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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

-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

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

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

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, 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, 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

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

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

Train wheels are manufactured by forging and casting method. Cast iron wheels have advantages in terms of cost. When vanadium element is added to the steel, it has mechanical properties enhancing properties. Repetitive heat treatment contributes to the breakdown of the carbides in the grain boundaries and an increase in strength can be observed at this point. In this study, microstructure, mechanical properties and wear behaviors of train wheel steel produced by casting method under laboratory conditions with a train wheel obtained by forging method were investigated.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ Hayrettin Ahlatçı Ercan CANDAN

Welding is made up of many scientific and technical works. In industrial applications, it is applied to increase work efficiency and safety, reduce size and weight, and reduce production cost. Welding in the railway is usually done at the joints of the rails. Rail junctions have caused serious problems since the early days of railroads. As a solution, durable algebras have been developed but not sufficient in this application. As a result, the request for removal of the rail joints has emerged. Accordingly, different welding techniques have been developed. Among these techniques, aluminothermite and combustion head are widely used today. In this study, ultrasonic inspection results of the incinerator application applied to the rails in Karabük train station are examined.

International Iron & Steel Symposium
UDCS

Mustafa DURSUNLAR Harun ÇUĞ

Bu çalışmada yakma kaynağı kullanılarak R260 kalite raylarda birleştirme işlemi yapılmıştır. Kaynak işlemi neticesinde mantar, ağ ve ayak kısmından sertlik ve mikroyapı ölçümleri yapılmıştır. EN 13674- 1 standardına göre bir metrelik raylara (hem orijinal hem de kaynak yapılmış) kalıntı gerilme ölçümü uygulanmıştır. Sonuçlar göz önünde bulundurulduğunda bazı bölgelerde tamamen perlitik mikroyapı elde edilirken ısı tesiri altında kalan bölgelerde kaba östenit yapısı görülmüştür. Kaynak bölgesinin ağ kısımında sertlik daha yüksek çıkmıştır. Bunun sebebi olarak ise kaynak sonrası gerçekleşen kesit alanından kaynaklı hızlı soğumanın etkili olduğu öne sürülmüştür. Kalıntı gerilme olarak çekme kalıntı gerilmeleri mevcut olmakla beraber kaynak sonrasında elde edilen gerilme dağılımında artış görülmüştür. n this study, R260 quality rails were used for the joining process. As a result of the welding, hardness and microstructure measurements were performed from the head, web and foot parts. According to EN 13674-1, residual stress measurement was applied to one meter rails (both original and welded). Considering the results, in some regions, completely perlitic microstructure was obtained and rough austenite structure was observed in the regions under the influence of heat. Hardness was higher in the web part of the weld zone. The reason for this is that fast cooling caused by the lower cross - sectional area after welding has been suggested to be effective. Although tensile residual stresses are present as residual stresses, there is an increase in the stress distribution obtained after welding process.

International Symposium on Railway System Engineering
ISERSE

Harun ÇUĞ Mustafa Dursunlar MUHAMMET EMRE TURAN

The importance and necessity of renewable energy sources more are felt day by day. The reason for the search for renewable energy sources is one of the major causes of global warming and the rapid depletion of fossil resources. The fact that piezoelectric materials, which are one of the renewable energy sources, are used very little in the field of energy production and there is not enough work in this field has inspired this study. These magical crystals, which are still unknown in the production of electricity and which you have not even heard of, are a candidate to have a share in the electricity production of our future. It is called the electricity generation feature in proportion to the amount of pressure applied externally to the objects of piezoelectric crystal structure. The potential difference (voltage) between these two ends can also be measured. Since the energy needs of trains are known to be high, the energy that can be obtained from the load weight of trains is analyzed and the piezoelectric materials are aimed to produce energy in this area. The aim of this study is; It is used to assemble a group of disc formed by parallel linking from piezoelectric discs to the rail pad and generate electricity with the help of vibration and load pressure generated during the passage of trains.

International Symposium on Railway System Engineering
ISERSE

Çağatay YILMAZ Harun ÇUĞ Furkan BAYSA

Demiryolunun en önemli alt yapısı olan raylarda kaynak ve aşınma olgusu, yük taşıma ve yolcu güvenliği açısından en önemli parametrelerdir. Bu çalışmada yakma kaynağı yöntemiyle demir yolunda yaygın olarak kullanılan R260 kalite raylara kaynak işlemi gerçekleştirilmiştir. Kaynak işleminin ardından ileri geri aşınma yöntemi uygulanarak aşınma dayanımı incelenmiş ve kaynaksız aynı kalite rayla kıyaslanmıştır. 2 farklı yük uygulanması neticesinde aşınma performansları değerlendirilmiş, mantar, ağ ve ayak kısımlarının aşınma sonuçları kayıt altına alınmıştır. Ağ kısmında aşınma hızının kaynak sonrası yüksek soğuma hızından dolayı daha düşük olduğu, mantar ve ayak kısmında ise rayların birbirlerine yakın aşınma performansları sergilediği tespit edilmiştir. The most important substructure of the railway is the welding and wear phenomenon on rails are the most important parameters in terms of cargo transportation and passenger safety. In this study, welding process was applied to R260 quality rails which are commonly used in the railway using the method of flash butt welding. After welding process, the abrasion resistance was investigated by applying reciprocating wear technique and compared with the same quality rail without welding. Wear performance was evaluated as a result of the applied two different loads and the wear results of head, web and foot parts were recorded. It has been determined that the wear rate in the web is lower due to the high cooling rate after welding, while in the head and foot part of the rails show close wear performances.

International Symposium on Railway System Engineering
ISERSE

Harun ÇUĞ MUHAMMET EMRE TURAN

AlSi12 alloys and alloys produced by Mg addition at different ratios (1% - 2% and 4%) were manufactured by pressurized casting method. Quartz tubes with an inner diameter of 8 mm were used in the castings of the alloys. All castings were carried out in an argon gas atmosphere. These samples (7 mm x 20 mm) were homogenized at 520 ° C for 6 hours. Samples prepared by standard metallographic procedures were immersed in a jar containing 30 gr/l NaCl + 10 ml/l HCl acid solution and samples were weighed at 2-6-12-24 hours intervals. It is clear that the increased Mg ratio reduces the corrosion resistance of the alloys. The reason for this decrease in corrosion resistance is Mg2Si which is likely to occur after Mg addition. Intermetallic are thought to accelerate corrosion by forming a galvanic couple with the matrix. As a result of the corrosion test, SEM images taken from the surface also support our corrosion graph. Thus, when we look at the samples without Mg addition, it is seen that the surface deformation is very small compared to the samples produced by Mg addition.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Engin ÇEVİK S. Yasin Harun ÇUĞ Necmi Ozdemir R. Yildiz S. Akka

It is called superstructure member rail which is made of cast steel which guides the wheels on the railway vehicles and transverses the forces coming from the axles to sleepers. The fish plate used in joining the rails; cause noise, prevent acceleration, increase repair costs, cause damage in vehicles, cause rail to break etc. it is due to the reasons for the rails welding. Rails usually welded by alumino-thermit rail welding, flash butt welding and electric arc welding methods. Alumino-thermit welding based on the removal of heavy metals by the aluminum of heavy metal oxides. In the flash butt welding method is the rail ends are heated to the melting point with the electrical resistance system without any additional elements then pressure is applied to the molten rail ends so that the rails are welded. In this study, hardness properties, optical and SEM images of alumino-thermit and Flash butt welded S49 rails were investigated. In the optical and SEM microstructure examination, the perlitic structure was generally observed in the source region of the sample to which the burn-in source was applied, while the decarburized regions were observed in the source region of the sample to which the thermit source was applied. Low stiffness values were obtained in the fungus and I profile regions of the rail specimen subjected to the effect of decarburized regions and of the rail specimens subjected to thermit welding compared to the burn-in origin specimen.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Harun ÇUĞ Soner ÇETİN Mustafa DURSUNLAR Hayrettin AHLATCI M. Hüseyin ÇETİN

Wear and noise problems in rail systems. Especially in urban inner rails systems are disturbing the environment. In rail systems, many materials are used as brake material. Composite braking materials have been developed to eliminate these adverse effects. In this study, the adhesive wear characteristics of the composite brake material used for braking of railway vehicle tools at different loads were investigated. The tests was carried out on two different braking loads, 15N and 30N, with composite sabo section as abrasive material and as abrasive surface with 220 mesh roughness. The total duration of each test is 15 seconds and the track taken is 10m. The counter-friction material has been renewed for every application. The amount of water added in the aqueous media tests is fixed at 200 ml. At the end of the test, mass losses in aqueous and dry media were investigated. In the conclusion is the following; Mass loss is less in aqueous media. However, similar studies have shown that the productive frictional force decreases, especially at high speeds. Although not very effective in sudden braking, the inefficiency of mass loss caused by friction can be reduced by using the appropriate continuous braking during cruising.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Harun ÇUĞ Orcun Zengin Engin ÇEVİK Hayrettin AHLATCI M. Hüseyin ÇETİN

In this study, the wear behavior of hot rolled AZ31 and AZ31-X wt% La Mg alloys were investigated. After the microstructure characterization, hardness and wear tests, the effect of La on the wear resistance of AZ31 Mg alloy were reported. Hot Rolling process introduced the twins and DRXs on the microstucture wherein the changing of grain boundaries density impart wear resistance to AZ31 Mg alloy.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

İsmail Hakkı Kara Hayrettin Ahlatçı Yunus Türen Yavuz Sun Harun ÇUĞ Mehmet Ünal

In this study, AlSi12 alloy and alloys produced by Mg addition at different ratios (%2 and 4%) were manufactured by pressurized casting method. Homogenization of 520 °C was applied to the produced alloys using electric resistance furnace. Wear behaviors were determined on the data obtained from experiments on the pin-on-disc type abrasion device. DIN 2379 quality cold work tool steel were used as a counter materials during the wear tests. Experiments were carried out at a shear rate of 0.5 m/s at a shear distance of 9000 m under two different loads (10-20 N). The test results were determined by measuring the weight loss of the samples. In order to determine the wear characteristics after the abrasion tests, the worn surfaces were examined with a SEM. The addition of Mg has resulted in significant improvement in abrasion resistance. It has been found that Mg2Si phases which may occur in the structure by Mg addition increase the abrasion resistance of the alloys. When the SEM photographs of the worn surfaces were examined, it is seen that the wear is in the form of groove formation and part plaster, which indicates that it is the adhesive wear characteristic.

International Conference of Advanced Materials and Manufacturing Technologies
ICAMT

Engin ÇEVİK S. Yasin Harun ÇUĞ D. Caliskan S. Gullu T. Cayir