Abstract: The response behavior of warm and humid airflows with different humidity(10% to 99%) on the adhesion of high-speed wheel-rail interfaces and wheel surface damages were studied by using a wheel-rail rolling testing machine under the environmental condition of -40 ℃. The results show that the adhesion coefficient will drop rapidly when the wheel-rail interfaces encounter warm and humid airflows in a low temperature environment, and with the increase of air humidity, the decrease amplitudes and the recovery time of the adhesion coefficient increase. Compared with wheel materials that are not exposed to warm and wet, the adhesion coefficient, wear amount, and plastic deformation layer thickness all increase significantly. With the increase of airflow humidity, the average adhesion coefficient decreases, and the wear amount and the thickness of the plastic deformation layer increase. Under the condition of low temperature and no moisture, the main form of wheel material wear is fatigue wear, and the section cracks are mainly surface cracks. Under the action of low-temperature intermittent warm and humid air currents, the main forms of wheel material wear are oxidative wear and adhesive wear. The third body layers formed by the accumulation of wear debris appear, and the section cracks appear multi-layer cracks and subsurface cracks. The warm and humid airflow has a significant effect on the adhesion of the trains wheel-rail interfaces and wheel damages in the low temperature environment. It is mainly reflected in the instantaneous drop in the adhesion coefficient and the more serious wear and fatigue damages of the wheel materials. Therefore, in order to ensure safer and more stable operation when trains pass through hot and humid tunnels in high-cold areas, special attention should be paid to the impact of warm and humid airflow on train wheels and rails.

Key words: low-temperature environment, warm and humid airflow, high-speed wheel-rail interface, adhesion coefficient, response behavior

摘要： 利用轮轨滚动试验机模拟了-40℃环境工况下不同湿度（10%～99%）暖湿气流对高速轮轨界面黏着与车轮表面损伤的响应行为。低温环境下轮轨界面遭遇暖湿气流时，黏着系数会迅速减小，且随着气流湿度的增大，黏着系数减小的幅度和恢复时间均增加；同时，与未遭遇暖湿的轮轨界面相比，黏着系数、磨损量、塑性变形层厚度均明显增大，且随着气流湿度的增大，平均黏着系数减小，磨损量和塑性变形层厚度增大。在低温无湿气作用工况下，车轮磨损机制主要为疲劳磨损，剖面裂纹以表层裂纹为主；低温间歇暖湿气流作用下，车轮磨损机制主要以氧化磨损和黏着磨损为主，磨损表面出现氧化磨屑堆积而成的第三体层，剖面裂纹出现了多层裂纹和次表层裂纹。低温环境下，暖湿气流对列车的轮轨界面黏着和车轮损伤影响显著，主要体现在黏着系数的瞬时大幅减小以及车轮材料更为严重的磨耗和疲劳损伤。因此，高寒地区应特别注意暖湿气流对列车轮轨损伤和黏着的影响，以保证列车的安全运行。

关键词: 低温环境, 暖湿气流, 高速轮轨界面, 黏着系数, 响应行为