本文研究了循环热处理或之后再加表面形变强化对中碳合金结钢疲劳强度的影响,对滚压形变后表面残余应力的分布进行了测定,用电子显微镜对断口形貌特征和组织结构的变化进行了观察,并探讨了这种复合强化的机理。结果指出:复合强化是一种充分发挥材料疲劳强度潜力的有效途径;其强化机理为表面强化效应及品粒细化效应相结合。 In this paper, the effects of cyclic heat treatment or after surface deformation strengthening on the fatigue strength of medium carbon alloy steel were studied. The distribution of surface residual stress after rolling deformation was measured. The changes of the morphology and structure of the fracture were observed by electron microscope The observations were made and the mechanism of this strengthening was discussed. The results show that: composite strengthening is an effective way to give full play to the potential of material fatigue strength; its strengthening mechanism is the combination of surface strengthening effect and grain refinement effect.