电弧弧长对激光-电弧复合焊飞溅和底部驼峰的影响

由于热源形式的特殊性，激光-电弧复合焊接过程中激光和电弧间易发生相互干扰，产生飞溅和底部驼峰等缺陷。以590 MPa级船用高强钢为研究对象，研究了电弧弧长对激光-电弧复合焊飞溅和焊缝底部驼峰的影响。为了深入研究激光-电弧复合焊飞溅和底部驼峰的产生机理，利用高速摄像设备对熔滴过渡行为和焊缝底部熔池进行了观察。结果表明，适当缩短电弧弧长可以降低激光和电弧间的相互干扰，提高复合焊接过程的稳定性，进而降低飞溅产生的倾向。底部驼峰是小孔熔透性差和底部熔池流动不连续所引起的。缩短电弧弧长可以对底部驼峰的产生起到抑制作用，这是因为缩短电弧弧长可以降低等离子体对激光的吸收，提高激光的能量利用率，增加小孔熔透性和稳定性。创新点： 研究了电弧弧长对激光-电弧复合焊飞溅和底部驼峰的影响，采用高速摄像方法对底部熔池流动进行了观察，进一步明确了激光-电弧复合焊接焊缝底部驼峰的产生原因。

Effect of arc length on spatter and root humping of laser-arc hybrid welding

Due to particularity of heat source, laser and arc often interferes with each other during laser-arc hybrid welding, resulting in spatter and root humping. 590 MPa grade marine high-strength steel was taken as research object, and influence of arc length on spatter and root humping during laser-arc hybrid welding was studied. In order to deeply study generation mechanism of spatter and root humping during laser-arc hybrid welding, high-speed camera was used to observe droplet transfer behavior and root weld pool. The results showed that shortening arc length could reduce interference between laser and arc, improve stability of hybrid welding process and reduce tendency of spatter. The root humping was caused by poor penetration of keyhole and discontinuous flow of bottom weld pool. Formation of root humping was inhibited by shortening arc length of laser-arc hybrid welding, it was due to the fact that shortening arc length could reduce laser absorption by plasma, improve laser energy utilization, and increase penetration and stability of keyhole.Highlights: Effect of arc length on spatter and root humping in laser-arc hybrid welding was studied, method of high speed camera was used to observe flow stages of bottom weld pool, and formation reason for root humping in laser-arc hybrid welding was further clarified.