安全阀弹簧断裂分析  

Fracture Analysis of Safety Valve Spring

作　　者：祁永东 万春阳 徐鑫 裴恺 王安友 周琛源 QI Yongdong;WAN Chunyang;XU Xin;PEI Kai;WANG Anyou;ZHOU Chenyuan(Zhejiang National Inspection and Testing Technology Co.,Ltd.,Zhejiang Haiyan 314300,China;Ningbo Qunli Fastener Manufacturing Co.,Ltd.,Zhejiang Ningbo 324400,China)

机构地区：[1]浙江国检检测技术股份有限公司,浙江海盐314300 [2]宁波群力紧固件制造有限公司,浙江宁波324400

出　　处：《失效分析与预防》2025年第1期73-78,共6页Failure Analysis and Prevention

基　　金：中国仪器仪表学会科学仪器托举计划项目(CIS海豚计划:CISTJ202408)。

摘　　要：压力容器的泄压安全阀弹簧在服役过程中发生断裂,通过采用宏观检查、断口形貌分析、金相分析、力学性能检测、化学成分分析等方法对弹簧的断裂原因进行分析。结果表明:弹簧表面存在大量点蚀凹坑,断面起裂区位于弹簧内侧表面点蚀凹坑处,弹簧内侧本身残余拉应力较大,加上点蚀凹坑引起的应力集中加速了裂纹的萌生。此外,弹簧表面及断面的腐蚀产物成分存在S、Cl等腐蚀性元素。弹簧本身强度、硬度较高,在拉应力和腐蚀介质共同作用下,于点蚀凹坑导致的应力集中部位发生应力腐蚀开裂,最终导致弹簧断裂失效。建议在满足工况要求的情况下适当降低弹簧硬度以降低应力腐蚀开裂敏感性,同时改进弹簧表面涂覆工艺以提高防腐性能。The spring of pressure relief valve on a pressure vessel broke during service.The reasons for the spring breaking were analyzed by macro-inspection,fracture morphology analysis,metallographic analysis,mechanical property testing and chemical composition analysis.The results show that there are a large number of pitting pits on the whole spring surface,and the crack initiation area is located at the pitting pits on the inner surface of the spring.The residual tensile stress on the inner side of the spring itself is large,and the stress concentration caused by pitting pits accelerates the initiation of cracks.In addition,there are corrosive sensitive media such as S and Cl on the surface and cross section of the spring.The spring itself has high strength and hardness.Under the combined action of tensile stress and corrosive medium,stress corrosion cracking occurs at the stress concentration part caused by pitting pits,which eventually leads to the failure of the spring.It is suggested that the hardness of the spring should be properly reduced to reduce the sensitivity of stress corrosion cracking,and the surface coating process of the spring should be improved to improve the corrosion resistance.

关 键 词：安全阀 弹簧 失效分析 点蚀 应力腐蚀 

分 类 号：TG157[金属学及工艺—热处理] TG115[金属学及工艺—金属学]