焊丝熔化方式对激光焊接过程的影响

研究了两种焊丝熔化方法(电弧预熔丝激光焊、激光填丝焊)激光焊接过程对匙孔稳定性以及焊缝成形的影响，进一步研究了焊丝熔化方法对焊接接头质量的影响，并对比分析了两种焊丝熔化方式对焊接速度的适应性. 结果表明，电弧预熔丝激光焊过程中，熔池表面匙孔开口尺寸变化不大，匙孔较为稳定；激光填丝焊方法由于熔化的液态金属距离匙孔边缘很近，焊接过程中熔池表面匙孔开口尺寸变化较大,而且容易出现熔池表面匙孔的闭合. 与激光填丝焊相比，电弧预熔丝激光焊熔化的焊丝端部可以沿熔池边缘流入，与匙孔边缘的距离较远，匙孔稳定性较好，焊缝气孔数量较少. 当焊接速度为8 m/min时，电弧预熔丝激光焊的焊缝成形良好；而激光填丝焊焊缝背面成形不连续，并且出现了未焊透的缺陷.

Effect of filler wire melting mode on laser welding process

The effects of two filler wire melting methods (laser welding with pre-melted liquid filler by arc and laser welding with filler wire) on the stability of keyhole and the formation of weld seam during laser welding were studied. The influence of filler wire melting method on the quality of welded joints was further studied, and the adaptability of two filler wire melting methods to the welding speed was compared and analyzed. The test results showed that during the laser welding process with pre-melted liquid filler by arc, the keyhole opening size on the surface of the molten pool did not change much, and the keyhole was relatively stable. Because the melted liquid metal was very close to the edge of keyhole, the keyhole opening size on the molten pool surface varied greatly during the laser welding process with filler wire, and keyhole closure on the surface of molten pool was easy to occur. Compared with laser welding with filler wire, during the laser welding process with pre-melted liquid filler by arc, the end of the wire melted by the arc could flow along the molten pool edge, the distance between the liquid metal and keyhole edge was far, the stability of the keyhole was good, the number of weld holes was small.When the welding speed is 8 m/min, weld seams was well during laser welding with pre-melted liquid filler by arc; while the weld seams back surface was not continuous during laser welding with filler wire, and there was a defect of incomplete penetration.