Zenan Chu and Qiang He*
Background: The Cr4Mo4V steel is widely used in high temperature bearings because of its excellent high temperature performance. According to the research status of Cr4Mo4V at home and abroad, this paper explores its mechanical properties and friction properties at high temperatures.Objective: To characterize the composition, microstructure and properties of Cr4Mo4V steel and to explore its tensile properties, hardness and friction properties at high temperature. Methods: Many methods are adopted, such as chemical element analysis, metallographic analysis, hardness test, tensile test, damping test, friction test and so on. Results: The microstructure of Cr4Mo4V is tempered martensite. The hardness and maximum tensile strength of Cr4Mo4V decrease with temperature increasing. The grain of the Cr4Mo4V steel after heating gets refined and the grain boundary increases. At room temperature, the surface friction coefficient and wear rate of Cr4Mo4V steel decreases. Moreover, Cr4Mo4V steel-ceramic ball shows the best friction resistance. At high temperature, the friction coefficient and the wear of Cr4Mo4V steel firstly decrease with temperature increasing and then increase sharply at 200°C. Conclusion: With the increase of temperature, the hardness, breaking force and tensile strength of Cr4Mo4V bearing steel decrease, whereas the friction property increases. By analyzing the three-dimensional morphology of different wear samples, the optimal working temperature of Cr4Mo4V steel for bearing is 200°C.
Cr4Mo4V steel, high temperature, chemical composition, tensile stress, friction, damping test.
Department of Mechanical Engineering, Anyang Institute of Technology, Anyang, Henan Province, Department of Mechanical Engineering, Anyang Institute of Technology, Anyang, Henan Province