CO2激光-MIG复合对接焊熔透工艺

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。因此研究了CO2激光惰性气体金属弧焊(MIG)复合焊接3 mm厚不锈钢板时激光功率、电弧电流、激光-电弧距离、焊接速度、坡口间隙等工艺参数对根部熔宽的影响，并通过CCD摄像机对焊接过程中的等离子体进行了观察。研究表明，随着焊接参数的变化，CO2激光-MIG复合焊存在四种熔透状态，对某一间隙范围，选择合适的激光功率、电弧电流、激光电弧距离与焊接速度可以获得“适度熔透”的良好根部成形。激光功率、电弧电流过小，速度过大则会产生“未熔透”或“不稳定熔透”，反之则“过熔透”。间隙较大时，激光功率对熔透的影响较小。另外还研究了不同激光电弧距离对等离子体形态及其对熔透的影响。

Statuses of CO2Laser-MIG Hybrid Butt Welding with Various Parameters

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 in CO2 laser-MIG hybrid welding of stainless steel with 3 mm thick, the effect of welding parameters such as laser power, arc current, distance of laser to arc, welding speed and gap width influencing root width of weld were investigated. Both laser plasma and arc plasma were also observed by CCD camera. The result indicates that there are four types of penetration status with the variation of welding parameters in CO2 laser-MIG hybrid welding. Fine root formation with “moderate full penetration” status can be acquired with appropriate laser power, arc current, distance of laser to arc and welding speed in certain gap. “Partial penetration” and “unstable penetration” will be produced with smaller laser power, or smaller arc current, quicker welding speed, contrarily it will be “excessive penetration”. Effect of laser power on penetration is not effective for bigger gap width. Effect of distance of laser to arc on plasma and root width of weld has also been discussed.