空气湿度对地铁车轮磨耗的影响及机理研究

摘要

Wheel wear affects the safety of metro and the operation cost.At present,the researches on metro wheel wear are mostly concentrated in the axle load,wheel-rail contact state and other factors,only few studies have considered the effects of air humidity.Through a long time monitoring of a certain urban metro line,the data about the average wear on the wheel and the relative humidity in each month are collated and analyzed.The result indicates that the wear volume declines with the increasing of relative humidity,then,combined with the available experimental data,this law has been verified.The mechanism of wear on humidity is further studied,when the temperature does not reach the dew point,humidity main impacts the wheel-rail contact surface roughness,hardness and the formation of the oxide film; when it has reached the dew point,wheel and rail surface will form a water film,which will reduced the coefficient of friction and the amount of wheel wear.%车轮磨耗影响着地铁的运营安全和运营成本.目前,关于车轮磨耗的研究多集中于轴重、轮轨接触状态等因素的影响,考虑空气湿度影响的研究较少.通过对某城市地铁进行了长期监测,对每月的车轮平均磨耗量及空气相对湿度进行了统计分析,得出了车轮磨耗量随空气湿度增加而降低的规律；并结合已有试验数据,对这一规律进行了验证.对空气湿度影响车轮磨耗的机理进行了探讨,发现在气温未达到露点温度时,湿度主要影响轮轨接触表面的粗糙度、硬度以及氧化膜的形成；在气温达到露点温度之后,轮轨表面将会形成水膜,这将会降低轮轨间摩擦系数,降低车轮的磨耗量.