Quantitative characterization of the relationship between wear and rolling contact fatigue of rail material

Wear and rolling contact fatigue (RCF) are two primary forms of rail damage. In this study, the relationship between wear and RCF damage was investigated, using an MJP rolling contact wear and fatigue testing machine. The experiments were conducted under dry-wet alternation conditions with various dry-wet time ratios, contact stresses, and slip ratios. The results indicated that as the dry-wet duration ratio increased, crack propagation was significantly accelerated due to the oil wedge effect, while wear initially increased before decreasing, reaching its peak when severe peeling occurred on the rail surface. With the increase in contact stress, the crack depth grew stably, while the wear depth initially increased gradually and then accelerated by large-scale severe spalling pits. As the slip ratio increased, rail wear exhibited a continuous increase, while crack depth initially increased but then decreased rapidly due to competition between the wear and RCF after exceeding a critical slip ratio value. The relationship between wear and RCF can be summarized into two states: RCF-dominant and wear-dominant. Under the RCF dominant state, the rail experienced severe peeling and spalling, leading to fatigue wear. In contrast, under the wear-dominant state, the crack propagation was suppressed due to the continuous removal of surface material and cracks, highlighting the competition between wear and RCF. Based on the competition between wear and RCF, a rail service life diagram was established, which can provide a framework for developing strategies for improving the rail service life.