An alternating magnetic field was designed to increase weld depth of laser-MIG hybrid welded 316 stainless steel joint. The influencing mechanism of alternating magnetic field on improving penetration ability of hybrid heat source of laser-MIG hybrid welding was revealed. The results suggested that the difference of weld depth under different magnetic flux density was attributed to the change of characteristics of arc plasma and laser-induced plasma, droplet transition and keyhole behavior. More compressed arc shape under lower magnetic flux density (LMFD) with 20 m T and 30 m T promoted laser-induced plasma to move along the channel of laser beam, leading to decrease of weld depth. However, the laser-induced plasmas could be dispersed away from the channel of laser beam under higher magnetic flux density (HMFD) of 60 m T and 90 m T, which was the main reason for the increased penetration ability of hybrid heat source. Besides, the droplet transferred to behind the keyhole instead of dropping into the keyhole and more stable keyhole was obtained under HMFD, which were also beneficial for deeper penetration depth of laser energy. Moreover, the motion behavior of charged particles of arc plasma and laser-induced plasma and forces condition of droplet transition were discussed in magnetic field assisted laser-MIG hybrid welding.

交变磁场旨在增加激光-MIG 混合焊接 316 不锈钢接头的焊接深度。揭示了交变磁场对提高激光-MIG复合焊混合热源熔深能力的影响机制。结果表明，不同磁通密度下焊缝深度的差异归因于电弧等离子体和激光诱导等离子体的特性、熔滴转变和小孔行为的变化。在 20 m T 和 30 m T 的较低磁通密度 (LMFD) 下，更压缩的弧形促进了激光诱导等离子体沿激光束通道移动，导致焊缝深度减小。然而，在 60 m T 和 90 m T 的更高磁通密度 (HMFD) 下，激光诱导等离子体可以从激光束通道中分散开，这是混合热源穿透能力增强的主要原因。此外，在 HMFD 下，液滴转移到锁孔后面而不是滴入锁孔，获得更稳定的锁孔，这也有利于激光能量的更深穿透深度。此外，还讨论了磁场辅助激光-MIG复合焊接中电弧等离子体和激光诱导等离子体带电粒子的运动行为和熔滴转变的受力条件。