LAUSR

Abstract The main parameters of resistance spot welding were optimized using Taguchi method for dissimilar joining of low carbon steel and Fe-Cu-C powder metallurgy compact. In order of importance, preheat current, preheat time, hold time, welding current and welding time affect the strength of weld. Different constituents such as lath martensite, ferrite, pearlite and carbide colonies were observed in the microstructure of welds. The maximum hardness and strength of joints was 735 HV and 5.75 kN, respectively. The presence of hard zone in the fusion zone improved strength values and encouraged the pullout failure mode. The width of hard zone was increased by application of high preheat current and low welding current.