Correlating Electrode Degradation with Weldability of Galvanized BH 220 Steel during the Electrode Failure Process of Resistance Spot Welding

Electrode degradation in the continuous resistance spot-welding process of baked hardening (BH) 220 steel was evaluated by an electrode life test, and weldability tests were conducted geometry feature measurement, mechanical property analysis, diameter measurement with 88 or 176 weld intervals. The analysis shows that heat-affected zone (HAZ) width, nugget diameter, area tend to decrease rapidly, while height tends increase repetitions until welding heat input becomes too small form effective nugget. maximum displacement failure energy welded joints show a decreasing trend during process, peak load increases slightly 88th then decreases. cavities pores mainly appear after 176th spot weld. welding. reason for may be contact between BH sheets smaller which causes sticking phenomenon sheets. In absence alloying, edge is geometrically deformed, Cu–Zn–Fe alloying occurs sheet.