论文部分内容阅读
本文论述了轧机轴承采用锻后喷雾冷却、快速球化工艺,在碳化物细化基础上,通过不同等温热处理方法,使在马氏体基体上获得贝氏体(B)及残留奥氏体(A_R)复合组织的强韧化方法。研究了显微组织对轴承钢强韧性及疲劳裂纹萌生期的影响。试验结果表明,在高于Ms点经一定时间等温,得到(M+B)复合组织,由于先析贝氏体分割及细化马氏体组织,具有最佳的强韧性及抗疲劳裂纹形成性能。在低于Ms点经适当时间等温,得到较高残留奥氏体量的(M+A_R)组织,其强韧性及抗疲劳裂纹形成性能均高于回火马氏体,但低于(M+B)复合组织。本文对不同显微组织及其相应断口形貌进行了讨论。
This paper discusses the mill bearing spray forging cooling, rapid nodular process, on the basis of carbide refinement, through different isothermal heat treatment methods, so that the martensite matrix to obtain bainite (B) and residual austenite Body (A_R) composite organization of toughening method. The effect of microstructure on the toughness and fatigue crack initiation of bearing steel was studied. The experimental results show that the (M + B) composite microstructure is obtained when isothermally higher than the Ms point for a certain period of time, and has the best toughness and anti-fatigue crack formation performance due to the first analysis of the bainite and the thinning of the martensite structure . The microstructure of (M + A_R) with higher residual austenite content at isothermal temperature lower than Ms isothermal is higher than that of tempered martensite but lower than (M + B) Complex tissue. This article discusses the different microstructures and their corresponding fracture morphology.