【摘要】 测定了经不同规范喷丸40Cr钢试样的三点弯曲表象疲劳极限;研究了喷丸后精磨的影响;结合试样表面残余应力场分布及疲劳源所在的位置,分析了其变化规律及机理;探讨了喷丸工艺的优化问题,提出了喷丸残余应力场深度应为奥氏体晶粒平均直径10～15倍的喷丸工艺优化准则;并指出,对重要零件,应在喷丸后进行表面磨削。还提出了应根据材料内部/表面疲劳极限的概念来计算优化喷丸表象疲劳极限的方法。更多还原

【Abstract】 Threepoint bending fatigue limits of shotpeened 40Cr steel specimens were determined and the influence of grinding after shot peening was studied. Their change rules and mechanisms are discussed in relation to the surface residual stress fields and the sites of fatigue crack sources. The technology optimization of shot peening is discussed and a criterion of optimization is proposed, which suggests that the depths of surface compressive residual stress fields produced by shot peening should reach 10～15 times the average diameter of austenite grains and it is better to grind some crucial parts after shot peening. It is also proposed a method to calculate the apparent fatigue limits of specimens shotpeened under optimum conditions according to a concept of "internal/surface fatigue limit".更多还原