Tribological Properties of MoS₂ Lubricating Coating on Gun Used PCrMo Steel by Laser Cladding

PCrMo steel is the main material of wear failure parts resulting in gun faults. In order to improve the life of parts, the solid lubrication technology is applied in the design of gun anti-attrition. The MoS₂ powders of two particle sizes, i.e. 8~10μm and 3~5μm, were selected as the solid lubrication material. The laser cladding was used to prepare lubricating coating on the surface of PCrMo specimens. In analysis of macroscopic properties of coating, MoS₂ coating of smaller particle size was thicker than that of larger particle size. The scanning electron microscope with energy dispersive spectrometer(EDS) was used to analyze the micro topography and chemical constituent of surface and subsurface. There were steel pits on the coating surface. The content of oxygen in the pit was higher than that of the smooth surface. The gap between the coating and substrate was observed. The EDS analysis revealed the infiltration between the coating and substrate. Compared with PCrMo steel, both the friction coefficient and wear of two coatings were low. The reduction of wear were 14.84% and 42.01% for the two coatings. The coating under larger particle size had better tribological properties. As a result, MoS₂ lubricating coating were effective to reduce the wear of gun parts.