高速TIG-MIG复合焊焊缝驼峰及咬边消除机理

Humping and undercutting suppression mechanism for high speed TIG-MIG hybrid welding

搭建了TIG-MIG复合焊试验平台及电参数—高速图像同步采集系统,进行了一系列低碳钢高速TIG-MIG复合焊工艺试验,研究了高速TIG-MIG复合焊的电弧形态、熔滴过渡及熔池行为对焊缝成形的影响,并确定了合适的匹配参数.结果表明,MIG焊电流在240~300 A,且TIG焊电流与MIG焊电流相当时,TIG-MIG复合焊焊接过程稳定,即使在焊接速度高达2.5 m/min时,焊缝仍无驼峰、咬边等缺陷,与传统MIG焊相比,熔深增加,熔宽减小.TIG-MIG复合焊由于电弧间的相互作用,两电弧指向发生偏转,电弧压力减小,焊接过程不产生弧坑,且熔宽变窄,这是避免驼峰和咬边缺陷的主要原因.

A TIG-MIG hybrid welding system was set up.A series of experiments on high speed TIG-MIG hybrid welding of low-carbon steel were launched. The effect of TIG-MIG hybrid arc characteristic,droplet transfer mode and the weld pool behavior on weld bead appearance was researched and the welding parameters were optimized. Excellent arc stability and weld appearance were obtained by setting the same value for MIG and TIG currents in the range of 240-300 A. The penetration increased and weld width decreased compared with the traditional MIG welding. Humping or undercutting were suppressed at a high welding speed up to 2. 5 m / min The suppression of humping and undercutting defects in TIG-MIG hybrid welding may be attributed to the decrease in hybrid arc pressure due to the interaction between TIG and MIG arc,the disappearance of gouging region and decreases in the weld width.