Dissimilar spot welding of DQSK/DP600 steels: the weld-nugget growth

The weld-nugget size is the key issue in determining the mechanical properties of resistance spot welds.This paper aims at investigating the weld-nugget growth of dissimilar-resistance spot welding of ferrite-martensite DP600 and drawing-quality special-killed (DQSK) low-carbon steel.It was revealed how the weld-nugget size is influenced by the main welding parameters: welding current, welding time and electrode force.The weldability lobe was established and proper welding conditions for the welds with a sufficient size and without an expulsion were determined.Using the experimental data, an empirical relationship between the weld-nugget size and the welding parameters was developed.