Abstract: In order to investigate the effect of rail hardness on rolling wear and damage of wheel and rail in the Gobi and desert moderate sandstorm environments, four types of pearlitic rail steels with different hardness are tested by a twin-disc rolling contact fatigue testing machine equipped with the windblown sand environment simulation device. The results show that in the Gobi and desert moderate sandstorm environments, with the increase in the rail hardness, there is no significant change in the average adhesion. The wear rate of wheel first decreases and then increases, whereas the wear rates of the rail in the Gobi and desert moderate sandstorm environments show a downward trend and an upward trend, respectively. In these two types of moderate sandstorm environments, the wear mechanisms of the wheel are mainly oxidative wear and fatigue wear, and the oxidative wear gradually aggravates as the rail hardness increases. The wear mechanism of the rail is mainly fatigue wear. As the rail hardness increases, the crack depth in the rail subsurface presents an overall decreasing trend in these two moderate sandstorm environments, which indicates the fatigue damage of rail gradually alleviates with the increase in rail hardness. Due to the more significant effect of fatigue damage than wear on the operation safety of wheel-rail, it can be concluded that the heat-treated rail material with high hardness is more suitable for moderate sandstorm environment by comprehensively considering the anti-rolling wear performance and anti-rolling contact fatigue performance of the rail materials.

Key words: rail hardness, sandstorm, oxidation, wear, fatigue damage