本文研究了超高强度40CrMnSiMoVA钢中准贝氏体组织和马氏体组织的疲劳强度。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,其光滑及缺口疲劳强度均较高。准贝氏体组织虽具有较低的强度,但因其中较多的残余奥氏体,结果并不损害其疲劳强度。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 this paper, the fatigue strength of quasi-bainite and martensite in ultra-high strength 40CrMnSiMoVA steel was studied. Compared with the martensite, bainitic ferrite and retained austenite composed of quasi-bainite, the smooth and notched fatigue strength are higher. Quasi-bainitic tissue, though of lower strength, results in no loss of fatigue strength due to the more retained austenite. As the organization has a good strength, plasticity, toughness, fatigue sensitivity to its lower gap. Tensile overloading simultaneously increases the notch fatigue strength of quasi-bainitic and martensitic tissues.