温度对高钴钼不锈轴承钢高周疲劳性能的影响  

Influence of temperature on high cycle fatigue properties of high cobalt molybdenum stainless bearing steel

作　　者：耿思远 杨卯生[2] 赵昆渝[1] GENG Si-yuan;YANG Mao-sheng;ZHAO Kun-yu(College of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093,Yunnan, China;Institute of Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China)

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]钢铁研究总院特殊钢研究所,北京100081

出　　处：《钢铁》2018年第12期77-85,共9页Iron and Steel

基　　金：国家高技术研究发展(863)计划资助项目(2012AA03A503)

摘　　要：为了提高宇航轴承的寿命和可靠性,研究了轴承用高钴钼不锈轴承钢在不同温度下的高周旋转弯曲疲劳性能和失效形式。结果表明,随着温度的升高,试验钢的疲劳极限强度逐渐下降,利用升降法测得25、300、500℃条件下疲劳极限强度分别为927、840、667MPa,与25℃相比,300、500℃条件下疲劳极限强度分别降低了9.4%、28.0%。25℃时裂纹萌生是由表面沟壑导致的应力集中引起的,当温度上升至300℃时,疲劳试样基体硬度下降,在长时间交变应力作用下出现驻留滑移带,并且由于碳化物析出和长大,加速了表面沟壑萌生裂纹的形成。500℃时基体硬度继续下降,使驻留滑移带更容易产生。在热力耦合作用下,疲劳试样边缘析出碳化物,在长时间热作用下碳化物长大,驻留滑移带内碳化物与位错交互作用,在碳化物边缘上萌生微小裂纹。碳化物的析出和长大加速了疲劳裂纹的扩展。In order to improve the service life and reliability of aerospace bearings,the high cycle rotating bending fatigue properties and failure modes of high cobalt molybdenum stainless bearing steel at different temperatures were studied.With the increase of temperature,the fatigue limit strength of steel decreased gradually.The fatigue limit strength of the steel was 927,840 and 667 MPa respectively under the condition of 25,300 and 500 ℃.The fatigue limit strength of the steel was reduced by 9.4% and 28.0% respectively at 300 and 500 ℃.At 25 ℃,the crack initiation was caused by surface ravine resulting in stress concentration.When the temperature rised to 300 ℃,the hardness of the fatigue specimen decreased and the persistent slip bands appeared under the action of long time alternating stress.At 300 ℃,carbides precipitate and growth accelerated crack initiation.At 500 ℃,the hardness of the matrix continued to decline,so that the persistent slip bands were more likely to occur.Under the action of thermomechanical coupling,the carbides on the edge of the fatigue specimen precipitated,and the carbides growed when heated for a long time.The carbides interacted with the dislocation and produced tiny cracks on the edge of the carbides in the persistent slip bands.The precipitation and growth of carbides accelerated the propagation of fatigue cracks.

关 键 词：不锈轴承钢 旋转弯曲疲劳 温度 碳化物 

分 类 号：TG142.71[一般工业技术—材料科学与工程]