热源空间位置对激光电弧复合焊接焊缝成形的影响

在激光电弧复合焊接中，热源空间位置关系，如热源间距、激光离焦量、焊炬倾角 等对激光、电弧之间的协同效应具有至关重要的作用，但是目前对此缺乏系统的专题研究。为此，采用5 kW CO2快轴流激光器和MAG(metal active gas)焊机对7 mm Q235钢板进行了激光电弧复合焊接工艺研究，集中探讨了空间位置参数对焊缝成形的影响规律。结果表明，热源空间位置参数对复合焊接焊缝成形具有显著影响，只有在合理的参数组合下才能够获得理想的焊缝质量。其中，热源间距对熔深的影响最大，不同间距处的熔深增幅高达55％，焊丝干伸长和离焦量对焊接熔深也具有较强的影响。焊接熔宽则对焊炬倾角和焊丝干伸长的变化更为敏感。上述参数主要通过改变激光电弧等离子体相互作用、热源能量叠加状态和熔池受力状况来决定焊缝成形。

Effects of Heat Sources Arrangement on Weld Shape of Laser-Arc Hybrid Welding

The heat sources arrangement is very significant for the laser-arc synergetic effects of hybrid welding, but there have been few researches about this. So a detail study of laser-arc hybrid welding process was carried out on the 7 mm mild steel by together a 5 kW CO2 laser with a MAG (metal active gas) welder. The results show that the heat sources arrangement parameters, such as heat sources distance, laser defocused distance, angle of weld torch, etc, have obviously effect on the weld shape, and the good weld shape was obtained only with the appropriate parameter combination. The increment of weld penetration depth caused by heat sources distance is the most, which is 55%, and the effects of wire stick-out and laser defocused distance on the weld depth are also stronger. The weld width is more sensitive to the wire stick-out and the angle of weld torch. The effects of these parameters are achieved by the interaction of three mechanisms: the change of laser-arc plasma interaction, the add state of the two heat sources and the state of the forces on the weld pool.