表面压应力对10Ni5CrMoV钢疲劳性能的影响
Effect of Compressive Surface Stress on the Fatigue of 10Ni5CrMoV Steel
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摘要: 分别采用精磨和冲击加工在10Ni5CrMoV钢试样表面形成不同的残余压应力,对具有不同表面压应力的试样进行高周和低周疲劳试验,采用扫描电子显微镜对疲劳断口进行分析,并测试经不同周次高应变幅循环加载后的试样表面应力。结果表明,较高的表面压应力能有效抑制小应力幅下疲劳裂纹在表面的起裂,从而有效的提高了高周疲劳性能;在高应变幅作用下,初始的表面压应力迅速发生松弛而失去对疲劳裂纹在表面起裂的抑制作用,因而对低周疲劳性能无明显影响。Abstract: The residual compressive stresses were introduced into the samples of 10NiSCrMoV steel by grinding or impacting on the surface.High-cycle and low-cycle fatigue tests were carried out on the samples with different stress values.The fatigue fractures were analyzed under scanning electron microscope.The surface stresses of the samples after a number cycles of high-strain fatigue loading were tested.The results indicate that the high compressive surface stress can restrain the rising of the fatigue crack on the surface and improve the high-cycle fatigue capacity of 10Ni5CrMoV steel when the stress amplitude is low.The initial compressive surface stress relaxes and cannot restrain the rising of the fatigue crack on the surface and cannot influence the low-cycle fatigue capacity when the strain amplitude is high.