原油脱钙剂注入管线法兰腐蚀失效分析  

Analysis of Corrosion Failure in Injection Pipeline Flange of Decalcifying Agent

作　　者：陈阵[1] 郭金彪[1] 邵鹏程[1] 汉继程[1] 

机构地区：[1]中国石油天然气股份有限公司兰州石化分公司,甘肃兰州730060

出　　处：《石油化工腐蚀与防护》2017年第2期52-54,共3页Corrosion & Protection In Petrochemical Industry

摘　　要：某石化公司脱钙剂注入点下游原油管线与旁路连接的法兰腐蚀严重。通过对腐蚀失效法兰的宏观腐蚀形貌、管线结构及理化检验结果进行综合分析发现,造成法兰环向内表面及密封面底部出现严重腐蚀的主要原因为:脱钙反应产物醋酸钙在法兰环向内表面沉积,与金属本体之间形成缝隙引发的缝隙腐蚀。提出了改进管线结构、改变脱钙剂注入点位置及在法兰表面采用耐腐蚀涂层或镀层等处理措施,提高了法兰的耐腐蚀能力。The flange was corroded seriously at the connection between the downstream crude oil pipeline and bypass pipeline h^r injecting decalcifying agent in a petrochemical company. Through comprehensive analysis of macroscopic corrosion morphology, pipeline structure and results of physical and chemical analysis, main cause for the severe corrosion at the inner wall of flange and the seal bottom was confirmed, that is, crevice corrosion was induced by the narrow gaps between the calcium acetate, decalcified reaction product deposited on the inner wall of flange, and metal body. According to the cause analysis of corrosion, several measures were proposed to improve the corrosion resistance of flange, that is, transforming pipeline structure, changing injection position of decalcifying agent or covering the flange surface with corrosion resistant coating.

关 键 词：脱钙剂 法兰 缝隙腐蚀 

分 类 号：TE986[石油与天然气工程—石油机械设备]