Chung Nguyen-Thuy, Hong Min-Sung, Kim Jung-Gu
School of Advanced Materials Engineering, Sungkyunkwan University, 300 Chunchun-Dong, Jangan-Gu, Suwon 440-746, Korea.
Materials (Basel). 2021 Jan 26;14(3):579. doi: 10.3390/ma14030579.
Several corrosion mitigation methods are generally applied to pipelines exposed to corrosive environments. However, in the case of pre-buried pipelines, the only option for corrosion inhibition is cathodic protection (CP). To apply CP, the required current should be defined even though the pipeline is covered with various oxide layers. In this study, an electrochemical acceleration test was used to investigate the synthetic soil corrosion of a pre-buried pipeline. Potentiodynamic polarization experiments were first conducted to ascertain the corrosion current density in the environment, and galvanostatic measurements were performed to accelerate corrosion according to the operating time. In addition, corrosion current density and the properties of the rust layer were investigated via potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) tests. The variation in surface corrosion was subsequently analyzed via optical microscopy (OM) and X-ray diffraction (XRD) measurements. Finally, an empirical equation for the optimized CP current requirement, according to the pipeline service time, was derived. This equation can be applied to any corroded pipeline.
几种腐蚀减缓方法通常应用于暴露在腐蚀性环境中的管道。然而，对于预埋管道，抑制腐蚀的唯一选择是阴极保护（CP）。要应用阴极保护，即使管道覆盖有各种氧化层，也应确定所需电流。在本研究中，采用电化学加速试验来研究预埋管道的模拟土壤腐蚀。首先进行动电位极化实验以确定环境中的腐蚀电流密度，并进行恒电流测量以根据运行时间加速腐蚀。此外，通过动电位极化试验和电化学阻抗谱（EIS）试验研究了腐蚀电流密度和锈层特性。随后通过光学显微镜（OM）和X射线衍射（XRD）测量分析了表面腐蚀的变化。最后，得出了根据管道服役时间优化阴极保护电流需求的经验方程。该方程可应用于任何腐蚀管道。
