SEARCH RESULT

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

—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

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

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 work we measure and estimate, experimentally and numerically, approximate fatigue strengths of steel filaments of 0.25 mm diameter with 80% C by the pure bending test method. All fatigue tests have been realized at room temperature and at a frequency of 10 Hz via a custom manufactured pure bending tester of which the fully reserved strain value, R = εmin/εmax, is −1. The applied value of cyclic deformation, ε, has been chosen from the range 0.46-1.07. The plots of S-N (Strain–Cycle) curves are based on high fatigue cycle (HFC) lives that are greater than or equal to 106 cycles.

International Iron & Steel Symposium
UDCS

Hüseyin Koymatcık Hayrettin Ahlatçı Yunus Türen Yavuz Sun SAİT ÖZÇELİK