Effect of the Size of Soil Particles on the Electrochemical Corrosion Behavior of Pipeline Steel in Saline Solutions

Abstract

By using a standard quartz replace of sandy soil particles, we investigate the effect of size of soil particles (0.1–0.25 mm, 0.6–1.0 mm) on the electrochemical corrosion behavior of X70 pipeline steel in sandy-soil corrosive environment simulated by 3.5 wt.% sodium chloride (NaCl) with the help of the polarization curve and electrochemical impedance spectroscopy (EIS) technology. The results indicate that the polarization resistance of X70 steel decreases as the particle size decreases. For all polarization curves, a right shift of the cathodic branch with decreasing particle sizes is observed. The corrosion of X70 steel is controlled by the cathode process of diffusion and oxygen reduction at the metalenvironment interface, the intensity of which increases as the particle size decreases.