某阀门螺栓断裂失效分析

Fracture Failure Analysis of a Valve Bolt

采用宏观分析、化学成分分析、微观分析、能谱分析、腐蚀产物分析等技术手段,并结合实际工况,对某气田管线阀门的4根螺栓的断裂原因进行了分析。结果表明:螺栓材质不符合标准要求,在海洋大气环境下,1#螺栓首先发生应力腐蚀开裂,失效后阀内气体介质泄漏,阀体失稳,腐蚀较严重的2#螺栓随后发生失效。1#、2#螺栓都失效后,泄漏量瞬间增大,导致阀内高压气体介质冲击力突增,气体冲击阀盖,最终导致3#、4#螺栓过载后断裂。

Using macro analysis,chemical composition analysis,microscopic analysis,energy spectrum analysis,corrosion product analysis and other technical means,combined with the actual working conditions,the reasons for the fracture of four bolts of a pipeline valve in a gas field were analyzed.The results showed that the material of the bolt did not meet the standard requirements.In the marine atmospheric environment,the 1#bolt firstly occurred stress corrosion cracking.After the failure,the gas medium in the valve leaked,the valve body became unstable,and the 2#bolt with severe corrosion failed subsequently.After both the 1#and 2#bolts failed,the leakage increased instantaneously,resulting in a sudden increase in the impact force of the high-pressure gas medium in the valve,and the gas impacted the valve cover,eventually causing the 3#and 4#bolts to break after overloading.