弹丸对喷丸强化效果的影响

Effect of shot on shot peening

为了研究喷丸强化工艺中弹丸类型对疲劳性能的影响规律,设计了应力集中系数为1.5的单细节结构疲劳试验件,分别采用陶瓷丸和不同尺寸的铸钢丸在低、中、高强度下对7055-T7451铝合金试验件进行喷丸强化和疲劳性能测试,通过细节疲劳额定值(DFR)方法对试验数据进行处理和分析,获取试验件喷丸强化后疲劳性能的增益。结果表明:喷丸强化可以明显提高材料的疲劳寿命,疲劳增益为9%~57%;喷丸强化采用的弹丸类型对试验件疲劳增益有明显的影响;同样强度下,陶瓷丸喷丸强化效果优于铸钢丸;弹丸种类相同时,小尺寸弹丸喷丸强化效果优于大尺寸弹丸;陶瓷丸喷丸强度对疲劳性能的影响规律表现为抛物线形,即随着喷丸强度的增加,疲劳性能先增加后减少。

In order to study the influence of shot type on fatigue performance in shot peening,a single detail structure fatigue test piece with a stress concentration coefficient of 1.5 was designed.Ceramic shot and cast steel shot of different sizes were used for shot peening of 7055-T7451 aluminum alloy test pieces at low,medium,and high strength,and fatigue performance testing was conducted.The test data was processed and analyzed using the detail fatigue rating(DFR)method to obtain the gain in fatigue performance of the test piece after shot peening.The results show that shot peening can significantly improve the fatigue life of materials,which can increase by 9%~57%.The type of shot used for shot peening has a significant impact on the fatigue gain of the test piece.Under the same strength,the effect of ceramic shot peening is better than that of cast steel shot.When the types of shot are the same,the effect of small size shot peening is better than that of large size shot peening;The effect of ceramic shot peening strength on fatigue performance exhibits a parabolic shape,which means that the fatigue performance first increases and then decreases with the increase of shot peening strength.