Effects of welding parameters on tensile properties and fracture modes of resistance spot welded DP1200 steel

Abstract

In this study, the maximum tensile shear load bearing capacity and fracture modes of resistance spot welded DP1200 steel were investigated, and the tensile shear properties of the joints were evaluated. The effects of different welding parameters on tensile shear properties, fracture modes, microstructure, microhardness, and heat affected zone softening were examined. Weld processes were performed by using 2 to 6 bar electrode pressure as well as 5 and 7 kA weld currents. The microstructure of resistance spot welded materials was evaluated, and the hardness profiles were determined. Experimental results showed that welding current and electrode pressure had a significant effect on the load-displacement characteristics of DP1200 welds. Three different fracture modes were observed in the tensile shear loads. It was also observed that the expulsion had a negative effect on the tensile shear properties.