外加磁场对TIG焊电弧行为及焊缝成形的影响

Effect of External Magnetic Field on Arc Behavior and Weld Formation of TIG Welding

为提高钨极惰性气体保护焊(TIG)电弧能量,实现高效焊接,通过在TIG焊焊枪上分别外加直流、交变纵向磁场,采用高速摄像对不同磁场频率下的电弧形态进行拍摄,研究分析了外加不同形式和频率的磁场对TIG焊电弧行为及焊缝成形的影响规律。结果表明:不加磁场时电弧稳定燃烧且形态呈圆锥形;外加直流纵向磁场时,电弧高速旋转且电弧上方收缩,下方略微扩张;外加不同频率的交变纵向磁场时,随着磁场频率的增大,电弧挺度增加,电弧形态先扩张后收缩又扩张且电弧高速旋转,呈钟罩状。外加1500 Hz交变纵向磁场,焊缝熔宽减小,熔深增大,焊缝表面均匀光洁,焊缝成形明显改善。

In order to improve the arc energy of tungsten inert gas welding(TIG)to achieve efficient welding,the DC and AC longitudinal magnetic fields are respectively applied to the TIG welding torch,and the arc shapes under different magnetic field frequencies are photographed by high-speed camera.The influence of different forms and frequencies of magnetic fields on the TIG welding arc behavior and weld formation is studied and analyzed.The results show that the arc burns stably and its shape is cone without magnetic field.When DC longitudinal magnetic field is applied,the arc rotates at a high speed and contracts above the arc and expands slightly below it.When the alternating longitudinal magnetic field with different frequencies is applied,the arc stiffness increases with the increase of the magnetic field frequency.The arc shape first expands,then shrinks and expands,and the arc rotates at high speed,showing a bell jar shape.With 1500 Hz alternating longitudinal magnetic field applied,the weld penetration width decreases,the penetration depth increases,the weld surface is uniform and smooth,and the weld formation is significantly improved.