Welding characteristics of similar and dissimilar metal using resistance spot welding

Abstract

The two main areas concern of weld nugget quality from resistance spot welding processes for galvanized steel joints and galvanized steel with stainless steel joints. This project analyzed only the quality of weld nugget growth on similar and dissimilar with respect to variation on weld current. The work carried out in two stages. First stage, dealing with the welding of galvanized steel together which as similar metal joints. Second stage is dealing with the welding of galvanized steel and stainless steel which as dissimilar metal joints. Both are using lap joints techniques. The welded samples were all equal in size for tensile test, hardness test, and metallurgical analysis to characterise the weld nugget formation. The tensile test displayed a relationship between the effects of weld current to obtain a proper weldment. The hardness distributions were measured the hardness from the heat affected zones, base metal zones and fusion zones. Microstructural of base metal, fusion and HAZs were observed. The dye penetrate test to reveal the defect on the weld nugget surfaces.