高氮轴承钢高温疲劳性能与裂纹萌生扩展机理  

High temperature fatigue properties and crack initiation and its expansion mechanism of high nitrogen bearing steel

作　　者：张志慧[2] 杨卯生[2] 孙世清[1] 李建新 罗志强[2] 李南[2] ZHANG Zhi-hui;YANG Mao-sheng;SUN Shi-qing;LI Jian-xin;LUO Zhi-qiang;LI Nan(School of Materials Science and Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,Hebei,China;Institute of Special Steel,Central Iron and Steel Research Institute,Beijing 100081,China;Northeast Special Steel Group Co.,Ltd.,Fushun 113001,Liaoning,China)

机构地区：[1]河北科技大学材料科学与工程学院,河北石家庄050018 [2]钢铁研究总院特钢所,北京100081 [3]抚顺特殊钢股份有限公司技术中心,辽宁抚顺113001

出　　处：《钢铁研究学报》2018年第7期555-562,共8页Journal of Iron and Steel Research

基　　金：国家863计划资助项目(2012AA03A503)

摘　　要：200℃下,40Cr15Mo2VN高氮轴承钢旋转弯曲疲劳性能测试结果表明其安全疲劳极限强度为883MPa,较室温条件下降了17%。通过SEM疲劳断口观察发现,疲劳破坏类型主要为表面缺陷起裂和内部非金属夹杂物起裂。与室温相比,200℃条件下疲劳应力强度因子门槛值ΔKth下降了20%,导致疲劳裂纹起始的临界非金属夹杂物尺寸减小;200℃条件下表面起裂中疲劳源附近细小裂纹的相互作用使得应力强度因子KI增加,加速表面初始裂纹扩展。同时,根据高氮轴承钢中非金属夹杂物所在位置的名义应力幅度与缺陷疲劳极限强度的比值,分析了非金属夹杂物尺寸、位置及温度对疲劳寿命的影响。The flexural fatigue properties of 40 Cr15 Mo2 VN high nitrogen bearing steel at 200℃ was 883 MPa,which was 17%lower than that at room temperature.The results show that the types of fatigue failure are surface failure initiation and internal non-metallic inclusion.Compared with room temperature,the threshold value of fatigue stress intensity factorΔKthat 200℃ decreases by 20%,leading to the reduction of the critical non-metallic inclusion size at the start of fatigue crack initiation.The interaction of small cracks near the fatigue source in the surface initiation cracks at 200℃ increases the stress intensity factor KIand accelerates the initial surface crack propagation.At the same time,according to the ratio of the nominal stress amplitude and the ultimate fatigue strength of the non-metallic inclusions in the high-nitrogen bearing steel,the influence of the size,position and temperature of the non-metallic inclusions on the fatigue life was analyzed.

关 键 词：高氮轴承钢 旋转弯曲疲劳 高温 非金属夹杂物 表面缺陷 

分 类 号：TG142.1[一般工业技术—材料科学与工程]