LAUSR

In this work, a NiCr-Cr3C2 coating was prepared on the AISI 1045 steel substrate by plasma spraying, then subjected to tungsten inert gas arc (TIG) remelting treatment. The microstructure, hardness and the wear test under different temperatures (25, 200, 400, and 600 °C) of the NiCr-Cr3C2 coatings before and after remelting were studied comparatively. The results show that after TIG remelting, the internal structure of the coating was dense, and the defects were greatly reduced. The hardness of the remelted coating surface became uniform and increased from 1007 HV0.1 to 1141 HV0.1, with an increase of 13.3%. At different temperatures, the weight loss of the remelted coating was always less than that of the sprayed coating, with a significant reduction of about 75%. The friction coefficients of the remelted coating and sprayed coating at 25 and 200 °C were basically the same, while the friction coefficients of the remelted coating at 400 and 600 °C were smaller than that of the sprayed coating. The wear mechanism of the remelted coating under different temperature were abrasive wear and adhesive wear, while that of the sprayed coating were fatigue wear, abrasive wear, and adhesive wear. Therefore, the TIG remelting treatment can optimize the microstructure of the NiCr-Cr3C2 coating and remarkably improve the wear resistance.