摘要
以不同厂家生产的两炉18Cr Ni Mo7-6齿轮钢(标记为IQ-T-1、IQ-T-2)为研究对象,分析了试验钢经亚温淬火-回火(Intercritical quenching and tempering,IQ-T)处理后的显微组织对其力学性能、旋转弯曲疲劳性能和疲劳裂纹扩展行为的影响。结果表明:IQ-T-1试验钢的强度和疲劳强度较IQ-T-2试验钢分别提高了97 MPa和96 MPa,具有更好的力学性能和疲劳性能。IQ-T-1试验钢组织为细小铁素体+小块马氏体+回火马氏体,而IQ-T-2试验钢组织为粗大铁素体+回火马氏体。IQ-T-1试验钢中细小铁素体+小块马氏体使裂纹分枝、裂纹闭合和应力屏蔽现象均更为显著,对裂纹萌生和扩展的阻碍作用更大。
Taking 18 CrNiMo7-6 gear steels(marked as IQ-T-1,IQ-T-2)produced by two different manufacturers as the research object,the effect of microstructure after intercritical quenching and tempering(IQ-T)on the mechanical properties,rotating bending properties and fatigue crack propagation behavior was analyzed.The results show that the IQ-T-1 tested steel has better strength and fatigue properties than that of the IQ-T-2 tested steel,with the strength and fatigue strength increased by about 97 MPa and 96 MPa respectively.The microstructure of the IQ-T-1 tested steel is composed of fine ferrite+small martensite+tempered martensite,while that of the IQ-T-2 tested steel is composed of coarse ferrite+tempered martensite.Fine ferrite+small martensite in the IQ-T-1 tested steel make the crack branching,crack closure and stress shielding phenomena more significant,giving rise to more inhibition of crack initiation and propagation.
作者
李云昆
周芸
时捷
尉文超
何肖飞
胡芳忠
王毛球
Li Yunkun;Zhou Yun;Shi Jie;Yu Wenchao;He Xiaofei;Hu Fangzhong;Wang Maoqiu(Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China;Institute for Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China;Technical Center,Maanshan Iron and Steel Company Limited,Maanshan Anhui 243000,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2020年第11期19-25,共7页
Heat Treatment of Metals
基金
国家重点研发计划(2016YFB0300102)。
关键词
亚温淬火
显微组织
旋转弯曲疲劳
裂纹扩展
闭合效应
intercritical quenching
microstructure
rotating bending fatigue
crack propagation
crack closure effect
