激光冲击强化冲击次数对8Cr4Mo4V钢表面状态和力学性能的影响

Effect of Laser Shock Peening Impact Times on the Surface Condition and Mechanical Properties of 8Cr4Mo4V Steel

为了研究激光冲击强化(LSP)不同冲击次数对8Cr4Mo4V钢表面状态和力学性能的影响,采用激光器对8Cr4Mo4V钢表面进行激光冲击强化,并且借助光学显微镜、扫描电子显微镜(SEM)、粗糙度测量仪、显微硬度仪、残余应力检测仪及旋转弯曲疲劳试验机对不同冲击次数的8Cr4Mo4V钢试样的表面状态和力学性能进行表征。结果表明:随着冲击次数的增加,经LSP处理后的8Cr4Mo4V钢表面冲击痕迹占比逐渐增大,最大可占比11.28%,冲击次数超过3次可对8Cr4Mo4V钢造成凹坑损伤;LSP后的8Cr4Mo4V钢表面显微硬度最大可提升4.8%,表面残余压应力最大可达870 MPa,疲劳极限可提升47.30%。

In order to study the effect of different laser shock peening(LSP)impact times on the surface state and mechanical properties of 8Cr4Mo4V steel,LSP is performed on the surface of 8Cr4Mo4V steel using a laser.With the help of optical microscope,scanning electron microscope(SEM),roughness measuring instrument,microhardness tester,residual stress tester and rotary bending fatigue tester are used to characterize the surface state and mechanical properties of 8Cr4Mo4V steel specimens with different numbers of impacts.The results show that with the increase of the number of impacts,the percentage of surface impact marks on the LSP-treated 8Cr4Mo4V steel increases gradually,and the maximum can be 11.28%,and the number of impacts more than 3 times can cause crater damage to the 8Cr4Mo4V steel.8Cr4Mo4V steel surface microhardness after LSP can be increased by 4.8%,the maximum surface residual compressive stress can be 870 MPa The fatigue limit can be increased by 47.30%.