Studies on Different Steels Welded by TIG and MIG Welding Processes

This study presents the comparison of microstructure and mechanical properties of SS-316 Stainless steel and SA-2062 alloys welded by TIG and MIG welding processes. Microstructures of base metal and weld metal were studied with SEM and EDAX software. Mechanical properties like tensile strength and micro hardness have also been evaluated. During research work it is investigated that the average tensile strength of weld joint with TIG welding is comparatively less than that of joint with MIG welding. Micro hardness of TIG welding is relatively more than that of MIG welding. The minimum HAZ is found directly proportional to maximum tensile strength. More coarse dimples are seen in TIG joints as compared to MIG joints. The dimple size exhibits a directly proportional relationship with strength and ductility, i.e. if the dimple size is finer, then the strength and ductility of the respective joint will be higher and vice versa. The higher hardness at weld interface may be due to enrichment of this zone with FE, Ni, and Cr and subsequent formation.