摘要
贝/马复相钢具有较低的夹杂物敏感性,组织因素对其超高周疲劳性能具有显著影响。组织因素引起的"非夹杂起裂"成为贝/马复相钢重要的裂纹萌生方式,贝/马复相组织的类型、形态、均匀性、细化程度等都对钢的超高周疲劳性能具有显著影响。讨论了组织纯净化、组织细化和残余奥氏体对贝/马复相钢超高周疲劳性能及其裂纹萌生机制的影响,在合理控制夹杂物水平的基础上,调控复相组织,可以在1 600MPa级别的贝/马复相钢中,获得超高周(循环周次大于108)疲劳强度达到900MPa的优异性能。同时对非夹杂起裂机理进行了初步探讨。
In order to improve the fatigue properties of the steel component used in high speed railway and oil exploration,the bainite/martensite(B/M)multiphase high strength steels with excellent fatigue properties have been developed.Many results showed that the very high cycle fatigue(VHCF)property of B/M steels is less sensitive to the inclusion than that of conventional tempered martensite steels.Hence,both non-inclusion and inclusion-induced crack initiations occurred in the B/M steels under VHCF test.The microstructure morphologies,i.e.,phase types,microstructure homogeneity and refinement degree,could influence the non-inclusion induced crack initiation.The VHCF crack initiation sites are determined by the competition between the inclusion level and the microstructure morphologies of the B/M steels.Enhanced VHCF properties of B/M steels have been achieved through coordinated adjustment of physical and/or chemical metallurgy treatment(e.g.,microstructure optimization and inclusion size reduction).The mechanism of non-inclusion induced crack initiations is also discussed.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2017年第20期48-52,共5页
Materials Reports
基金
国家自然科学基金面上项目(51271013)
中央高校基本科研业务费(2014JBM101)
关键词
贝氏体
超高周疲劳
非夹杂起裂
复相组织
高强度合金钢
组织纯净化
组织细化
残留奥氏体
bainite
very high cycle fatigue
non-inclusion induced crack initiation
multiphase microstructure
high-strength alloy steel
purification
grain refinement
retained austenite
