铸铁滑动摩擦副表面温度对其磨损机制的影响

Influence of the Surface Temperature of Cast Iron Pairs on Wear Mechanisms in Lubricated Sliding Wear

在铸铁摩擦副油润滑和线接触的滑动条件下，测定了试样摩擦磨损表面层的温度及其温度分布梯度，考察了表面层的相变特点、组织结构和形貌特征，并且分析了温度对磨损机制转化的影响．可以将摩擦磨损表面的热效应分为３个区：弱热效应区（对应于塑性流动磨损区）、热效应区（对应于氧化磨损区）和强热效应区（对应于严重磨损区）．在临界载荷前，表面层的γ相含量增加，但到临界载荷时，由于表面层的剥落，γ相的含量明显减少．摩擦磨损表面的强热效应是导致表面层塑性流动、αγ相变、γ相含量增大、氧化物膜破裂、粘着和擦伤发生的重要原因．

The temperature and its distribution gradient in friction surface layers was measured in the lubricated sliding of cast iron in linear contact. The phase change and microstructure of the worn surface layers and the microtopography of the worn surface were investigated. The relationship between the temperature effect and wear mechanisms was analyzed.The temperature effect of the frictionwear surface could be devided into the region of weak thermal effect (the region of plastic flow), the region of thermal effect (the region of oxidation wear) and the region of strong thermal effect (the severe wear region).Before the critical load, the relative content of γphase in the worn surface layers increased. It decreased considerably at the critical load because of the breakage of the surface layers.The strong thermal effect of frictionwear surface was one of main reasons that caused plastic flow, γphase change, increase of γphase content, breakage of the oxidation film, and adhesion and scuffing.