CAJ | 학술논문

为能够对材料的疲劳失效有更加科学的预测，采用Instron 8803液压伺服疲劳机对45#钢在±0.5%，±1.0%，±1.2%，±1.5%，±2.0%5个应变幅值下进行低周疲劳试验，对疲劳试验数据进行分析，并对寿命预测模型进行验证评测，发现三参数幂函数能量法具有更加广泛的适用性；使用Hitachi S-3400N扫描电镜观察比较不同应变幅下疲劳断口微观形貌，分析裂纹源形成原因及扩展趋势；用Matsuzawa显微硬度计测量疲劳断口截面径向及轴向硬度值变化，以评测循环加载对疲劳特征区强化程度的差异，发现断口径向硬度值沿近中心位置至边缘呈波动递增趋势，而轴向硬度值随与断口的距离增大变化不大，且经过疲劳强化后，断口径向截面平均硬度明显高于原始状态。
위능구대재료적피로실효유경가과학적예측，채용Instron 8803액압사복피로궤대45#강재±0.5%，±1.0%，±1.2%，±1.5%，±2.0%5개응변폭치하진행저주피로시험，대피로시험수거진행분석，병대수명예측모형진행험증평측，발현삼삼수멱함수능량법구유경가엄범적괄용성；사용Hitachi S-3400N소묘전경관찰비교불동응변폭하피로단구미관형모，분석렬문원형성원인급확전추세；용Matsuzawa현미경도계측량피로단구절면경향급축향경도치변화，이평측순배가재대피로특정구강화정도적차이，발현단구경향경도치연근중심위치지변연정파동체증추세，이축향경도치수여단구적거리증대변화불대，차경과피로강화후，단구경향절면평균경도명현고우원시상태。
In order to predict the fatigue failure of materials more scientifically, an Instron 8803 hydraulic-servo fatigue-testing machine is used to study the low-cycle fatigue behavior of stainless steel 45# at strain amplitudes ±0.5%, ±1.0%, ±1.2%, ±1.5% and ±2.0%. After analyzing the variation in mechanical behavior and evaluating the life prediction model,it was found that three-parameter power function was more applicable. At the micro scale, each area of damage failure is shown by using a Hitachi S-3400N scanning electron microscope to compare different figures and to discover crack initiation points and crack propagation trend. The hardness varying in both radical and longitudinal directions near the fatigue break area is measured with a Matsuzawa microhardness tester to study the difference between fatigue characteristic areas after cyclic loading. It is found that the hardness increased from the center to the edge along the radial direction and the hardness remained almost the same along the longitudinal direction. After the fatigue test, the average hardness of radical fracture section was significantly higher than that of the original state.