外加纵向磁场GTAW焊缝成形机理

以外加间歇交变纵向磁场GTAW（气体保护钨极氩弧焊）为研究对象，通过采用测量相关参数和拍摄电弧的方法，研究了间歇交变纵向磁场GTAW焊接低碳钢、不锈钢和铝合金等材料焊缝成形发生变化的规律和原因。认为在本研究条件下，无论处于溶池下方还是上方的单励磁线圈产生的外加纵向磁场都使GTAW焊接电弧特征、熔池行为和结晶过程发生了变化，从而导致焊缝成形的改变；同时发现当励磁线圈和电弧中心线不同轴心时，外加磁场对焊缝成形的影响较为强烈，其中铁磁性材料所受影响较显著。

Mechanism of Longitudinal Intermittent Alternative Magnetic Field on Weld Formation in Tungsten Inert-gas Arc Welding

The cause and rule of weld formation of mild steel,stainless steel and LD10CS aluminum alloy are studied in GTAW (tungsten inert gas arc) welding with a longitudinal intermittent alternative magnetic field,by measuring the parameter and taking the weld arc photograph.Under the research conditions described in this paper,the actions of GTAW welding arc property,fluid flow in pool and solidification process are changed due to the applied longitudinal intermittent alternative magnetic field,which produced by the single excitation coil above or under the pool,so the weld formation changes.When the excitation coil and arc center are non coaxial,the effect of applied magnetic field on weld formation is stronger,especially for the ferromagnetism metal.