Effects of electrode wear on weld quality of hot galvanization steel with high strength in resistance spot welding

Electrode wear characteristics were studied;the electrode life of uncoated steels was much lower and pitting changed more obviously than that of galvanization steels when welding.The effect of electrode wear on weld quality was studied;the expulsion was serious and more micro-cracks were grown at early electrode wear stage, which decreased weld quality greatly.And then based on the experiment results of effect of electrode wear on weld quality, welding technique step-current was established according to the current density that micro-crack degree was less than 0.25 mm to reduce the effect of electrode wear on weld quality.