Mechanical properties and nugget evolution in resistance spot welding of Zn–Al–Mg galvanized DC51D steel

Abstract Zn–Al–Mg coating galvanized steel in resistance spot welded (RSW) different configurations of DC51D was investigated to illustrate the nugget evolution process and mechanical properties joints. Results show that microstructure joints can be divided into zone (FZ), heat-affected (HAZ), base metal (BM). FZ composed lath martensite. The average hardness value weld joint 110 HV 0.2 while up 300 due formation failure modes interface fracture (IF) pull-out occurred (PF) under welding parameters, which shear dimples showed had a typical plastic morphology. best range for parameters found 12–18 cycles diameter reached 5.5 mm. HAZ discussed.