热镀锌高强钢电阻点焊的点蚀对熔核形成的影响  

Effect of pitting on nugget formation in spot welding hot-galvanization steels with high strength

作　　者：张旭强[1] 张延松[2] 刘衍聪[1] 陈关龙[2] 

机构地区：[1]中国石油大学(华东)机电学院,山东东营257061 [2]上海交通大学机械与动力工程学院,上海200030

出　　处：《焊接学报》2009年第5期17-20,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(50575140)

摘　　要：热镀锌高强钢由于高强度特性以及良好的抗腐蚀性,可满足汽车轻量化与安全性需要,在车身制造中逐渐得到广泛应用.但热镀锌高强钢点焊的电极磨损严重,点蚀磨损特征变化明显,对熔核形成产生较大影响.建立点焊过程的点蚀有限元模型,采用数值分析与试验方法研究点蚀对熔核形成影响.结果表明,点蚀的产生与发展增加了工件之间的实际接触面积,使电流密度降低,熔核直径减小;同边缘位置点蚀相比,电极中心位置点蚀由于对熔核区域的电流分流作用,更加不利于熔核的形成.随着点蚀面积的增大,形成环状熔核几率增加.Hot galvanization steel with high strength was widely applied in auto body manufacturing because of its high strength and good corrosion resistance,but it had serious electrode wear and obvious pitting change in spot welding,which had great effect on nugget formation.FEA model of pitting was established during spot welding to study the effect of pitting on nugget formation and corresponding experiments were carried out.It was shown that the growth of pitting increased real contact area between parts,which decreased current density and reduced nugget diameter.Compared with pitting produced at edge region of electrode surface,the pitting produced at center region was more disadvantageous for the nugget formation.Ring-nugget would be formed with the pitting area being increased.

关 键 词：点焊 热镀锌高强钢 熔核直径 点蚀 

分 类 号：TG455[金属学及工艺—焊接]