Investıgatıng Of The Effect Of Joınıng Surface Angles Of The S355j2 Materıal On The Flash Butt Weldıng Connectıon


Thesis Type: Postgraduate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2019

Thesis Language: Turkish

Student: MERVE KÖROGLU

Supervisor: UĞUR ARABACI

Abstract:

Nowadays flash butt welding is spread over a wide area. It is a common method for the welding of railways and production of chains as well as industries such as automotive, electricity and aerospace. The method is used for the welding of flat and cylindrical shaped butt, corner and ring parts have vertical cross section. The aim of this study was to investigate the effect of the modified joint surface angle on the weld quality and metallurgical properties of the material before the S355 J2 Ø28 mm material was combined with the welding of the forehead. In the study, S355 J2 material was again combined with S355 J2 material by flash butt welding method by using angles of 30°, 45°, 60°, 75° and 90° respectively. Samples which welding were subjected to tensile, macro and micro hardness tests. In addition, microstructure photographs were taken and quality of welding was examined. The S355 J2 option can be combined in different directions than 90°, which is a standard incineration angle. The modified surface angles (90° to 30°) caused the joint surface area to increase, while the heat in the cooling system samples slowed away more slowly. Therefore, it was observed that ITAB region and coarse grains were higher than the others. Tensile test results were obtained in parallel with the hardness results at lower levels, average lower hardness and tensile stage. The lowest hardness degree was obtained in the weld regions of the welds.