三丝间接电弧焊电弧形态及焊缝成形分析

气体保护三丝间接电弧焊是一种新型的焊接方法，电弧建立在主丝与边丝之间，工件不连接电源.文中建立了稳定的三丝间接电弧，针对焊缝侧壁熔合问题，分析了不同焊丝分布方式产生的电弧形态对侧壁熔合的影响；针对焊缝层间熔合问题，采用后置钨极的方法实现了焊缝层间熔合.结果表明，主丝与边丝送丝速度与熔化速度相匹配，可建立稳定的三丝间接电弧；焊丝分布Ⅳ沿焊接方向的电弧偏向两侧壁，垂直于焊接方向的电弧形态集中，电弧稳定性好，可实现焊缝侧壁均匀熔合，熔合深度为1~1.2 mm；施加后置钨极，可实现焊缝层间熔合，焊缝抗拉强度为420 MPa，断裂位置发生在母材.

Analysis of arc shape and weld forming in triple-wire indirect arc welding

Gas shielded triple-wire indirect arc welding is a novel welding method. In this paper, a stable triple-wire indirect arc system is established. Aiming at solving the problem of sidewall fusion, the influence of arc shape produced by different welding wire distribution on sidewall fusion is analyzed. Aiming at solving the problem of weld seam interlayer fusion, the method of post-tungsten electrode is put forward. The results show that the stable triple-wire indirect arc system can be established by matching the feeding speed with the melting speed of the main wire and the side wire; the arc of wire distribution IV deviates to both sides of the wall along the welding direction and is concentrated form perpendicular to the welding direction, the arc stability is good, the weld sidewall can be fused evenly and the fusion depth is from 1 to 1.2 mm; the weld seam interlayer fusion can be realized by adding the post-tungsten electrode and the tensile strength of the weld can reach 420 MPa.