Study on microstructure and property of laser cladded Ni-WC/Cr₃C₂ coating

Ni-WC/Cr₃C₂ coating was prepared on 45# steel surface by laser cladding technology, and the microstructure, phase and composition were studied by means of SEM and XRD, while the corrosion resistance and wear resistance were also studied. The results show that cellular dendrites were formed at the bottom of the laser cladding Ni-WC/Cr₃C₂ coating, while fine dendrites were at the middle and upper region of the coating. The cladding coating is mainly composed of γ-(Fe, Ni), M₂₃C₆ type carbides and undissolved WC particles. The microhardness is increased to 711HV0.1 due to the synergetic effect of fine grain strengthening, solid solution strengthening and carbides. Moreover, a reduction of the corrosion current density of about four times compared with 45# steel indicating the improved corrosion resistance. In addition, the weight loss of both the laser cladding coating and 45# steel was increased with the increase of wearing speed, and the weight loss of cladding coating is lower than that of 45# steel.