摘要
为研究表面微损压痕对典型核电材料低周疲劳性能的影响。采用MTS810-100 kN型电液伺服材料试验机研究了Inconel 718、304不锈钢及10Cr9Mo1VNb三种核电材料在室温及±0.3%~±0.5%应变幅下预制压痕前后的低周疲劳性能,并利用扫描电子显微镜(SEM)对试样进行断口分析。结果表明:预制压痕未明显影响3种材料的低周疲劳性能,其中Inconel 718疲劳寿命始终最高。不同应变幅下预制压痕对304不锈钢的疲劳条带间距无明显影响,说明预制压痕不会促进疲劳裂纹扩展。±0.4%应变幅低周疲劳试验后,Inconel 718试样断口表面的疲劳条带间距小于1μm,而另两种材料达到3~5μm。本研究揭示了小尺度表面损伤不主导疲劳寿命的机理,为优化核电材料构件在实际工程中的在役检测资源分配和延寿评估提供了试验依据。
To investigate the influence of surface micro-defect indentations on the low-cycle fatigue(LCF)performance of typical nuclear power materials,an MTS810-100 kN electrohydraulic servo material testing machine was used to study the low-cycle fatigue properties of three nuclear materials—Inconel 718,304 stainless steel,and 10Cr9Mo1VNb—before and after introducing pre-indentations,under room-temperature conditions and at strain amplitudes ranging from±0.3%to±0.5%.Fractographic analysis of the specimens was conducted via scanning electron microscopy(SEM).The results show that pre-indentations did not significantly alter the LCF properties of any material,with Inconel 718 consistently exhibiting the highest fatigue life.At different strain amplitudes,pre-indentations had no noticeable effect on the fatigue striation spacing of 304 stainless steel,indicating that such indentations do not promote fatigue crack propagation.After LCF testing at a strain amplitude of±0.4%,the fatigue striation spacing on the fracture surface of Inconel 718 specimens was less than 1μm,while that of the other two materials reached 3~5μm.This study reveals the mechanism by which small-scale surface damage does not dominate fatigue life and provides an experimental basis for optimizing in-service inspection resource allocation and life-extension assessments of nuclear material components in practical engineering applications.
作者
胡明磊
陈乐
文杰
胡斌
洪晓峰
宁方强
李红军
Hu Minglei;Chen Le;Wen Jie;Hu Bin;Hong Xiaofeng;Ning Fangqiang;Li Hongjun(CNNP Operation Management Co.,Ltd.,Haiyan,Zhejiang,314300,China;National Key Laboratory of Nuclear Reactor Technology,Nuclear Power Institute of China,Chengdu,610213,China;School of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao,Shandong,266590,China)
出处
《核动力工程》
北大核心
2025年第S2期151-157,共7页
Nuclear Power Engineering
基金
国家自然科学基金(12202426,U21B2058)。
