Influence of RSW Process Parameters on Microstructure and Mechanical Properties of Interstitial Free Steel Joints

For this study, joints of interstitial free steel sheets were prepared using a resistance spot welding machine under varying power input and electrode pressure conditions. With the increase in power input from 18.75 to 26.25 kVA, dimension of the weld zone was found to have doubled. Besides, a decrease in electrode pressure by 5 psi has increased weld zone width by 5%. The decrease in electrode pressure from 25 to 15 psi has resulted in the increase in cavity tendency, i.e., from nil to nearly 25% of weld zone width. The change in processing conditions has also effectively altered the mechanical performance and failure mode of the spot welds. For the shear tensile and coach peel tests, joints prepared using higher power input and electrode pressure have reported better load-carrying and energy absorption capabilities. The failure mode for high-power input and electrode pressure joints was the pull-out type; while, it was an interfacial type for others.