高温对发动机气门磨损特性影响的试验研究

Experimental Investigation in the Effect of Elevated Temperature on Wear Property of Engine Valve

根据摩擦学原理，采用动态磨损模拟试验和表面微观分析研究的方法和技术，对气门动态磨损特性进行了系统的试验研究。着重温度对气门材料的力学性能、蠕变和疲劳裂纹形成与扩张的影响等问题进行分析和研究。结果表明：气门接触面是以反复弹、塑性疲劳变形和金属滑动而产生的疲劳裂纹、片状疲劳剥落，最终导致气门的失效；而材料在高温下产生的变形滑移和蠕变又是促使气门疲劳点蚀和剥落磨损加速的主要原因。

The wear properties of valve are systemically investigated by using dynamic simulation testing and surface microscopic analysis techniques based on principle of tribology. The study work is focused on the effect of temperature upon mechanical properties,creep, initiation and propagation of fatigue crack for the valve material. It is shown that repeated elastic and plastic deformations, and metal-slioing cause the fatigue crack, spalling which finally led to failure on valve contact surface,while deformation-sliding and creep of valve material at high temperature are main causes for bringing about fatigue pits of valve and speeding-up ist spalling wear.