保温层下金属材料的腐蚀与防护

Corrosion of Metals under Insulation and Protection

近年来多个装置的设备和管线存在严重的保温层下腐蚀,有些部位因Cl-含量高,导致管线发生严重点腐蚀,腐蚀深度达4 mm以上,有些地方甚至发生了介质泄漏现象。中国石油化工股份有限公司镇海炼化分公司对公司内近几年的20套生产装置6 420处保温层下腐蚀进行了检查分析,总结出一套可操作的腐蚀防护措施。在保温材料、保温结构、防腐蚀涂层的选择及腐蚀检测等方面提出了推荐性建议,对保温层下腐蚀防治中的难点问题提出了导波检测等有针对性的解决方法。

In recent years, the equipment and piping in a number of process units suffered from serious corrosion under insulation. Serious pit corrosion oecurred on the pipelines and corrosion pits were over 4 mm deep because of high C1^- in the media, leading to leaking in some locations. On the basis of the investigation and study of corrosion under insulation and testing of corrosions under insulation at 6420 places in 20 process units by SINOPEC Zhenhai Refining ＆ Chemical Co. , Ltd. , practical corrosion protection measures were developed and recommendations were presented in respect of insulation material selection, insulation construclion, selection of corrosion resistant coatings and corrosion testing, etc. Solutions to the difficulties in protection of corrosion under insulation such as guided wave testing, etc were proposed.