摘要
为探究压水堆核电站一回路主管道用不锈钢长期在服役过程中冲击性能的变化规律,本文将Z3CN20-09M钢经模拟工况介质(400℃、16.5 MPa含硼离子水蒸气)分别加速热老化3 000h、5 000h、10 000h、15 000h后进行示波冲击试验,利用扫描电子显微镜对冲击断口进行分析.试验结果表明:随着热老化时间的延长,试样的屈服力F_(gy)、最大力F_m、不稳定裂纹扩展起始力F_(iu)均表现为逐渐增大,试样的不稳定裂纹扩展起始功W_(iu)、不稳定裂纹扩展终止功W_a、冲击总功W_t逐渐降低,裂纹扩展功W_t-W_(iu)降低幅度较小.当热老化时间超过10 000h后,试样的上述性能指标变化幅度趋缓,出现老化饱和迹象.试样的断裂方式由具有拉长韧窝特征的微孔聚集型韧性断裂逐渐转变为具有解理台阶和撕裂棱特征的准解理断裂.
The paper is aimed to explore the change in the impact properties of stainless steel for the main pipe of the primary loop in a PWR nuclear power plant during its long service.The thermal ageing process of Z3CN20-09M steel was accelerated for 3 000 h,5 000 h,10 000 h and 15 000 h in a simulated working medium(400℃,16.5 MPa,water vapor containing boron ions),and then an instrumented Charpy impact test was conducted,in which an SEM was used to analyze the impact fracture morphology.Experimental results show that with the aging time increasing,the yield force F gy,the maximum force F m,and the unstable crack initial force F iu of Z3CN20-09M steel were gradually increasing;its unstable crack extension initial work W iu,unstable crack extension terminal work W a and the total work of impact W t were gradually decreasing;but there was a small decline in the crack extension work W t W iu.When the ageing process exceeded 10 000 hours,the changes of the above mentioned properties slowed down,a sign of thermal aging saturation emerging.With the aging time increasing,the fracture mechanism of the sample changed gradually from the microvoid aggregation fracture with elongated dimples to the quasi cleavage fracture with tear ridges and cleavage steps.
作者
高雨雨
王正品
金耀华
刘志学
要玉宏
GAO Yuyu;WANG Zhengpin;JIN Yaohua;LIU Zhixue;YAO Yuhong(School of Materials Science and Chemical Engineering,Xi’an Technological University,Xi’an 710021,China)
出处
《西安工业大学学报》
CAS
2018年第1期52-57,共6页
Journal of Xi’an Technological University
基金
国家自然科学基金(51371132)
陕西省教育厅重点实验室项目(15JS038)
关键词
Z3CN20-09M不锈钢
模拟工况
热老化
示波冲击试验
断裂机理
Z3CN20-09M stainless steel
working condition of simulated
thermal aging
oscillographic impact
fracture mechanism