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研究了A-100钢单边缺口三点弯曲试样经拉伸超载处理后,冲击疲劳性能的变化。在室温下测得拉伸超载处理前后,冲击能量-冲击疲劳寿命曲线,并对冲击疲劳断口进行微观分析。结果表明:拉伸超载可延长A-100钢的冲击疲劳裂纹起始寿命而对裂纹扩展寿命无影响;试样超载后裂纹源区微观形貌发生变化,缺口根部残余压应力的存在是造成这些变化的主要原因。
The change of impact fatigue property of A-100 steel single-notch notched three-point bending specimen after tensile loading was studied. The impact energy-impact fatigue life curves were measured before and after tensile overloading at room temperature, and the microstructural analysis of impact fatigue fracture was carried out. The results show that: the tensile overload can prolong the impact fatigue crack initiation life of A-100 steel and have no effect on the crack propagation life; the microcosmic morphology of the crack source area changes after the sample is overloaded, and the residual compressive stress at the notch root causes these The main reason for change.