Rolling–sliding wear and damage behaviors of 304L stainless steel laser cladding on a damaged wheel tread under high ambient temperature conditions

To prolong the service life of wheels, damage to wheel tread was repaired locally by laser cladding. However, wheels in service in open environments are subject to high ambient temperatures, especially in the southern coastal areas of China, and the repair effects have not yet been verified. Therefore, in this study, laser cladding was used to clad 304L stainless steel powder on a damaged wheel tread to implement local repair of the damaged wheel. A friction and wear test was carried out using a twin-disc tester with a climate chamber to explore the influence of different loading cycles on the wear and damage behavior of repaired wheels at a high ambient temperature. The results showed that with increasing number of loading cycles, the friction coefficient between the wheel and rail gradually stabilized at 0.30–0.35, and the wear rate exhibited a similar trend. After 1 × 105 r, the surface hardness and plastic deformation thickness remained stable. The damage form changes from small spalling pits and nonpropagating microcracks to bulk material spalling and parallel cracks with large-angle branches. A high ambient temperature had little effect on the metallurgical bonding between the cladding layer and the wheel substrate, and no crack damage occurred.