45#车轴钢疲劳性能试验研究  

Experimental Study on the Fatigue Properties of 45# Axle Steel

作　　者：黄国[1] 黄海明[1] 王超[1] 李玮洁[1] 

机构地区：[1]北京交通大学工程力学研究所,北京100044

出　　处：《中国铁道科学》2013年第4期71-76,共6页China Railway Science

基　　金：国家自然科学基金资助项目(11272042)

摘　　要：通过非金属夹杂物检验和室温拉伸试验,在确保材料的冶金质量和力学性能符合标准要求的基础上,进行旋转弯曲疲劳试验和断口分析,对45#车轴钢的疲劳性能进行研究。结果表明:与光滑试件相比,带有深度为0.75mm缺口的试件,其疲劳极限应力降低44%,其S—N曲线左段部分的斜率更大;其缺口敏感系数为0.79;表面应力集中是导致光滑试件萌生疲劳裂纹的原因;在有缺口的试件断口截面上存在多个疲劳源区,裂纹萌生在缺口的前缘,而且主要是由于缺口处应力集中所致;较大尺寸的非金属夹杂物也是导致车轴钢可能产生疲劳裂纹的启裂源。In the non-metallic inclusion inspection quality and mechanical properties of materials were and tensile test at room temperature, the metallurgy checked whether they were up to standards. And then the fatigue properties of 45# axle steel were studied by rotary bending fatigue testing method and fracture analysis. The results show that, compared with smooth specimen, the fatigue limit of notched specimens with the notch depth of 0. 75 mm is decreased 44%, and the left slope of its S-N curve is greater than that of the smooth. The sensitive coefficient of notched specimen is 0.79. Moreover, the initiation of fatigue cracks in the smooth specimen is due to the stress concentration on the surface of specimen. There are multi-source areas of fatigue on the cross sections of the notched specimens and the cracks initiate at the lip of the notch, which is mainly caused by the stress concentration at the notch. In addition, larger size non-metallic inclusions may also lead to the initiation of fatigue cracks in axle steel.

关 键 词：车轴钢 性能试验 疲劳极限 S—N曲线 断口分析 

分 类 号：U272[机械工程—车辆工程] U270.331.1[交通运输工程—载运工具运用工程]