激光-MIG复合焊熔透状态评价方法

Evaluation method of penetration statuses in laser-MIG hybrid welding

在有坡口间隙对接焊时,焊缝根部成形状态是衡量复合焊搭桥质量及其适应能力的重要指标.提出了以背面相对熔宽作为CO2激光-MIG复合焊熔透状态的定量评价指标,并以此为依据将熔透状态分为未熔透、适度熔透和过熔透,其中适度熔透是最佳的熔透状态.基于相对熔宽的评价指标,研究了工艺参数及坡口间隙变化对熔透状态的影响规律:通过调节激光功率、焊接电流或焊接速度增加热输入,都可使背面相对熔宽增大,从而改变熔透状态;随着坡口间隙的增大,熔透状态从未熔透过渡到适度熔透,再过渡到过熔透.

The formation of weld root is an important criterion to evaluate the gap bridging ability and weld quality of hybrid welding in gapped butt welding. Therefore the concept of relative root width of weld was proposed as the criterion to evaluate penetration status in CO2 laser-MIG hybrid welding. Base on relative root width of weld, the penetration statuses including moderate full penetration, partial penetration and excessive penetration were distinguished, and the effects of the variation of welding parameters and gap width on penetration status were further investigated. The results show that the relative root width can be increased by the change of welding parameters, and so the penetration status is changed. Under certain situation, as the gap width increases, the penetration status changes from partial penetration to moderate full penetration, and from moderate full penetration to excess penetration.