蒸汽伴热管开裂失效分析

Cracking Failure Analysis of Steam-traced Pipe

某沿海石油化工公司不锈钢蒸汽伴热管道在碳钢固定扎带部位发生开裂失效。通过对失效件进行宏观检查、无损检测、材料理化性能检验和断口扫描电镜及能谱分析,结果表明:伴热管失效的原因为氯化物应力腐蚀开裂。建议蒸汽伴热管应与主管材质相同,主管线与伴热管固定时采用的绑扎材料应与主管及伴热管材质相同;提高保温层包覆质量,防止硅酸铝纤维浸湿,同时应该对其余碳钢材料绑扎和保温防水效果不佳部位进行PT检测。

The stainless steel steam-traced pipe of a petrochemical company by the sea has cracked and failed at the carbon steel fixing strap.The reasons of crack failure of the double-pipe were comprehensively analyzed by the macroscopic inspection,nondestructive testing,physical and chemical properties test,SEM and Energy Spectroscopic Analysis.The results show that steel steam tracing pipe crack failure was mainly caused by chloride stress corrosion cracking.It is recommended that the steam-traced pipe should be made of the same material as the main pipe,the binding material used when fixing the main line and the heat tracing tube should be the same material as the main pipe and the heat tracing tube.Improve the coating quality of the insulation layer and prevent the aluminum silicate fiber from wetting.At the same time,PT testing should be carried out on the other carbon steel material binding and poor thermal insulation and waterproof effect.