喷丸强化对材料旋转弯曲疲劳强度影响的定量研究

以往的工作已经提出了金属表面及内部疲劳极限的新概念，成功地分析了喷丸对三点弯曲（应力比Ｒ＝０．０５）条件下材料疲劳强度的影响。本文采用３００Ｍ钢研究了喷丸强化对旋转弯曲疲劳强度的影响。结果表明，经适当表面强化后，疲劳裂纹萌生于试样的次表层，萌生疲劳裂纹的；陆界应力（称内部疲劳极限）为未经喷丸强化试样疲劳极限（称表面疲劳极限）的１．３９倍，表明内部疲劳极限理论在旋转弯曲条件下仍然有效。

Quantitative Investigation of Influence of Shot Peening Upon the Rotating Bending Fatigue Strength of Material

ffect of shot peening on the fatigue strength under rotating bending condition was investigated with 300M steel.The result shows that the fatigue crack of the spoci mens with an appropriate shot peen ing con-dition intiates in the subsurface and the critical stress to initiate the crack(internal fatigue limit)is about 1.39 times of the fatigue limit of the corresponding unpeened speccmen(Surface fatigue limit).