GCr15及G20CrNi2Mo轴承钢高温润滑条件下摩擦磨损性能

Friction and Wear Properties of GCr15 and G20CrNi2Mo Bearing Steels under High Temperature Lubrication

为了探究轴承钢在高温润滑条件下的摩擦磨损性能,采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、洛氏硬度计等对GCr15高碳轴承钢和G20CrNi2Mo渗碳轴承钢组织、物相及硬度进行了表征,利用QG-700型气氛高温摩擦磨损试验机研究轴承钢材料不同条件下的高温润滑摩擦磨损性能,并分析其磨损机制。结果表明:2种轴承钢的组织主要为马氏体、碳化物和残余奥氏体,其中G20CrNi2Mo渗碳轴承钢的表层硬度高于GCr15高碳钢轴承钢;在高温润滑条件下,2种轴承钢的磨损率都随着载荷和摩擦速度的增加而增大;GCr15轴承钢的平均摩擦因数随着载荷和摩擦速度的增加逐渐降低,而G20CrNi2Mo轴承钢的平均摩擦因数随载荷的增加而降低,随摩擦速度的增加而变化不大。G20CrNi2Mo渗碳轴承钢的耐磨性能总体优于GCr15高碳轴承钢,这与渗碳轴承钢的高硬度和具有回火稳定性的渗层有关;2种轴承钢高温润滑条件下的磨损机制是主要为磨粒磨损和氧化磨损。

In order to investigate the friction and wear performance of bearing steels under high temperature lubrication conditions,the microstructure,phase and hardness of GCr15 high-carbon bearing steel and G20CrNi2Mo carburizing bearing steel were analyzed by the scanning electron microscope(SEM),X-ray diffraction(XRD)and hardness tester,etc.The friction and wear properties of high temperature lubrication of the bearing steels under different conditions were studied by QG-700 friction and wear tester,and the wear mechanism was analyzed.The results show that the microstructures of the two bearing steels are mainly Martensite,carbide and retained Austenite.The surface hardness of G20CrNi2Mo carburizing bearing steel is higher than that of GCr15 high-carbon steel.The wear rate of two kinds of bearing steels increases with the increase of load and friction speed under high temperature lubrication.The average friction coefficient of GCr15 bearing steel decreases with the increase of load and friction speed,while the average friction coefficient of G20CrNi2Mo bearing steel decreases with the increase of load,but changes little with the increase of friction speed.The wear resistance of G20CrNi2Mo carburized bearing steel is generally better than that of GCr15 high carbon bearing steel,it is because that the carburized bearing steel has high hardness and has the carburized layer with tempering stability.The wear mechanisms of two kinds of bearing steels under high temperature lubrication conditions are abrasive wear and oxidation wear.