【摘要】 目的建立喷丸强化模型,模拟点式移动感应淬火零件过渡区残余拉应力改善情况。方法采用X射线衍射法,测量感应淬火零件过渡区残余应力分布情况,获得的残余应力作为初始应力条件被赋予到喷丸强化模型中,并通过X射线残余应力测试验证模型预测残余应力的准确性。最终通过被验证的喷丸强化模型,探究喷丸处理对初始残余应力状态的改善情况,以及不同喷丸参数对残余应力分布的影响。结果经喷丸强化处理过的淬火零件过渡区表层区域残余拉应力全部转变为残余压应力,不同残余应力状态模型喷丸后残余应力分布差异极小,说明初始残余应力状态对喷丸后残余应力分布的影响微乎其微。增加喷丸速度、弹丸直径和喷丸覆盖率可使残余压应力值增大,残余压应力层深增加,但是二者的增加存在饱和现象,即达到一定程度后变化非常小。结论喷丸强化前,过渡区残余拉应力最大值为295 MPa,喷丸处理后,过渡区残余压应力最大可达-973 MPa,喷丸强化工艺对点式移动感应淬火零件过渡区残余应力改善效果明显。更多还原

【Abstract】 The work aims to simulate improvement of residual tensile stresses in transitional area of the spot continual induction hardening(SCIH) components by establishing shot peening(SP) model. Distribution of residual stresses induced by SIH was measured in the method of X-ray diffraction, and resulting residual stresses were assigned to the SP model as initial residual stresses. The X-ray residual stress test was performed to verify accuracy of SP model-based residual stress prediction. Finally, the verified SP model was used to study improvement effect of SP on initial tensile residual stresses in transitional area and influences of SP parameters on the distribution of residual stresses. The tensile residual stresses in transitional area on the surface were transformed into compressive residual stresses after SP treatment. The difference in residual stress distribution of the model was very small after SP treatment in different residual stress states, which indicated that the residual stresses introduced by the previous process had little effect on the distribution of residual stress after SP. Increase in shot velocity, shot diameter and peening coverage could lead to increase in both compressive residual stresses and depth of compressive residual stresses. However, increase of the two was saturated, which meant that the values changed slightly after reaching a certain level. The maximum tensile residual stress in transitional area is 295 MPa before SP and-973 MPa after SP, which indicates that SP can improve distribution of tensile residual stresses in the transitional area of SCIH components efficiently.更多还原