(1. 湖北汽车工业学院 材料工程系， 十堰 442002；
2. Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada)
摘 要: 研究了表面处理对微型点焊镀镍钢板和镍板时电极失效的影响。 结果表明： 微型点焊镀镍钢板和镍板时电极的失效主要是电极头部的塑性变形以及电极和镀镍板之间局部焊接的断裂发生在电极表面而导致的电极磨损；表面涂敷TiC的CuCrZr电极的寿命(1 200点)是CuCrZr电极寿命(600点)的两倍， 表面处理能提高电极寿命的主要原因是表面涂敷的TiC颗粒能阻碍电极和镀镍板之间的局部焊接， 以及减小电极表面的塑性变形。
关键字: 镀镍钢板; 微型点焊;电极失效机制; 表面处理
electrode degradation during micro-resistance spot welding
（ 1. Department of Materials Engineering,
Hubei Automobile Industrial Institute, Shiyan 442002, China;
2. Department of Mechanical Engineering,
University of Waterloo, Waterloo, Ontario N2L 3G1, Canada）
Abstract: The effects of TiC coating on electrode tip surface on electrode degradation mechanism were studied during micro-resistance spot welding of nickel-plated steel to nickel sheet. The results indicate that the electrode degradation mechanism is basically caused by deformation at electrode tip and wear due to fracture of local welding between the electrode tip face and sheet happened at electrode surface during micro-resistance spot welding of nickel-plated steel to nickel sheet. The electrode tip life of CuCrZr electrode with TiC coating (1 200 welds) doubles that of CuCrZr electrode (600 welds), because the TiC particles contained in the coating deposits can prevent local welding between the electrode surface and nickel-plated steel, then decrease the deformation of electrode surface.
Key words: nickel-plated steel; micro-resistance spot welding; electrode degradation mechanism; surface treatment
