改进型M50高温用轴承钢的设计与研发  

Design and development of improved M50 high-temperature bearing steel

作　　者：杨平[1] 罗海文[1] Yang Ping;Luo Haiwen(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学冶金与生态工程学院

出　　处：《金属热处理》2018年第8期1-7,共7页Heat Treatment of Metals

摘　　要：分析了高温轴承用M50钢中碳化物粗大的原因,为降低V偏析和MC一次碳化物的析出数量,通过热力学计算重新设计了成分并进行了试制。通过电解萃取方法,研究了新钢种在热锻、等温退火后碳化物的类型、尺寸和成分,并检测了该钢在淬火、回火热处理后的硬度。结果表明：新设计钢种在退火后存在M23C6、M6C、M2C三种碳化物,平均尺寸为0.45μm,最大不超过5.3μm;未检测到MC,球状碳化物M23C6增多;经过淬火、回火处理后,新设计钢的室温硬度不低于64 HRC,400℃下高温硬度不低于60 HRC,完全符合高温轴承的服役要求。Formation of coarse carbide in the conventional M50 bearing steel for service at high temperature was analyzed.The composition of M50 steel was redesigned in order to reduce the segregation of V and the precipitation of coarse MC carbide via thermodynamic calculation,and the steel with the new composition was trial produced.The type,size and composition of carbides in the new steel after both hot forging and annealing were examined after electrolytic extraction.The hardness of new steel after quenching and tempering was measured.The results show that there are 3 types of carbides,including M23C6,M6C and M2C after annealing.Their average size is about 0.45μm and the maximum size is about 5.3μm.Compared with the carbide particles in the conventional M50 steel,no MC but more M23C6carbide particles are observed.After quenching and tempering,the hardness of new steel at both room temperature and 400℃are higher than 64 HRC and60 HRC respectively.The above results fully satisfies the requirements of high temperature bearing.

关 键 词：高温轴承 热力学计算 碳化物 硬度 

分 类 号：TG142.7[一般工业技术—材料科学与工程]