成分设计与热处理对轴承钢组织与性能的影响

Effect of Composition Design and Heat Treatment on Microstructure &Mechanical Properties of Bearing Steel

采用成分设计与热处理相结合的方法,对G20Cr2Ni4轴承钢的组织与性能进行了研究。结果表明,距表面越远,3种轴承钢的碳含量均呈逐渐降低的趋势,渗碳层深度约为1.5 mm,表层区域的碳含量约为0.85～0.90%。以HV550所在位置作为有效硬化层深度评判依据,G20Cr2Ni4SiMo钢的有效硬化层深度高于G20Cr2Ni2SiMoAl钢,两种轴承钢盐浴等温淬火后表层组织均为针状贝氏体+少量残余奥氏体,而G20Cr2Ni4轴承钢的组织为马氏体。盐浴等温淬火热处理后G20Cr2Ni4SiMo轴承钢综合力学性能最佳。

The microstructure and mechanical properties of G20Cr2Ni4 bearing steel were studied by combining component design and heat treatment.The results show that with the increase of the distance from the surface,the carbon content of the three kinds of bearing steels is gradually decreasing,the depth of the carburizing layer is about 1.5 mm,and the carbon content in the surface area is about 0.85～0.90%.The effective hardening layer depth of the G20Cr2Ni4 SiMo bearing steel is higher than the G20Cr2Ni2 SiMoAl bearing steel based on the position of HV 550 as the depth of the effective hardening layer,the surface microstructures of G20Cr2Ni4 SiMo and G20Cr2Ni2 SiMoAl bearing steel after isothermal quenching of salt bath are acicular bainite and a small amount of retained austenite,and the microstructure of G20Cr2Ni4 bearing steel is martensite.After isothermal quenching of salt bath,G20Cr2Ni4 SiMo bearing steel has the best comprehensive mechanical properties.