使用旋转弯曲疲劳试验机进行了中碳钢10^9cyc的疲劳实验,分析了直径100μm的钢球和陶瓷球喷丸处理后材料的疲劳性能及实验过程中残余应力的稳定性.与未喷丸试样相比,2种微粒子喷丸试样的疲劳极限分别提高了35%和23%.根据实验过程中对残余应力的跟踪测试,详细分析了残余应力松弛的过程及机理,阐述了疲劳极限提高机理及其控制因素.
In order to analyze the fatigue property and residual stress relaxation process of microshot peened medium carbon steel, the 10^9 cyc fatigue tests of the specimens unpeened and shot peened by steel balls and ceramics balls with 100 pm in diameter were carried out by rotary bending fatigue machine in air at room temperature. The result shows that the fatigue limits of specimens peened by steel balls and ceramics balls are improved by 35% and 23% respectively, compared with that of unpeened specimen. Based on the test result of the residual stress in the fatigue process, the process and mechanism of residual stress relaxation are analyzed in detail. The cyclic yield strength of the material is the main factor eontroled the improvement level of the fatigue limit.