Research on wear and corrosion resistance properties of various coatings for railway steel

Purpose This study aims to focus on the evaluation of the mechanical properties, corrosion resistance and microstructure of various metallic coatings applied to rail steel. Design/methodology/approach Six coating materials, including 1Cr18Ni9, 3Cr13, 7Cr17 stainless steels, Al, Zn and Zn–Al alloy, were examined. The coatings were subjected to corrosion tests in a 0.5% NaCl solution and wear tests under wet conditions. Microstructural analyses revealed that the corrosion resistance of the coatings was closely related to their microstructure and the formation of protective oxide layers. Findings The results indicated that the aluminum coating exhibited the best overall performance, demonstrating both high corrosion resistance and good wear resistance. The 3Cr13 stainless steel coating showed a good balance of both properties. In contrast, the 1Cr18Ni9 stainless steel coating exhibited superior corrosion resistance but poorer wear resistance, while the Zn–Al alloy coating performed well in wear resistance but poorly in corrosion resistance. The 7Cr17 stainless steel coating exhibited unsatisfactory performance in both aspects. Originality/value This understanding of the wear–corrosion relationship, gained through in-situ testing, is crucial for the informed selection and development of rail steel coatings designed to withstand the demanding, coupled degradation challenges of railway operations.