涂层与阴极保护下的管道外腐蚀研究与控制

长期以来 ,一直认为管道在涂层和阴极保护协同保护下不会产生外壁腐蚀或腐蚀轻微。应用第三代高精度智能清管检测器对榕山—佛荫长为 2 5 4km的管线进行检测 ,发现了 455处外壁腐蚀 ,研究结果表明 :管道建设时 ,涂层施工的质量较差 ;使用维护过程中涂层材料老化严重、失修 ;管线上阴极保护系统长期故障使管道欠保护 ;执行了有严重缺陷的行业标准 ,至今不知管线上监测到的保护电位距真实的极化电位的差距有多大 ;管线的阴极保护度数据难以采集到。针对上述问题提出了控制腐蚀的方法。

Corrosion Survey and Control for Pipelines With Coating under CP System

For long time,it i s consider ed that a pipe can not be corroded under the combination protection of coating a nd CP system.When Rongshan-Foyin gas pi peline section of 25 4 km was inspected by intellectual pigging operation,a tota l of 455 external corrosion defects were inspected. The survey result shows that the coating quality is not so good when the pipeline was co nstructed;the coating material becomes a geing more and more,and lack of maintena nce since the pipeline was put into comm issioning;the real CP level has not been clearly recognized due to using an indu strial standard with some significant de fects;the pipeline CP protection data is difficult to pick up.For these troubles ,this paper gives out corrosion control measures to refer by pipeling operators.