Effects of Different Tungsten Carbide Contents on Microstructure and Properties of Ni-based Tungsten Carbide Cladding Layer by Plasma Arc Cladding Technology

Ni-based tungsten carbide cladding layer was fabricated on the surface of Q345 steel by plasma arc surfacing technology, the effects of diffe-rent tungsten carbides contents on the microstructure and property of Ni-based tungsten carbide cladding layer were investigated. The microstructure and morphology of the cladding layer were analyzed by using optical microscopy (OP), scanning electron microscopy (SEM), and X-ray diffractometer (XRD). The hardness and wear resistance of the cladding layer were tested with a microhardness tester and a friction-wear test machine. The results showed that there was a metallurgical bonding between the cladding layer and the base material, and no porosity existed on the surface of the cladding layer. The microstructure of the cladding layer was composed of the tungsten carbide particles in the form of WC and W2C and Ni-based binders which contained SiC, Cr23C6, Ni3Si, γ-Ni. When the content of tungsten carbide in the powder increased from 15%(mass fraction, the same below) to 50%, the number of hard phases in the microstructure of the cladding layer increased, which significantly improve the hardness and wear resistance of the cladding layer. When the content of tungsten carbide was 50wt%, the hardness of cladding layer was up to 1 024HV10 and the wear resistance reached the optimum. © 2021, Materials Review Magazine. All right reserved.