核电站主泵冷却系统法兰螺栓断裂失效分析  

Analysis on Fracture Failure of Main Pump Cooling System Flange Bolts in a Nuclear Power Plant

作　　者：扶靓虔 唐彬[2] 徐祺[2] 赵宇翔[2] 陈乐[2] 陈高詹[2] FU Liangqian;TANG Bin;XU Qi;ZHAO Yuxiang;CHEN Le;CHEN Gaozhan(China Nuclear Control System Engineering Co.,Ltd.,Beijing 102401;Nuclear Power Institute of China,Chengdu 610213)

机构地区：[1]中核控制系统工程有限公司,北京102401 [2]中国核动力研究设计院,成都610213

出　　处：《发电设备》2025年第2期115-119,共5页Power Equipment

摘　　要：在某核电站的大修例行检查中,发现主泵冷却系统的外热屏与内套的法兰螺栓在运行过程中发生了断裂,对断裂的法兰螺栓进行了宏观观察、化学成分分析、硬度测试、金相检验和能谱分析,结合主泵法兰螺栓的运行环境,对螺栓的断裂原因进行了分析。结果表明:螺栓的失效模式为低周疲劳断裂;在正常运行时,温度循环变化和机械约束形成了螺栓产生疲劳断裂失效的2个必要条件。为确保核电站主泵冷却系统运行可靠,建议将螺栓的检查周期由5a缩短至2~3a。During the routine inspection of major maintenance in a nuclear power plant,it was discovered that the flange bolts of outer heat shield and inner sleeve of the main pump cooling system had fractured during operation.Macroscopic observation,chemical composition analysis,vickers hardness test,metallographic inspection,and energy spectrum analysis were conducted on the fractured flange bolts.The reasons of the fracture were analysed in combination with the operating environment of main pump flange bolts.Results show that,the failure mode of the bolts is low-cycle fatigue fracture.In normal operation,temperature cycle changes and mechanical constraints form the two necessary conditions for fatigue fracture failure of bolts.In order to ensure the reliable operation of the main pump cooling system in the nuclear power plant,it is recommended to shorten the inspection cycle of bolts from 5 years to 2-3 years.

关 键 词：核电站 主泵 冷却系统 法兰螺栓 低周疲劳断裂 失效分析 

分 类 号：TM623[电气工程—电力系统及自动化]