阀门螺栓断裂失效分析

某化工厂阀门螺栓发生断裂,采用宏观检验、扫描电镜及能谱分析、金相检验等方法分析了该螺栓的断裂原因。结果表明:断裂是由于材料未经固溶处理,或固溶处理温度不高、时间较短,碳化物未经充分溶解,合金化程度较差,长期使用中造成晶界附近的金属贫铬,且在腐蚀介质中发生电化学反应,从而在较小的外力作用下发生晶间腐蚀断裂。

Analysis of valve bolt fracture failure

In view of valve bolt fracture happened in a chemical plant,this paper analyzed fracture reasons by using testing methods like macrographic examination,SEM&energy spectrum analysis,etc..The results showed that:The fracture was caused by the fact that the material has not been solution treated or the treating temperature and duration had not been sufficient that the carbide were not fully dissolved,the alloying level was poor,and so the long-term usage led to poor chromium near grain boundary,which caused electrochemical reaction in corrosive medium,thus the inter-granular corrosion and fracture was very likely to happen under small external force.