Effects of Cathodic Polarization on the Corrosion Behavior of X60 Pipeline Steel in a Simulated Soil Solution

The objective of this study is to investigate the relationship between the cathodic polarization, the evolution of hydrogen, and its effect on the formation of calcareous deposits on X60 pipeline steel in a simulated soil solution and its behavior at open-circuit potential (OCP) after interruption of cathodic polarization. Electrochemical measurement (chronoamperometry, potentiodynamic polarization, OCP evolution, electrochemical impedance spectroscopy (EIS)), and surface characterization techniques are used. The time evolution of EIS spectra is examined. The results show that cathodic polarization favors the release of hydrogen, and weakens and/or prevents the formation of calcareous deposits on the steel surface. After stopping polarization, the corrosion kinetics is retarded for high cathodic potentials, which could be due to the blocking of the surface by the adsorbed hydrogen.