面能量对激光—电弧复合焊接焊缝及熔滴过渡的影响

Influence of Area Energy for Welding Seam and Droplet Transfer on Hybrid Laser-arc Welding

引入面能量的定义,从激光功率、电弧参数和焊接速度等方面来研究面能量的变化对焊缝熔深、熔宽、焊缝成形系数和熔滴过渡的影响,试图建立激光能量与电弧能量之间的最佳配比关系以及面能量与熔深的定量关系。采用高速摄像系统观测熔滴过渡模式和等离子体形态的变化,并采集焊接过程中的电弧和熔滴图像;利用激光共聚焦显微镜观察焊缝形貌,并测量焊缝熔宽、熔深等数据。试验研究发现:激光与电弧两热源之间存在最优匹配范围;电弧电压与焊接电流之间存在U(15 1)0.05I的关系式;焊接速度的降低与焊缝熔深的增加并非线性关系,可选择的焊接速度是一个区间,该区间内存在一个最佳的焊接速度,并对应一个最佳的面能量。因此,在具体的激光—电弧复合焊接中,需要根据板厚、接头形式等确定激光与电弧的能量参数,选择合适的面能量。

The definition of area energy is introduced and its effect is investigated on weld penetration depth, weld width, forming coefficient and droplet transfer through laser power, arc parameters and welding speed. The best matching is intended to establish between laser energy and arc energy and the quantitative relationship between area energy and penetration depth. Camera high-speed video system is used to observe the droplet transfer model and the morphological changes of plasma, and acquire the image of welding arc and droplet image. Confocal scanning laser microscope is used to observe the weld morphology~ and measure the weld width and penetration depth. The study shows that optimal match range between laser energy and arc energy exists. The relationship between arc voltage and welding current can be described as U = （15±1） ＋ 0.05I. The relationship between welding speed and weld melt depth is nonlinear, and the welding speed selected should be a interval, in which the optimal welding speed lies corresponding to an optimal area energy. Therefore, in specific laser-arc hybrid welding, the appropriate area energy must be selected with respect to the parameters of laser and arc energy according to the thickness of steels welded, forms of joint, and so on.