激光-MIG双丝复合焊电弧特性与熔滴过渡研究

利用搭建的激光-熔化极惰性气体保护(Metal inert-gas,MIG)双丝复合焊接系统进行焊接试验。在试验中,主要研究激光功率、送丝速度、光丝间距和离焦量等几个主要变量对复合焊接稳定性、电弧特性和熔滴过渡的影响规律。分别选取电弧电压变异系数、电弧偏转角、熔滴过渡方式及过渡频率作为评价参量对稳定性、电弧特性和熔滴过渡进行分析。研究发现,随着激光功率增加,电弧偏转角先减小后增加,在1 000 W附近偏转角最小,焊接过程最稳定。引导丝熔滴始终为粗滴过渡,而跟随丝熔滴为粗滴过渡+少量短路过渡,熔滴过渡频率呈现先增加后下降的趋势。在送丝速度为4 m/min时引导丝和跟随丝的电弧稳定性最好,电弧偏转角先减小后增加最终趋于稳定。在离焦量为–1 mm时,引导丝和跟随丝熔滴过渡频率均达到最大值,分别为8.6Hz和6.3Hz。

Study on the Arc Characteristic and Metal Transfer in Laser-MIG Double Wires Hybrid Welding

The effect of laser power, wire feeding velocity, laser-arc distance and laser defocusing distance on welding stability, arc characteristic and metal transfer are investigated with the welding system of laser-metal inert-gas(MIG) double wires hybrid welding,. Meanwhile, some parameters are selected to evaluate the welding stability, arc characteristic and metal transfer including the coefficient of variance of welding voltage, the arc offset angle and the mode and frequency for metal transfer. It is found that, when the laser power is 1 000 W, the welding process is the most stable. With the laser power increasing, the arc offset angle decreases firstly and then increases. The mode of metal transfer is globular transfer and the metal transfer frequency increases firstly and then decreases. When the wire feeding velocity is 4 m/min, the stability for the leading and trailing arc is the best. As the wire feeding velocity increases, the arc offset angle decreases firstly, then increases and finally keeps unchanged. When the laser defocusing distance is–1 mm, the metal transfer frequencies for leading and trailing wire are 8.6 Hz and 6.3 Hz respectively.