Effect of Process Parameters on Arc Behavior and Weld Formation in Weaving Gas Tungsten Arc Welding

The arc welding with weaving has been used widely to obtain better weld quality by avoiding lack of side wall fusion and improve the weld efficiency by obtaining the wide weld. But the effect of weaving process parameter on the weld is not clear. The aim of this work is to study the effect of process parameters on arc behavior and weld formation in Weaving-Gas Tungsten Arc Welding (W-GTAW), those parameters include welding current, tungsten electrode height from the electrode tip to upper surface of workpiece, weave angle, weave speed, and weave stop time on the left and right sides. The instantaneous arc shape and electrical signal data were collected by high-speed camera and electrical signal acquisition system, respectively. Furthermore, the weld morphology was also systematically analyzed. This result shows that the bottom surface radius of the arc changed with weaving in the W-GTAW. When the weave speed increased to 0.40 × 10−1 rad/s, the change of the radius was the least, with only 0.10 mm drift, and the difference between the arc forces in the middle and the two sides of the molten pool was smallest in all experiments. Compared with the welding stability of each process, decreasing the tungsten electrode height, weave angle and speed could significantly enhance the welding stability. The forming coefficient of weld with a weave angle of 1.9° was 3.11. It shows that increasing reasonably the weave angle and speed can increase the weld penetration and might help reduce stress concentration and hot crack tendency of the weld. When the welding current is reduced to 130 A for W-GTAW welding, the hardness transition from base metal (BM) zone to weld zone (WZ) is more gentle. Furthermore, the W-GTAW technology shows great application potential in weld forming control by adjusting process parameters.