激光对脉冲MIG焊熔滴过渡的改善作用

Improvement of laser on metal transfer in pulsed MIG welding

采用脉冲熔化极惰性气体保护焊(MIG)的方法焊接304不锈钢,在试验中利用电信号采集系统和高速摄像进行同步采集,研究熔滴过渡情况.结果表明,送丝速度调节适当时,可以实现一脉一滴的射滴过渡形式.送丝速度偏大时,焊接过程中会夹杂部分瞬时短路过渡,短路时间小于1 ms,影响焊接过程的稳定性.当采用激光-脉冲MIG复合焊时,对瞬时短路现象有改善作用.在一定范围内,激光功率增加,瞬时短路过渡出现的次数减少,改善作用增强.当激光功率达到一定阈值时可完全消除瞬时短路现象,实现一脉一滴的过渡形式,焊接过程稳定.即激光的加入提升了焊接品质与焊接效率.

304 stainless steel was welded by the method of pulsed metal inert gas( MIG) welding,and electrical signals and high speed camera pictures were acquired synchronously in the experiment in order to study the metal transfer. It was found that the projected spray mode of one droplet per pulse could be achieved when the wire feed speed was appropriate. When the wire feed speed was too high,some instantaneous short circuiting transfer mixed in the welding process,and duration time was less than 1 ms,which had a negative effect on the stability of the welding process. The instantaneous short circuiting transfer could be improved by using the method of laser-pulsed MIG hybrid welding. The number of the instantaneous short circuiting transfer decreased with increasie of the laser power,which contributed to improving unfavorable phenomenon. When the laser power reached a certain threshold value,the instantaneous short circuiting transfer could be completely eliminated to achieve the transfer mode of one droplet per pulse,and the welding process was stable. That is,the addition of laser made the welding quality improve and the efficiency increase.