In this study, the corrosion resistansce of TiZrVCrAl coating in a seawater environment was tested, providing a theoretical basis for expanding its application in a wider field. The results show that sputtering time below 1 h is beneficial to improve the coating flatness, and too long sputtering time will impel agglomeration on the coating surface. The coating raises the open circuit potential and decreases the current density of the bearing in seawater by increasing the impedance. Coating before heat treatment (coating I) was easier to be damaged during the corrosion and wear process, forming three-body wear and aggravating the coating failure. The heat-treated coating (coating II) facilitates the collection of abrasive debris and raises the dynamic fluid pressure. Although coating II has a negative impact on the corrosion resistance of the coating, it reduces the friction coefficient by 40% and prolongs the wear resistance life of the coating, which is even more valuable under the dynamic corrosion wear effect of M50 bearing steel as the background.

High-entropy alloy (HEA) coatings have attracted wide scientific attention in academic research and industrial innovation. In the present paper, the NiCoCrAlY HEA coatings are successfully synthesized on the surface of M50 steel to improve the corrosion resistance and tribocorrosion resistance of M50 steel in salt-contaminated lubricating oil. The corrosion and tribocorrosion behaviors of M50 steel and NiCoCrAlY coatings are studied systemically under the same conditions. The experimental results show that NiCoCrAlY coatings have good, densified microstructures and improve effectively the corrosion resistance and tribocorrosion resistance of M50 steel because the protective passivation films and oxide films are formed on the surface of NiCoCrAlY coatings. NiCoCrAlY coatings have high corrosion potential, a low corrosion current density, and a corrosion rate that is comparable with M50 steel. The corrosion potential of M50 steel decreases and the corrosion current density increases with the increase in load due to wear-induced corrosion. The corrosion and tribocorrosion mechanisms of M50 steel and coatings are discussed in light of the experimental results. The wear mechanism of M50 steel is abrasive wear. It is accompanied by corrosion wear for M50 steel and oxidative wear for NiCoCrAlY coatings.