高压调节汽门阀盖螺栓断裂失效分析

Fracture Failure Analysis of Bolt for High Pressure Regulating Valve Cover

针对一起高压调节汽门阀盖螺栓断裂失效案例,对螺栓进行宏观检查、成分分析、硬度测试、金相组织分析及断口显微分析。结果表明:在蠕变、疲劳的共同作用下,在螺栓应力集中部位,首先在弱化的晶界上产生裂纹,然后在腐蚀作用的促进下,裂纹不断扩展,最终造成脆性断裂。

According to a case of bolt fracture for high pressure regulating valve cover, by means of macroscopic examination, OES, OM and SEM, the fracture bolt was analyzed. The results showed that under the creep, fatigue, the cracks in the weakened grain boundaries were first produced at the stress concentration site of the bolt, and then under the influence of corrosion, and the cracks expanded, the bolt finally brittle fractured.