合金化镀锌板连续点焊电极的变化

Variations in Consecutive Spot Welding Electrode for Alloying Galvanized Steel Sheet

通过试验研究了合金化镀锌汽车板在连续打点过程中电极端面及焊点的变化。结果表明,无论是铬铜还是弥散铜电极,其端部随着焊点的增加而变大。在连续点焊后,电极端面呈现凹凸不平及不均匀的Zn的吸附,导致电极端部导电分布不规则。最初焊点较小且热量集中,而连续打点后,加热面积扩大且分散,使产生不合格焊点的倾向增加。端面为弧形的电极对连续点焊有更好的适用。

Variations in the electrode surface and welded spot surface during consecutive spot welding of galvanized steel sheet are studied. The results show that, for either chromium-alloyed copper electrode or Al2O3 dispersed copper electrode, its tip area increases with the increase of the welded spots. After consecutive spot welding, the tip surface becomes concave-convex, is covered with a film with uneven chemicals, and is attached with Zn around the tip, leading to irregular electric conducting on it. The starting welded spot is smaller and heating is concentrated; however, after a number of welds were completed, the heating area increases and is decentralized, increasing the tendency of the formation of failure welds. Electrode with curve tip is more suitable to consecutive spot welding.