润滑油摩擦学性能对滑滚接触表面微点蚀影响机理

Influence Mechanism of Tribological Properties of Lubricants onthe Micropitting Performance in Rolling-Sliding Contacts

使用微点蚀试验机对两种商用润滑油在不同滑滚比和相对湿度条件下进行了测试,评估摩擦学性能与微点蚀程度之间的关系.微点蚀试验后,使用光学显微镜对滚子表面微点蚀程度进行了评估.结果表明,相对湿度或滑滚比的增加会导致较高的磨损,而摩擦系数变化没有统一趋势.滚子表面微点蚀程度受到摩擦和磨损的综合影响,并对磨损和微点蚀程度关系的两种机制进行了说明.这两种机制与应力(与摩擦系数相关)作用下形成的裂纹所导致的微点蚀扩展速度,以及磨损导致的微点蚀去除速度密切相关,将有助于评价滑滚接触中润滑剂的性能.

The mechanism of surface micropitting has been widely studied,while the relationship between the micropitting formation process and friction/wear was scarcely researched.In this study,two commercial lubricants were tested in a micropitting rig under different slide to roll ratios and relative humidities to evaluate the relationship between tribological properties and micropitting levels.After the micropitting test,the micropitting level on the roller surface was evaluated by an optical microscope.The results show that the increase of relative humidity or slide to roll ratio led to higher wear,while the change of friction coefficient had no uniform trend.The micropitting level on roller surface was affected by the combined effect of friction and wear,and two mechanisms of the relationship between wear and micropitting level were explained.The two mechanisms are closely related to the growth rate of micropitting caused by cracks formed under stress(related to friction coefficient)and the removal rate of micropitting caused by wear.The research results will be beneficial to evaluate the performance of lubricants in rolling sliding contacts.