Research on Weld Formation and Multi-bead Overlapping Process of Tri-Arc Doulbe-electrode Welding

Tri-arc doulbe-electrode welding tests with different feeding speed, welding speed and M arc current were carried out. The influence of different process parameters on forming quality of tri-arc doulbe-electrode weld was analyzed and the optimal combination of parameters was determined. The cross section profile of tri-arc doulbe-electrode single pass weld was fitted by three kinds of curves: parabola curve, cosine curve and arc curve, the results show that the parabola curve is the best. The traditional lap models of single-layer multi-pass welding were analyzed, and the existing lap model was improved according to the forming characteristics of tri-arc doulbe-electrode welding, and the deduced ideal lap spacing is0.689 time of the melt width. In order to improve the advantage of the improved lap model, the welding test was carried out with different lap spacing. The comparison and analysis of the cross-section morphology of lap weld shows that the improved model is more suitable for tri-arc double-electrode welding.