激光-电弧复合焊熔滴过渡的受力行为研究

Study on Force Behavior of Droplet Transfer on Laser-arc Hybrid Welding

以6.0mm厚超高强度钢板为试验材料,进行了CO_2激光-熔化极活性气体保护焊(Metal active gas,MAG)电弧复合焊接试验。采用高速摄像系统观测熔滴形态的变化,并采集焊接过程中的电弧和熔滴图像,通过试验深入研究激光功率对复合焊接过程中熔滴形态及受力状态的影响。研究表明,激光的加入,改变了熔滴形态尺寸和受力状态。随着激光功率的改变,熔滴受力状态发生变化,导致熔滴的半径随时间的上升而增加,而熔滴脱落时的半径随激光功率的增加而先增加后减小;激光功率对电磁收缩力影响显著,在熔滴长大的初始时电磁收缩力方向为负,当熔滴长大到一定程度之后,电磁收缩力方向为正;熔滴的过渡频率随激光功率的增加而先减小后增加。

A CO2 laser-metal active gas （MAG） arc hybrid welding was used to weld the ultra high strength steel plate of 6.0 mm thick. A high-speed video system was used to monitor the changes of droplet shape and collect the arc and droplet images during welding. By means of this, the effects of laser power on droplet shape and force state in hybrid welding process were studied. The results show that the inputting of laser changes both the droplet shape size and the stress state. The stress state of the droplet changes as the change of the laser power , this leads to the increasing of the drop radius with rising time, but the drop radius when dropping off shows a first increase and then decrease with the increase of laser power. Laser power has a significant effect on the electromagnetic contraction force. When the droplet grows up in the initial phase, the direction of electromagnetic contraction force is negative; and the direction of electromagnetic contraction force is positive after the drop grows up to a certain extent. The frequency of the droplet transfer shows a first decrease and then increase with increase of laser power.