Comparison of Three Surface Treatment Methods for Preparing WC-containing Coatings

A coating containing WC was prepared by induction cladding, laser cladding and plasma powder surfacing. The microstructure, chemical composition, hardness and corrosion resistance were analysed by optical microscope, scanning electron microscope, EDS, X-ray diffraction, micro hardness tester and electrochemical workstation. The results show that the forming quality of the samples deposited by induction cladding is very poor. The microstructures of LC and PS are mainly composed of dendrites, cellular crystals and interdendritic eutectic structure. Both of them contain Fe3C and Cr3C2 phase, as well as W2C phase. In addition, the PS alloy layer also contains other complex alloy phases and hard phases. The hardness decreases with the increase of current, while the hardness of laser cladding alloy layer is similar to that of plasma sample with 150A current. The best corrosion resistance is plasma sample with 125A current. The corrosion resistance of laser cladding sample is between 150A and 175A plasma sample.