文摘
Laser-MIG hybrid welding of 316L stainless steel was carried out to investigate influence of welding process parameters, i.e., laser power (P), welding current (I), distance between laser and arc (D), and welding speed (V) on arc characteristics, droplet transfer, and weld quality. Arc characteristics and droplet transfer behavior were investigated using high-speed imaging technology. Microstructures of the joint were observed by optical microscope, and microhardness was measured by microhardness tester. The results showed that the maximum deviation angle of the arc from the wire axis decreases with the increasing laser power. Welding current played a dominant role in arc length and droplet transfer mode. Optimal weld with no spatters and humps was obtained when P = 3 kW, I = 140 A, D = 3 mm, and V = 1.2 m/min. Microstructures in the weld zone mainly consist of columnar and equiaxed dendrites. Microhardness decreased toward the center of the weld zone, increased toward the WZ boundary, and decreased sharply at the heat-affected zone (HAZ).
