Laser Cladding Stellite6−60WC Composite Coating Process and High- temperature Wear Resistance

Taking Co-based Stellite6 alloy powder and WC ceramic powder as cladding powder,a Stellite6−60WC cladding layer was prepared by adding 60% WC powder to the 316L substrate of the sinking roller using laser cladding technology. The effects of process factors such as laser power, scanning speed and powder feeding amount on the morphology of the cladding layer were studied to determine the optimal cladding process parameters, The phase and hardness and wear resistance were studied to explore the mechanism of improving the high-temperature wear resistance of the cladding layer. The results show that when the laser power is 1.5 kW, the scanning speed is 300 mm/min, and the powder feeding rate is 18.8 g/min, the surface quality of the cladding layer is good.The metallurgical bonding between the coating and the substrate, and the surface of the coating is free of cracks and holes. The phase composition of the cladding layer is mainly composed of hard phases such as γ−Co, M₇C₃, M₂₃C₆ (M=Co, Cr, Fe), W₂C and other hard phases, which is beneficial for improving the hardness of the cladding layer. The hardness can reach 736.2 HV, which is 3.5 times that of the substrate. The high-temperature wear resistance of the cladding layer is better than that of the 316L substrate, which is 6.1 times higher than that of the substrate, mainly because of the various hard strengthening phases and unmelted WC particles in the cladding layer.