电弧熔丝脉冲GTAW熔滴过渡行为分析

提出了电弧熔丝脉冲GTAW焊接工艺，在非熔化极与工件之间的GTA电弧加入脉冲电流，不仅具有传热与传质分离和无飞溅等优点外，同时通过脉冲GTAW控制熔池熔深与形状，减小热影响区，减少合金元素的烧损.结果表明，随着焊丝距离工件高度的减小，熔滴过渡形式从大滴过渡转为无飞溅搭桥过渡，并且距离越近，熔滴过渡频率越快.当焊丝距离工件一定高度，焊接过程一脉一滴时，存在一个最优的频率可以实现最小的熔滴尺寸.

Droplet transfer of arcing-wire pulse GTAW

An arcing-wire pulse GTAW welding process was presented in this paper.Pulse current was added into the GTA electrode arc between the non-consumableelectrode and the workpiece.Besides the advantages of separation of heat and mass transfer with no spatter, this process technology could reduce the heat-affected zone and the burning of alloying elementsby controling the shape andthe penetration of welding pool with pulse GTAW. It was tested that with the reduction of the distancebetween the wire and the workpiece, the droplet transfer changed from big drops transition intonone arc contact transition.And the closer the distance was, the faster the droplet transfer frequency would be.When the wire was kept at a certain distanceto the workpiece, there was an optimal frequency that could achieve the minimum droplet size with the welding process ofone drop withone pulse.