熔化极气体保护焊熔滴过渡分析

Observation and analysis of droplet transfer in gas metal arc welding

利用高速摄影图像与电信号波形观察熔化极气体保护焊的熔滴过渡,分析了影响熔滴过渡的主导因素。结果表明,CO2气体保护焊时熔滴沿非轴向排斥过渡,氩气保护焊时熔滴沿轴向过渡;焊接电流对熔滴过渡方式的转变起主导作用,随着焊接电流的增大,CO2气体保护焊中依次出现短路过渡和大滴排斥过渡,熔滴尺寸依次增大,过渡频率依次减小,氩气保护焊中依次出现短路过渡、大滴过渡、射滴过渡、射流过渡和旋转射流过渡,熔滴尺寸逐渐减小,过渡频率逐渐增大;氩气保护焊中,由滴状过渡转变为喷射过渡的临界电流约为170 A。

The droplet transfer processes in gas metal arc welding are observed by using high-speed photography images and electrical signal waveforms,the dominant factor influencing droplet transfer is analyzed. The results show that the droplets transfer along non-axial in CO2 gas shielded arc welding while along axial in argon gas shielded arc welding. The welding current plays a dominant role in droplet transfer modes conversion,with the increasing of welding current,there occurs short circuiting transfer and globular repelled transfer in CO2 gas shielded arc welding,the droplet size increases while the transfer frequency decreases in turn. In argon shielded arc welding,there occurs short circuiting transfer,globular transfer,projected transfer,streaming transfer and rotating streaming transfer,the droplet size decreases while the transfer frequency increases in turn. In argon shielded arc welding,the critical current from globular transfer to spray transfer is about 170 A.