重型车辆发动机电镀Cr活塞环的摩擦学性能

Tribological Property of Plated Cr Piston Ring for Heavy Vehicle Engine

利用SRV试验机模拟重型车辆发动机电镀Cr活塞环/缸套摩擦副的工作状态,测试了不同条件下摩擦副的摩擦因数和磨损量。采用扫描电镜(SEM)、能谱仪(EDS)分析了磨痕形貌和表面化学成分,研究了电镀Cr活塞环的磨损机制。结果表明,随载荷的增加,摩擦副的摩擦因数减小,总失重量增加。随滑动频率的增加,摩擦副的摩擦因数减小,总失重量先减小后增加,滑动频率为20Hz时,总失重量达到最小值。随温度的升高,摩擦副的摩擦因数增大,总失重量增加。活塞环和缸套的磨损机理以磨粒磨损为主,在高载荷,高频率或高温条件下,活塞环的磨损机理转变为磨粒磨损和黏着磨损。

Working conditions of piston rings coated with Cr platings/cylinder liner mate for heavy vehicles were simulated by SRV test rig. Different working conditions of friction coefficient and weight loss of the mate were tested. The wear marks and chemical contents were analyse by SEM and EDS. Wear mechanisms of pis- ton rings were researched. The results show that the friction coefficient of mate decreases and weight loss in- creases with increasing. The friction coefficient decreases, while the weight loss first decreases then increases with increasing sliding frequency. The weight loss reaches the minimum when the sliding frequency is 20 Hz. Both the friction coefficient and weight loss increase with increasing of the temperature. The main wear mech anism of piston rings and cylinder liners is abrasive wear. The wear mechanisms of piston rings coated with Cr platings are abrasive wear and adhesion wear under the conditions of high load, frequency, or temperature.