丙烯球罐底部排放阀连接螺栓断裂原因分析

ANALYSIS FOR FAILURE OF EXHAUST REJECTION VALVE STUDS USED FOR PROPENE BELL-FLANGE JUNCTION

对开裂和断裂的丙烯球罐底部排液阀连接螺栓进行了宏观和微观观察分析,结果表明,螺栓断裂起源于螺栓表面的晶间腐蚀,后以晶间型应力腐蚀开裂(SCC)扩展至断裂,腐蚀介质为SO2-4和Cl-。对在大气中使用的奥氏体不锈钢螺栓产生SCC的原因进行了分析和讨论,并提出防止该螺栓断裂的工程措施。

The failure of exhaust rejection valve studs used for propene bellflange junction was analyzed. Results showed that the cracks had initiated at intergranular corrosion on studs smoothing surface, and cracking proceeded as intergranular stress corrosion cracking. The elements such as S, Cl, O were found on the failure surface. The failure mechanism of austenitic stainless steel studs exposed in atmosphere was discussed, and protection measure was proposed.