核级石墨密封垫片压缩蠕变性能研究  

Investigations on compression creep performance of nuclear-grade graphite gaskets

作　　者：马俊宏 沈火明[1] 刘娟[1] 王宇星 傅孝龙[2] MA Junhong;SHEN Huoming;LIU Juan;WANG Yuxing;FU Xiaolong(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of Nuclear Reactor System Design Technology,Nuclear Power Institute of China,Chengdu 610041,China)

机构地区：[1]西南交通大学力学与航空航天学院,成都610031 [2]中国核动力研究设计院核反应堆系统设计技术重点实验室,成都610041

出　　处：《重庆理工大学学报（自然科学）》2022年第11期161-166,共6页Journal of Chongqing University of Technology：Natural Science

基　　金：西南交通大学横向项目(SQ-KFKT-09-2018006)。

摘　　要：密封垫片的压缩蠕变性能是影响密封系统安全性和可靠性的重要力学性能之一,为研究现代核电运行系统中核级石墨密封垫片的蠕变性能,基于垫片压缩蠕变模型试验以及数值模拟,对比分析了预紧应力、服役温度以及垫片径向尺寸等因素对压缩蠕变性能的影响。试验结果表明:密封垫片存在一个使垫片金属环与法兰发生接触的门槛应力。在蠕变过程中,垫片压缩蠕变量随着环境温度的升高而增加,随着螺栓预紧应力的增大而增加,但垫片蠕变量受径向尺寸的影响较小。综合不同工况下垫片蠕变结果,发现其最大蠕变率为3.5%,远低于现行核电工程中对密封垫片蠕变性能的规范要求。研究表明:核级石墨密封垫片处于高温或高压环境下均具有较好的抗蠕变性能,可满足核电密封系统的可靠性要求。The compression creep performance of gaskets,one of the important mechanical properties,significantly affects the safety and reliability of the sealing system.To investigate the creep performance of the nuclear-grade graphite gaskets used in modern nuclear power systems,this paper analyzes the effects of the pre-tightening stress,service temperature,and the gasket radial length on the compression creep performance using model tests and numerical simulations.The experimental results show that there is a critical stress on the gasket,so-called threshold stress,which makes the metal ring of the gasket be pressed on the flange surface.In the compressive process,the creep of the gasket increases with the increasing temperature or bolt pre-tightening stress,but is less affected by the gasket radial length.In the present study,the maximum creep rate of nuclear-grade graphite gaskets in various working conditions is 3.5%,which is far lower than the requirementof the current nuclear power specification.The obtained results also show that the nuclear-grade graphite gasket has prominent creep resistance,especially in high-temperature or high-pressure cases,which can significantly build up the reliability of the nuclear power sealing system.

关 键 词：核级石墨密封垫片 蠕变性能 试验 有限元模拟 

分 类 号：TH136[机械工程—机械制造及自动化]