were used for bending analyzes. In addition, the effects of bending parameters on springback were identified using the Taguchi method. Studies have been carried out based on the Taguchi L27 vertical index. The effects of bending parameters on springback were evaluated by using variance analysis (ANOVA) and the main effect graph with the 95% reliability. Finally, a regression analysis was performed to estimate springback values and a model was created.

International Iron & Steel Symposium
UDCS

Selin Yıldırım Hakan Gürün Hakan Dilipak

—In the aim of this study; the determination of life in steel materials used in different temperature conditions in thermal power plants has been conducted. In these systems, basic steels with low C levels are use at low temperatures and Cr-Mo added special series steels are use at high temperatures. In cases where the creep resistance is of great importance, the choice of material according to the level of creep resistance comes to the fore. In the industry, non-destructive testing methods have been develop in order to conduct investigations in the actively working systems. There are many volumetric and superficial tests in welded joints. In the non-destructive tests carried out on the material, with replica microstructure copying and mobile measurements come to the fore. In this study, the determination of life of ASTM SA192 quality steel materials, which a reactive at low temperatures, has been studied. Replica microstructure was replicate through a working system and the images were compare according to the first material. Because of this comparison, changes in material microstructure were determined as grain growth. Hardness and thickness values obtained by mobile devices were also exam according to the first material. As a result, 338C temperature and 39 bar internal pressure in the working material, because of 140000 hours, a 17% reduction in thickness and hardness (HB) was seen a decrease of 21%.

International Iron & Steel Symposium
UDCS

Bünyamin ÇİÇEK Yavuz Sun Hayrettin Ahlatçı Yunus Türen

The modern automotive industry is increasingly reducing the weight of vehicles by applying new technologies to materials processing and lightweight materials, thus reducing the fuel consumption. Advanced High-Strength Steels are good potential for this purpose. In this context, Dual Phase steels of grade 600 and 800 were investigated in this study. A tailor-welded blank was produced by CO2 welding of DP600 and DP800 steels in 1,8 mm and 1,5 mm thickness, respectively. The effects of laser power and welding speed on mechanical properties of tailorwelded blanks were examined. It was found that laser power of 3 kW and welding speed of 4 m/s are the best combinations in terms of yield and tensile strength, strain hardening exponent and strength coefficients of the laser welded blanks.

International Iron & Steel Symposium
UDCS

Ekrem Öztürk Hüseyin Arıkan Serkan Toros Mehmet Kayrıcı

Reference materials (RMs) are one of the basic materials used by the laboratories to prove the reliability of their test results. In this research, preliminary studies have been carried out to develop reference materials (RMs) according to ISO 6892-1 tensile testing standard. For this purpose, EN 10130:2006 quality 1 mm thin sheet steel was prepared as appropriate to standard. Homogeneity tests and inter-laboratory comparison tests were performed. Results of these tests and reproducibility criteria that specified in ISO 6892-1 were evaluated to understand the qualification of the produced RMs. It was considered that samples can be accepted as RMs with the application to IAF member organizations.

International Iron & Steel Symposium
UDCS

Betul ERCAN Alper Incesu Engin ÇEVİK Yasin Akgül

One of The main purpose of fracture mechanics is materials selection compatible with the fracture toughness. The higher stress at crack tip and lower zone of fracture area provides less dimensions and crack length of specimens. According to ASTM E 399, evaluated KIC, measured plane strain fracture toughness (KIC) related to parallel direction of crack propagation which is lower than cross sectional area, occurrence of pre-crack, selection of COD gauge, type of cracks, and drawbacks during the measurements are clarified.

International Iron & Steel Symposium
UDCS

Fazil Hüsem

Iskenderun Iron and Steel Co. (ISDEMIR) is an integrated iron and steel facility, which produces both long and flat products from production of iron ore. Wire rod, billet, coil with mill edge, slitted or trimmed coil and cut length plate can be stated Isdemir’s product mix. Each of these products have different usage areas and customer expectations. ISDEMIR has a wide range of application areas with the hot rolled flat products or long products, which are expressed as wire rods-billets in order to respond to the customers', who operated in the industrial area and have different demands and expectations, requests. Some of the usage areas in long products are carbon steels for thin wire drawing, carbon steels for wire drawing, high carbon steels, steels for mesh quality steel production, micro alloyed and non-alloyed high strength carbon steels for wire-spring-rope production, steels for electrode and welding wire production, steels for bolt production, carbon steels for nail, angle iron and profile production, steels for ship profile production, structure steels for angle iron and profile production and sulphur alloyed high carbon steels etc. Micro-alloy high-strength steel grades with excellent results in high-strength applications for flat products are used in the production of wheel rim and chassis parts, which requires high strength and superior formability in the basic input of automotive. Boiler steels suitable for use under high temperature and pressure are used in the production of boiler and pressure vessels. Due to high formability, excellent weldability and toughness properties, tube steels are used production of LPG tubes, which are exposed to high temperature and pressure. Medium and high strength shipbuilding steels, which provide superior weldability and desired toughness values, are used in shipbuilding (ship parts, keel etc.). General structural steels, which can be welded by conventional methods, provided ductility and toughness optimization with guaranteed their mechanical properties, are mainly used in manufacturing of construction and construction equipment, general construction plates, road and railway vehicles, storage tanks and containers.

International Iron & Steel Symposium
UDCS

Muhammet Bilen Nalan Gül Uğur

The cryogenic process is a complementary process that has been used for the development of mechanical and physical properties for a variety of materials. It has been accepted commercially as an effective procedure for achieving complete martensitic transformation in alloyed steel. The aim of this study is to investigate the effect of deep cryogenic process (- 196°C) on the wear properties of spring steels with different alloying elements. For this purpose, conventional heat treatment (CHT) and deep cryogenic treatment (DCT) procedures were applied to spring steels which alloyed with different elements in order to reveal the effectiveness of deep cryogenic treatment. Consequently, by examining the hardness and wear resistance of the cryogenic-treated steels, it is aimed to reveal the effect of alloying elements on the cryogenic processing of steels.

International Iron & Steel Symposium
UDCS

Reşat Can ÖZDEN Mustafa ANIK

In today's industry, synergistic controlled MIG/MAG welding machines are widely used. These machines are used in automotive, construction, white goods, almost all sectors. In order to increase efficiency in production and the desired quality standards, it is great importance to increase the speed, penetration and quality of the welded seam especially during welded production. In order to achieve high wire feed rate, metal transfer in high amperes is required. This situation creates a restrictive factor for certain materials below certain thicknesses, as this leads to high heat input. To understand the metal transfer methods and to determine which parameters provide optimum mechanical properties are important in synergistic controlled welding machines. The comparison of the geometry and mechanical properties of the weld beads obtained by changing in the parameters of synergistic controlled MIG/MAG welding machines is the subject of this study. The samples which were welded using constant welding speeds and voltage values were investigated.

International Iron & Steel Symposium
UDCS

Yavuz Selim Ceran Mustafa ACARER Necati Ataberk

In this study, isothermal annealing was performed to C70 quality steel sheet in a salt bath at 250 °C and 350 °C for 10 s, 1 min, 10 min, and 60 min after austenitizing performed at 850 °C for 150 s and the samples were then tempered at 415 °C for 150 s. Effect of these heat treatments on microstructure, hardness and bending properties was then investigated. Results showed that the initial ferrite and pearlite microstructure generally transformed into martensite. Tempered martensitic microstructure was obtained after tempering heat treatment. Hardness of the samples has a decreasing tendency with increasing annealing times at a given annealing temperature. Tempering heat treatment decreases the hardness values obtained after isothermal annealing, as expected. However, hardness values after tempering did not exhibit a significant variation with respect to isothermal annealing time. As compared to original sample, the application of tempering after isothermal annealing increases bending strength, and bending strain also increases getting closer to values exhibited by the original sample.

International Iron & Steel Symposium
UDCS

Serdar Kuzkaya Yakup Yurekturk Faiz Muhaffel Murat Baydogan

In this study, laser surface hardening process was applied to the 8620 steel which is used in the parts, for the machines and automobiles, gear wheels, pins and shaft enamel. Laser power and laser feed rate were determined as laser surface hardening parameters. It has been studied between 1050 and 1400 W as laser power. 4 and 6 mm velocities were preferred as the feed rate. The hardness of the samples was measured under 500 g (HV0,5) load for 15 seconds. Nikon brand optical microscope is used for microstructure studies. According to the hardness results, the hardness of hardness of 8620 steel was obtained with 1400 W laser force and 6 mm feed speed.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ Mehmet Akif Erden İsmet Faruk AYDIN

Inconel 718 superalloy was nitrided for 10 h in a fluidized bed reactor containing Al2O3 particles as the carrier of the ammonia + nitrogen gas mixture in between 375 and 450°C. The structural characteristics of the nitride layers and the effect of nitriding on high temperature wear properties of Inconel 718 superalloy were investigated. A significant increment in surface hardness (from 495 to 1735 HV) was achieved after nitriding treatment carried out at 400 °C. The applied nitriding treatment led to formation of a nitrogen enriched surface layer exhibiting superior wear resistance at 600 °C when compared to untreated state of the Inconel 718 superalloy.

International Iron & Steel Symposium
UDCS

Tuncay Turan Hasan Guleryuz Huseyin Cimenoglu

In this study, the DP600 and DP1000 steel sheets were joined with the pulsed Nd: YAG (Neodymium-doped Yttrium Aluminum Garnet (Y3Al5O12)) laser welding and mechanical properties of the welds were investigated. Performing dissimilar weld of DP steel sheets is an inevitable demand in the modern automotive industry. In the laser welding process the selection of the welding parameters affects the final properties of the welds substantially. So, the main objective of this study was determining the influence of pulse frequency on the mechanical properties of pulsed Nd:YAG laser welded DP600-DP1000 steel sheet joints. So, dissimilar (DP600-DP1000) steel sheets were welded in the flat position with the butt joint. In order to evaluate the welding performance, macrostructural studies and mechanical tests were performed and experiments carried out in this context including optical microscope examinations, tensile tests and Vickers microhardness measurements.

International Iron & Steel Symposium
UDCS

Oguz Tuncel Hakan Aydin Sukriye Cetin

This study aims to investigate the effect of reduced graphene oxide (rGO) on microstructure, hardness and electrochemical corrosion performance of pure iron. The microstructure investigations were carried by optical and SEM microscopes. The electrochemical corrosion tests were conducted by potentiodynamic polarization test in 3.5% NaCl solution. The results showed that rGO-reinforced sample showed slightly higher hardness value. On the other hand, the corrosion performance of pure iron was significantly improved by the addition of rGO due to the reduced reduction kinetics.

International Iron & Steel Symposium
UDCS

Hüseyin Zengin MUHAMMET EMRE TURAN

In the present study, the effect of section thickness on the austemperability of Cu alloyed GGG-70 (EN-GJS-700-3) nodular cast iron automotive crankshafts have been investigated. Crankshafts were austenized at 950 °C for 2 h and austempered at 350 for 90 and 120 min. Optical microcope equipped with image analyse software was used to perform microstructural investigation and hardness tests were done to determine mechanical properties. It was shown that section thickness had important influence on austemperability. In the thin sections, ausferrite microstructure has been observed, whereas, in the thick sections, pearlite was formed to due to insufficient cooling rate.

International Iron & Steel Symposium
UDCS

Ali Keleş Gönül Coşkun Mehmet Yıldırım

In this study, Fe-based composites containing 1, 2 and 4% (by weight) SiC were produced by conventional powder metallurgy method. The powders were weighed in the sensitive balance and pressed under pressure of 750 MPa after 1 hour of blending. After pressing, the composite materials were sintered at 1100 °C for 1 hour. With the increasing the amount of SiC, the decrease in density amounts, the increase hardness and porosity values were determined.

International Iron & Steel Symposium
UDCS

Mehmet Akif Erden Hasan Karabulut

In this study, low alloy Cr-W steels containing 3% and 5% Cr and 3% W as main alloying element were produced via casting in ceramic mold and then hot rolled. Steels were produced both without Ta and with 0.1% by weight Ta. The purpose of this study is to investigate the effects of addition of Ta as alloying element to the microstructure and hardness of low alloy Cr-W steels. Before microstructure characterization and hardness test all samples were heat treated. Heat treatments were performed as (annealing, air quenching) and (annealing, air quenching and tempering). Annealing were performed at 1100 ℃ for 1 hour and tempering were performed at 710 ℃ for 2 hours. Microstructures were analyzed by optical microscope and the Brinell hardness test was used to determine the hardness of steels. 3 Cr steel has a microstructure of ferrite and bainite. 3 Cr steels containing 0.1% Ta has a microstructure of ferrite and bainite, too. But Ta-containing 3 Cr steel has less ferrite than Tafree 3 Cr steel. 5 Cr steel has a microstructure of bainite and martensite. 5 Cr steels containing 0.1% Ta has a microstructure of bainite and martensite, too. But Ta-containing 5 Cr steel has less bainite than Ta-free 5 Cr steel. 5 Cr steels which annealed and air quenched have highest hardness and 5 Cr steel which annealed, air quenched and tempered has lowest hardness.

International Iron & Steel Symposium
UDCS

Gökhan Arıcı Mesut Uyaner Mustafa ACARER

-In this study, termite welding process was applied to R260 quality railway rails. Residual stress of original and termite welded rails was measured according to the DIN EN 13674-1 standard. Strain gauges were attached in the middle of the rail foot (also welded part of rail). Cutting was performed than strain values were obtained. Wear test was also performed under 50N. Results show that, residual stress was increased after the welding process and wear rate value was lower than original rails in head part of termite welded rail.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ M. Emre TURAN Mustafa DURSUNLAR

GX300CrMo27 samples which were reinforced by Ti-B as 1-2.5 wt% have been produced. The first three samples for each samples were heat treated at 1000 oC. The specimens’ heat treatment time have been changing between 1, 3 and 6 h. The last sample was not heat treated for comparison. The abrasive wear tests which have loads of 10, 20 and 30 N was performed to the samples to determine the abrasive wear characteristic. In addition, SEM images of all samples were taken to examine the effect of reinforcement and heat treatment on the carbide morphology

International Iron & Steel Symposium
UDCS

SERDAR OSMAN YILMAZ Nurdoğan AKSOY Alper KARAKOCA

Low carbon steels have been used in a wide range of shipbuilding applications due to their low cost, high workability and good weldability. However, they have relatively low hardness which lead to low wear resistance. As well known, wear of engineering materials is an important phenomena and needs to be improved by any means. It is also well known that harder materials provide relatively high wear resistance and low friction coefficient. There are various ways to enhance the hardness of steels. Grain refinement by sever plastic deformation (SPD) is one of them. Among SPD methods, equal channel angular pressing (ECAP) is one of the most commonly used one due to its capacity for achieving bulk fine-grained (FG) materials. According to the available literature, no study has been performed on tribological properties of FG low carbon shipbuilding steels via ECAP. Therefore, the main purpose of this study is to enhance the wear resistance of a low carbon ship building steel (ASTM 131A) by formation of FG via ECAP. The tribological behavior of the steel before and after ECAP was investigated by a reciprocating-type tribometer (UTS Tribometer T30M-HT). According to the experimental results, FG formation by ECAP resulted in a considerable increase in hardness from 130 Hv0.5 to about 283 Hv0.5. FG formation affected the wear resistance of the steel. After ECAP, the wear rate of the steel samples slightly decreased due to the improved hardness values.

International Iron & Steel Symposium
UDCS

Dursun Murat Sekban

In this study, it was aimed to determine the effect of welding current on tensile shear load, elongation, nugget diameter and indentation in triple welded FEP05 and FE 600 DP steel sheets by electrical resistance spot welding. In the triple welding process, FE 600 DP sheet was in the middle and FEP05 sheets were on the edges. Electric resistance spot welding operations were carried out successfully. When the welding current values were increased from 7 kA to 10 kA, the tensile shear load increased while the overall elongation decreased. With the increase of the welding current, the percentage of indentation showed an increase close to the linear. The nugget diameter increased with the welding current up to 9 kA, but the welding current decreased over 9 kA.

International Iron & Steel Symposium
UDCS

Oguz Tuncel Hakan Aydin Levent Selova

Reactions between refractory-slag and refractory-liquid steel adversely affect the chemical and mechanical stability of refractories. Therefore, the development of slag corrosion and wear resistance, chemical stability and mechanical properties of refractories are important for the enterprises. In this study, the effects of metal antioxidants on the physical, chemical and mechanical properties of MgO-C bricks were investigated. Al, Mg and Al + Mg (1:1 ratio) metal antioxidants were added in 1-2-3 wt.% to MgO-C refractories containing different amounts of C (8 and 12 wt.%). Slags obtained from Kardemir A.ġ. was placed inside the refractory crucibles produced from MgO-C. Refractory crucibles containing slag were gradually heated up to 1555 ˚C and refractory-slag corrosion tests were carried out by holding for 2 hours and then cooling in the furnace. Also, carbon oxidation index, porosity, cold compressive strength and density of the refractories were determined. Increasing the amount of antioxidants in refractory materials have positive effects on the porosity and oxidation index. According to the results, the lowest porosity and oxidation index were observed at the refractory material containing 12 %C and 3 %Mg. However, the best cold compression strength and mass loss values were observed at the refractory material with 8 %C that contains Al+Mg antioxidants. According to the density measurements, the refractory material with 8 % C and 3 % Mg antioxidant have the highest density. The addition of antioxidants positively influenced the porosity, density, cold compression strength and oxidation resistance of refractory materials. Among the antioxidants, Mg antioxidant was found to be more effective.

International Iron & Steel Symposium
UDCS

S. ZENCİ A. GÜNGÖR

Integrated iron and steel industries have many plants that generate more than one industrial waste, especially in the iron production unit. Whereas some of these industrial wastes are used in the iron-making process, some of them are stored in open areas. Blast Furnace Sludge (BFS) and Tar Decanter Sludge (TDS) are good examples as a waste material which are stored in the open areas. These materials cannot be used in iron and steel production due to some restrictive reasons. Within the scope of the evaluation of these two wastes at the same time, a serial of tests was carried out in the Moving Wall Coking Test Oven at Erdemir and Isdemir Coal and Coke Laboratories. In these tests, single seam coking coals (low, medium and high volatile) were milled to be 85% below 3, 15 mm and the BFS was fixed at 0.5% and the TDS was added in certain percentages. The results obtained from the coke produced in the Moving Wall Coking Test Oven were interpreted by considering Coke Strength after Reaction (CSR), Coke Reactivity Index (CRI), stability and hardness values.

International Iron & Steel Symposium
UDCS

Kenan Akgün Tayfun Pamuksuz Barış Avar Ferhat Parlak Can Erarslan Safi Ahmet Çal

In this study, up to 38ppm of boron was added to 4140 steel and the effects of this addition on microstructure and tribocorrosion were investigated. Tribocorrosion behavior was investigated in a 3.5% NaCl solution with a pin on disc method. As a result of the studies, it was found that the hardness and tribocorrosion behavior increased with the addition of boron but these values decreased with the increase in boron amount after 17ppm.

International Iron & Steel Symposium
UDCS

Tayfun AKSOY Engin ÇEVİK Hüseyin DEMIRTAS Yavuz Sun Cemal ÇARBOĞA

The cryogenic process, which triggers the hardening mechanisms, such as the transformation of the retained austenite to martensite and the precipitation of secondary carbides, is generally used in the development of wear properties. A number of publications available in the literature reported that as well as improving the wear properties, various mechanical properties can also be improved by cryogenic processing. In this experimental study, the effects of cryogenic treatment on the mechanical properties of 52CrMoV4 medium carbon spring steel were investigated. For this purpose, conventional heat treatment (CHT) and deep (-196°C) cryogenic treatment (DCT) procedures were applied. Hardness, tensile and impact toughness tests were performed for determination of mechanical properties. The cryogenic process brings about a more homogeneous and finegrained structure in the matrix, and mechanical properties can be improved without loss of toughness. As a result, by evaluating the performed tests, it is aimed to determine the usability of the cryogenic process in improving the mechanical properties of medium carbon spring steels.

International Iron & Steel Symposium
UDCS

Reşat Can ÖZDEN Mustafa ANIK

Duplex stainless steels have equal amount of ferrite and austenite phases. Ferrite and austenite phase balance have been provided with solution treatment process. Solution treatment is applied between 1000 ˚C - 1200 ˚C and phase balance occurs due to applied solution treatment temperature and time. Microstructure properties such as ferrite and austenite phase proportions, ferrite grain size and grain boundary affect directly the corrosion behavior of the duplex stainless steels after the solution treatment. In this study, UNS32205 was solution treated between at 1100 ˚C and 1150 ˚C for 2 hours and 8 hours. Microstructure properties of the solution treated samples were characterized by light optical microscopy and image analysis. Moreover, electrochemical corrosion behavior of the samples was determined in 3.5% wt. NaCl solution.

International Iron & Steel Symposium
UDCS

Alptekin Kısasöz Ahmet Karaaslan

Accelerated rising for energy needs, energy cost,our dependency on foreign energy sources and also competition conditions as well as in the world also makes it obligatory for the efficient use of existing energy resources in Turkey, therefore the energy saving work stands out in the industry. Iron and Steel Industry is one of the most energy consuming sectors in the world. Energy intensive use of iron and steel sector, its share in total energy consumption in Turkey, 7.5% and the share of industrial consumption is around 22.9%. In iron industry areas where energy consumption is very high, coke plants, blast furnace, coke, electric arc furnaces, annealing furnace, energy plants that supply the furnace, and cooling water and dust holding facilities are carried out to reduce energy expenditures. In the Iron and Steel sector, the share of energy input costs is second after raw material and has a high amount of 15-25%. The share of energy use in production costs is sufficient to show how energy has a priority in the iron and steel industry. Energy management and saving in rolling mills holds an important place in Iron and Steel Industry. In this study, the effect of energy efficiency and efficiency in iron and steel industry has been investigated by making an industrial energy study. In many industries and Iron-Steel sectors keep hold in sector and the effort for keeping the position at enough level with production capacity at competition race, efforts for achieving standards and besides high quality, low cost strategies because of variable energy prices and high energy costs entailed energy saving. Energy saving is an important way to increase predictable winnings and decreases dependence on costs and energy supply.

International Iron & Steel Symposium
UDCS

Yaşar YETİŞKEN İsmail EKMEKCİ Nevzat ŞADOĞLU

Blast furnace is a kind of vertical fusion furnace producing pig iron using raw materials; fine or lumped iron ore/pellet/coke/flux materials, has a variable capacity and the height of between 30 m and 90 m. Basicity of the BF slag is calculated according the formula of (CaO+MgO)/(Al2O3 +SiO2). In the furnace, iron ores and pellets are used to produce liquid pig iron, limestone and dolomite are used to obtain slag with a desirable basicity level and coal or coke are used to get heat and supply an atmosphere to reduce iron ore oxides to metallic phase. Blast furnace is running according to the counter current principle in which charging materials (iron ore, pellet, coke, limestone etc) charged from top to bottom and blowing hetaed air and reducing gas flow from bottom to top in the furnace. Producing hot metal in blast furnace has two goals; the former is producing pig iron and the latter is producing metallic iron that will be processed and become a value added product in different steel production lines (steel workshop, continous casting and hot/cold rolling) One of the basic parameter screened in the process is sulphur emmision by the care of environmental consideration. For that scope, the sulphur content in Raw Materials, in BF Slag and in Pig Iron shall be known exactly to maintain sulphur emmision to atmosphere within a specified limit. Besides, sulphur content in pig iron is important for down stream processes for steel production. Since sulphur is one of the main elements affects the mechanical properties of steel, it should be under control. In this work, adjusting the basicity of the BF slag using limestone, dolomite or quartz, estimation of sulphur in the pig iron has been studied. Data used in the study is driven from the production of BF-1 and BF-2. Composed models for both furnaces gives the correlation of data around 70 % in consistency. That means, it is possible to estimate of desired pig iron sulphur content before production via adjusting the propotion of fluxing agents.

International Iron & Steel Symposium
UDCS

Orhan ORUÇ Hulya KAHYA Caner KORKMAZ

Reviewed the possibility of high strength construction steel fatigue evaluation based on analysis of dislocation steel martensite structure tempering after quenching in water and tempering at 650 0С (1 hour). The degree of influence of the dislocation mechanism of destruction depending on the number of test cycles, expressed in terms of the sensitivity of cyclic stress to the fractal dimension of dislocations, is established. Experimentally established, that sensitivity of dislocation to fractal dimension is decreases with increasing number of test cycles, leading to an increase in the number of dislocations to a critical value after which the sample is destroyed. A model of predicting steel fatigue indices 14Х2ГМР was obtained, which allows the use of the fractal approach in assessing the fatigue of high-strength steels with a higher dislocation density.

International Iron & Steel Symposium
UDCS

V. I. Bolshakov V. M. Volchuk O. F. Parhomenko

Testing laboratories need to verify their test procedures and testing capability for reliable results. In this study, equivalent samples are prepared by steel rod material. Randomly selected test samples having specified dimensions are sent to the participant laboratories. Then, they are tested and results are analyzed according to previously defined parameters. Each laboratory applied tensile test on the samples according to procedures given in ISO 6892-1 standard. Test results are evaluated according to same procedures explained in related standards by the participant laboratories. TUBITAK UME Force Laboratory being the pilot laboratory collected to the all evaluated results including associated measurement uncertainties. Then the collected results evaluated according to ISO 17043:2010 are reported by each laboratory as a part of the proficiency test report. Z scores of the participant laboratories are presented.

International Iron & Steel Symposium
UDCS

Cemal VATAN Bulent AYDEMIR Ufuk KURU Haldun DİZDAR

Resiudal stress has a vital importance for evaluation of mechanical properties of steel products. It can be formed during cooling stage and hot rolling processes which are indispensable for iron&steel industry. In this study, heat treatment was applied to st 37 steel, which is widely used for construction applications, at 1100 ℃. Then, st 37 was hot rolled with using 14 pass at 1000 ℃. Microstructure of samples were characterized before and after rolling process using Optical Microscope. Residual stress was measured by cutting method. Also, hardness values of samples were compared.

International Iron & Steel Symposium
UDCS

Neslihan Akgül Yasin Akgül Muhammet Emre Turan

Under the conditions of global competition, to sustain economic activities, enterprises must choose the most appropriate alternative option in any decision. Multi-Criteria DecisionMaking Methods can be used to express the decisions to be taken with reliable and objective values on behalf of the enterprises. The aim of this study is to evaluate the financial performance of a company traded on the Borsa Istanbul Metal Main Index by using TOPSIS method which is one of the Multi-Criteria DecisionMaking methods. As a result of the analysis, it was seen that the most successful year was 2008 and 2015 was the least successful year. In addition, it was observed that the success ranking in the analysis using cost and profitability ratios did not show a linear improvement over the years.

International Iron & Steel Symposium
UDCS

Murat YILDIRIM Ömer Karakaya

Laser cutting is a technology that has added innovation to the industry with its precise and fast processing capabilities. The parameters used in laser cutting processes have effects on material cutting quality and thickness. In this study, AISI 304 stainless steel sheet metals were cut in different focus, nozzle, cutting speed, sheet thickness and gas pressures, and their effects on surface roughness and cutting thickness were investigated. According to the results, changes in the surface roughness values were obtained by changing the parameters. It was observed that the increased cutting speed improved the surface roughness, but the thick materials could not be cut at high speeds.

International Iron & Steel Symposium
UDCS

Ahmet Serdar Güldibi Halil DEMİR Hasan Basri UlaĢ

In this study, laser surface hardening process was applied to the low carbon steel which is used in the parts, for the machines and automobiles, gear wheels, pins and shaft enamel. Laser power and laser feed rate were determined as laser surface hardening parameters. It has been studied between 1050 and 1300 W as laser power. 4 and 6 mm velocities were preferred as the feed rate. The hardness of the samples was measured under 500 g (HV0,5) load for 15 seconds. Nikon brand optical microscope is used for microstructure studies. As a result of the hardening, the expected hardness on the surface could not be obtained due to the low carbon content. Due to the effect of the laser, carbon is deposited on certain areas and formed non-uniform regions. As a result, it was found that it was difficult to achieve the desired effect from laser hardening process without carburizing the low carbon steels.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ Mehmet Akif Erden

The rare earth elements (REE) are a group of chemically similar elements consisting of scandium, yttrium and the lanthanides. They are essential to most new and “green” technologies, but their production is anything but green. Today, China produces more of these elements than the rest of the world together, and dominates the market. Demand is rapidly exceeding supply, yet only about 1% of rare earths are recycled. Because the main use for rare earths is in electrical applications, efficient recycling of electrical waste will soon be vital to the continued use of these elements. Rare earths occur naturally as oxides, and good methods have been established for their extraction. During the recycling shredding process of WEEE. Scrap is broken into very small pieces or even turning to dust and REE will stick largely to ferrous fractions due to the magnetic nature. These ferrous fractions are generally sold to steel recyclers, where they are melted in electric arc furnace (EAF) treatment and the rare earth elements will be lost due to dilution. This paper presents the separation of rare earth elements and the base metals which contains Co, Cu, Mn etc in Fe, using pyrometallurgical methods.

International Iron & Steel Symposium
UDCS

Mertol Gökelma Gabriella Tranell

Crack occurrence and its effect on materials are one of the crucial problems in defence, aircraft and railway industry. Related to the phenomena, the evaluation of the methods and analysis on the materials selection gains inmportance. In this study, ASTM E647 and BS ISO 12108 standards are investigated used in the calculation of FCGR ( fatigue crack growth rate).

International Iron & Steel Symposium
UDCS

Fazil Hüsem

AISI 52100 steel is considerably attracted in making bearings and shafts due to its greater strength and better corrosion immunity. However, high power consumption is encountered in machining operations due to their hard machinability. The consumption should be eliminated for cleaner production in terms of sustainable machining. Therefore, this study aims modelling of cutting forces in hard turning of AISI 52100 steel based on finite element method. The cutting parameters are chosen as cutting speed and depth of cut with three levels and constant feed rate. The average of 6.6% difference is achieved between experimental and simulated feed forces while 7.5% difference for main cutting forces. The finite element modelling of cutting forces is quite compatible with the experimental results and it can be performed by high accuracy without excessive machining experiments of difficult-to-cut materials.

International Iron & Steel Symposium
UDCS

Mehmet Erdi KORKMAZ

In this study, high chromium white cast iron and AISI1030 steel with nickel interlayer were combined by friction welding method, using different friction times (8, 10 and 12 s). Welding morphologies were analyzed by optical microscopy (OM), energy dispersive spectrometry (EDS) and microhardness analysis. Accordingly, as indicated in the literature, weld joints were divided into four zones as extremely deformed zone, deformed zone, partially deformed zone and base metal. Consequently, depending on increasing friction time, atom transitions occurred in the weld zones. Moreover, the highest microhardness values were obtained in the weld joint with 10 s.

International Iron & Steel Symposium
UDCS

Tanju TEKER Eyyüp Murat KARAKURT

The integrated iron and steel plants produce a large part of their electrical needs (50-80%) with natural gas as well as process gases from the coke factory, blast furnace and steel mill processes. Electricity generation takes place in both steam boilers and gas turbines. A portion of the 45 bar steam produced in the steam boilers is reduced to 15 bar and charged to the units at the rate of the process. There are 5 projects for 15 bar steam production from waste heat boiler, two investment projects for reduction of electricity consumption, and one project of electricity production from top pressure recovery turbine (TRT), which are realized between the years of 2012 and 2017. In this study, the effects of these projects on greenhouse gas emissions of energy production processes were investigated. In 2017, CO2 emissions were reduced by 15.41% due to 15 bar steam production from 4 waste heat boilers. With the TRT project, the CO2 emissions from the total electricity consumed decreased by 3.43% in 2017. The emission gains from electricity reduction projects have been realized as 22.5% for sintering plant and 31% for the rolling plant.

International Iron & Steel Symposium
UDCS

İrem Gürsoy Didem İnceoğlu Okşan Tartanoğlu Mehmet Beyazçiçek

Material conditions are very important in systems operating at high vapor pressure and temperatures. Cr-Mo series special steels used in the thermal power plants of such structures have high creep resistance and long lasting materials. The time from the first production phase to the usage area and subsequent welded joint processes should be carefully monitor. The P91 and P92 series are the highest-grade creep resistance of the steels mentioned in different standards. All stages of these steels should be keep under control. Otherwise, they cannot meet the desired efficiency after welding. In our study, the whole process for the P91 steels from the beginning of the weld to the end is summary as a technical report. For P91 materials, the requirements for pre-welding, welding and post-welding are explain together with the academic data. Many studies on materials P91 have been compile and tried to form a technical guide.

International Iron & Steel Symposium
UDCS

Bünyamin ÇİÇEK Yavuz Sun Hayrettin Ahlatçı Yunus Türen

The aim of this study was to investigate the effect of the material hardness and microstructural characterization of the spring steels having the qualities of 51CrV4, 54SiCr6, 55Cr3 and 60SiCr7 produced according to the heat treatment application conditions. Fragments cut to appropriate sizes from spring steels were subjected to hardening process for 1 hour and tempering temperature for 1.50 hour at austenitization temperature determined from Fe-C balance diagram. When the applied heat treatments were evaluated generally, no differences were observed in the structure of the spring steel as a result of the cooling of the oil and the cooling of the austenitization zone in different cooling environments resulted in differences depending on the internal structure of the mechanical properties. As a result of the cooling process, internal stresses occurred and the microstructure turned into a mantle, resulting in rigidity and brittleness. This martensite structure tempering process reduced the internal stresses of the metallic material, the hardness fell a little and softened.

International Iron & Steel Symposium
UDCS

Esma KESKİN Hayrettin Ahlatçı Yunus Türen Mustafa Ali KÜÇÜK Yasin SUBAŞI

The aim of this study was to investigate the effect of the material hardness and microstructural characterization of the spring steels having the qualities of 51CrV4, 54SiCr6, 55Cr3 and 60SiCr7 produced according to the heat treatment application conditions. Fragments cut to appropriate sizes from spring steels were subjected to hardening process for 1 hour and tempering temperature for 1.50 hour at austenitization temperature determined from Fe-C balance diagram. When the applied heat treatments were evaluated generally, no differences were observed in the structure of the spring steel as a result of the cooling of the oil and the cooling of the austenitization zone in different cooling environments resulted in differences depending on the internal structure of the mechanical properties. As a result of the cooling process, internal stresses occurred and the microstructure turned into a mantle, resulting in rigidity and brittleness. This martensite structure tempering process reduced the internal stresses of the metallic material, the hardness fell a little and softened.

International Iron & Steel Symposium
UDCS

Esma KESKİN Hayrettin Ahlatçı Yunus Türen Mustafa Ali KÜÇÜK Yasin SUBAŞI

Hot-dip aluminizing (HDA) process is an effective coating technique to protect the surface of steel and cast irons from corrosion, oxidation, decarburization and wear at high temperatures. Because of these advantages, HDA is used to protect the surface of steels used in the hot stamping process in automotive industry against oxidation and decarburization. Also, HDA can provide additional oxidation resistance to high silicon ductile irons used in high-temperature applications such as furnace parts and exhaust manifolds. HDA is generally performed by dipping the substrates into molten Al or Al–Si alloys. This process results in the formation of various Fe–Al intermetallics along the coating. For example, immersing the substrate into pure Al produces Fe2Al5 phase close to the substrate, and FeAl3 phase close to the surface. A high-temperature diffusion annealing after HDA provides interdiffusion within the coating and thus can change the type and order of the intermetallics. In this study, the effect of HDA on structural, morphological and mechanical properties of the coating formed on a low carbon steel, a stainless steel and a high silicon ductile iron were addressed. In addition, effect of successive application of HDA and austempering on wear and corrosion properties of the ductile iron was also discussed.

International Iron & Steel Symposium
UDCS

Murat Baydogan

Hot shortness mechanism is related to tramp elements in steel. Copper is the most effective and the most common tramp element in steel. Generally related with recycled steel production hot shortness is a problem that causes failure of steel material in processing. In this study hot shortness is investigated in low carbon steel. Smelting and casting is done in induction furnace, SEM and optical microscopy is used for metallographic investigation. Micro hardness tests are done. XRD technique is used for understanding oxidation behaviour of low carbon steel and its relation with copper content via mill scale phase analysis.

International Iron & Steel Symposium
UDCS

Selçuk Yeşiltepe Mustafa Kelami Şeşen

— Image analysis in many fields of science requires a certain level of automation, especially when analyzing a thousands of features on a large amount of images, where manual analysis would be extremely time consuming, if not impossible. The automation level depends mainly on the contrast between the pixels of the features to be analyzed and the background, e.g., carbo-nitrides in a steel matrix. The aim of the present work is to improve the accuracy and shorten the time of automatic image analysis of a large number of precipitates in two grades of steels, X20 and P91. SEM images at different magnifications (3k to 20k) were acquired, depending on the optimal accuracy both in the size and shape of particles analyzed (pixels per particle), and their number density (particles per surface area analyzed). On SE images, precipitates usually appear brighter on a darker background, however a non-uniform gray value intensity in many areas of micrograph is equal for both precipitates and background, which makes it impossible to perform a simple thresholding segmentation. Thus advanced segmentation techniques employing sophisticated algorithms along with image preprocessing in order to improve the segmentation performance itself were applied. It was found that there is no general image processing and segmentation technique, no matter how sophisticated it is, which can cover a wide spectra of different images, even if they might have been acquired from the same material. Thus different combinations of image processing and segmentation algorithms should be applied for each image in particular, in order to achieve acceptable levels of characterization accuracy.

International Iron & Steel Symposium
UDCS

Fevzi Kafexhiu

Hot work tool steels are generally used in plastic forming processes of metals as extrusion dies and punches. Service life of these parts are related to their surface defects and dimension changes arising from exposure to high pressure and wear at high temperatures during plastic forming. Therefore, it is important to enhance the surface properties of these parts to extend their lifespan and mitigate the consequences of surface defects and wear damage. Simulating damages on the dies occurring during their service period is critical to estimate their lifetime. A homemade impact-sliding wear testing machine was designed and used for accelerated simulation for observing performance of quenched and tempered hot work tool steels in laboratory. Impact sliding wear tester can be used for simulating extrusion process to evaluate wear performances of different kind of die materials used for metallic component production. In the scope of this study, two different kinds of hot work tool steel A and B were quenched and tempered with the carbon equivalent of 1.91 and 1.66 respectively. Structural features of hot work tool steels were characterized by optical microscopy, scanning electron microscopy, X-Ray diffractometer and hardness measurements. Furthermore, sliding and impact sliding wear tests were conducted at room temperature (RT) to evaluate their wear performances. Wear tracks were examined by profilometer to compare wear damages of the steels. Results of characterization analyses showed that steel A with the carbon equivalent of 1.91 sample exhibited better resistance against impact sliding wear compared to steel B with the carbon equivalent of 1.66.

International Iron & Steel Symposium
UDCS

Ezgi Akyıldız Faiz Muhaffel Mert Altay Seçkin Özkurt Erdem Atar Huseyin Cimenoglu

In this paper, some information about impact testing method and its applications in steel industry are presented, in additionally, it has been given knowledge related to uncertainty analysis of Charpy impact test, also application of sample uncertainty calculation according to ISO 148-1:2016 standard intended for laboratories that implement this test and review the measurement results.

International Iron & Steel Symposium
UDCS

Haldun DİZDAR Bulent AYDEMIR Cemal VATAN

Combustion processes ensure that the energy produced by the combustion of air and fuel mixture can be directly or indirectly used. In order to ensure that these processes are carried out under suitable conditions, the air/fuel ratio needs to be well adjusted. Inefficient combustion processes occur when the air/fuel ratio is not well adjusted. For the determination of the air/fuel ratio, the oxygen content in the flue gas must be measured. Zirconium Dioxide oxygen measurement sensors are used for the measurement of oxygen content in the flue gas. These sensors can be used to measure oxygen directly at high temperatures. In this study, the importance of oxygen ratio measurement in flue gases and air/fuel ratio optimization occurring in combustion processes are explained.

International Iron & Steel Symposium
UDCS

Şaban PUSAT

Combustion process is one of the main processes for industry. Due to the direct fuel use in combustion process, efficiency is very important for optimum fuel consumption. The most significant points to be considered in terms of energy efficiency are the places where energy is being thrown away. When the flue gases from the combustion process are examined, it is seen that the waste heat recovery potential is very high. In this study, importance of the waste heat recovery potential in the flue gases will be determined.

International Iron & Steel Symposium
UDCS

Şaban PUSAT

This steel teeth and coupons were produced by the casting process. Steel having MC chemical content was alloyed with 0.15 (MC15) and 0.20 (MC20) % wt. Ti. Respectively, normalizing, quenching and tempering heat-treatment were carried out for improved mechanical properties. The typical lath martensite structure in martensitic steels was observed when microstructure of specimens investigated via an optical microscope. Mechanical properties of heat-treated specimens were determined to use of tensile and hardness test. Wear behaviors of MC, MC15, and MC20 specimens were found out with the pin-on-disk test device. The field test was done for teeth. Working life, volume changes of teeth were calculated as a result of this field test.

International Iron & Steel Symposium
UDCS

Ali Keleş Mehmet Yıldırım Gönül Coşkun

In this study, Vickers hardness values change of the 100Cr6 steel as a result of the induction surface hardening and tempering were investigated. Load values selected for experimental studies are total 7 values from 50 grams to 2000 grams. The experimental result curves were compared with Meyer’s law, PSR, MPSR and Hays-Kendall models. Furthermore, the most appropriate mathematical equation for experimental curve was investigated. The comparison results showed that the Matlab curve fitting model was the most concordant of the equation obtained from the Power 2 Lar Trust-Region analysis.

International Iron & Steel Symposium
UDCS

Erdal Karadeniz Aykut Argıncıklıgil

In this paper, TiAlZrN coatings were deposited on AISI H13 steels with various bias voltage and working pressure ranging between -50 V to -90 V and 2 x10-3 to 3x10-3 Torr respectively. Closed field unbalanced magnetron sputtering technique which is a kind of PVD was used for the deposition process. Among the different PVD methods, closed field unbalanced magnetron sputtering method is one of the most successful and sophisticated technology for the metal, alloy and ceramic coatings to control microstructure, surface morphology and phase composition. After the deposition process, the effects of bias voltage and working pressure on the microstructure, hardness, scracth and wear properties were investigated by SEM, EDS, nanoindentation, scratch and wear volume measurements. All produced films exhibited classic surface of granular structure and the cross-sectional morphology showed that all films have columnar structure which was altered from massive columnar to denser columnar structure due to increase the bias voltage and working pressure. TiAlZrN films deposited at -90 V and 3x10-3 Torr exhibited dentest structure, besides possessed the best nano hardness, scratch and wear properties. The highest nano hardness of 42 GPa is obtained under highest bias and working pressure. Also compared untreated AISI H13 steel which is the substrate, the produced TiAlZrN with aforementioned coating parameters considerably enhance the wear resistance.

International Iron & Steel Symposium
UDCS

Yaşar Sert Levent KARA Tevfik Küçükömeroğlu

FeTi and FeB particulates having 150 µm were inoculated to molten 27Cr high chromium white cast iron as 0.5 wt.% and over 50 °C above the melting temperature. Samples were analyzed using optical microscopy and XRD to examine the influence of the addition of titanium and boron. The effect of inoculant on the size and carbide volume fraction were determined. The microstructures of the samples were examined by matrixstructure of austenitic and M7C3 carbides with austenite layer surrounding the carbides. From the heat treatment results, it can be say that the size of the austenite reduced, and the decomposition of the austenite resolved M7C3 carbides.

International Iron & Steel Symposium
UDCS

S. Osman YILMAZ Tanju TEKER

In metal forming process, improving mechanical and surface properties of tool steels has been significant issue, since the productivity is mainly related with the service life of tools. In order to enhance service life of tools, wear is the most challenging problem to tackle due to its detrimental effects on surface and dimensional characteristics of components especially produced by hot forming process. In the present study, influence of nitriding on the wear resistance of famous AISI H13 tool steel was investigated by homemade impact-sliding wear tester to simulate forces which affects tool steels during extrusion process. Structural characterization of nitrided and bare samples via using X-ray diffractometer, optical and scanning electron microscopes was conducted along with hardness measurements. Wear tracks of samples subjected to impact-sliding wear test at room and elevated temperature were examined under scanning electron microscope in order to determine their wear mechanism. 2-D profilometer was also used to measure the wear loss. Results of these examinations revealed that nitriding leads to increment in impact-sliding wear resistance of H13 tool steels at room and elevated temperature.

International Iron & Steel Symposium
UDCS

Belda Aydın Birsen Baş Mertcan Kaba Mert Altay Faiz Muhaffel Utku İnan Seçkin Özkurt Erdem Atar Huseyin Cimenoglu

Having combine mechanical properties (e.g. strength, toughness and ductility makes the austempered ductile iron (ADI) finding wide range of application areas. In recent years, to obtain greater ductility than that by the conventional austempering process, intercritical austempering process has been focus of researches on ADI. This study deals with intercritical austempering of GGG40 ductile cast iron by isothermally treatment at 350 °C for a range of 25-150 minutes following partly austenizing it at 800 °C and microstructural examination of as-threated cast irons. Digital image processing method was used to determine graphite nodularity having responsibility of ductility and matrix phases influencing other mechanical properties in the cast iron. Results showed that while number of graphite particles decreases, their size and circularity increases with increasing treatment time and a useful austempering range can be defined as 100-150 min.

International Iron & Steel Symposium
UDCS

Erol Kilic Cengiz Bagci Kubilay Karacif

Studies are carried out to minimize earthquake damages during rapid and irregular construction process since our country is on an active earthquake zone. Especially in recent years, steel structure systems find out a large application area due to their high construction speed and the fact that a significant part of their production is done in factories. Therefore, these are also, as in other building types, the importance of earthquake resistant designs increases. On the other hand, depending on technological developments, the methods used in the design and elaboration vary. For these reasons, the regulations used in their design are updated from time to time. In this study, the changes in the new TS 648 design regulation, which came into force in January 2018, which replaced the TS 648 dated 1980 which was used in steel structures design, will be emphasized. For this purpose, some design principles of the TS648 steel structures regulation which has newly entered into force with the old steel structures regulation are presented comparatively. The findings obtained at the end of the study reveal that there are significant differences between the design regulations considered.

International Iron & Steel Symposium
UDCS

Ayşegül YILMAZ Şenol GÜRSOY

Accessing to global markets and gaining a larger share from global trade is one of the most important factors that will accelerate the economic development of countries, and this is becoming more difficult under increasing competition conditions. On the other hand, due to the fact that the steel sector is the main input of many sectors such as automotive, construction, white goods and machinery production and is a strategically important sector, international competition has become more difficult especially with the increasing protectionism and tariffs which have increased in recent years. As a consequence of the high customs tariffs implemented by the US as a result of section 232 investigations, exports to the US have ceased to be attractive and countries searching for new markets. As a result of this, the EU has taken a safeguard measures in order to protect the steel sector and has started to implement quota on a country basis. In case of a country exceeds the quota, EU will start to implement a tariff of 25% and in this circumstance international competition for the Turkish steel sector has become more difficult. With this study, it is expected to have a scientific contribution to Turkish steel sector. Thus, in order to increase exports in the steel sector, this study determines international target markets among twenty alternatives based on AHP considering three main criteria and twenty sub-criteria. Computational analysis shows that USA, China and India are the first three international target markets for Turkish steel sector.

International Iron & Steel Symposium
UDCS

Merve Bayata Mehmet KABAK Fulya Altıparmak

In this study, a dual phase steel DP600 which is frequently used for automotive industry because of lightness, durability performance and economical attainability, was joined by resistance spot welding (RSW) method that are used frequently in automobile industry, and then exposed to cyclic bending load with different amplitude values. In addition, fatigue test was repeated with additional tensile force that is applied with bending forces and results that obtained from bending fatigue tests and bending-tensile fatigue tests are evaluated and compared with each other. As a result of the fatigue tests that performed to the samples, it was observed that the axial tensile force decreased the fatigue life. In literature frequently axial forces were applied to resistance spot welded specimens for fatigue tests in most research. In real condition, fusion zone can be exposed to different axial forces. It is necessary to know and investigate the fatigue life due to tensile and bending resultant force as well as axial force, which is very important for vehicle stiffness and reliability.

International Iron & Steel Symposium
UDCS

Mustafa Göktaş Muhammed Elitaş Bilge Demir

This study aims to fabricate nano boron nitride (BN) reinforced with 1 wt. % fraction iron matrix composite using semi powder technique. Powders were mixed using mechanical agitator in ethanol and drying process was completed in vacuum distillation system. Powders were pressed and the obtained bulk materials were sintered in atmosphere controlled furnace. Microstructure was examined with Scanning Electron Microscope (SEM). Wear test was conducted under 20N, 40N and 60N during 500 m. sliding distance. Results indicated that BN reinforced composite showed lowest wear rate under 20N load. In general, BN exhibited good lubricant effect.

International Iron & Steel Symposium
UDCS

Muhammet Emre Turan

Carbon steels have a wide range of applications such as construction, machine components (shafts, bolts etc.) and transportation. Corrosion is one of the important reason for the failure of these materials. In this study, the corrosion behavior of hot-rolled carbon steel against dimethylformamide (DMF) was investigated. Also, the corrosion resistance of the sample was compared to untreated carbon steel and heat treated carbon steel. Stress relieving heat treatment was applied at 550 ℃ for 90 minutes. Electrochemical corrosion tests were performed for all samples. In addition, while the chemical composition of the sample was determined by spectral analysis, microstructure studies were carried out by an optical microscope.

International Iron & Steel Symposium
UDCS

Yasin Akgül Hamza Simsir Hayrettin Ahlatçı

Investigations on cutting force, surface quality and dimension accuracy etc. are ongoing considering the feed rate and cutting speed despite the development of new drill qualities in terms of the material and geometry in drilling. In this study, the drillability of AISI 430 ferritic stainless steel used in many industrial environments such as automobile chassis parts, hot water tanks, kitchen utensils and decorative applications was investigated. The effects on thrust force, torque and surface quality of cutting speed and feed rate was evaluated in the drilling of workpiece prepared in sheet form. Experiments were performed with three different cutting speeds and feed rate with the uncoated carbide drill bit. Variance analysis was applied to determine the effect levels of the drilling parameters on the machining outputs. According to the experimental results, it was determined that as the feed rate increases, thrust force, torque and surface roughness increases. On the other hand, it has been observed that as the cutting speed increases, the machining outputs tends to decrease.

International Iron & Steel Symposium
UDCS

Tolga MERAL Mustafa GÜNAY

In recent years, analysis of product and production processes with the help of numerical simulation methods; the effects of production processes on mechanical and microstructural properties of products, efficiency studies in the processes, material flow, determination of cooling regime, distortion, folding, etc., provides a significant contribution to the determination of the relationship between production-structure-propertyperformance in R & D / Design studies. Hot and cold forging, rolling and extrusion can be solved under finite elements and finite volume method with the help of computer aided analysis. In this study, the solution of the phase transformations in the material microstructure, due to the heat transfer coefficient in different cooling environments as a result of the production with hot forging, is investigated by the numerical simulation method. Critical phase conversion temperatures of 1.7035 and 1.1191 code steels, nonrecrystallization temperature, critical forging temperatures were calculated according to alloy composition. Hot forging operation was carried out by finite volume method and cooling process was solved by finite element method. Simufact.Forming software was used in numerical simulation supported solutions. As a result of hot forging and cooling process; phase ratios, strength, distortion in the product, residual stress values were revealed.

International Iron & Steel Symposium
UDCS

Osman Çulha Fulya Eyçin Serhat Bardakçı

Chemical composition and steel alloy structure are the most important process inputs affecting the material properties in production with hot forging. Different mechanical properties can be obtained in the product due to the cooling regime applied at the end of the forging operation. Especially, as a result of the cooling process, the alloy phase structure is transformed into different phases at room temperature. The microstructure of micro alloyed steels at room temperature, which is obtained by thermomechanical forging at high temperatures, differs from one another depending on cooling atmosphere. According to the literature review; microstructure of forged material shows that the finer grain structure has higher toughness and fatigue strength. In this study, 1.1141 coded cardan shaft fixed forked flange produced by hot forging at 1200 oC and 5 different operations, used as sample. Microstructural; grain size, type, distribution and rate of phase and mechanical properties; hardness and strength variations of hot forged samples under four different cooling media such as; controlled, air, oil and water cooling, were investigated in simulation. Phase transformation and distribution were calculated according to the cooling rate and TTT-CCT diagram of sample.

International Iron & Steel Symposium
UDCS

Osman Çulha Fulya Eyçin Serhat Bardakçı

This work can be located to two parts. In the first part, hydrothermal carbon (HTC) was synthesized from cellulose at 180 ℃ for 20 hours. In the second part, HTCs reinforced iron matrix composites were fabricated via powder metallurgy. For this fabrication process, HTCs and iron powders were mixed by turbula mixer for one hour. Then, obtained mixtures of powders were compacted by press machine at 700 Mpa. After that, green billets were sintered at 1100 ℃ for one hour. Microstructures of samples were characterized by Scanning Electron Microscope (SEM). Density measurement was applied according to Archimedes method. Hardness and compression tests were conducted to determine mechanical properties of samples.

International Iron & Steel Symposium
UDCS

Hamza Simsir Yasin Akgül Mehmet Akif Erden

In this study, Fe-5Cr-3W steels containing without Co and 1.5 wt% Co were produced via casting and following that they were hot rolled. The effect of Co addition on microstructure and hardness of steels after heat treatment ((annealing, air cooling) and (annealing, air cooling and tempering)) was investigated. Co-free and Co-contained steels have bainitic and martensitic microstructure. However, martensite volume fraction of Co-free steel is higher than Co-containing steel. Hardness of air quenched samples was decreased after tempering. Co increased hardness slightly both air quenched and tempered samples.

International Iron & Steel Symposium
UDCS

Gökhan Arıcı Mustafa ACARER Mesut Uyaner

— Cr-Mo steels with high creep resistance used in power generation plants vary according to the region where they are used. As the temperature and pressure increase, the amount of CrMo increases in the alloy. The welding of these dissimilar steels is obligatory in the regions that make up the temperature difference. For example, when P91 quality steels are use at high temperatures, P22 quality steels are use at lower temperatures. In the transition from the walls of the boiler to the outside, these two dissimilar steel are weld together. In such processes, all stages before and after the welding should be keep under control. In this welding process, relevant standards should be follow and witnessed sample (PQR) must be perform prior to welding. After that, the weld are valid, which meet the desired values from the mechanical tests (when the values of the standards are meet). A PQR study was follow in our study. In this weld, P91-P22 coupling was make by TIG method. Afterwards, tensile, bending, charpy and hardness tests were apply according to the relevant standards and it was observe that they met the standard requirements.

International Iron & Steel Symposium
UDCS

Bünyamin ÇİÇEK Yavuz Sun Mehmet Ünal

In this study, the surface of EN 10130 steel used in deep drawing processes in industry is coated with CMT technique. Al2O3 powder with different ratios of Al, Zn, Sn and Ni metal powders were used as coating material. Nano-sized metal powders and ceramic powders were used. This coating has been made to improve wear and corrosion resistance after deep drawing of EN 10130 steel. However, due to the lack of sufficient time for the operation and the failure of the wear device, only SEM and EDX studies were applied. In SEM studies, it was observed that the Al2O3 + Ni composition and the coating interface were not smooth. Other coating surfaces are in good condition. Although the average coating thickness varies regionally, it is 20-60 µm thick.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ Erkan Koç Hüseyin DEMIRTAS

Hybrid composites are materials that have a combination of two or more reinforcements. These materials have extensive engineering applications that have a low strength/density ratio, low cost and ease of manufacturing. Hybrid composites provide a combination of properties such as tensile modulus, compressive strength and impact resistance, which cannot be realized in composite materials. The surface properties of the materials must be improved against corrosion and wear. It is therefore essential and important that the coating layer has both wear and corrosion resistant phases. In this study, the surface of AISI 316L stainless steel is coated with metal powder having different composition by tungsten inert gas (TIG) welding surface coating method. Ti, B4C and SiC metal powders of different ratios were used as coating powder. The corrosion properties of coated samples were characterized by potentiostatic polarization test. Corrosion test results showed that corrosion properties vary depending on the coating components.

International Iron & Steel Symposium
UDCS

Serkan Islak Mehmet Akkaş Cihan Özorak Aytekin Ulutaş

In this study, a mixture of unalloyed steel material in the desired composition via powder metallurgy method is obtained by adding 0.5% by weight of graphite element in Fe matrix. The powders obtained were mixed by using a 4, 5 and 6 mm ball in the mechanical mixing device and the mixture was mixed with powder and ball ratio 1/10 for 1 hour. Powders obtained after mixing were squeezed at pressures of 700 MPa at 1350⁰C sintering temperature in 1 hour in the molds designed as tensile specimens. The particle size of the produced steels and the distribution of the phases were determined by optical microscope. After microstructure analysis, tensile test was applied to steel samples prepared in tensile specimen dimensions. The elongation, yield-tensile strength of the samples are explained depending on the ball diameter. As a result, steel samples with a ball diameter of 5 mm exhibited the highest yield and tensile strength.

International Iron & Steel Symposium
UDCS

Mehmet Akif Erden Selim Erman Harun ÇUĞ

In this study, Fe based SiC reinforced composites were produced by powder metallurgy method. Fe-Graphite and SiC powders were weighed with a scale of 0.0001 g and then blended for 1 hour. It was then pressed under pressure of 750 MPa. After the pressing process, the composite materials were sintered at 1100 °C, 1200 °C and 1300 °C for 1 hour in argon atmosphere. With increasing sintering temperatures, an increase in density values and a decrease in porosity were determined. The ideal hardness results for the composites were obtained by sintering at 1100 ° C.

International Iron & Steel Symposium
UDCS

Hasan Karabulut Mehmet Akif Erden

Single point incremental forming (SPIF) is a method which allows better formability properties compared to forming processes using a sheet metal die. However, the production time is considerably higher compared to using a die. Therefore, this method is generally used in low production quantities or in prototype manufacturing. In the present work, DP600 Dual Phase sheet material are selected for SPIF. Two material thicknesses were took (1mm, 1,5mm) and a truncated cone form was designed with three different wall angles. The finite element (FE) modeling of SPIF was generated with and without applying a pressure force from lower side of the sheet material. The FE analyzes have been done by using Abaqus software. It was determined that fluid assisted SPIF application caused to homogenously distribute the wall thickness of the sheet material while forming and increased the forming properties of the sheet metal.

International Iron & Steel Symposium
UDCS

Hakan Gürün Onur Çavuşoğlu Gökhan Küçüktürk Onur Çetinkaya

The research was carried out to determine critical temperature and to investigate the kinetics of decomposition of supercooled austenite with continuous cooling of steel for rails with high content of manganese and microalloyed of vanadium. Dependences of interlamellar spacings of perlite on the speed of cooling and hardness from the interlamellar spacings of perlite with changes in the cooling rate of steel with 0,80% C; 0.25% Si; 0.97% Mn; 0,055% V.

International Iron & Steel Symposium
UDCS

A. Babachenko G. Kononenko

The microstructure investigation of springback formed after sheet metal forming by the drawing mold is the basis of this study. In this study, microstructure properties after springback were investigated in two different metal groups such as high-strength steel and Al. The estimation of the amount of springback, the ways of avoidance and microstructure investigations are of great importance in producing parts with high commercial value. Specially designed deep drawing mold was used in experimental studies. The staple radius in the drawing die was used as a die factor and kept constant in all experiments. Four different materials and four different thicknesses were used as material factors. The microstructure was examined after the forming, the amount of springback was calculated as angular. The results showed that the increase in sheet metal thickness increased the amount of springback and the difference in chemical composition was more effective than the resistance.

International Iron & Steel Symposium
UDCS

Abdülsamet ÖZDEN Bilge Demir

in this study copper nanoparticle (CuNP) deposited on the 316L stainless steel (316L SS) by physical vapour deposition (PVD) technique. The development of thermal conductivity is essential for thermal application, especially in solar energy applications. The distinctive method transient plane source (TPS) for measuring the thermal conductivity of the copper thin film was used in comparison with the 316L SS base metal, while the ambient conditions including heating power, measurement time and sample temperature were 6.9 W, 5 Sec and 34 o C respectively, were employed in this test. The results show that the prepared film by a thermal vacuum evaporation technique has an enchantment on the improvement of physical properties like absorption and thermal conductivity in comparison with parent 316L SS substrate. It was noted that the thermal conductivity improved dramatically with 39.82 % comparing with 316L SS substrate. Structural properties of thin film layer achieved have been analyzed by (XRD). The other characterization likes surface morphology has been investigated by using SEM, FESEM, and AFM. This improvement from an economical energy point of view for the 316L SS-CuNP enhanced the heat gaining process of solar collector system considerably with high efficiency.

International Iron & Steel Symposium
UDCS

Ahmed S. Abbas Mohammed J. Kadhim Khalid A. Sukkar

In this study, different rates of boron at 1635 ºC were added to the 21CrNi5 steel using the induction furnace. The casting process was melted and cooled in air to 40x40 mm thick ceramic ceramic molds heated up to 850 ºC. The obtained 40x40 mm square materials were rolled in 2 passes and deformation was applied at about 200-300%. Parts with a 15x15x10 mm were cut and sanded. The effects of boron on the wear behavior, which were added to the samples under 10 N load test and added at different rates, were examined by optical microscope.

International Iron & Steel Symposium
UDCS

Cemal ÇARBOĞA Bülent KURT Serkan DAL

In this study, different rates of boron at 1635 ºC were added to the AISI 1040 steel using the induction furnace. The casting process was melted and cooled in air to 40x40 mm thick ceramic ceramic molds heated up to 850 ºC. The obtained 40x40 mm square materials were rolled in 2 passes and deformation was applied at about 200-300%. Parts with a 15x15x10 mm were cut and sanded. The effects of boron on the wear behavior, which were added to the samples under 10 N load test and added at different rates, were examined by optical microscope.

International Iron & Steel Symposium
UDCS

Cemal ÇARBOĞA Bülent KURT Serkan DAL

This document includes the studies carried out during the optimization of the casting parameters as a result of the revision performed in the continuous casting machine of the ÇEMTAŞ/BURSA plant.

International Iron & Steel Symposium
UDCS

Gürcan KIRNAK Cemalettin YAMAN

In the diesel common rail systems, it is necessary to increase the fuel pressure up to 2500 bar to make engines more efficient and economical as well as to correspond more strict environmental standards. Bainitic forging steels were recently developed for the common rail systems and also becoming increasingly attractive for many forged parts such as crankshafts, injection rails, axle pivots in the automotive industry. A controlled cooling route comprising of hot forging without any quenching and tempering has been established for developing ductile high strength steels with tensile strengths up to 1250 MPa. In this study, the austenite grain growth of a microalloyed bainitic forging steel was investigated using light microscopy. It is well known that the precipitation of microalloying elements can prevent the austenite grain growth. Therefore, phase transformation temperatures were calculated using Thermo-Calc software to obtain an overview about the possible austenitization temperatures. In order to investigate the austenite grain growth, annealing experiments were performed at temperatures between 1000 ºC and 1300 ºC for 5 minutes. The mean intercept length of the grains has been determined according to ASTM E112 intercept method. The results showed that prior austenite grain size and distribution depend on austenitization temperature.

International Iron & Steel Symposium
UDCS

Sibel Ün Emre Alan Nurten Başak Dürger Caner Güney Ersoy Erişir

In this study; The effect of the heat treatment applied to the samples taken from the domestic production gear part used in the construction machinery, on the heavy abrasive wear is investigated. Samples removed from the threaded part were allowed to stand at 900 ºC for 1 hour and then cooled by quenching. Water samples were tempered at 400 ºC for 1.5 hours. Non-heat-treated and heat-treated samples were subjected to abrasive wear test against 60 mesh Al2o3 sandpaper under 40N, 80N, and 120N load. The abrasive wear resistance of the examined domestic nail in severe abrasive wear conditions improved by 37% in heat treatment

International Iron & Steel Symposium
UDCS

Cemal ÖZGENÇ Hayrettin Ahlatçı Yunus Türen Süleyman Yaşın Esma KESKİN Mustafa Ali KÜÇÜK Yasin SUBAŞI Burcu Çetintaş

Welding technologies; automotive, transportation, steel construction, machine manufacturing, iron and steel sector, pipe sector, ship construction, power plants, mining sector, defense industry etc. has a strategic importance in many sectors. The role of welding as a locomotive in the industry is of great importance both for its development and its progress. Turkey, in accordance with the needs of the market, keeping up with constantly evolving technology, have high competitiveness, good quality and affordable welding wire, welding electrode, skilled electrodes, soldering wires and it can increase the export capacity by producing welding machines of various capacities. Due to the presence of large-scale welding wire and covered electrode producers in the domestic market with economies of scale, high tonnage raw material purchasing power, warehouse and storage capacities cause the iron-steel mills of the wire rod manufacturer to focus on these firms. Small and medium sized new entrepreneurs are ignored by these producers due to their insufficient purchasing and storage capacities. Therefore, new entrepreneurs cannot enter the market, causes prices in the domestic market are increasing. This increase leads consumer and manufacturer firms that demand low price products to Far Eastern companies' products. In the resource sector, while access to European standards and quality in Turkey, both producer and consumer reduce the competitive strength of the company. Reduce the share of Far Eastern products in the domestic market and large suppliers of wire rods to increase the production of materials such as welding electrodes, welding wires, solder wires, etc., must meet the reasonable demands of small and medium sized entrepreneurs. The market price balance of the welding consumables will be ensured thanks to the new small and medium sized new entrepreneurs. The new price balance, by reducing imports of far-eastern products has captured the European quality standards and will contribute to Turkey's exports of welding consumables.

International Iron & Steel Symposium
UDCS

Soner ÇETİN Volkan Temizkan

AISI 304 stainless steel accounts for approximately 50% of the world's stainless-steel production and consumption. It is important to improve the machinability properties of stainless steels due to the intensive use in the industry. In this study, the effect of machining parameters on surface roughness was investigated in water jet turning of AISI 304 material. The test parameters were determined as nozzle feed rate, abrasive flow rate, turning speed of the chuck and nozzle distance. During the experimental study, the pump pressure (380 MPa), the abrasive size (80 Mesh in Garnet form) and the nozzle diameter (0.75 mm) were kept constant. According to the experimental results, the surface roughness decreased as the turning speed and the abrasive flow rate increased. On the other hand, the surface roughness value increased as the nozzle feed rate and nozzle distance increased.

International Iron & Steel Symposium
UDCS

Fuat KARTAL M. Hüseyin ÇETİN Hasan GÖKKAYA

Low carbon steels have been gained special attention for being used in transportation industries like automotive and railway sectors. Improving the mechanical properties of low carbon steels in any manner may decrease the total weight of the vehicles and structures and thus reduce the fuel consumption. Although mechanical properties of low carbon steels can be optimized by heat treatment, severe plastic deformation (SPD) techniques based on imposing very high strain to the material provide much more increase in the strength values of them. Therefore, low carbon grade-A steel was processed via equal channel angular pressing (ECAP) known as one of the most commonly used SPD method. ECAP did not cause considerable decrease in the grain size of the steel, but it increased hardness and strength values significantly due to the increase in the dislocation density in the microstructure. On the other hand ductility of the steel decreased after ECAP process. Impact energy of the ECAP-processed sample was found to be dependent on the notch position of the Charpy impact test sample.

International Iron & Steel Symposium
UDCS

Muhammet Demirtaş

Copper, which is known to have very good electrical and thermal conductivity, has poor mechanical properties. In order to overcome this negativity, the production of coppermatrix composites is becoming increasingly popular. In this study, copper (Cu) matrix ferrochromium (FeCr) and ferroboron (FeB) reinforced composites were produced. Cold pressing and sintering process were preferred as production methods. Microstructure and phase composition of the composites were examined by using scanning electron microscope (SEM). Hardness properties were carried out microhardness device. Also, Densities of composites were studied. SEM images showed that FeCr and FeB reinforcements were partially homogeneously dispersed in the Cu matrix. In the presence of FeCr and FeB in the Cu matrix, the hardness of the Cu matrix was considerably increased.

International Iron & Steel Symposium
UDCS

Mehmet Akkaş Serkan Islak Uğur Çalıgülü Mustafa Boz

Low carbon steels are well-known ones among the traditionally shipbuilding materials due to their low cost, high workability and good weldability. However, they have relatively low mechanical properties such as hardness and strength due to their low carbon content. Grain refinement via sever plastic deformation (SPD) seems to be an essential strengthening mechanism without changing the chemical composition of metallic materials. Among SPD methods, equal channel angular pressing (ECAP) is one of the most commonly used one due to its capacity for achieving bulk ultrafine-grained (UFG) materials. When the literature is examined, very limited investigations have been undertaken regarding the low carbon steels and none of them are shipbuilding steels. Therefore the mean purpose of this study is to apply ECAP to a shipbuilding low carbon steel (ASTM 131A) to be able to achieve finer grained microstructure for gaining improved mechanical properties. ECAP brought about a substantial grain refinement. Two different microstructures observed on flow and transverse planes of the ECAPed sample. On the flow plane, microstructure consists of elongated ferrite and perlite grains aligned in a direction having mainly 45° angle with the extrusion direction while on the transverse plane nearly equiaxed grains were formed. Hardness increased significantly from 130 Hv to about 290 Hv on the transverse plane after UFG formation. ECAP also increased both yield and tensile strength values from 280 MPa and 410 MPa to about 420 MPa and 790 MPa, respectively.

International Iron & Steel Symposium
UDCS

Dursun Murat Sekban Muhammet Demirtaş Gençağa Pürçek

The assessment of microstructure of polycrystalline materials is a very complex task. In practice it is usually gathered through observations of 2D cross-sections of material. In the literature there are many references that theoretically deal with the problem of mapping the 2D structure onto 3D space. This is a very complex geometrical problem. Any kind of idealization of grain shapes might lead to erroneous conclusions. The contribution describes the concept of 3D model where a large quantity of grains is generated randomly in shape and size. They are randomly distributed in a unit volume space. The space crosssections are made, producing the 2D grain distributions. The grains are randomly shaped and initially represented by geometrical formalisms and further on neural networks are used to form a non-geometric representation of extremely large number of grains. Further step to create the virtual 3D microstructure is to form the large repository of randomly created grains. When used, such grains are randomly selected and placed into the 3D space, scaled, rotated and fit to the grains that already occupy the 3D space. The results of modeling and simulation are presented.

International Iron & Steel Symposium
UDCS

Igor Belic

Blast furnaces are vertical melting furnaces and their capacities change according to their height. They are used in the production of liquid raw iron by melting coke, limestone and iron ore. High quality raw materials are demanded for the blast furnace operations and from one of the raw materials, metallurgical coke, is produced in the batteries of coke plants. Coke production take place by mixing low, medium and high volatile coking coal in calculated proportions, than feeding this blend into closed system, airtight ovens and heating the blend to 1250 ° C - 1350 ° C for 18-19 hours. In the coking process, first the moisture in the coal is separated by vaporization, then the volatiles separates by gasification after a series of cracking reactions. The final product is metallurgical coke which is rich in carbon, porous and has a hard structure. The quality of the produced metallurgical coke is directly affected by the coals used in the blend and the coking conditions. Because of the increasing production targets and needs, integrated iron and steel plants can supply metallurgical coke from outside producers. One of the most important input that increases the cost of liquid raw iron is the amount of coke used in blast furnaces. The most important parameters that determine the quality of the coke are CRI, CSR, Stability and Hardness. Considering that the facilities provide coke from suppliers in order to meet their production targets, the quality of the purchased coke affects the consumption in the blast furnaces and has a direct negative or positive impact on the costs. From time to time, it is observed that the analyses result of the four quality parameter values mentioned above in the loading port and discharge port are not matched, the discharge port sample’s analysis result are low than loading port. In such cases, the articles in the contract are valid and buyer can accept the shipment with penalty or reject the raw materials. In this study, the results of CRI, CSR, Stability and Hardness analysis are modeled from the ash, volatile matter and ash components of coke and 77,14% - 77,30% - 91,51% - 80,8% R-square values were obtained respectively. With the model a tool has been developed, which can be used by the purchasing departments at the proposal evaluation stage.

International Iron & Steel Symposium
UDCS

Can Erarslan Tayfun PAMUKÇU Erdem YILDIZ

The results of modelling of temperature fields, kinetics of deposition of layers of dissimilar metals and nature of structural transformations in formation of multi-layer structure of 17G1S and 30KhGS steels are presented. Computer modelling was performed using COMSOL Multiphysics package. The work takes into account effect of temperature on thermal and physical parameters of steels. To increase productivity of additive process the work has studied simultaneous effect of 3 arcs on process of deposit formation, kinetics of structural transformations and diffusion processes of alloying elements redistribution. The calculations show that preheating of the substrate by arc in the beginning of the process before application of deposited material is necessary in order to decrease a stress level between additive deposit and substrate to 50 MPa. It is shown that the time of passing between neighbor arc heat sources shall be kept in 5- 30 s range. It is determined that low power of arc (1 kW) mainly provokes formation of ferrite-bainite structure in the deposit, portion of bainite in which makes 71 %, ferrite 28% and martensite  1%. Application of larger power arc (5 kW) forms in the deposit bainite-martensite structure, portion of bainite in which makes  50%, portion of martensite rises up to 40% and that of ferrite to 10%. Increase of arc power results in rise of maximum temperature of liquid pool to 1750-1850 C, growth of cooling rate to 15 – 25 C/s , and, as a consequence, increase of martensite portion in the structure of deposited layers. Developed software can be used for mathematical modelling of metallurgical additive process of formation of products from different steels, titanium, aluminum etc. alloys.

International Iron & Steel Symposium
UDCS

КОSTIN V.A LAUKHIN D.V ROTT N.O.

Manufacturing Practicing Code (MPC) is the key number which is consisted of 13 parameters and given to all the flat (coil, plate) and long products (wire rod, billet) regardless of A1 or A2 quality manufactured in Iskenderun Iron and Steel Co. (ISDEMIR). It underlies the basis of the follow-up systematic in the factory. These 13 parameters are aimed to be increased till 28 parameters at a later time. All information about the product come under MPC which contains customer demands which affect production and quality parameters in all phases from the stage of order placement until delivery to the customer. These components identify the product and customer requirements. Isdemir Production Management System (PMS), Production Control System and Long Product Sales System are established on MPC from demand to shipment. Product type, steel grade, thickness/diameter, width, length, domestic/export, size tolerance, length tolerance, type of packaging, outside/inside diameter, test report, special mark and weight' create the infrastructure of MPC. All information in this code determine the production line where the product has to be followed, processing parameters and tolerances in production lines. Thus, production and effective control can be ensured accordingly. MPC which characterizes identification of customer demands, provides continuity of the process and systematic along with PMS. ISDEMIR has 4 levels of computing and automation system in the production process: The first three level is consist of machining, line or division basis whilst fourth level provides production and control, gives production orders, allows quality control and production monitoring functions generally in whole ISDEMIR. The other name of Level-4 is Production Management System (PMS). Quality Design, Production Planning, Quality Control and Production Monitoring etc. are sub-systems of PMS. Quality design, order acceptance, order entering and order confirming are performed in the PMS. MPC is a necessary code on PMS because of the production planning and the continuation of the product or semi-finished products to the next line. Therefore, MPC becomes the main component of the Production Management System. It is a key that reflects the final product characteristics consisting of a product code and a sequential number, expressed in 9 characters.

International Iron & Steel Symposium
UDCS

Muhammet Bilen Nalan Gül Uğur

Nowadays, one of the most important problems of businesses is to optimize projects with many conflicting goals. Goal programming model is very commonly used tool for solving multi objective programming solving. However, the concept of uncertainty is very important in optimizing model where there are many targets. In these reason, the complexity of uncertainties in our environment or insufficient capabilities of decision-makers lead researchers to concentrate on new methodologies. One of the best ways to decide in case of uncertainty is to use the fuzzy goal programming model. The production targets of an integrated iron and steel plant are becoming more complex in a changing production environment where the suppliers need to be diversified. In the iron and steel industry, mathematical programming techniques have been used since 1958 and since then many optimization applications have been reported. In this study, firstly concept of fuzzy and fuzzy logic was explained. Then goal programming and fuzzy goal programming methods were investigated. Finally, the product supply problem of the integrated iron and steel plant was solved by two different Fuzzy Goal Programming approaches and the most appropriate procurement program was found. Then, the results obtained by these two methods were compared and the findings were interpreted.

International Iron & Steel Symposium
UDCS

Neslihan Yağcı Köse Ramazan ŞAHİN

Powder metallurgy method is production of parts widely used today. This use is widely used in many areas of the steel materials industry, especially from powder metal parts produced by powder metallurgy method. Since these materials take the form of the final product at the end of production without requiring any machining process. Also, these materials can be used as an iron based bearing material because of the machine parts such as filter, cutting tool bits and they have self-lubricating property due to its porosity. The aim of this study is; stainless steel matrix, boron carbide reinforcement in different ratios (5%, 10%, 15%) is the production of functional graded material. For this reason, stainless steel and boron carbide powders were mixed in V-type mixer for 3 hours. After this process, the samples were produced by means of powder metallurgy under pressure of 45 MPa at 900°C in the hot press machine. The microstructure and boron carbide distribution of the produced samples were examined in the SEM device and hardness measurements were made in order to observe the changes in mechanical properties. When microstructures were examined, it was determined that boron carbides were distributed homogeneously. It was observed that the hardness increased as the rate of support and the transition between the stages increased.

International Iron & Steel Symposium
UDCS

Batuhan Özusta Yasin Akgül Hayrettin Ahlatçı Süleyman Yaşın İsmail Esen Yavuz Sun Yunus Türen

In the past 10 years, the progression on research and development of graphene incorporated steel matrix composites has attracted enormous attention of scientists and industries aiming to combine the advantages of each component producing multifunctional materials with exceptional properties. Due to its unique properties, graphene is strong candidate for reinforcing and decorating the structure of steel matrix and high expectations have been placed on it for various technological applications. Recently, numerous studies directed toward on composites of graphene with steel particles. The interactions between graphene and steel, either noble or non-noble steels, have enhanced durability, chemical, mechanical, thermal, and electrical properties to a large extent. Herein, this paper addresses the most recent progress on graphene-based steel composites, their properties and the applications.

International Iron & Steel Symposium
UDCS

Kamal Bin Yusoh

Oily sludge is considered as waste in steel processing plants. Although it is treated as waste, it could be used as raw material since high metal content. Mill scale on the other hand is used in integrated steel factories and is a large source as raw material or recycled material. In this study, oily sludge of pipe production is mixed in different ratios with mill scale and pelletizing behaviour is studied. Starting materials are characterized for particle size, chemical composition and phase analysis. Produced pellets are controlled for free fall test, moisture content and compressive strength. Reduction experiments are done in laboratory scale furnace in order to evaluate reduction behaviour of pellets and effect of oily sludge content.

International Iron & Steel Symposium
UDCS

Samet Ballı Selçuk Yeşiltepe Mustafa Kelami Şeşen

The contribution of neutron scattering to progress in the physics of magnetism is very large and important, especially its contribution to the understanding of magnetism in metals. The spin wave dispersion relations of Fe and Ni were measured by neutron scattering techniques, around 1970 and the results were in good agreement with the band theory based on a generalized random phase approximation (RPA). Therefore, band theory can explain the magnetism in metals not only for the ground state but also for the excited states. Otherwise, the high strength and hardness properties, cobaltbased alloys have been used as structural materials in nuclear reactors and activated cobalt materials in corrosion products are significant in determination of dose levels during maintenance after a coolant leak at a nuclear fusion reactor. In this study, we have been investigated some nuclear and magnetic properties of Fe-Co and Co-Ni alloys. Magnetic behaviours of these alloys can be investigated by Monte Carlo simulations for different and predefined exchange energies or coupling strengths. For ferromagnetic interactions, magnetization and susceptibility curves of the alloys have been computed with Monte Carlo method based on classical Heisenberg model. Magnetic characters of these type of alloys can be reached by neutron scattering experiments as well. The cross sections values for 59Co(n,p)59Fe and 59Co(p,n)59Ni nuclear reactions have been calculated with TALYS code and have been compared with the available experimental cross section data reported in the literature. Also, the half-lives of these transitions have been calculated in the proton-neutron Quasi Particle Random Phase Approximation (pn-QRPA) framework. The obtained results are compared with the experimental data and the other theoretical values.

International Iron & Steel Symposium
UDCS

Necla Çakmak Rıdvan Baldık Ulvi Kanbur

Stainless steel - copper nanoparticles selective surfaces were deposited by a thermal evaporation technique. Stainless steel type 316L (316L SS) was chosen as a substrate, while the copper nanoparticles (CuNP) were deposited on 316L SS by physical vapor deposition (PVD). The absorption and emissivity were also measured in the UV-Vis and IR regions respectively. The results show that the prepared film by PVD has an enchantment in optical properties. A solar absorption of 0.78- 0.94 and thermal emissivity of 0.01-0.05 at room temperature has been achieved for the 316L SS-CuNP solar selective coatings. Also, the results displayed that the presence of copper nanoparticles combined with 316L SS has a better performance than 316L SS alone. The absorption and the emissivity have been an improvement; in addition to a good thermal stability have been obtained. The improvement of the solar absorber using CuNP combined with 316L SS was found to be better than CuNP singly. Other characteristics like structure and phases of coating layers achieve investigated using XRD in another side, topographic was examined via AFM and SEM.

International Iron & Steel Symposium
UDCS

Ahmed S. Abbas Mohammed J. Kadhim Khalid A. Sukkar

In this study; Distaloy AE alloy powder which is type of diffusion alloyed powder used and this alloy powder pressed on the 400 and 600MPa pressures with traditional pressing technique. Pressed Distaloy AE samples sintered 1200°C temperature for 2 hours under N2 atmosphere. Density and structural properties of sintered these alloy samples performed. In order to investigate density properties of Distaloy AE samples; Archimedes water displacement test performed ; bulk and apparent solid density (g/cm3 ) , apparent porosity (%) and water adsorption (%) values recorded. With SEM images and EDS spectrums; surface properties of these alloys examined and by XRD patterns crystal structures on the surface of these alloys are recorded.

International Iron & Steel Symposium
UDCS

Ayşe Nur ACAR Abdul Kadir EKŞİ Ahmet EKİCİBİL

The feature of the microstructure of carbon steel EA1N (chemical heterogeneity inherited from the dendritic segregation of silicon and manganese) in a cast, deformed and heat-treated state has been investigated. After the longitudinal rolling, the deformability evaluation of structure of the axial billets has been executed. The effect of inherited chemical heterogeneity of silicon and manganese on formation of final microstructure of the railway axles has been established.

International Iron & Steel Symposium
UDCS

Оleksandr Babachenko Kateryna Domina

This paper aims to investigate the effect of Laser surface melting (LSM) and Mo alloying on plasma transferred arc (PTA) deposited Co-Based Stellite 6 Hardfacings. LSM'ed and Mo alloyed samples were characterized using X-ray diffractometer and scanning electron microscopy. LSM’ed unalloyed Stellite 6 exhibited a microstructure similar to its PTA state in terms of constituent phases but at finer scale as a result of high cooling rate of the melt pool followed the LSM process. Whereas in the LSM’ed Mo-alloyed Stellite 6, only two distinct phases have been observed, whereby the complex carbides appear as interconnected network and the matrix phase appears in fine cellular dendritic morphology. The subsequent LSM process of the unalloyed and Mo-alloyed Stellite 6 led to an increment in the surface hardness as compared to the PTA version. Room temperature wear resistance was examined under testing loads of 1, 2, 3 and 4N and corresponding wear coefficient 'k' was determined. The k values showed that there was almost 25% reduction in wear loss upon the LSM process. This dual approach of Mo alloying and LSM led to a 75% reduction in wear loss than the PTA version.

International Iron & Steel Symposium
UDCS

Ali Abdul Munim Alhattab Shaikh Asad Ali Dilawary Amir Motallebzadeh C. Fahir Arisoy Huseyin Cimenoglu

Hard turning is an alternative machining method instead of cylindrical grinding. In this method, more efficient results can be obtained for surface integrity (surface roughness, hardness, residual stress, etc.) of the machined parts when the cutting conditions are optimized. This study includes the optimization of cutting parameters for the minimum surface roughness (Ra) and the development of a mathematical model for estimation of Ra in turning of hardened X40CrMoV5-1 tool steel with ceramic cutting tools. In this context, hard turning tests were made at three different levels using the cutting speed (V), cutting depth (a) and feed rate (f). According to the Taguchi methodology, the optimum cutting parameters were determined as the a2V3f1 test sequence. According to the results of the analysis of interactive variance, the most important parameter was determined as the feed rate.

International Iron & Steel Symposium
UDCS

Mehmet Erdi KORKMAZ Mustafa GÜNAY

In present study, the morphological structure and hardness properties of electroless NiP alloy and NiP/h-BN composite coatings on AISI 1040 steel were investigated. The synthesized nano h-BN particles (0.25, 0.5 and 1 g/l) were added into the NiP bath to develop NiP/h-BN composite coatings. Chemical composition of the coatings was analysed by EDX. The morphology of h-BN particles and coatings were examined by SEM. Hardness of the coatings are evaluated using Vickers microhardness tester. The results show that the incorporation of nano h-BN particles in the deposit has been found to decrease the hardness of composite coatings. The nano h-BN particles are uniformly distributed in the nickel-phosphorous matrix.

International Iron & Steel Symposium
UDCS

Ulaş MATİK

Tavan vinçleri ağır sanayide, ciddi öneme sahip olan adeta işletmenin eli kolu konumunda olan kaldırma ve iletme makinalarıdır. Buna karşın vinçler, iş kazalarının ve proses kazalarının yoğunlukla meydana geldiği makinalar arasında yer almaktadır. Hem vinç kaynaklı proses ve iş kazalarını önlemek hem de üretkenliği ve verimliliği artırmak için eğitimli ve tecrübeli vinç operatörlerine yardımcı olacak akıllı sistemler ihtiyaç vardır. Burada şirketimizde kendi imkânlarımızla vinçlere eklediğimiz iki akıllı özellik sunulacaktır. 1. Vinç kancalarına çarpma uyarısı: Yüksekte çalışan ve birden fazla kedi ve kancaya sahip olan vinçlerde operatörlerin, kancalardan birine odaklanırken diğer kancanın unutularak vincin altındaki tesislere çarparak zarar vermesini engellemek için uyarı ikaz sistemi tesis edilmesi. 2. Cüruf havuzlarındaki vinçlerde gevşek halat engelleme: Özellikle cüruf havuzlarında çalışan vinçlerde, yoğun buhardan dolayı vinç operatörleri kepçenin havuza indiğini görememekte ve halatlar gevşeyip dolaşarak üretimin durmasına sebep olabilmektedir. Biz, vinçlerdeki mevcut imkânlarımızı kullanarak gevşek halat engelleme sistemi ekledik vinçlerimize. Bu şekilde, yük indirilirken kaldırma tertibatı tahrik ünitesi yükün ne zaman zemine indiğini algılayıp hareketi durdurur. Kaldırma tertibatı halatları gevşemez, böylece halatlar kanca blokunun dışına kaymaz ve kepçe de yana yatmaz.

International Iron & Steel Symposium
UDCS

Mehmet Sönmez

The surface of sheet metals should have a certain level of roughness in terms of forming and dyeing quality. Surface roughness is mainly introduced to the material by cold rolling with straight rolls, which are textured by different methods. These methods have some advantages and disadvantages compared to each other. In this study, these methods are examined, and their superior sides are indicated.

International Iron & Steel Symposium
UDCS

Bilal ÇOLAK Fatih BAŞOĞLU Naci KURGAN

In this study; Rod drew 54SiCr6 and 60SiCr7 steel’s resistance to severe abrasive wear response were examined by the means of comparing Si and Cr contents. The sample pieces with 10 mm diameter and 20 mm high from the medium carbon steels were subjected to abrasive wear test against Al2O3 sandpaper with a particle diameter of 210 µm under 40, 80, 120 N loads. It has been observed that the abrasion resistance of 54SiCr6 and 60SiCr7 medium carbon steels has improved with the decrease of Si content in the structure of steel and the increase of Cr content at the same time.

International Iron & Steel Symposium
UDCS

Esma KESKİN Hayrettin Ahlatçı Yunus Türen Mustafa Ali KÜÇÜK Cemal ÖZGENÇ Yasin SUBAŞI Burcu Çetintaş

— In this study, Fe based composites containing Al2O3 at 1, 3 and 5% by weight were produced by powder metallurgy method. The powders were weighed in the sensitive balance and pressed under pressure of 750 MPa after 1 hour blending. After pressing, the composite materials were sintered at 1100 °C for 1 hour. With the increase in Al2O3, the density decreased, the hardness and porosity increased.

International Iron & Steel Symposium
UDCS

Mehmet Akif Erden

In this study, a mixture of unalloyed steel material in the desired composition via powder metallurgy method is obtained by adding 0.5% by weight of graphite element in Fe matrix. The powders obtained were mixed by using a 5 mm ball in the mechanical mixing device and the mixture was mixed with powder and ball ratio of 1/10 for 1-2 and 3 hours. Powders obtained after mixing were squeezed at pressures of 700 MPa at 1350⁰C sintering temperature in 1 hour in the molds designed as tensile specimens. The particle size of the produced steels and the distribution of the phases were determined by optical microscope. After microstructure analysis, tensile test was applied to steel samples prepared in tensile specimen dimensions. The elongation, yield-tensile strength of the samples are explained depending on the mechanical alloying time. As a result, steel samples for 1 hour exhibited the highest yield and tensile strength.

International Iron & Steel Symposium
UDCS

Mehmet Akif Erden Selim Erman Harun ÇUĞ

In this study, at Kardemir Co. Inc., during the absorption of BOF gas with basic oxygen furnaces (BOF) in the steel production phase with high suction ID fan (Induced Draft), it was provided that wear of the ID fan blades was improved. As a result of the investigations, it was determined that BOF gas eroded ID fan body and wings and an increase in ID fan vibration values due to abrasion happened. ID fan blades have been improved to eliminate wear on ID fan blades. As a result, improvements have resulted in reduced production stoppages due to vibration, improved production efficiency and reduced production costs.

International Iron & Steel Symposium
UDCS

Halil İbrahim EMİROĞLU Hasan GÖKKAYA Ahmet Fatih YILMAZ

In this study; The effect of the solution and aging heat treatments on the corrosion behavior on high chromium cast steel samples with the compositon of 1.61% C + 25% Cr + 0.74% Si + 0.55% Mn + 0.38% Mo + 0,23% Ni + 0.15% V were investigated. The samples solution heat treatment - rapid cooled for 4 hours at 1150 ℃, aged for different times between 5-25 and in cast (original) status were subjected to corrosion treatment. Corrosion behavior was investigated by immersion method in 10% FeCl3 and 10% H2SO4 medium. As a consequence, the least corrosion rate was seen on the sample kept at the solution condition and then cooled by water rapidly while higher corrosion rates were observed on cast (original) status and aged samples.

International Iron & Steel Symposium
UDCS

Mustafa Ali KÜÇÜK Hayrettin Ahlatçı Yunus Türen Soner Arı Yasin SUBAŞI Süleyman Yaşın

—In this study for a teeth wire that has a quality of 316, diameter of 0.4 mm and a tensile strength of 800 MPa, we investigated its fatigue behaviour in two environments: atmosphere and 3,5% NaCl using the methods of simple bending tests. In order to do those tests we decided to use stainless steel braces of model REF500-040-00 and calculated the wire’s length before starting the test using the following law: (L = (c * 2.17) +31). The tests have been done according to the room temperature and frequency of 10 Hz. We used the lean bias device to perform the test which requires the fully reversible stress (R=min/ max= −1). After that we examined the fractured surfaces of fractured samples that were close to the deformation limit of fatigue using SEM in order to know their fracture mechanism. We have observed that the corrosive environment caused the fatigue to result in a different mechanism.

International Iron & Steel Symposium
UDCS

Rahma Shaaban Tuğba Akçabaş Hayrettin Ahlatçı Yunus Türen Yavuz Sun Yasin SUBAŞI Ömer Onat Hüseyin Koymatcık

Advanced High Strength Steels (AHSS) grades are currently the fastest growing materials in the automotive industry. AHSS offer a great potential for the development of automobile bodies with their mechanical properties of high formability and strength. Dual phase (DP) steels are increasingly popular AHSS grade in the automotive industry due to the excellent combination of high strength and good formability. The intercritical annealing of DP steel is generally two-stage heat treatment. DP steel sheet is annealed in the intercritical temperature range to produce ferrite and austenite and followed by accelerated cooling to transform the austenite phase to martensite. This study aims to examine effect of a cyclic intercritical annealing below and above A1 temperature on DP steel microstructure with comparison to the conventional intercritical annealing. The specimens were conventional intercritically annealed at different temperatures between 720 °C and 760°C. In cyclic intercritical annealing experiments, the temperature is cycled between 630 °C and an intercritical annealing temperature without any isothermal holding. After the conventional and cyclic intercritical annealing, the samples were investigated using light microscope and scanning electron microscope. Experimental results showed that a refinement of martensite and ferrite dual phase microstructure compare to conventional intercritical annealing.

International Iron & Steel Symposium
UDCS

Ayşe Kavruk Oğuz Gürkan Bilir Özge Ararat Ahmet Efe Gezmişoğlu

—In this study, fatigue strength and microstructural changes of AISI 1040 steel with different heat treatment parameters were investigated. 1040 steel is a material used in many areas today. Some of the material application areas can be subjected to cyclical loads. Fatigue strength, such as abrasion and tensile strength, is also very important in these materials. AISI 1040 steel can be easily heat- treated to increase strength. The samples were incubated at 920 ° C for 4 hours and controlled cooling in air, oil, water and oven. The microstructures of the samples after heat treatment were examined by optical microscope. Vickers hardness was performed for all samples. Force controlled fatigue test was performed. Broken surface images of fractured specimens were taken on Nikon ShuttlePix device during the test. The hardness of the water cooled sample was better than other heat treatment samples. It was observed that the increase in fatigue strength as a result of the hardness and pulling points increased.

International Iron & Steel Symposium
UDCS

Salih Bektaş Fazil Hüsem

In this study, the effect of the heat treatment parameters on the hardness of the asymmetric profile was investigated. For this purpose, at first, the asymmetric profile samples of R260 quality were austenitized at 790 C for 60 minutes. Then, quenching was performed at different quenchant media (water, oil and polymer-based water). The quenched samples were tempered at different temperatures. The results showed that the highest hardness value was obtained at the sample at quenched in water among the samples. The main reason for this highest hardness value is due to the fact that the cooling rate in water quenching is much faster than the other quenching medias. After the water quenching process, tempering at three different temperatures (610 C, 630 C and, 640 C) for 80 minutes were carried out. As a result of these processes, the optimum hardness values (26,2 – 31,6 HRc) were obtained at the sample tempered at 630 C. After oil quenching, the tempering processes at various temperatures (500 C and, 520 C) were performed for 80 minutes. The required hardness values were reached by the tempering process at 500 C for 80 minutes. After the polymer-based quenching prosess, samples were tempered at the various temperatures of 550 C, 590 C and, 640 C for 80 minutes. It was found that the sample tempered at 590 C for 80 min. showed optimal hardness performance. To sum up, variable results were determined in three different regions by the hardness measurements which performed to observe the results of the different heat treatment parameters caused by the hardness of the R260 quality asymmetric profile. The main reason for this is due to the asymmetric form and the differences in cross-section thickness of the profile. At this point, the most homogeneous hardness distribution throughout the section was observed in the water quenched sample.

International Iron & Steel Symposium
UDCS

Gürkan Gümüş Hakan Erçay Tuncay Dikici

In this study; the effect of nitration process applied to coldforged 32CrMoV1210 samples with 100-mm, 24, 5 mm in outer diameter and 7, 5 mm in inner diameter, which is used in production of the barrel rifle, on the abrasion behaviour is investigated. For this purpose, hardness measurements, microstructure investigation and coating thickness determination of the gas nitrated 32CrMoV1210 steels at 500 °C for a period of 12 hours has been carried out. The original sample and the heattreated sample have been subjected to an over ring pin-type abrasion test under 80N-120N load. While the 1.2344 (X40CrMoV51) quality tool-steel, which is 56(HRC) in hardness, is used as a pin, the materials which have been examined with nitration and without nitration are used as a ring. In comparison with the severe abrasion resistance of 32CrMoV1210 samples without nitration; nitrided samples have shown an increase in abrasion resistance at the rate of %90.

International Iron & Steel Symposium
UDCS

Ali Akkuş SAİT ÖZÇELİK Mehmet Ünal Yusuf Gökalp Burcu Çetintaş Furkan Ayhan Tezer

In this study, the effect of gas nitration on the wear behavior of crankshaft was investigated. For this purpose, gas nitration was applied to crankshaft for 12 hours at 500 ° C, and hardness and microstructure images were examined. Nitrided and unnitrided samples were subjected to abrasive wear test under 20N, 40N and 60N load. While 100Cr6 balls were used as abrasive, crankshaft with nitriding and unnitriding was used as counter-material. Nitrided samples have increased wear resistance by about 20% compared to the wear resistance of unnitrided crank shaft samples.

International Iron & Steel Symposium
UDCS

Yusuf Gökalp Yavuz Sun Mehmet Ünal Emre Küçük SAİT ÖZÇELİK Ali Akkuş Burcu Çetintaş Emre Demirci

In this study, the hardening process was performed in air, water and oil environment after austenitizing to 8620 steel which is used in parts, machines and automobiles, gear wheels, pins and spindles. The austenitization process was carried out in a Protherm brand oven with an electrical resistance for 1 hour at 900 °C. The cooling in air was carried out in a stagnant atmosphere at 25 °C. For engine cooling, the waste engine oil at room temperature was used, while for the cooling of the water environment, the tap water at room temperature was used. The sample thickness studied is approximately 20 mm. As a result of the optical microstructure studies, the air-cooled samples have a hardness of up to about 1 mm below the surface, and the hardness in the material center is about 400 HV. In the oil cooling process, the classrooms, which have 750 HV on the surface, have decreased down to 550 HV at 2,5 mm depths. In the hardening process, 800 HV hardness values on the surface are replaced by 600 HV values in the center.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ Erkan Koç

The term dual phase steels, or DP steels, refers to a class of high strength steels which is composed of two phases; normally a ferrite matrix and a dispersed second phase of martensite, retained austenite and/or bainite. Martensite phase fraction, morphology, and phase distribution play an important role on mechanical properties and fracture behaviour of DP steel. DP steels were developed in the 1970s. The development was driven by the need for new high strength steels without reducing the formability or increasing costs. In particular, the automotive industry has demanded steel grades with a high tensile elongation to ensure formability, high tensile strength to establish fatigue and crash resistance, low alloy content to ensure weldability without influencing production cost. For years later, the demand for DP steels is still strong. Materials that can combine high strength and good formability and thus reduce the weight of vehicles and other products give an environmental and economic advantage. In this study, plate shaped specimen was used. The specimens were subjected to normalization annealing at 850 °C for 1 hour and cooled in air at room temperature. The specimens were inter-critical annealed at 740°C, 750 °C, 760°C and 770°C for 1 hour and quenched in water at room temperature. Light microscope and SEM were used for the microstructural investigations. Changes of microstructure properties and material hardness were investigated due to different heat treatment conditions. The tensile test was applied to the samples to determine mechanical properties and the results were discussed.

International Iron & Steel Symposium
UDCS

Mustafa Çöl Ersoy Erişir Funda Gül Koç Burak BARUTÇUOĞLU

In this study; The effect of heat treatment of ER7 quality train wheel samples was investigated under severe abrasive wear. The train wheel of ER7 quality samples were heated to 900 oC and brought to austenite phase for 1 hour, then cooled by water. Cooled samples were tempered at 400oC for 1.5 hours. Severe abrasion test was applied to the samples on sandpaper containing 210 µm Al2O3 particle under 40N, 80N and 120N loads. Microstructure and hardness measurements of samples were investigated after quenching and tempering heat treatment. As a result of these tests, the abrasive wear resistance of the heat treated sample by containing by a 3-fold increase in hardness improved by 36%.

International Iron & Steel Symposium
UDCS

Burcu Çetintaş SAİT ÖZÇELİK Süleyman Yaşın Yusuf Gökalp Ali Akkuş Emre Demirci

Diamond cutting tools have been widely used in natural stone industry as the circular sawing, frame sawing, wire sawing and core drilling. The diamond cutting tools are manufactured by powder metallurgy techniques. They are consisted of diamond particles embedded in metal matrix. Chemical interaction between diamonds and matrix is primary importance for diamond cutting tools. As the most used binder to provide these reaction is iron and its alloys. The aim of this study is to enhance the cutting performance of diamond tools by the investigation the effects of iron addition on to the matrix compositions. In this study; 30,50 and 80 wt% Fe containing matrices were determined and their mechanical properties, microstructures and wear resistances were examined comparatively. All materials in the form of powders were cold pressed and then the pellets were sintered with Spark Plasma Sintering (SPS). Microstructural and mechanical characterizations were performed by SEM-EDS, XRD, hardness, compression tests and wear tests. According to the results, control on the grain size and reaching the theoretical density values were achieved by SPS method due the lower sintering temperature and shorter sintering time. Results showed that Fe additives had no negative effect on properties of the samples. Moreover, the mechanical properties of the samples increased with increasing Fe contents.

International Iron & Steel Symposium
UDCS

Berrak Bulut Murat Baydogan Eyup Sabri Kayali

In this study, a mixture of unalloyed steel material in the desired composition via powder metallurgy method is obtained by adding 0.5% by weight of graphite element in Fe matrix. The powders obtained were mixed by using a 5 mm ball in the mechanical mixing device and the mixture was mixed with powder and ball ratio of 1/5, 1/7 and 1/10 for 1 hour. Powders obtained after mixing were squeezed at pressures of 700 MPa at 1350⁰C sintering temperature in 1 hour in the molds designed as tensile specimens. Tensile test was applied to steel samples prepared in tensile specimen dimensions. The elongation, yieldtensile strength of the samples are explained depending on the powder and ball ratio. As a result, steel samples with powder and ball ratio 1/10 for 1 hour exhibited the highest yield and tensile strength.

International Iron & Steel Symposium
UDCS

Mehmet Akif Erden Selim Erman Harun ÇUĞ

In this study, Fe based Al2O3 reinforced composites were produced by powder metallurgy method. Fe-Graphite and Al2O3 powders were pressed under 750 MPa pressure in one direction after 1 hour blending. After pressing, the composite materials were sintered at 1100°C, 1200 °C and 1300 °C for 1 hour in argon atmosphere. The ideal hardness results for the composites were obtained by sintering at 1100 ° C. With increasing sintering temperatures, an increase in density values and a decrease in porosity were determined.

International Iron & Steel Symposium
UDCS

Hasan Karabulut

In this study, fatigue behavior of 55Cr3 metal alloy spring steel which is produced as hot and cold was examined. Fatigue samples with a diameter of 10 mm, extracted from 55Cr3 spring steel in accordance with ISO 1143 standard, were subjected to rotational bending fatigue testing of different masses under repeated bending stresses according to a continuous rotating neutral axis. As a result of the investigations, the fatigue strength of 55Cr3 spring steel decreased with hot process, while the cold process increased.

International Iron & Steel Symposium
UDCS

Esma KESKİN Hayrettin Ahlatçı Yunus Türen Hüseyin Zengin Mustafa Ali KÜÇÜK Yasin SUBAŞI

This study reports the effect of different size of particulates on wear behaviour of iron (Fe) matrix composites. Fe / 5 wt. % Al2O3 , Fe / 5 wt. % B4C and Fe 2.5 wt. % Al2O3 -2.5 wt. % B4C composites were produced thorough powder metallurgy. The samples were compacted under load of 500 MPa and followed by sintering at 1050 ºC for 1.5 h. The dry sliding wear behaviour of the samples were investigated by reciprocating wear tests under loads of 10, 20 and 40 N. In order to clarify wear mechanisms, worn surfaces were analysed by Scanning Electron Microscopy. The hybrid Fe 2.5 Al2O3 -2.5 B4C composites has the highest wear resistance. Oxidation and delamination are the main wear mechanisms.

International Iron & Steel Symposium
UDCS

Fatih AYDIN

Metallic material producers, users and those who work to determine the properties of materials, most commonly use tensile testing. As you know, the tensile test of metallic materials at room temperature is done according to the ISO 6892-1 standard. The tensile testing laboratories provide the reliability and worldwide validity of the test results through accreditation. In this study, after briefly discussed important issues of the ISO 6892-1 standard, laboratories involved in the accreditation system in Turkey will be discussed. The number of laboratories accredited by the same standard in Europe is determined. As a result, the locations of the test laboratories in our country will be compared according to their global competitors and the shares will be presented for the future road map of the laboratories.

International Iron & Steel Symposium
UDCS

Bulent AYDEMIR

In this study, it was investigated whether there was a correlation between the production of steel and the number of accredited laboratories of countries. For this purpose, the metallic material competence (MMC) coefficients of countries were calculated. According to the results, Germany, known as a quality steel producer, was the country with the highest coefficient. Moreover, Germany's made in country index has the best value in other countries. However, China, which is the market leader in steel production, was a country with the lowest MMC coefficient among the compared 10 countries. It was foreseen that countries should focus on non-destructive tests in order to become quality steel producers. This study for the iron and steel industry was thought to be a guide for other sectors.

International Iron & Steel Symposium
UDCS

Alper Incesu Yasin Akgül Betul ERCAN Muzeyyen ABUNAZ Bulent AYDEMIR Murat KAVRUK

— In this study research, the RSW process was applied at various welding currents and in different electrode pressures in electrical spot welding of commercial DP600 steel sheets which has 1 mm thickness that was investigated and calculated the relationship between the effects of the electrode force and that of the welding current has an effect on the weld quality and the diameter of the weld nugget. The current and electrode force been adjusted through the increment of 2 kA from 4 to 8 kA and 1 Bar from 3,5 to 5,5 respectively. The results of the experimental reveal that the tensile shear load and the nugget diameter are increases as the current increases and then it decreases as the electrode pressure increases.

International Iron & Steel Symposium
UDCS

Abdulkarim Alzahougi Muhammed Elitaş Bilge Demir

On the example of the carbon steel, issues of structuring in the process of accelerated cooling are considered. The emerging gradient of structures at different distances from the surface of the heat transfer is presented in the form of a dependence, which is adequate to the effect of the temperature of individual heating during the release of steel after the quenching. It is shown that after the forced cooling is stopped, the increase of distance from the cooling surface accompany higher the tempering temperature of the metal. In the volumes of the metal, the microstructure close to the middle of the disk wheel is formed by the diffusion mechanism.

International Iron & Steel Symposium
UDCS

Vakulenko I Proidak S Raksha S Akay, M. E Cuğ. H Askerov K

In this study thermal properties of graphene reinforced Fe-Cr-Ni-Cu alloys were investigated. This alloys were produced with a two-step process. Firstly, Fe, Cr, Cu, Ni powders were mechanically milled for homogenous mixing. Secondly, these powders were cold pressed and sintered at 1150oC. For comparative study, graphene (GNP) powders were milled with Fe, Cr, Cu, Ni powders and finally, these powders were pressed and sintered at 1150oC. Hence, two types of alloys i.e Fe-Cr-Cu-Ni and graphene reinforced Fe-Cr-Cu-Ni were produced. The specimens were evaluated by thermal, microstructure and mechanical properties. DSC and TGA analysis was carried out for determining the melting points, phase transformations and entropy values. It was found that the graphene reinforced-alloy exhibits lower entropy values than that of obtained from Fe-CrCu-Ni. But the existence of graphene has increased the melting point of alloy. However, the existence of graphene has reduced compression strength of alloy.

International Iron & Steel Symposium
UDCS

Yuksel Akınay Muhammet Emre Turan

The purpose of this paper is to review in some detail how and why the surface degradation of steels through mechanical and chemical mechanisms can be mitigated by the application of specific thermochemical diffusion processes. Of these, carburising, carbonitriding, vanadizing, boriding, nitrocarburising and nitriding are considered in depth. It is shown that wear resistance is not a simple property that can be determined by a single test since many mechanisms of wear are possible. The paper discusses the possible prevailing surface degradation processes and how these can be mitigated by the various thermochemical diffusion processes. Vanadized steels (e.g., produced via the TD process) have sufficient hardness to resist abrasion by the hardest of abrasives (such as SiC). They are best used on very hard, very tough and strong steel substrates, which maintain such properties up to 450ºC. Nitrided/nitrocarburised steels have the advantage that they demonstrate good functionality in mildly oxidational environments at elevated temperature (up to 400ºC); outperforming untreated, carburized and carbonitrided steels. The development of an exterior, micro- -Fe2-3N layer via nitrocarburising, has specific advantages under lubricated high pressure (>1GPa) rolling contact conditions as found in some low alloy steel pinion gear applications.

International Iron & Steel Symposium
UDCS

Peter Dearnley

Iskenderun Iron and Steel Co. (ISDEMIR) has four blast furnaces(BF) 80-90% liquid crude iron is used in basic oxygen furnece (BOF). Liquid crude iro is transfer to BOF by torpedocars.The purpose of our application is monitoring the level of crued liquid iron filling the the blast furnace. With this application, we get the production values of the Blast Furnace and arrange logistics of the torpedocars. The other advantages of this application are as follows; 1. BF workers can monitor the blast furnace process and ensure that the furnace to help understand the rate of discharge, 2. Helps to monitor the full aperture of the drain hole to empty the BF, 3. To be able to understand when the furnace should be closed with instant tonnage information, 4. To make the maneuvering program of the logistics maneuver better, Obtaining data about refractory thickness, 5. Increasing data and digitalization of demonstrable about BF process In addition, the advantages of location tracking system with wireless RFID, which is established for maneuvering of torpedocars. and locomotives, are as follows: 1. Digitally tagged and numbered for easy tracking of torpedocars. and locomotives, 2. Tracking of torpedocars.refractory thicknesses can be monitored faster via ID, 3. Time and speed data of logistics maneuvers have been obtained, 4. All employees in the iron and steel production can follow the torpedocars. through the system. This system is finish the verbal communication, 5. The operating times and maintenance times of the locomotives can be monitored.

International Iron & Steel Symposium
UDCS

Cemil Bayramoğlu Sertaç Kaya Ümit Gebenli Ramazan Yaraşır

In this study, Fe matrix composites with different amounts of graphene nanoplatelets (0.2-0.5-0.8 wt%) were produced via powder metallurgy. Tribological behaviors of samples were determined with a dry sliding wear test. Results were compared with Fe-Graphite (C) composites. Microstructures of samples were investigated by the optical microscope. Vickers hardness and density measurement were performed for all samples. Also, worn surfaces of samples were observed with a Scanning Electron Microscope (SEM). Results show that all graphene nanoplatelets (GNPs) containing samples showed better wear resistance behavior compared to graphite containing samples. However, the same trend was not observed according to hardness test results. 0.8 wt% graphite-Fe sample has a higher hardness value than 0.8 wt% (GNPs)-Fe sample.

International Iron & Steel Symposium
UDCS

Salih BEKTAS Mehmet Akif Erden Ahmet Nusret Tanrıverdi Yasin Akgül

Pig iron production costs are very high in blast furnaces where conventional iron and steel production is carried out, and therefore, iron and steel producers seek alternative methods, two of which are the production of sponge iron and iron nuggets. Depending on furnace temperature and waiting time, reduction of magnetite to pure iron results in three products, one of which is Direct Reduced Iron obtained from iron oxide ore in a reducing atmosphere between temperatures of 900-1100 oC. The second product is Transition Direct Reduced Iron (TDRI) obtained at temperatures at which partial melting occurs. The third product is iron nuggets in which complete melting occurs, and metal and slag are separately obtained. The aim of this study was to investigate the effect of biomass waste on iron nugget production from magnetite ore using carbothermic method. Biomass waste was carbonized at 800 °C for 1440 min to obtain a 94.68% C and 0.03% S carbonized product with a thermal value of 8823 cal/g. Composite pellet samples with and an O/C of 0.5, 1 and 2 were treated in a high temperature furnace at 1300 and 1350 °C for 5, 10 and 15 min. Results showed that samples contained Fe and C as well as FeO. Macro images showed that metal-slag separation was not fully achieved and that the product exhibited TDRI properties.

International Iron & Steel Symposium
UDCS

Bayram Bostancı Elif ARANCI ÖZTÜRK Mustafa BOYRAZLI Engin ÇEVİK Zeki Çizmecioğlu

In this study, the welding images, which were taken in HURSAN Pres company, were classified as good welding / bad welding. The aim is to minimize human errors by artificial intelligence methods during welding defact detection. Welding images were taken on weldings, which were done by three different experts, with 13MP mobile phone camera. The images were labelled as good welding / bad welding by an expert. The dataset consists of 27 good welding images and 70 bad welding images.

International Iron & Steel Symposium
UDCS

Yavuz Selim Ceran Musa Yılmaz Mücahit Barstugan

The management of industrial wastes, which may have negative effects on the environment and human health, has become an important issue in recent years when it has been thrown away or discharged directly to the environment. The most important step in industrial waste management is the determination of wastes from each process and the selection of appropriate waste management technology. Within the scope of this study, a road map that can be used to achieve zero waste targets in the iron and steel industries has been prepared and application proposals are presented.

International Iron & Steel Symposium
UDCS

H. Duygu BİLGEN

In this study, the wear performance of the hardfacing process used to economically extend the life of the forging dies used in the hot forging process in the steel industry was investigated. Hardfacing is a rapid die repair method that is applied locally or completely to the damaged areas in the hot forging die. In this study, 56NiCrMoV7 (DIN 1.2714) hot work tool steel was used as the base material. CITODUR 600/B Febased electrode, i.e. Fe-7%Cr-0.4%C, was used for hardfacing. Hardfacing was carried out by the arc welding method. The wear tests were performed using ball-on-disc CSM Instruments Tribometer. A counter ball specimen was Al2O3 with dimensions of Ø6 mm. Wear performance was reported for both tool steel and hardfaced layer at normal load of 10N and linear speed of 12.8 cm·s -1. It was shown that the hardfacing layer exhibited better wear resistance than the tool steel for all testing results. The overall friction coefficient was higher in hardfacing layer than in tool steel. Surface hardness of the hardfaced layer and tool steel samples was obtained. It was observed that the hardfacing with CITODUR 600/B leads to an increase the wear life of the dies which are made from 56NiCrMoV7 tool steel.

International Iron & Steel Symposium
UDCS

Simge Gençalp İrizalp Yiğit Erçayhan Ezgi Yeter

In this study, at Kardemir Co. Inc., during the absorption of BOF gas with basic oxygen furnaces (BOF) in the steel production phase with high suction ID fan (Induced Draft), it was provided that wear of the ID fan blades was improved. At the end of the wear improvement work, the ID fan blades are plated with AISI 304L stainless steel to remove the wear on the ID fan blade wings. Briefly, improvement of the ID fan blades with the AISI 304L stainless steel, a decrease in the production stops time during the steel production phase with BOF so depending on the decrease, steel production has increased.

International Iron & Steel Symposium
UDCS

Halil İbrahim EMİROĞLU Hasan GÖKKAYA Ahmet Fatih YILMAZ Abdullah UĞUR

Emission standards getting harder and tougher day by day, therefore this challenge causes a decrease in diesel engine and increase in hybrid systems usage. But, for heavy duty industries; diesel engines are still very economic and feasible because of today’s technological developments and market competitions. In this direction, research and development process of heavy duty diesel engines continues on process optimisation and weight reductions. In this study, weight reduction and design development is applied for a tractor diesel engine block which manufactured for prototype to gain an industrial advantage. New light weight design is optimized according to manufacturing parameters and moulding requirements via casting simulation software. In additional, a commercial finite element-based analysing program is used to simulate the mechanical properties of the new design, and to predict possible deviations by comparing the first and final design.

International Iron & Steel Symposium
UDCS

Ümit Kirenci Ali Serdar Vanlı Anıl Akdoğan

The residual stresses induced by any machining process affects fatigue life, corrosion crack resistance and part distortion. Therefore, residual stresses should be predicted better and the cutting parameters should be arranged for minimum value. This paper presents a 2D finite element analysis (FEA) on residual stresses during hard turning of AISI 4140 steel with HSS tools. The cutting parameters are chosen as feed rate and cutting speed with three levels and constant depth of cut. In simulation after the cutting process is finished, both the chip and tool are removed and the workpiece can thermo-mechanically relax. The average of three extraction points on eight different depths of machined surface for residual stresses is calculated for better results. FEA results showed that both tangential and axial residual stresses act as tensile in the depths near the surface until about 75 µm while they act as compressive stress after the depth of 75 µm until about 300 µm. Also, increasing cutting speed has decreasing effect on tensile residual stresses while increasing effect on compressive residual stresses.

International Iron & Steel Symposium
UDCS

Mehmet Erdi KORKMAZ Nafiz YAŞAR Mustafa GÜNAY

Prices are falling in the world iron and steel industry due to China's high production capacity. This leads manufacturers to produce high-yielding products with less amount of production. Rail and rail equipment is one of the increasingly being produced iron and steel product in our country in recent years. In this study, by analizing export data of rail and rail equipment (including wagon wheel) of Turkey, a forecasting for the years 2016-2020 has been made with the aim of guiding producers and giving an idea about exporting of these products. Grey prediction method and Holt's exponential smoothing technique were used for forecasting and the results were compared.

International Iron & Steel Symposium
UDCS

Ahmet Ziyaeddin Bulum Muharrem DÜGENCİ Mümtaz İPEK Halil İbrahim DEMİR

In this paper, a literature review was conducted for the development of the aerial work platform with a working height of 60 meters, which was installed on the truck. And mentioned to why needed for work platforms, how they were developed, and their history as well as areas of use. In the near future, this study has been thought that the platform to be designed will help to be secured, technologically and low cost.

International Iron & Steel Symposium
UDCS

Yasin Yaman İlhan Asilturk

This paper proposes a new method for the assessment of performance of protective oil on galvanized and skin passed sheets. 11 different protective oil products were applied (1 g/m2) to hot dip galvanized and skin passed 66 sheet samples and subjected to Neutral Salt Spray Fog Testing (NSSFT) with 5% NaCl solution. Amount of white rust on the samples has been determined at 2, 6, 9 and 24 hours. Test results showed that application of NSSF test for 9 hours gives best deterministic results.

International Iron & Steel Symposium
UDCS

Özgür KARAKAŞ Erdogan KANCA Faruk CAVDAR Alper AKÜN İbrahim GÖÇER

High technology based production with the advent of industrialization has created some new issues. Foremost among them is the occupational health and safety. The facts that the business environment is particularly unsafe and puts health at risk have increased the importance of health and safety in work places. Measures in regards to work safety in the iron and steel sector are at the forefront of the issues that must be prioritized. It is crucial that job satisfaction levels of occupational health and safety specialists, who not only have good knowledge of both the workplace and the production process but also can determine, along with best safety measures, hazards related to the nature of work and production tools, are high so that they can work effectively and efficiently. Considering this factş a field study was done in order to measure job satisfaction levels of health and safety specialists working in the Black Sea Region. The data obtained from the questionaire with 379 samples was evaluated with factor analysis and then, it was analysed to see if there is variation by applying nonparametric Mann-Whitney U ve Kruskal-Wallis H tests. As a result of the analysis, it was found that job satisfaction levels of occupational health and safety specialists did not vary in respect to age, sex and OHG (Occupational Health Safety) certificate but varied in respect to occupational experience.

International Iron & Steel Symposium
UDCS

Volkan SANCI Abdullah KARAKAYA

Families act in an environment of financing system which includes the pressure of the economic powers like the changing economic balances, increasing unemployment rate, changing purchasing power of money, inflationist pressures, increasing tax load, changing government policies, increasing interest rates, complicating consumer market, and the competence gradually increasing between the businesses. In such an environment, the behaviours of family related to usage of the income on one hand affect the social and economic welfare of family itself, and on the other hand the national economy and welfare. In this context, economic functions are of a significant center for the families to obtain their wishes and needs and to maintain their lives better and happier. In this article we focus on families’ financial behaviours. For this purpose we have observed 1) financial status of families, 2) financial decision making forms of families’, 3) families' financial status evaluation. The sample consists of individuals, who are working in Kardemir Inc. (n=245). A total of 245 employees are participated in the study on a voluntary. Findings indicated that 65.3% of the responses keep record for income and expenses every month. Economic decision making are always shared by couple (47.3%). The rate of monthly income scarcely satisfies needs (46.1%) are higher among the reasons for not saving. The majority of participants (89.0%) have stated that their monthly incomes are not sufficient or scarcely sufficient to satisfy the needs of families and thus, they cannot make savings. Finally, some recommendations are suggested for individuals, families, executives and researchers.

International Iron & Steel Symposium
UDCS

Gülay GÜNAY Ahmet OĞUZ Fatih BAYRAM Murat YILDIRIM

In general, design of abrasion resistant steel is based on the assumption that abrasion resistance increases with hardness. However, in practical use, some problems are created with an increase in hardness exceeding 500 HB. Therefore, abrasion resistant steels should have a combination of high abrasion resistance, good cold formability and sufficient impact toughness. Relia® is ArcelorMittal’s new range of high hardness, low-alloyed martensitic steels, offering outstanding resistance to wear and abrasion. Despite their extreme hardness, the properties of Relia® plates are specifically designed for improved workability such as cutting, forming, drilling and welding to realise any kind of applications and designs.

International Iron & Steel Symposium
UDCS

Oktay Elkoca

Heat treatment methods are the most commonly used production steps because they can interfere with all the mechanical properties of the material without altering the chemical composition of the metal in industry. Accelerated cooling is also one of the most prominent points in the series production process in these heat treatment methods. This method is used in the manufacturing process of thin pearlitic steel, double phase steel, rayon sheet steel which is used for bainitic steel production, from construction bar to profile in many different quality and size products. In this study, S355J2 corrugated corrugations and S275JR quality HEA-HEB structural section steels were produced from hot rolled billets produced by open casting method. Intensive inclusions were found in both of the materials examined and it was seen that they could not meet the mechanical strength values in the sizes with low crushing rates. These materials, especially those with low impact strength, have been subjected to accelerated cooling to increase their impact strength.

International Iron & Steel Symposium
UDCS

Fatma KÖZ Furkan ACAR Emre Demirci Hayrettin Ahlatçı Yavuz Sun Yunus Türen Mustafa DEMİRKAZIK Mesut KAYMAZ Şerafettin ÖNER

— Grain refinement is a unique approach to improve physical and mechanical properties of metallic materials without need to change their chemical compositions. Friction stir processing (FSP), is technique for microstructural refinement of metallic materials down to micrometer levels. In this process, a specially designed rotating tool is plunged into the sheet to be processed and traversed along the line of interest. The most important advantage of process is providing weight reduction by effectively strengthening of metals. However, applicability of this process to thin sheets have been found difficult. In this study; thin interstitial-free steel (IF-steel) was subjected to FSP using a carbide-tungsten tool with the diameter of 14 mm. Ultrafine grain structure was successfully achieved in 1.2 mm thick IF steel sheet via position controlled processing technique and selection of the proper tool dynamics. The microstructural evolutions were characterized using scanning electron microscopy (SEM) techniques. The results show that the FSP of IF-steel resulted with the fine grains with a mean grain size of 5 µm (initial grain size was 35 µm). FSP steel exhibited a good combination of yield strength of 500 MPa with uniform elongation of 16%.

International Iron & Steel Symposium
UDCS

Mümün YILMAZ Imren OZTURK YILMAZ Onur SARAY

Flat steel products are coated with zinc to ensure decorative requirements and prevent the steel from corrosion. Galvanized cold rolled (GCR) sheets has three main characteristics for decorative requirements, these are metallic effect, spangle and gloss. High gloss value is one of effective parameter on the customer demand. In order to define influencing factors on gloss value, GCR sheet samples, with different dimensions and produced with different parameters, had been taken. Influencing factors such as zinc coating mass, sheet thickness, chemical composition of zinc coating, line speed were investigated under constant zinc pot metallurgy conditions. This study finds out increase in strip thickness and Al% content of zinc coating leads to increase in gloss value, increase in coating mass leads to decrease in gloss value and gloss-line speed data gives a Gaussian curve where the gloss value reaches a maximum magnitude at about 100 m/min.

International Iron & Steel Symposium
UDCS

Özgür KARAKAŞ Erdogan KANCA İbrahim GÖÇER Alper AKÜN Erkan PÜGE Güzin Müge LÜLE Ali DOĞAN Ahmet ÖZDEMİR

The effects of artificial aging on A356 aluminum billets were investigated. Low superheat casting (LSC) was performed in order to prepare appropriate samples by equiaxed grains formation instead of dendrites for further semi-solid metal process. Specimens were cast at 635°C in LSC technique and nondendritic grains were obtained. Produced billets were reheated at 595°C where both solid and liquid phases of the alloy coexist. Samples were held in this semi-solid region for varied times followed by quenching. After reheating step, specimens were solution treated, water-cooled and artificial aged. The microstructural evaluation and related hardness changing of reheated billets were examined by image analyser assisted light optical microscopy and Brinell hardness measurements. Aging process leads to attain relatively uniform microstructure with newly formed precipitates which provide increase in hardness considerably.

International Iron & Steel Symposium
UDCS

Ridvan Gecu Serhat Acar Alptekin Kısasöz Kerem Altug Guler Ahmet Karaaslan

Aluminium is usually used for de-oxidation of liquidsteel production in Basic Oxygen Furnaces. For this process, Aluminium ingots that have 5 kg nominal weight are feeding manually in a ladle for this kind of Plant. This situation can lead to some problems such as quality error and loss of efficiency. The problem was solved by designing automatic aluminium ingot feeding system. Hereby feeding system performance variables had improved considerably and also risks caused by occupational health and safety aspects have been eliminated.

International Iron & Steel Symposium
UDCS

Ahmet Kayrak Mesut Tutal İsa Keskin

Today, the most important factors in the evolution of people's living standards are the development of industrialization and production capabilities. In the industrial sector, fossil-based energy sources are widely used and cause production costs to increase and competitiveness to decline, especially in countries that are dependent on energy supply. In addition to this, the use of energy as efficiently as possible and the recycling of waste energy can reduce both costs and adverse environmental problems. In the study, the use of the waste heat from the basic oxygen converter process used in the iron and steel industry has been examined again to meet the demand for demineralized water and to convert the overproduced water into a financial resource and to avoid adverse environmental effects. For this purpose, a demineralized water production system that operates on the basis of a humidification-dehumidification method compatible with the amount of waste heat, whose investment costs are more advantageous than other methods, is designed and the production capacity is calculated. It has been determined that the obtained data is at a very high level of demineralized water producing potential of the designed system and that this recycling application can be funded considerably.

International Iron & Steel Symposium
UDCS

Aytaç AYDIN Mustafa Karagoz Emrah Deniz

Today, rapid industrialization, manufacturing innovations and the growing population rate has caused an increase in energy needs in many countries. This increase in energy needs of people to produce more energy, energy efficiency and led the search for renewable energy. The next few centuries studies renewable energy sources and focus on the efficient use of energy has been caused because of run out of fossil origin fuels. The industrial sector of energy consumption of fossil origin energy sources are widely used and especially in countries that are dependent on foreign energy supply of increased production costs and causes it to fall of its competitiveness of firms. How much more energy if the benefit is reduced to that amount of production costs and emissions, emission caused environmental problems by reducing wastes, imply avoided. In the study, both the iron & steel industry is being used in basic oxygen converter process occurring from organic rankine cycle from waste heat produced electricity with satisfying the energy needs of a partition and use in order to prevent negative environmental impacts have been studied. To this end, the waste heat from power generation system with organic rankine of cycle designed and production capacity was calculated. The data from the potential for producing electricity system designed fairly high level, and that substantial financial resources through the application of recycling have been identified that can be instantiated.

International Iron & Steel Symposium
UDCS

Mustafa Karagoz Aytaç AYDIN Emrah Deniz

In the present study, the commercially available TRIP800 steel having 1.5 mm thickness was joined with resistance spot welding method by using optimum welding parameters which is assessed with developed weld lobe diagram. A group of samples were post weld heat treated (stress relief annealing treatment) at the temperature of 600oC for 30 minutes. The effect of stress relief annealing treatment on the tensile shear load bearing capacity, energy absorption, hardness and microstructure of weldment was investigated so, the relation with microstructure-mechanical properties was determined. The other group of samples was tested as welded condition for sake of comparison. Conclusively, it is believed that stress relief annealing treatment applied for resistance spot welded TRIP800 weldment did not affect to the constituent phases and failure mode of tensile test sample. However, the hardness decreased in the weld nugget and HAZ. Meanwhile, the tensile shear load bearing capacity and energy absorption of weldment affected negatively.

International Iron & Steel Symposium
UDCS

Hayriye ERTEK EMRE Ramazan KAÇAR

Modern industrial manufacturing processes and modern societies need to use chemical substances. Chemistry and chemical products are described as the key elements in development of modern societies. In addition, chemical substances are used extensively in almost every stage of industrial production including in the iron and steel industry. Thus, production of chemicals and their usage are getting increased through the worldwide. Due to transboundary nature of flyaway distribution of chemical substances, in terms of human health and environmental should be required of national and international cooperation. Therefore, there are a lot of applications in field of international collaboration. One of these applications is the REACH System developed by the European Union. The REACH System is aimed to higher level protection of human health and environmental. Thanks to this system, will have more knowledge about chemical substances and this knowledge will be shared with the society. In this study, developing on chemicals control by the European Union will be discussed through implementation areas of the REACH System. An Erasmus+ project related to field will also briefly presented.

International Iron & Steel Symposium
UDCS

Bora Balun Gazanfer Erbay

In this study, many operations carried out by traversing laser beam on 6 mm thick S960 steel plates for various laser welding speeds and powers in order to determine influence of welding speed and power on penetration, shape of fusion zone and heat affected zone. A 16 kW Ytterbium fibre laser and pure argon as shielding gas were used in this experimental study. Data was evaluated and compared with some previous studies. Furthermore, an empirical formula between heat input and weld bead width was developed from results.

International Iron & Steel Symposium
UDCS

Ömer Ekinci John Francis Anıl İMAK Zülküf BALALAN

Innovation is the application of an idea, item or a new process to the real life for income. In coating sector, it is possible to talk about some new and innovative processes for different kind of parts, especially for small parts. However, the subject of coating for steel sheets or plates having large surfaces with Fe-based alloys, especially for resistance to wear, is still open for investigation. For coating of large steel surfaces, common method is welding using different kind of electrodes. However, coating with welding has some disadvantages such as; dependent on electrodes, low coating rate, high surface roughness and so on. However, in the continuous coating method that was invented under this study has more advantages. In the experimental study, st 37 steel plates having dimensions of 4 x 800 x 800 mm were coated using continuous coating method with three different kinds of Fe-based alloys, austenitic manganese steel, high chromiumhigh carbon alloy and nodular cast iron, with the thickness of 4 mm. After coating process, microstructural investigation was conducted using optical and scanning electron microscope (SEM) with EDS analysis and microhardness measurements were obtained from coating to substrate. The results showed that there is a good bond between substrate and coting layers and the continuous coating method is much more suitable for coating the surfaces of large sheets or plates safely and economically.

International Iron & Steel Symposium
UDCS

Mehmet Eroğlu

As the known lightest structural metal, Magnesium (Mg) has attracted interests for automotive, electronics and aircraft industries. There is a common usage at industrial applications of Mg alloys because of their distinguishing performance characteristics. However, there almost isn’t an integrated mass production line at the industrial scale in Turkey which can supply high density and strong mechanical property Mg products due to the lack of experience and knowledge in this subject. Unfortunately, Turkey deliberately avoid to manufacture Mg alloy parts thus can only use them by importing. Honestly, there is an integrated mass production system including a dosing furnace, a molten metal transfer system, a gas mixing unit, a die heating-cooling device, and a cold chamber die casting machine for Mg alloys mass production in Yildiz Technical University, Mechanical Engineering Department, Die Casting Laboratory. Today, it is possible to get acceptable mechanical and metallurgical propertied, high density parts by considering the three basic production steps i.e. melting, dosing, and casting precisely.

International Iron & Steel Symposium
UDCS

Ali Serdar Vanlı Anıl Akdoğan

In recent years, steel manufacturers have been focused to develop the 3rd Generation Advanced High Strength Steels (AHSS) for automotive industry. In this study, parametric studies have been done on the electrical resistance spot welding of the DP1000 steel, which is widely used in the automotive industry, with the newly developed QP1180 steel. Welding studies were carried out by the process window method with different welding time and welding current while keeping other parameters constant. The effects of welding current and welding time on the mechanical properties of spot welded joints were investigated. In order to determine the mechanical properties of spot welded joints, welding specimens were subjected to tensile shear tests. In this context, the relationships between welding parameters, nugget size and mechanical properties of the spot welded joints were established.

International Iron & Steel Symposium
UDCS

Imren OZTURK YILMAZ Abdullah Yasin BILICI Hakan Aydin

In this study, machinability tests were carried out on Toolox 44 hot work tool steel (44 HRC) an important material in developing industry. The tests were carried out dry through milling method at four different cutting speeds (150, 180, 210, and 240 m/min), four different feed rates (0.4, 0.8, 1.2 and 1.6 mm/tooth) and at two different depth of cut (0.2 and 0.4 mm). Cutting forces developed during milling and surface roughness of the machined surfaces were measured. The results showed that increasing feed rate increased the surface roughness while increasing cutting speed decreased the cutting forces. The lowest surface roughness value (0.533 μm) was obtained at 180 m/min cutting speed, 0.4 mm/tooth feed rate and 0.2 mm depth of cut while the highest one (3.126 μm) was obtained at 180 m/min cutting speed, 1.2 mm/tooth feed rate and 0.2 mm depth of cut. The lowest cutting force was obtained at 0.4 mm depth of cut, 0.4 mm/tooth feed rate and 180 m/min cutting speed.

International Iron & Steel Symposium
UDCS

Rüstem BİNALİ Halil DEMİR İbrahim ÇİFTÇİ

In this study, the resistance spot weldability of DP600 and TRIP800 dissimilar steels, which are used preferentially in automotive industry due to their high strength and good ductility, was investigated in detail with using different electrode force. The tensile shear load bearing capacity, cross tension strength, energy absorption, weld nugget size, the hardness profile of weldment was determined and the metallographic evaluation was also carried out on the cross section of weldment. Thus, the relationship between mechanical properties and microstructure has been confirmed. It was found that electrode force is one of the most important welding parameters which affect to the nugget geometry and mechanical properties of dissimilar steel weldment.

International Iron & Steel Symposium
UDCS

Khaled Omer H. Marwan Ramazan KAÇAR Hayriye ERTEK EMRE

The purpose in this study was to investigate the effects of keyhole laser welding parameters (laser beam power, laser welding speed, and heat input) on weld bead shape and integrity such as fusion zone and heat affected zone. Hence, butt-joint keyhole laser welding practices were conducted on S700 steel plates thickness of 13 mm by applying various laser beam power and welding speed with a 16 kW Ytterbium fibre laser and using pure argon as shielding gas in the Mechanical Engineering Laboratory of The University of Machester. The weld crosssections were examined under an optical microscope and widths of fusion zone, coarse grained heat affected zone and intercritical heat affected zone were measured and also defects that occurred during welding were determined based on laser beam power and welding speed. As a result, effects of laser beam power and laser welding speed on fusion zone width and heat affected zone width were plotted and results were compared with previous studies published.

International Iron & Steel Symposium
UDCS

Ömer Ekinci John Francis Zülküf BALALAN

Inserted powder injection molding (IPIM) is developed to produce a larger volume parts in powder injection molding (PIM). In this method, the injection process is carried out on the part called insert. Since the injection volume gets smaller, the debinding time decreases. However, the insert diameter/the molding diameter ratio (Di/Dm) is the important parameter in that method. There could occur crack in the injection side unless the ratio determines properly. In this study, the insert and injection’s materials is high speed steel (HSS) and WC-%9Co feedstock, respectively. Different amount of expansion occurs since the materials have different thermal expansion coefficients. This difference causes a thermal stress in the connection surface. If the resulting thermal stress exceeds the compressing strength of the material in the injection side, then thermal cracks occur. Mathematical calculations have been carried out to determine the optimum ratio of Di/Dm. In order to validate the calculations, finite element analysis was performed by ANSYS software. Theoretical results were supported with experimental studies. The risk of cracking in the injection side increases as the ratio of Di/Dm increases. As a result of the study, the optimum ratio of Di/Dm was determined as 0.45 for the part produced by PIM.

International Iron & Steel Symposium
UDCS

Oğuz Yılmaz Kamran Samet Harun Koçak Çetin Karataş

Machining of many polycrystalline shape memory alloys CoNiAl (SMA) has been considerably a new phenomenon. CoNiAl alloys should be made available for final use after being formed, without loss of their shape memory properties. In this study, the effect of cutting parameters on kerf width and dimension tolerance of the Co based Shape Memory Alloy (SMA) have been investigated on the Abrasive Water Jet (AWJ) machine. After the cutting process, kerf width of the samples were investigated. The experimental results showed that water pressure, traverse speed and abrasive flow rate have a great effect on kerf width and dimension tolerance.

International Iron & Steel Symposium
UDCS

Ali GÜNEN Mehmet DEMİR Erdogan KANCA Mustafa Serdar KARAKAŞ Murat YILDIZ Ersan KIRAR M. Mustafa ERŞEN

In this study, machinability experiments on hardened AISI H10A hot work tool steel with CBN inserts were performed in dry and minimum quantity lubrication (MQL) conditions. Hard turning experiments were conducted according to Taguchi L9 orthogonal array. The effects of cutting parameters (cutting speed, feed rate and depth of cut) and cutting conditions on surface roughness were analysed. The analysis of variance (ANOVA) in 95% confidence level was applied in order to effects of cutting parameters surface roughness. It was observed that average surface roughness (Ra) increased with increasing feed rate and depth of cut in dry cutting condition with CBN inserts. In dry and MQL cutting conditions, the most important parameter on surface roughness were determined as depth of cut with 51.79% PCR and 69.68% PCR, respectively.

International Iron & Steel Symposium
UDCS

Rıfat Akdere Halil DEMİR Gültekin Uzun Mustafa GÜNAY

- Prepainted galvanized (PPG) steel coils, comparing to galvanized coils, have better corrosion resistance and fascinating decorative properties with their color alternatives and glossy appearance. Color of PPG coils, during service period, by the effect of environmental conditions, fades and their surface lose their glossy appearance. This study investigated the color and gloss stability of PPG steel sheet samples, painted with 14 different colors and 3 different paint type. 23 parallel samples were exposed to natural environmental conditions during 2 years at two different locations, Florida/USA and Dörtyol/Hatay/Turkey. For natural tests, environmental meteorological parameters such as temperature, humidity, rain and various weather conditions are recorded monthly. This study shows the effect of natural environment of Dörtyol/Hatay/Turkey location and the regions similar meteorological conditions like Dörtyol/Hatay/Turkey on color and gloss of PPG coils.

International Iron & Steel Symposium
UDCS

Özgür KARAKAŞ Tuğçe TUNÇBİLEK TOP Erdogan KANCA Hatice Arslan Hazar Çelik Fahri Akça Güzin Müge LÜLE

Process control for optimizing factors such as product quality, energy and cost becomes increasingly important in industry. In this study, the analysis and optimization of the rolling parameters were carried out in steel profile hot rolling process applied in Kar-demir Rolling Industry Trade Ltd. Co. which execute R&D and production activities in the rolling industry. In this context, the analysis of the rolling parameters such as roll position, force, moment, temperature, thickness and crushing amount belonging to rolling mechanics were carried out based on the empirical models widely used in the hot rolling process. As the result of the study, optimum roll positioning and crushing amount calculations are proposed to minimize energy and time cost.

International Iron & Steel Symposium
UDCS

Didem Kılıç Metehan Bacaksız Orhan Akyol Engin Tan

As a conformity assessment activity, testing is a crucial step in iron and steel industry. The characteristics and quality of the material are determined by the test. Manufacturers who manufacture in the sector and manufacturers who buy products make the acceptance of the material according to the results of the test. The reliability of test results is ensured through accreditation. In this study, the scope of the accredited laboratories in Turkey serving the iron and steel industry has been examined in detail. These results are compared with the same sector-based laboratories that are accredited in Germany. As a result, proposals have been made for future plans of test laboratories serving the iron and steel industry.

International Iron & Steel Symposium
UDCS

Murat KAVRUK Bulent AYDEMIR

Today steel is one of the most common material used in almost everywhere from seat belt mechanism to petroleum pipeline. Steel production requires many steps including the steel making and continuous casting plants. Starting with first drafts in 1856 continuous casting machines has evolved today’s modern machines. One of the most important part of continuous casting machines effecting the quality, productivity and yield is the openended copper mould. With time there is needed more control over casters due to the increasing quality demand and machine yield. When liquid steel is poured through the mould first solidification occurs around slab strand. When the strand of steel is continuously withdrawn from the mould through roller, friction happens between strand shell and mould. Mould friction should be kept in optimum range. Beyond this range there can be breakout or produced slab having bad surface quality. Variety of continuous casting parameters effect mould friction such as casting speed, steel grade, mould level, mould powder viscosity, mould oscillation parameters, etc. In this research there can be found how different slab caster parameters effects the mould friction.

International Iron & Steel Symposium
UDCS

Hakan KAPUSUZ Selçuk Mıstıkoğlu

Rolling has an important place in iron and steel industry due to the advantages such as production speed, continuity and easy to process applications. Roll materials must be resistant to high heat temperature conditions, high breaking resistance, good surface quality, proper hardness, good wear resistance and thermal shocks. However, producing an alloy material with all of these features together will be very costly. Instead of producing a roll material having all of these properties, it is more economical and practical approach to provide these characteristics by surface modification. In this study, External cooling rollers (ECR) coated by different four techniques which, Flame spray, boriding, titanizing and borotitanizing. After the coating process, the thickness of the coating layer, hardness, and layer structures examined by optic microscope, scanning electron microscope, micro hardness, and X-ray analyses. A wide range of coating thicknesses and microhardness values obtained depending on coating technique. The highest mircohardness obtained in the titanized sample, but the lowest coating thickness. The obtained hardness values were 3 times higher than those in the current application. The cost of rolling will be reduced by increase in ECR tool life.

International Iron & Steel Symposium
UDCS

Mehmet DEMİR Ali GÜNEN Mustafa Serdar KARAKAŞ Vahdettin Koç Mustafa Sabri Gök Ahmet ÇÜRÜK

—A non-conventional material removal process, Abrasive Water jet (AWJ) machining is also an ideal manufacturing process for very hard materials. This study aims to optimize the parameters involved in AWJ machining of 316 stainless steel material such as abrasive material grain size, nozzle speed, standoff distance, abrasive mass flow rate and pumping system pressure. The analysis of the impact of parameters involved in this study was conducted using the L27 Taguchi orthogonal array, S/N ratio and ANOVA. Five controllable factors were used to obtain the minimum surface roughness and each parameter was assigned with three different values in order to define the optimal factor and level combination. Results showed that the surface roughness is in strong correlation with abrasive material grain size. The findings of this study suggest that the study design used is much more effective than the full factorial design in terms of the number of experiments conducted.

International Iron & Steel Symposium
UDCS

Fuat KARTAL Hasan GÖKKAYA

This work was carried out to study the usability of stainless steel (SS) types 304L instead of 316L for plate heat exchangers without sacrificing their operating efficiencies and performances. In line with this purpose, corrosion behaviour of 316L and 304L SS were studied under the simulated service conditions to assess the replacement of 316L by 304L SS which is more economical. Operating and boundary conditions of plate heat exchangers, such as temperature, pH, Chloride ion concentration of the solution etc., were taken as the experimental parameters. Electrochemical corrosion tests were carried out to measure pitting behaviours of both stainless steels under the simulated service conditions and the preselected test parameters associated with the types of pitting corrosion. Studies were carried out by employing electrochemical polarization tests to determine the resistance to pitting corrosion of materials which plays a decisive role in the service life of plate heat exchangers produced by the use of the stainless steels.

International Iron & Steel Symposium
UDCS

Haluk ERDEMİR Cem ÇAKIROĞLU Ahmet ÇAKIR

In this work, the wear resistance behavior of GG-25 gray cast iron was investigated. Three specimens with different austempering time (120, 90 and 60 minutes) and one specimen, which is not austempering, were used. With this manner it has been tried to examine the effect of the parameters of austempering process on each specimen. Pin-on-disc wear resistance test with one loads (20N) on every specimens has been applied according to of ASTM 99 standards. SEM to observe the microstructures characterized the austempered specimens. In addition, brinnel hardness test was applied. With the results of the wear resistance test, as the austempering time increased, wear resistance also increases.

International Iron & Steel Symposium
UDCS

Abdulsamet YILDIRIM Yunus Türen Hayrettin AHLATCI Yavuz Sun Mustafa GUÇLU Hamza Serhat AYDEMIR Mehmet Sami TAKVA

While rail steels are being developed, the main objective is to improve wear performance. For this purpose we are continuing to work harder on the production of rail steel. However, a certain degree of hardness can be obtained by conventional methods. Bainitic microstructural rail steels can achieve higher hardness than conventional perlitic rail steels. In this study, it has been tried to obtain a bainitic structure with isothermal transformation to this steel with hardened rayon steel of eutectoid alloy. Two different austenite temperatures (850°C and 900°C) and two different bainitic transformation temperatures (350°C and 450°C) were determined. Abrasive abrasion tests have shown that the specimen with a bryitic structure at 350°C was annealed at 900°C compared to perlitic rayon steel, resulting in higher wear resistance.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ Hayrettin Ahlatçı Derya BULGAN Mustafa DONMEZ

There are many destructive and non-destructive tests for detecting microstructural changes and faults in steel parts. The term “non-destructive testing” (NDT) is used for material testing methods that can be applied without harming the material. NTD can be applied to materials, parts, assemblies or structures. One of the non-destructive evaluation methods is Barkhausen Noise (BN) that is magnetic based and is used mainly in the automotive and aviation industry. Barkhausen noise (BN) measurement is an electromagnetic testing method that is suitable for ferromagnetic materials. Ferromagnetic materials are made up of small magnetic domains which are separated by domain walls and orientated in different direction. As a result of the external magnetic field applied, domains will turn to the direction of magnetization, moving the domain walls which will cause jumps of magnetic flux denstiy. These jumps are called Magnetic Barkhausen Noise (MBN). MBN is sensitive to different material properties such as microstructure, composition, residual stress and hardness. This paper focus on describing an improved Non-Destructive Testing methology based on the analysis of BN. It also explaines the relationship between material properties and BN profile. Also, it is aimed to introduce applications and test equipments of BN.

International Iron & Steel Symposium
UDCS

Oğuz KOÇAR

In the present study, shielded metal arc welding electrodes containing boroncarbide in the shield were produced for making boride coatings and low-carbon steel plates were surfaced with single-double and triple pass welds. The effects of the boron content on the microstructure and hardness of the coatings were investigated. After deposition, microstructural analyses including metallographic examination, wavelengthdispersive X ray (WDX), X-ray and microhardness measurements of the coatings were evaluated. From the results, it was seen that different boron contents formed primary and eutectic Fe2B, and consequently had an effect on the hardness of the coating.

International Iron & Steel Symposium
UDCS

Mehmet Eroğlu Yusuf DONAT

In this study, the (hkl) plane energies of bcc and bct Fe crystals were calculated as a function of internal interactions between atoms. The Classical Morse Potential Function applied in the theoretical studies of transition elements was used in Fortran code for analytical calculations. Since the force applied to the crystal at the equilibrium has bcc → bct conversion, we calculated the variations of the a2 lattice parameter depending on the a1 lattice parameter. The (hkl) plane energies of bcc and bct crystals were determined using calculated lattice parameters. Calculations are limited to 9 (hkl) planes. For the bcc Fe (h00) planes, the internal energy passed through the minimum points, while the energy in the (hk0) and (hkl) planes changed parabolically. In the case of bct, no stability point was determined on any plane. Theoretical calculations show that the total energy is the nearest plane energy of the incoming feeds. In bcc → bct phase transformation, the system has a single equilibrium point and the stability range is not very large. This calculation method can be successfully applied to cubic Fe and Fe-based alloys in the theoretical studies.

International Iron & Steel Symposium
UDCS

Hamza Yaşar Ocak Gökay UĞUR Şule UĞUR

Red iron oxide which is produced by regeneration of waste hydrochloric acid from steel pickling line contains chloride. Chloride has negative effects on industrial productions which use red iron oxide as a raw material. This paper asserts red iron oxide particles have different chloride content according to their particle size. Regenerated red iron oxide was sampled from different production batches and these samples were grouped according to their particle size with sieving them from 1 mm to 75 µm. Sieved red iron oxide samples were analysed with spectrophotometer to determine chloride content. The study found out that chloride content slightly increased by increasing particle size up to 710 µm, after that size chloride content was drastically increased, such that, removing particles bigger than 1 mm from the iron oxide provides a 11,97 % reduction of the total chloride content and causes only 0,27 % loss from the total material.

International Iron & Steel Symposium
UDCS

Özgür KARAKAŞ Erdogan KANCA İbrahim GÖÇER Alper AKÜN Erkan PÜGE Güzin Müge LÜLE Tuğçe TUNÇBİLEK TOP

The aim of this study is to produce new generation biodegradable iron-based alloys and to investigate their compatibleness for using as transient implantable materials. Produced iron-cobalt alloys were immersed in SBF to simulate the degradation properties in human body. Degradation behavior of the Fe-Co alloys were investigated using both mass loss tests for following the rate of degradation and observed growth of the apatite structure in the simulated body fluid. Also, general characterization methods (XRD, SEM and EDS) were used for investigation of the samples.

International Iron & Steel Symposium
UDCS

Yucel Gencer Mehmet Tarakci Yunus Azakli Sezgin Cengiz

In this study, Fe-Ni binary alloys containing 1, 2 and 4 at. % Ni were prepared under controlled atmosphere conditions and then these alloys along with pure Fe were pack boronized at 1100°C for 3 h. The boronised samples were characterized by SEM, SEM-EDS, XRD and microhardness measurements. The boride layer with saw-tooth morphology on the substrate materials changed to compact morphology and the branchy structure around the boride crystals was formed with the increasing amount of Ni in the substrates. The main boride layer was composed of FeB and Fe2B phases with homogeneously distributed Ni in the main boride layer and accumulation of Ni in the boride layer/substrate was detected for the borided samples. Ni addition was ineffective on microhardness and thickness of boride layer while the thickness decreased with high addition of Ni.

International Iron & Steel Symposium
UDCS

Naim B. Mackan Yucel Gencer

Anthropogenic air pollution is increasing in the earth. And highest portion of the anthropogenic air emission is caused by energy consumption. The biggest section of the energy consumption in the transport sector is originated from the road transportation. Therefore, the road transportation is highly emitting direct and indirect GHGs caused by gasoline, diesel and LPG consumption on the roads. This sector is needed to be examined in detail for climate change studies. The uncertainties in road transportation emission calculations are very high, because the other sources emissions, meteorological conditions, vehicle using behaviour and age of vehicles have some pressures on the emissions. Direct greenhouse gases, including CO2, N2O and CH4, emitted by the road vehicles are the key sectors for Turkey. In long-term struggle with climate change, Turkey should reduce emissions from this sector. Therefore, the studies related to the emission control on road transportation are supporting climate change mitigation. In this study, the direct GHGs emissions from the road vehicles in Karabük province have been calculated and the effect on the climate change is considered. The IPCC methodology was used for calculating the emissions. The vehicles were classified in different categories and the CO2, N2O and CH4 emissions were calculated as time series for each category. The road vehicle statistics of Karabük province were obtained from TURKSTAT and the total fuel consumption was estimated due to the average km covered by vehicles and total consumption of fuels taken from the energy balance tables. The final results are showing that the diesel consumption on the road is increasing CO2 equivalent (CO2 equ.) emission until the 0.22 million tonnes in 2014. It is just 0.5% of total Turkey’s road emission. Moreover, the gasoline consumption in the city is remaining constant although the number of automobile is increasing in the city. The main reason is the people living in the city prefer diesel or LPG automobiles. Consequently, the emission related to the diesel vehicle is highest and it is concluded that 75% of total CO2 equ. emission from road vehicles in Karabük province is coming from the diesel vehicle. The GHGs emissions caused by automobiles, van and caterpillar are causing highest pollution in Karabük province. The CO2 equ. emissions from these three type vehicles are 83% of total city’s road emissions.

International Iron & Steel Symposium
UDCS

Ali Can

In order to prevent fatalities and injuries in the accidents occurred in railway transportation, crash zones were developed at the front and back ends of the coaches. These crash zones are aimed to absorb the kinetic energy in a controlled manner and protect the health of the passenger and the structure of occupied areas in the coach. The primary energy absorber is one of the most important components of the system and is able to absorb an impact energy of about 1.3MJ. In this study, deformation behaviours of tube like structures with square and circular cross sections under the axial impact load were investigated by means of finite element analysis. The investigated tube like structures are the same size and weight and have five different wall thicknesses. At the end of the study, the performances of square and circular sections were compared in terms of energy absorption capacities and average deformation forces

International Iron & Steel Symposium
UDCS

Ramazan Özmen Tuncer TOPRAK

Stainless steels are primarily utilized on account of their high corrosion resistance. However, the scope of excellent mechanical properties offered by the various classifications and grades within the family of stainless steel render them extremely versatile materials. Austenitic stainless steel wires are widely used in industrial applications and have a rapidly growing demand. With the wire drawing process, the mechanical properties change considerably after the diameter reduction process. In this study, the mechanical properties of austenitic stainless steels (304, 309 and 316L) were compared in three different qualities. As a result of experimental studies, the highest mechanical properties were observed in 304 and 309 series stainless steels, respectively. There is an effect on the phase transformation as well as the rate of cold deformation in the increase of mechanical properties.

International Iron & Steel Symposium
UDCS

Ekrem ALTUNCU Yılmaz YILDIRIM

The investigation of the fatigue behaviour of metals under non-proportional multi-axial stress states is an important problem to minimize design-induced errors and improve structural durability, especially for cast and light-weight sheetmetal structures. Various approaches that can be used in fatigue analyses make use of stress states, strain states and strain energy densities to obtain an endurance limit value, a fracture plane estimate, S-N curve and/or a combination of these. Thus, the determination of the possible initial cracking plane and an estimation of crack initiation is an important step in fatigue analysis of structural design, especially under multiaxial stress states based on theories that are stress-based where the method of critical planes is the most commonly applied. Such methods seek for the orientation of fracture plane by using different parameters based on the assumed input parameters. The purpose of this research is to identify and compare critical plane orientations using various stress approaches to critical plane methods. The determination of several parameters in different stress based critical plane search is indicated. Furthermore, critical planes are found for different stress states with using pre-assumed material properties from available test data. Based on the outcomes, a method of better versatility and ease of application is proposed among the methods investigated for practical applications of fatigue analysis.

International Iron & Steel Symposium
UDCS

Tuğçe Leblebici Emin Sünbüloğlu S. Ergün Bozdağ

In this study, the effect of C addition on the corrosion behavior of wire rods of 5.5 mm in diameter was investigated. The horizontal and vertical cross sections of the wire rods with 0.7, 0.8, 0.9 C ratio were taken during the metallographical process. The microstructure of the examined specimens was examined by light optical (LOM) and scanning electron microscopy (SEM). Hardness test of steel containing 0.7- 0.9 C was carried out in shimadzu brand micro hardness tester. Corrosion tests of the prepared samples were evaluated according to both the weight loss and the Potentiodynamic Polarization measurements in 3.5% NaCl solution. Despite the increased hardness of the specimens examined, the corrosion resistance decreased. This can be caused by inclusions in the microstructure.

International Iron & Steel Symposium
UDCS

Medine Kilinc Gulheser Dogancik Yunus Türen Yavuz Sun Hayrettin AHLATCI İbrahim AFŞAR Serhat ÖZDEMİR Hüseyin Koymatcık Hüseyin Zengin

Recently, new generation, promising functional alloys for different applications, developed via high entropy (HE) alloying method, have gained attention both from academia and industry. This technique is mainly alloying of at least five major elements in equiatomic or near equiatomic ratios and positioning all the elements in the same lattice using the high entropy of mixing of the system. These unique HE alloys can be obtained using the suitable combinations of almost all the metallic elements present on the periodic table. The main question is, “what is the most important property for a stainless steel?” Clearly, the answer is corrosion resistance. In addition, it is well known that protective surface films play a key role in corrosion resistance of the stainless steels. HE alloys are innovative and promising materials due to their excellent corrosion properties. Key documents on the corrosion behaviour of the high entropy stainless steels have been reviewed under this study.

International Iron & Steel Symposium
UDCS

Burak Dikici Hakan YILMAZER

Controlled accelerated cooling of R350HT head hardened rail joints immediately after their welding is critical in order to secure that these joints have similar mechanical properties with the rest of the rail. In practice this accelerated cooling can be achieved by sending forced air through an apparatus placed over the welded area of the rail joint just after welding operation. The apparatus should be designed in a way to create homogenous and effective cooling around the railhead. For this purpose, airflow and cooling simulations were performed in order to optimize the design of such apparatus. Number and diameter of air nozzles, their positions, nozzle-to-rail surface distance and airflow rate were employed as the main input parameters for the simulations performed using ANSYS 15 (thermal and fluid flow). The main focus was on finding the design and operation parameters that give homogenous air flow around the rail head which in turn would produce uniform cooling. In this publication, the results of the simulations run under various conditions will be compared and an optimum set of design and operating parameters will be offered.

International Iron & Steel Symposium
UDCS

Nizar Ramadan Kazım Tur Erkan Konca

White cast irons are hypoeutectic alloys in which the carbon remains dissolved in the iron carbide phase, called cementite, without decomposing into graphite during solidification. Because of the hard cementite phase, they preferred in high abrasion resistance required applications. In order to improve further the wear resistance they are alloyed with strong carbide forming elements (W, Mn, Mo, S, Cr, V, Mg, etc.). There is a strong relationship between the mechanical properties of alloys and the internal structure they possess. In order to reveal the effect of the internal structure, the diagrams showing the phase equilibria of the material should be known. Today, various software programs are used to make thermodynamic calculations relevant to phase equilibria. In this study, using the Materials Calculator software program, it is aimed to simulate the pseudo binary phase diagrams (i.e. isoplethal maps) where the molar fractions of alloying elements other than carbon are fixed. In order to check the accuracy of the constructed diagrams, the casted samples with determined compositions will be analyzed by differential scanning calorimetry (DSC) and the theoretical and experimental data will be compared. The diagrams for changing the type and amount of the alloying addition will be examined and the effects of changing the amount and distribution of carbides with increasing carbon content and temperature will be discussed to improve the wear resistance.

International Iron & Steel Symposium
UDCS

Öncü AKYILDIZ Duygu CANDEMİR

Developments and innovations in financial market, product variety and the complexity of the products’ content entail people to take part in financial system consciously. Recently, the importance of financial literacy dramatically increased due to some factors such as the rise in people’s responsibility on decisions, innovations information and communication technology, swift changes in retirement and taxing policy, demographic changes in population, the failure of individual attempts and financial fraud. Each individual should be financially literate for financial security and comfort. Individuals’ self-consciousness on financial issues will not only prepare them for prospective hard economic conditions that may emerge in the future but also supports the development of the country on strong basis. In this perspective, the awareness of financial literacy will help to use the limited sources more affectively. In addition to this, it will also prevent the waste of sources by contributing the economy and improving the life-standards of the citizens. In this regards, the aim of the study will examine individuals’’ who are working in Kardemir Inc., financial literacy levels. The sample consists of individuals, who are working in Kardemir Inc. Data were collected through a demographic information form, Financial Literacy Index developed by Van Rooji et al. (2011). The obtained data will be evaluated by "SPSS for Window" statistical program. Finally, the findings are compared with the literature and some recommendations are suggested for individuals, executives and researchers.

International Iron & Steel Symposium
UDCS

Murat YILDIRIM Fatih BAYRAM Ahmet OĞUZ Gülay GÜNAY

Influence of different austenitization conditions on retained austenite quantity and composition investigated on SAE 52100 steel. SAE 52100 steels are being widely used as bearing component regarding to their hardness and wear resistance. Traditional production cycle includes hot rolling, spheroidization, cold rolling, quenching from two phase region and tempering steps. This cycle results with martensitic matrix and undissolved course carbides. Course carbides maintain adequate wear performance but due to course carbides providing appropriate nucleation sites for crack propagation and growth this structure shows poor fatigue behavior. Previous studies showed better carbide size and distribution with experimental two step hardening cycle. This cycle results with considerable increase at retained austenite fraction. It’s well known that mechanically unstable retained austenite improves fatigue resistance in this type of steel. Transformation retained austenite to martensite caused by deformation eliminates local stresses and retards crack propagation and growth. XRD studies are carried on to determining retained austenite quantity with various austenitizing conditions. Computational simulations with Thermo-Calc and Dictra are used for predicting carbon concentration gradient of austenite during austenitization which determines retained austenite fraction at the end. A good correlation between XRD data and simulation results was obtained.

International Iron & Steel Symposium
UDCS

Ersoy Erişir Oğuz Gürkan Bilir Ahmet Efe Gezmişoğlu

Duplex stainless steels (DSSs) have both higher mechanical properties and corrosion resistance in the cause of austenitic and ferritic microstructure. DSSs, generally have equal amount of austenite and ferrite phases. Solution heat treatment is applied to DSSs for providing homogenous microstructure, composing desired austenite-ferrite phase fraction and resolving intermetallic phases. After the solution treatment, mechanical properties and corrosion resistance of DSSs can be alter, especially with changes in austenite-ferrite phase ratio. In this study, effect of solution treatment conditions on corrosion behaviour of EN 1.4462 was investigated. Solution treatments were applied at 1100˚C and 1150˚C for 2 hours and 8 hours. Corrosion test was applied in FeCl3 (10% wt.) media for solution treated specimens. Corrosion properties of the specimens were determined with weight loss and also, microstructural characterization was carried out by optical microscopy analysis.

International Iron & Steel Symposium
UDCS

Alptekin Kısasöz Ahmet Karaaslan

Niobium (Nb) and Chromium (Cr), being crucial alloying elements in the high value alloys such as the High Strength Low Alloys (HSLA) and Stainless Steels, especially Austenitic Stainless Steels (AUST.SS), have been identified and classified as critical raw materials (CRM). The potential of not producing these high value alloys has an adverse effect on the EU and Turkish economy due to the fact that Nb and Cr. Therefore, it is necessary to develop a new generation of structural alloys that will be free from CRM elements and exhibiting superior performance. However, it is difficult to develop such proposed high performance alloys by conventional alloying, which are formed around a dominant element like iron in the steel. The High Entropy Alloying, an innovative approach introduced in the last decade, is the alloying using the alloying elements at equiatomic or near equiatomic percentage, consequently the presence of the high mixing enthalpy positioned the alloying elements within the same phase crystal lattice system. As alternatives to HSLA and AUST.SS alloys, the novel structural alloys can be designed and developed by means of HEA approach and gain to industries. The purpose of the study is the designing and developing novel structural alloys as an HSLA and AUST.SS) using innovative High Entropy Alloying (HEA) approach. The proposed High Entropy Structural Alloys (HESA) in this project will be manufactured through the conventional melting and thermomechanical processing. The HESA alloy groups, which will have key roles in many important industrial applications, are aimed at exhibiting superior mechanical properties and corrosion values and meeting the industrial and economic conditions of production.

International Iron & Steel Symposium
UDCS

Hakan YILMAZER Burak Dikici

In this study, head hardening process was applied for R260 quality rails. Microstructures of rails were carried out using Scanning Electron Microscope (SEM). Hardness distribution of head parts were also evaluated for two category samples (heat treatment and non heat treatment). Wear tests were performed under three different loads (10N, 20N and 40N) in both %3.5NaCI solution and dry conditions. Worn surfaces were characterized by Nikon Shuttlepix, Profile projector and SEM. Results clearly show that, head hardened rails exhibited better wear performance especially under load of 10N in dry conditions.

International Iron & Steel Symposium
UDCS

M. Emre TURAN Fazil Hüsem Yasin Akgül Yavuz Sun Hayrettin Ahlatçı

Iron and steel production and consumption values are the most important indicators which demonstrate development and industrial growth of countries. In our study, world iron and steel sector production capacities and development of steel production values are examined by years. During this period, except global crisis times, iron and steel capacities and production values’ constantly increasement are observed. Growth rates and iron and steel production values are compared, during economic crisis where world and our country are affected. In the last part of our study, a regression model of salable billet and ribbed bar steel prices was set up to estimate with using independent variables such as the global and Turkey liquid steel production, world and Turkey% growth rates. Except negative effects of economic crisis’ on sector’s development; low capacity usage rates due excess supply over demand, raw material procurement price fluctuations, China's iron and steel sector developments, decreasing other producers’ competion ability due to imports from China to all over world and protective tax regulations on behalf of protection of local producers, create uncertainty to development and future of sector.

International Iron & Steel Symposium
UDCS

Nazmi Sarıkaya Ahmet Gürbüz

In this study, the effect of boron addition at different ratios (2-38 ppm) on the microstructure and corrosion properties of Cr-Mo steels was investigated. Square cross-sections of the boron containing steels obtained at different ratios measuring 40×40 mm were rolled in three passes, and a deformation of totally 200-300 percent was obtained. The rolled specimens were examined by optical microscopy and corrosion test. Electrochemical potentiodynamic polarisation measurements were taken to evaluate corrosion behaviours of the examined steels. Analysing the potentiodynamic corrosion test results applied to the CrMo steels containing boron at different ratios, it is seen that there has been increase at the corrosion rates when the boron amounts are low.

International Iron & Steel Symposium
UDCS

Cemal ÇARBOĞA Bülent KURT B. Demirel Yavuz Sun Hayrettin Ahlatçı Engin ÇEVİK

In this study, the effect of carbon content in the range of 0,7-0,9 on wear resistance was investigated. The examined specimens in 5.5 mm diameter are manufactured with drawing process. Wear tests of the cylindrical samples with a length of 20 mm were examined in pin-on-disc type wear tester on counter face of 1.2379 cold work tool steel under the load of 30-60 N. The weight losses of the samples examined increase with the increase of carbon content and hardness. Wear Mechanism is mild wear to oxidative wear.

International Iron & Steel Symposium
UDCS

Semih Gezer Hayrettin Ahlatçı Çağatay Aslan Yunus Türen Yavuz Sun Melike Birinci Meryem Yıldız Neşe ÇAĞLAYAN Hüseyin Koymatcık

In this study, the boronizing of Fe-Cr binary alloys (2, 4, 8 at. % Cr) was investigated by pack boronizing treatment at 1100°C for 3 hours. Fe-Cr binary alloys were prepared under controlled atmosphere. The characterization of the borided alloys was carried out XRD, SEM, SEM-EDS and Vickers microhardness measurements. The boride layer on the Fe-Cr alloys was composed of Fe2B phase. The saw tooth morphology changed to a smoother interface layer (coating-substrate), the boride layer thickness decreased while microhardness did not change significantly with chromium content in the Fe-Cr alloys. The Cr-rich precipitates formed in the transition zone and their amount increased with increasing amount of the chromium in the substrates.

International Iron & Steel Symposium
UDCS

Mehmet Tarakci Yucel Gencer