Study on salt spray corrosion and friction wear performance of CrN coated cemented carbide sealing ring

Abstract

To enhance the durability of cemented carbide sealing rings under severe working conditions, CrN-coated cemented carbide sealing rings were prepared by arc ion plating technology. The microstructure, physical properties, corrosion resistance and frictional properties of these coated sealing rings were evaluated through acid salt spray corrosion and friction wear experiments, replicating real-world operational environments. Results indicate that the hardness of the coated rings 2128HV _30 surpass that of the uncoated ring 1780HV _30 , with negligible changes observed in coercive magnetic force and magnetic saturation strength post-coating. The average corrosion rate of the coated sealing ring was 0.18 g·m ^−2 ·h ^−1 , and the average corrosion rate of the uncoated sealing ring was 0.51 g·m ^−2 ·h ^−1 , and the corrosion rate decreased with the increase of corrosion time. Coated rings exhibited an average wear rate of 1.45E-07 mm ^3 /N·m, while uncoated rings showed a higher rate of 2.20E-07 mm ^3 /N·m, with wear rates increasing with prolonged corrosion. The coefficient of friction for coated rings was lower initially compared to uncoated rings, though post-corrosion, both exhibited similar friction coefficients. Surface roughness after friction wear was 91.66 nm for coated rings and 171.81 nm for uncoated rings. These findings underscore the superior corrosion resistance and frictional performance of CrN-coated cemented carbide sealing rings compared to their uncoated counterparts.

Keywords

• CrN-coating
• cemented carbide seal ring
• salt spray corrosion
• friction wear