脉动送丝MIG焊的熔滴过渡及焊缝成形分析

Analysis of droplet transfer and weld appearance in pulsed wire feeding MIG welding

文中在等速送丝MIG焊基础上,搭建了脉动送丝MIG焊系统,利用焊接电流电压信号采集系统以及高速摄像等设备对焊接过程进行检测,研究了脉动送丝对MIG焊熔滴过渡及焊缝成形的影响.结果表明,试验发现,脉动送丝条件下熔滴所受轴向机械力是影响熔滴过渡形式的关键因素.在相同的脉动送丝频率下,脉动送丝速度基值与峰值时熔滴过渡形式有所差异;随着脉动送丝频率的改变,熔滴过渡形式也会发生变化;相比于等速送丝,脉动送丝条件下形成的焊缝熔宽更宽,且随着脉动送丝频率的增加,熔宽逐渐增大.

On the basis of MIG welding with constant wire feeding speed,the pulsed wire feeding MIG welding system was built up. The waveform of welding current and arc voltage were acquired through synchronous electrical signal acquisition system and the arc behavior and metal transfer processes were monitored by high-speed camera. The effect of pulsed wire feeding on MIG welding process was studied. It is found that the axial mechanical force on the droplet is the key factor on the form of the droplet transfer. In the same pulsed wire feeding frequency,the droplet transfer forms at the base value and the peak value of the pulsed wire feeding speed are different. And with the change of the pulsed wire feeding frequency,the droplet transfer modes are also different. Additionally,the weld width of pulsed wire feeding MIG welding is wider than that of constant speed wire feeding MIG welding,and the weld width increases with the increase of the pulsed wire feeding frequency.