海底管道腐蚀缺陷处阴极保护数值模拟

海底管道表面很容易因为腐蚀形成缺陷点,具有深度大、传播快且检测困难的特点,对管道安全运行产生很大隐患。通过数值模拟方法研究了X80海底管道钢表面存在腐蚀缺陷时缺陷点内部对阴极保护产生的屏蔽作用,利用有限元方法模拟缺陷处的局部电位和阳极/阴极反应电流密度。结果表明:在腐蚀缺陷处阴极保护电流被部分屏蔽,特别是在缺陷的底部位置;缺陷处对阴极保护的屏蔽作用随着缺陷深度的增加和宽度的减小而越来越强。研究结果可为现场海底管道腐蚀状况和剩余寿命的评估提供指导。

Numerical simulation on the cathodic protection at corrosion defects of submarine pipelines

The formation of defects on the surface of submarine pipeline due to corrosion is quite easy, and this kind of defect is characterized by large geometrical depth, rapid propagation and difficult detection and brings great potential risks to pipeline accidents. In this paper, the shielding effect on the cathodic protection by the interior of defects when there were corrosion defects in the surface of X80 steel submarine pipeline was investigated by means of numerical simulation. And local potential and anodic/cathodic current density at the defects were simulated by virtue of finite element method. It is indicated that the cathodic protection current is partially shielded at corrosion defects, especially at their bottom. And the shielding effect on the cathodic protection at defects is increased with the increase of defect depth and the decrease of defect width. The research results provide the guidance for estimating on-site corrosion status and remaining life of submarine pipelines.