文献类型：期刊文献

中文题名：缺口和环境对Custom450钢高周疲劳强度的影响

英文题名：Effects of Notch and Environment on High Cycle Fatigue Strength of Custom450 Steel

作者：金龙[1];朱明亮[1];轩福贞[1]

机构：[1]华东理工大学机械与动力工程学院承压系统与安全教育部重点实验室,上海200237

年份：2018

卷号：35

期号：5

起止页码：1

中文期刊名：压力容器

外文期刊名：Pressure Vessel Technology

收录：CSTPCD;;北大核心:【北大核心2017】；

基金：国家自然科学基金项目(51575182)

语种：中文

中文关键词：蒸汽环境;缺口;高周疲劳;疲劳强度;疲劳缺口系数;应力集中系数

外文关键词：steam environment;notch;high cycle fatigue;fatigue strength;fatigue notch factor;stress concentration factor

摘要：通过开展室温空气和低氧蒸汽环境下Custom450叶片钢光滑和缺口试样的轴向疲劳试验,分析环境和缺口对疲劳强度、裂纹萌生机制和缺口敏感性的影响,讨论疲劳缺口系数K_f的理论计算模型。结果表明,缺口和低氧蒸汽环境均可显著降低试样的疲劳强度,但较高的应力集中系数的缺口(K_t=2.53)对疲劳强度的影响更大;环境对疲劳强度的弱化作用主要表现在裂纹表面起裂,但随循环周次提高、因发生内部起裂而逐渐减弱。同时,缺口和环境的交互作用,使K_f值超过应力集中系数K_t,表明K_f受到环境较大的影响,使用现有经验计算公式会得到不保守的结果。
Axial push-pull fatigue tests using both smooth and notched specimens of Custom450 were carried out under the environment of room temperature air and low-oxygen steam. The effects of environment and notch on fatigue strength,crack initiation mechanism and notch sensitivity were analyzed; and the theoretical calculation model of fatigue notch factor Kf was discussed. The results show that both the notch and low-oxygen steam environment can reduce fatigue strength of the specimens significantly,though the notch with higher stress concentration（ Kt= 2. 53） has greater effect; the degradation effect of environment on fatigue strength is mainly exhibited as crack initiation from specimen surface,but slightly decreases with the increase of the cycles due to crack initiation within the specimen. At the same time,the interaction of environment and notch leads to higher Kf value than stress concentration factor,Kt,showing that Kf is influenced by the environment relatively greatly,and non-conservative results will be obtained using the existing empirical formulas.