304不锈钢TIG非熔透搭接点焊工艺及数值模拟  

TIG non-penetration lap spot welding process and numerical simulation of 304 stainless steel

作　　者：徐正杰 杨文振 刘禹 陈彦秋 王嘉伟 XU Zhengjie;YANG Wenzhen;LIU Yu;CHEN Yanqiu;WANG Jiawei(School of Mechanical Engineering,Jiangnan University,Wuxi 214122,Jiangsu,China;Longsheng Technology Co.,Ltd.,Wuxi 214028,Jiangsu,China)

机构地区：[1]江南大学机械工程学院,江苏无锡214122 [2]隆盛科技股份有限公司,江苏无锡214028

出　　处：《焊接》2025年第4期57-65,共9页Welding & Joining

摘　　要：【目的】文中通过对304不锈钢平板搭接点焊工艺参数的研究,旨在为发动机废气再循环(Exhaust gas recirculation, EGR)阀焊接工艺参数提供参考依据。【方法】采用非熔化极惰性气体保护焊(Tungsten inert gas,TIG)对304不锈钢进行平板搭接点焊试验。研究了恒定电流为140 A时不同焊接角度(15°~75°)与峰值电流为200 A、基值电流为80 A时不同脉冲频率(5~25Hz)的微观组织和力学性能;使用数值模拟软件与高斯热源模型,研究了恒定电流焊接与脉冲电流焊接的温度场变化。【结果】结果表明,随着焊接角度的增加,焊点宏观尺寸中水平尺寸、熔深与最大拉伸力均逐渐减小,而垂直尺寸与焊脚宽度均先减小后增大;随着脉冲频率的增加,焊脚宽度逐渐收缩而焊接熔深增加较小,最大拉伸力逐渐降低。【结论】合理的参数选择有益于控制焊点的尺寸。通过数值模拟,脉冲电流的温度呈现锯齿状的上升趋势,在各个脉冲周期内温度变化均显示出快热快冷的特点;由于热传导过程的原因,2种焊接方式的焊点中心背面温度变化相较于焊点中心均有一定的滞后性。[Objective]The reference basis is provided for the welding process parameters of engine exhaust gas recirculation(EGR)valve by studying the welding process parameters of 304 stainless steel flat plate lap welding.[Methods]304 stainless steel plate lap joint spot welding test is carried out by tungsten inert gas(TIG)welding.The microstructures and mechanical properties of different welding angles(15°~75°)under constant current 140 A and different pulse frequencies(5~25 Hz)under peak current 200 A and base current 80 A are studied.By using the numerical simulation software and Gaussian heat source model,the temperature field changes of constant current welding and pulse current welding are studied.[Results]The results show that,as the welding angle increases,the horizontal size and penetration depth of the macroscopic size of the soldered joint and the max tensile force decrease gradually,while the vertical size and the width of the weld leg first decrease and then increase.As the pulse frequency increasing,the width of the weld leg shrinks gradually while the weld penetration increases slightly.[Conslusion]Reasonable parameter selection is beneficial to control the size of the soldered joint.Through numerical simulation,the temperature of pulse current presents a zigzag rising trend,and the temperature change in each pulse period shows the characteristics of rapid heating and rapid cooling.Due to the heat conduction process,the temperature change of the backside of the soldered joint center of the two welding methods has a certain hysteresis compared with the soldered joint center.

关 键 词：304不锈钢 非熔透点焊 微观组织 力学性能 数值模拟 

分 类 号：TG457.11[金属学及工艺—焊接]