不同材质闸瓦和车轮滑动摩擦磨损试验及其结果分析

Wear Test and Analysis of Brake Shoe Made of the Different Materials and Wheel During Sliding Friction

为了研究不同材质闸瓦和车轮滑动摩擦磨损性能,采用M2000型摩擦磨损试验机,针对4种材质闸瓦摩擦块与车轮钢摩擦环摩擦副,开展滑动摩擦磨损试验,试验结果表明,4种材质闸瓦摩擦块对车轮钢的体积磨损量由大到小对应的材质依次为钢轨钢、粉末冶金闸瓦、合成闸瓦、铸铁闸瓦。用扫描电镜观察4种材质闸瓦摩擦块和车轮钢摩擦环摩擦磨损试验后的摩擦环表面形貌,结果显示,摩擦环表面均出现磨粒磨损和疲劳磨损,LH2型高摩擦系数合成闸瓦和QU70型钢轨钢对车轮钢的磨损以磨粒磨损为主,高磷铸铁闸瓦和M型粉末冶金闸瓦对车轮钢的磨损以疲劳磨损为主。用能谱仪测试4种材质闸瓦摩擦块和车轮钢摩擦环摩擦磨损试验后的摩擦环表面元素,结果显示,摩擦环表面均发生氧化反应,出现闸瓦材料向车轮钢转移现象。

In order to study wear performance during friction by sliding of brake shoes and wheels of different materi⁃als,M2000 machine for testing friction and wear was used to carry out the wear tests with the friction pair composed of friction blocks made of brake shoes of four kinds of material and friction rings made of wheel,during sliding friction.The results show that the volume wear of different materials of brake shoe on wheel steel from large to small correspond⁃ing materials are rail steel,powder metallurgy brake shoe,synthetic brake shoe and cast iron brake shoe.The surface morphology of the friction rings after the wear test of friction block samples of brake shoe made of four kinds of material and friction ring sample of wheel steel were obeserved by scanning electron microscope,the results show that abrasive wear and fatigue wear appear on the surface of friction ring.The wear of the LH2 high friction coefficient composite brake shoe on the wheel steel and the QU70 rail steel on the wheel steel were mainly abrasive wear.The wear of high phosphorus cast iron brake shoe and M type powder metallurgy brake shoe on wheel steel is mainly fatigue wear.The surface elements of the friction ring after the wear test of friction block samples of brake shoe made from four kinds of material and friction ring sample of wheel steel were measured by energy spectrum,the results show that oxidation reac⁃tion occured on the surface of friction ring,and the materials for brake shoe are transferred to the surface of the friction ring made of wheel steel.