Leak-before-break analysis of thermally aged nuclear pipe under different bending moments

Nuclear Engineering and Technology

Zhaoxi Wang¹  Shilei Li²  Xuming Lv²  Hailong Zhang²  Xitao Wang²  Yanli Wang²  Fei Xue³ 

[1] CPI Nuclear Power Institute, 18 Xizhimen Street, Beijing 100044, China;State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, China;Suzhou Nuclear Power Research Institute, 1788 Xihuan Road, Suzhou 215004, China;

关键词: Circumferential cracked pipe;    Leak-before-break;    Leak-before-break assessment diagram;    Leak-before-break curve;    Thermal aging;   

DOI  :  10.1016/j.net.2015.05.006

来源: DOAJ

【 摘 要 】

Cast duplex stainless steels are susceptible to thermal aging during long-term service at temperatures ranging from 280°C to 450°C. To analyze the effect of thermal aging on leak-before-break (LBB) behavior, three-dimensional finite element analysis models were built for circumferentially cracked pipes. Based on the elastic–plastic fracture mechanics theory, the detectable leakage crack length calculation and J-integral stability assessment diagram approach were carried out under different bending moments. The LBB curves and LBB assessment diagrams for unaged and thermally aged pipes were constructed. The results show that the detectable leakage crack length for thermally aged pipes increases with increasing bending moments, whereas the critical crack length decreases. The ligament instability line and critical crack length line for thermally aged pipes move downward and to the left, respectively, and unsafe LBB assessment results will be produced if thermal aging is not considered. If the applied bending moment is increased, the degree of safety decreases in the LBB assessment.

【 授权许可】

Unknown