Analysis of welding groove configurations on strength of S275 structural steel welded by FCAW

Abstract

The quality of welded joints depends on many factors such as welding current, voltage, welding speed, shielding gas type, and welding position. One of these factors is the welding groove design. This is because different stresses (tensile, compression, bending, etc.) can occur on the weldments. For this reason, while designing welded constructions, it is important to join them with the most appropriate welding groove configuration by considering the stresses the welded joints can be exposed to. In this study, the effect of the welding groove configuration on the mechanical and metallurgical properties of S275 structural steel joined by flux cored arc welding (FCAW) method was investigated. For this purpose, different welding groove configurations were formed for structural steel sheets. Tensile, bending, and hardness tests were performed to determine the mechanical properties of the weldments. In addition, metallographic investigations were carried out to determine the metallurgical properties of the weld zones. As a result of the tests, the effect of the welding groove configuration on the mechanical and metallurgical properties of the welded joints was determined. As a result of the microstructure studies, different structures such as grain boundary ferrite, widmanstatten ferrite and acicular ferrite were determined to form in the weld metal and coarse grained zone. It was determined that hardness of the weld metal was higher than HAZ and base metal in all welding groove configurations. As a result of the tensile and bending tests, the highest tensile and bending strengths were obtained from the samples welded by X 2 type welding groove configuration after the base metal. Furthermore, the X-type welding groove configurations showed better mechanical properties than the K-type welding groove configurations.