Effects of welding parameters on tensile properties and failure modes of resistance spot welded DC01 steel

Abstract

In this study, different resistance spot welding joints were made on DC01 steel with welding parameters of 8–10–12 kA welding currents and 1.96–2.94 kN electrode forces. Measurements of the nugget diameter and tests of the tensile shear were performed. Also, various failure modes were determined. The importance of welding parameters on the value of the tensile shear force was determined, and a statistical model was established with the ANOVA study. The microstructure of the joint was characterized by optical and scanning electron microscopes. As a result, the nugget diameter and the tensile shear force were increased with an increase in the welding current and the electrode force. Two failure modes, namely, interfacial and plug failures, were observed. The effect of the electrode force was higher than the welding current on the tensile shear force. The base material was densely composed of the ferrite phase, heat-affected, and the fusion zone consisted of the coarse ferrite phase.