Laser-MAG hybrid welding 10CrNi3MoV steel was fabricated with different arrangements (the leading mode, and distance between laser beam and electrode tip (D_LA)). Welding characteristics and defect formation mechanisms were investigated by high-speed images (HSI) and real-time electric signals. Arc behaviors, droplet transfers and defects (pores, undercut and spatters) were observed with the increased D_LA in arc leading mode and laser leading mode. electric signals and HSI observations revealed that the leading mode and D_LA significantly affected the welding characteristics (Weld morphologies, process stability and droplet transfer) and defect formation. For two leading modes, stable welding process and sound welded formation was achieved by adjusting D_LA = 2-4 mm. Synergistic effect of laser and arc made the arc stabilize and droplets transfer smoothly and steadily in projected transfer mode. And the final weld morphology for arc leading mode was superior to one for laser leading mode. As D_LA increased, defects began to form. Arc leading mode was susceptible of pore and undercut formation. Because the increased D_LA provoked the irregular molten metal movement, leading to keyhole collapse, and caused the previous solidified layer rim hinder the center molten metal to fill the weld toe. While Laser leading mode was susceptible of spatter formation since the increased D_LA caused the swelling formation by the arc forces and droplets impact on the back wall of the keyhole, and the swelling was collided by laser evaporation reaction and formed liquid column, final disintegrating into spatters.

激光-MAG混合焊接10CrNi3MoV钢采用不同的布置方式（引导方式以及激光束与电极头之间的距离（D _LA））制成。通过高速图像（HSI）和实时电信号研究了焊接特性和缺陷形成机理。在电弧引导模式和激光引导模式下，随着D _LA的增加，观察到了电弧行为，熔滴转移和缺陷（孔，底切和飞溅）。电信号和HSI观察表明，超前模式和D _LA会显着影响焊接特性（焊接形态，工艺稳定性和熔滴转移）和缺陷形成。对于两种主导模式，通过调整D可以实现稳定的焊接过程和良好的焊接成形_LA = 2-4毫米。激光和电弧的协同作用使电弧稳定，液滴在投影传输模式下平稳平稳地传输。电弧引导方式的最终焊接形态优于激光引导方式的最终形态。随着D _LA的增加，缺陷开始形成。引弧模式容易产生孔隙和底切。由于增加的D _LA会引起熔融金属的不规则运动，导致锁孔塌陷，并导致先前的凝固层边缘阻碍中心熔融金属填充焊趾。由于增加的D _LA，激光引导模式容易形成飞溅 电弧力导致溶胀形成，液滴撞击小孔的后壁，溶胀因激光蒸发反应而碰撞并形成液柱，最终崩解成飞溅。