Effect of Process Parameters on Microstructure and Properties of Laser Cladding Ni60+30%WC Coating on Q235 Steel.

A Ni60+30%WC composite coating was prepared on the surface of Q235 steel by utilizing a high cooling rate, small thermal deformation of the substrate material, and the good metallurgical bonding characteristics of laser cladding technology. This paper focuses on the study of the composite coatings prepared under different process parameters in order to select the optimal process parameters and provide theoretical guidance for future practical applications. The macroscopic morphology and microstructure of t he composite coatings were investigated with the help of an optical microscope (OM) and a scanning electron microscope (SEM). The elemental distribution of the composite coatings was examined using an X-ray diffractometer. The microhardness and wear resistance of the composite coatings were tested using a microhardness tester, a friction tester, and a three-dimensional (3D) profilometer. The results of all the samples showed that the Ni60+30%WC composite coatings prepared at a laser power of 1600 W and a scanning speed of 10 mm/s were well formed, with a dense microstructure, and the microhardness is more than four times higher than the base material, the wear amount is less than 50% of the base material, and the wear resistance has been significantly improved. Therefore, the experimental results for the laser power of 1600 W and scanning speed of 10 mm/s are the optimal process parameters for the preparation of Ni60+30%WC.