双丝脉冲MAG焊的熔滴过渡及工艺特征

搭建了并列式双丝脉冲MAG焊工艺试验系统，通过双丝脉冲协调控制器连接试验所用的两台电焊机，在试验过程中采集了焊接电流、电弧电压信号，并用高速摄像机对焊接过程的电弧行为与熔滴过渡过程进行了同步拍摄．应用上述试验系统，在实现稳定焊接过程的基础上，分别研究了脉冲峰值电压与脉冲基值电压、两个焊丝在垂直于焊道方向上的距离、焊枪倾角这三个因素对电弧行为、熔滴过渡过程及焊缝表面成形与焊缝几何尺寸的影响．确定了最理想的脉冲峰值一基值电压，并且发现在文中所述试验参数下，焊丝间距11mm为两电弧形成共熔池、同焊道的上临界距离．结果表明，随着焊枪倾角的增加，焊缝熔深增加，熔宽减小，在焊接速度和送丝速度不变的前提下余高增加．

Metal droplet transfer and welding processing characteristics of double-wire pulse MAG welding

A parallel double-wire pulse MAG welding system has been developed, in which the two welding power sources were connected by the double-wire pulse controller.The current signals and voltage signals of the two arcs were collected.Synchronously high-speed photography system was used to observe the metal droplet transfer process and arc behavior.On the basis of a stable welding process, three factors, i.e.peak and base value of pulse voltage, the distance between the tips of the two wires in the vertical direction of the weld, inclination angle of the two welding torches were studied.Their influences on the arc behavior, metal droplet transfer and the formation and dimension of the weld were analyzed.The optimal peak and base value of pulse voltage was found out.The upper critical distance of the two arcs which could still form one weld pool and weld was 11 mm.It was found that the bigger the inclination angles of the torches, the deeper the penetration and the narrower the weld width, and also the higher the reinforcement of the weld at the same welding and wire feeding speed.