极性比对高速方波交流TIG-MIG复合焊电弧稳定性及焊缝成形的影响

Effect of Polarity Ratio on the Arc Stability and Weld Formation of HighSpeed Square Wave AC TIG-MIG Hybrid Welding

通过板上堆焊研究了极性比对高速方波交流TIG-MIG复合焊焊接过程稳定性和焊缝成形的影响。结果表明,TIG电弧极性比为0(直流TIG)时,由于TIG和MIG两个电弧之间相互排斥作用时间长,小电流(不高于50 A)TIG电弧电流易因过度拉长而熄灭,TIG-MIG复合焊接过程稳定性差,焊缝成形不良。TIG电弧极性比控制在10~40时,两个电弧之间周期性地排斥和吸引,小电流TIG电弧不会过度拉长,可在50 A的TIG电弧电流下获得稳定的TIG-MIG复合焊过程,可抑制直流TIG-MIG复合焊易于产生的驼峰缺陷,极性比为10时焊缝成形最佳。极性比过大时,焊缝表面光滑程度有所下降,焊趾部位呈现明显的波动,且存在较多的大颗粒飞溅。

The effects of polarity ratio on the stability and weld formation of high speed square wave AC TIG-MIG hybrid welding process were studied by using bead on plate welding experiment for.It is found that when the polarity ratio of TIG arc is zero,low current TIG arc is susceptible to distinguishing due to its over-elongation caused by long time mutual repulsion between TIG and MIG arcs.TIG-MIG hybrid welding process is unstable and weld formation is poor.When the polarity ratio of TIG arc is in the range of 10~40,a stable TIG-MIG hybrid welding process can be obtained under the TIG arc current of 50A,and the hump defects easy to occur in DC TIG-MIG hybrid welding can be suppressed。When the polarity ratio is 10,the weld forming is the best.When the polarity ratio is too large,the smoothness of the weld surface decreases,the weld toe fluctuates obviously,and there are more large particle spatters.