不同电流密度下的TIG焊电弧行为分析  

Analysis of TIG arc behaviors under different current densities

作　　者：张晓鸿[1] 陈静青[1] 张康[1] 马朋召 陈辉 

机构地区：[1]西南交通大学材料科学与工程学院,成都610031 [2]不详

出　　处：《焊接学报》2017年第12期77-80,118,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51504198)

摘　　要：文中以TIG焊电弧为研究对象,通过流体力学和电磁学耦合理论建立了不同电流密度下的二维轴对称数学模型.通过Fluent用户自定义函数(UDF)二次开发,对自由状态下的TIG焊电弧行为进行了数值模拟,获得了不同电流密度下的TIG焊电弧热场和流场的分布规律.结果表明,TIG焊电弧阴极温度较高,在较大的电流密度下,阴极区域存在较大的电势差,等离子体受到向下向内的电磁力增大,造成其最大运动速度增大,对阳极造成了强有力的冲击,形成较大的电弧压力.同时验证了TIG焊电弧的热场呈现典型钟罩形态,在焊接过程中氩气比热容在钟罩电弧内部存在带状低谷区域.TIG arc was investigated through the theory of hydrodynamics coupling N-S equation,energy conservation equation and Maxwell equations. A model of 2 D axisymmetric TIG arc in natural state was established under different current densities. By applying the boundary condition through UDF,the TIG arc in natural state was numerically simulated,and the variation law of TIG arc under different current densities was obtained.The result revealed that a larger potential was produced in the cathode region with the increase of current. The plasma was subjected to a downward and inward electromagnetic force,which caused an increasing maximum velocity and a strong impact on the anode,resulting in greater arc pressure. Meanwhile,the thermal field of TIG arc was proved to be a typical bell shape.During welding,the specific heat of argon has a band trough region inside the bell cover arc.

关 键 词：钨极氩弧焊电弧 电弧压力 电势场 流体计算 

分 类 号：TG444[金属学及工艺—焊接]