镀锌三层板电阻点焊的数值模拟

根据三层板电阻点焊的特点以及锌层的性质,选用1/4模型建立三层板数值模拟的模型.在经验参数的基础上优化工艺参数,以寻求最佳的熔核.在优化后最佳工艺参数下,分析各个不同材料内最高温度的变化趋势,熔核的形成与长大过程.加入无镀锌层进行比较,重点突出镀锌层对整个过程的影响.结果表明,镀锌层对整个形核过程有着很大的影响,改变了熔核的产生位置及长大趋势.含镀锌层的三层板熔核是先在无镀锌层的两块板接合面处形成,沿径向和轴向长大,最后形成包含三块板的熔核.结果表明,模拟计算结果与实际焊接结果比较吻合.

Numerical simulation of resistance spot welding of three-layer galvanized steel sheets

Based on the characteristics of resistance spot welding of three-layer sheets and properties of zinc coating,1/4 model was established to numerically simulate the three-layer sheets. On the basis of experimental parameters,the nugget was investigated through optimizing the parameters. Then under the peak temperature,nugget formation and growth in different materials were analyzed with the optimized parameters. It was found that,comparing to the sheets without Zn coating,the Zn coating can affect the nugget formation,change the location of nugget nucleation and growing trend. For three-layer galvanized sheets, the nugget initially formed in the interface between two sheets without Zn coatings,and then grew radially and axially,finally penetrated three sheets. The simulated results agreed well with the experimental results.