不锈钢多脉冲点焊过程热膨胀电极位移的变化规律  

Research on Electrode Displacement Based on Simulation of Resistance Spot Welding for Stainless Steels Using Multi-Pulse

作　　者：李昊 李鹏[3] 张国涛 楼铭 李永兵[1,2] LI Hao;LI Peng;ZHANG Guotao;LOU Ming;LI Yongbing(State Key Laboratory of Mechanical System and Vibration,School of Mechanical Engineering, Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Spaceflight Equipments Manfacturer Co. ,Ltd,Shanghai 200245,China)

机构地区：[1]上海交通大学机械系统与振动国家重点实验室,上海200240 [2]上海交通大学上海市复杂薄板结构数字化制造重点实验室,上海200240 [3]上海航天设备制造总厂有限公司,上海200245

出　　处：《机械设计与研究》2019年第4期134-139,共6页Machine Design And Research

基　　金：国家重点研发计划资助项目(2016YFB0101606-08)

摘　　要：热膨胀电极位移是反映电阻点焊质量变化的重要指标,然而多脉冲焊接条件下热膨胀电极位移的动态变化与熔核生长的关系规律尚不清楚。基于商业有限元仿真软件ANSYS建立2D轴对称电-热-力耦合模型,对奥氏体不锈钢点焊过程中熔核生长、热膨胀电极位移变化以及各阶段电流对熔核形成的影响规律进行研究,并通过点焊实验对数值计算模型的有效性进行验证。研究结果表明:熔核首先在工件接触面处产生,然后沿径向与厚度方向生长,最终形成椭球状焊核;热膨胀电极位移与液态熔核尺寸具有相同的变化趋势,在焊接后期熔核进入平稳生长后,二者趋于线性相关。多脉冲焊接条件下焊接脉冲对熔核生长影响最大,预热脉冲和回火脉冲对其无明显影响。Electrode displacement is an important indicator to reveal the quality of spot welds. However,the relationship between electrode displacement and nugget growth under multi-pulse welding is still unknown. In this study,a 2D axisymmetric electrical-thermal-structural coupled FE model was established using commercial ANSYS software to investigate the nugget growth and electrode displacement variation. Parallel physical tests were conducted using the same welding schedule to validate the model. The results showed that the nugget firstly generated at the faying surface,then grew toward to the center of the faying surface and along the thickness direction,and finally became an ellipsoidal shaped nugget. The electrode displacement and the liquid nugget size showed similar variation tendency and presented linear relationship in the late stage of welding,when the nugget grew steadily. The final nugget size highly depended on the welding pulse instead of the preheating and tempering pulse.

关 键 词：多脉冲 电阻点焊 有限元仿真 耦合 电极位移 

分 类 号：TG443[金属学及工艺—焊接]