附加补偿保护气体对高速脉冲MIG焊焊缝的影响

针对高速脉冲MIG焊易出现咬边、驼峰焊道等焊接缺陷,首次采用附加补偿保护气体方法,在靠近脉冲MIG焊焊枪喷嘴保护气罩的后端专门构建保护气体支路,通过该支路三通气阀控制补偿保护气体流量,对刚脱离焊枪喷嘴的高温固液态焊缝实施人工干预成形和焊缝表面二次气体保护. 以18-8型奥氏体不锈钢薄板为母材作平板堆焊试验,结果表明,引入适量附加补偿保护气体后,既能明显改善焊缝成形,又能对焊缝表面实施及时跟踪保护,对抑制单丝高速脉冲MIG焊时易出现的焊接缺陷改善效果明显,焊接效率可实现较大提升,在理论和工艺实践上具有进一步研究价值.

Effects of additional compensation shielding gas on high-speed pulsed MIG welding seams

Aiming to provide a solution to frequently occurring weld defects such as, undercuts and humping beads, an additional compensation shielding gas technique has been adopted for the first time. A shielding gas branch channel has been specially built near the end of rear protective gas hood of the pulsed MIG welding gun nozzle. By using a three-way air valve, to control the flow of the compensation shielding of gas as to conduct manual intervention to facilitate the formation of high-temperature solid and liquid welding seams that have just left the welding gun nozzle and provide secondary protection for the seams. The surfacing plate test in which the 18-8 austenitic stainless steel plate has been used as the base metal, has been conducted. The test results have shown that the introduction of appropriate additional compensation shielding gas not only improves the formation of welding seams apparently but also tracks and protects the welding seam surfaces in time, which significantly reduces the weld defects that frequently occur during the use of the high-speed pulsed MIG welding technique and substantially increases the welding efficiency. Therefore, the technique is worth being studied further theoretically and in technological practice.