Preparation, Microstructure, and Interface Quality of Cr₃C₂-NiCr Cladding Layer on the Surface of Q235 Steel

In this study, a Cr3C2-NiCr cermet cladding layer was prepared on the surface of Q235 steel via a high-speed laser cladding method. The effects of laser power, scanning speed, and overlap rate on the microstructure, cladding quality, and interfacial elements diffusion of Cr3C2-NiCr/Q235 steel were studied. The results show that there was an obvious transition layer at the interface of the Cr3C2-NiCr cladding layer and Q235 steel, indicating that the Cr3C2-NiCr cladding layer had an adequate metallurgical bond with the matrix. Fe, Cr, and Ni were diffused distinctly between the cladding layer and the matrix. The height and width of the Cr3C2-NiCr cladding layer increased, while the dilution rate decreased with the increase in the laser power. The maximum thickness of the transition layer was about 50 mu m for the 6 mm/s sample, the weld heat affected zone was smaller, and it was shown that the productivity can be effectively improved. The sample with a 40% overlap rate exhibited the best flatness. The optimal laser power, scanning speed, and overlap rate of the Cr3C2-NiCr/Q235 steel were 1500 W, 6 mm/s, and 40%, respectively.