SUJ2轴承钢超声疲劳GBF内裂纹扩展规律  

Fatigue crack growth behavior in GBF area of SUJ2 bearing steel in very high cycle regime

作　　者：李永德[1] 郭卫民[1] 徐娜[1] 吴晓峰[1] 时军波[1] 马虹[1] 

机构地区：[1]山东科学院山东省分析测试中心,山东省材料失效分析与安全评估工程技术研究中心,山东济南250014

出　　处：《材料热处理学报》2014年第1期49-54,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金项目(51101094);山东省科学院科技发展基金项目(2011-4)

摘　　要：利用超声疲劳低-高应力两步变幅加载技术研究了JIS SUJ2高强轴承钢疲劳断口上GBF(granular bright facet)内裂纹萌生与扩展规律。结果表明,随外加应力幅增加GBF尺寸减小,固定应力幅下的GBF尺寸为恒定值,与夹杂物尺寸无关;且在固定应力幅下,N f∝A槡inc-8,疲劳寿命N f随着夹杂物尺寸的增加而降低。研究表明,GBF形成于疲劳初期(在105周次左右,相应于小于1%的总寿命),随循环周次的增加,GBF尺寸基本不增加,直至接近最终疲劳寿命时(超过90%总寿命)GBF裂纹快速扩展直到最终尺寸。Fatigue crack initiation and growth behavior in the granular bright facet （GBF） area of a high strength bearing steel SUJ2 were studied by ultrasonic fatigue testing under low-high two step variable loading. The results show that the GBF size reduces with increasing applied stress amplitude, and that the GBF size at a given stress amplitude is a constant which is independent of inclusion size. The fatigue life at a given stress amplitude, which is proportional to -8 power of the inclusion size at the crack origins, reduces with increasing inclusion size. It is shown by two-step variable amplitude loading tests that GBF is formed at the earlier stage of fatigue （approximate 105 cycles corresponding to less than 1% total fatigue life in the regime Nf ≥ 10^7 cycles） and propagates hardly until near to the final life （more than 90% total fatigue life） , and the GBF crack will rapidly propagate to the ultimate size in short time.

关 键 词：轴承钢 超高周疲劳 夹杂物 颗粒状亮区 变幅加载 

分 类 号：TG142.4[一般工业技术—材料科学与工程]