摘要
本文研究了 40CrMnSiMoA 钢中准贝氏体组织和马氏体组织的缺口疲劳强度。结果表明,与马氏体组织相比,由贝氏体铁素体和残余奥氏体组成的准贝氏体组织,其缺口疲劳强度较高。准贝氏体组织较低的强度及其中较多的残余奥氏体,并不损害其疲劳强度。相反,由于该组织具有良好的强度、塑性、韧性配合,使其疲劳缺口敏感性较低。拉伸超载同时提高准贝氏体和马氏体组织的缺口疲劳强度。
In present paper the notch fatigue strength of meta-bainite and martensite in 40CrMnSiMoV steel is studied.The result shows that the notch fatigue strength of the meta-bainite consisting of bainitic ferrite and retained auste-nite is higher than that of martensite.The lower σ_(0.2) value and larger retain-ed austenite of meta-bainite may not lower the fatigue strength of the micro- structure.Relatively,the fatigue notch sensitivity of the meta-bainite is low due to its good combination of strength,ductivity and toughness.The ten-sional overload increases the notch fatigue strength of both microstructures in the steel.
