采用喷丸强度分别为0.424 mm和0.576 mm的两种工艺对300M钢进行高强度喷丸强化,从表面完整性、残余应力场、显微硬度及抗疲劳性能等方面研究了高强度喷丸对300M钢的强化效果。结果表明:喷丸强化处理后,300M钢试样喷丸面均被弹坑完全覆盖,表面粗糙度显著提高;喷丸后试样表层形成较高的残余压应力场,表面显微硬度得到提高;喷丸后试样疲劳寿命比喷丸强化前的有小幅提高,较高的表面粗糙度造成的应力集中以及微裂纹的产生是其疲劳寿命没有明显提高的主要原因。

300M steel was strengthened using two kinds of high intensity shot peening process in different intensities of 0.424 mm and 0.576 mm,the strengthening effects were investigated through surface integrity,residual stress field,microhardness and fatigue resistance. Results show that the shot peening surface of 300M steel was completely covered by craters,and the surface roughness raised significantly after shot peening treatment. High strength residual compressive stress fields formed in the sample surfaces,and their microhardness was enhanced. The fatigue life after shot peening increased slightly compared with that before shot peening. The stress concentration caused by high surface roughness and the appearance of microcracks could be used to explain that fatigue life did not increase significantly.