Electrochemical Corrosion Behaviour of X80 Steel in Sandy Soil under a Natural Air-drying State

Based on the relationships among electrochemical theory, corrosion of sandy soil and corrosion principle of X80 steel, the corrosion mechanism of X80 steel in sandy soil under a natural air-drying state was comprehensively studied in this paper. The results show that with increasing age, as the water content in sandy soil decreased, the polarization curve of X80 steel shifted to the upper left, and its corrosion rate gradually weakened. The X80 steel exhibited slight corrosion, and the average corrosion rate was 1.65E-2 mm/a. Near the limit volume content of the liquid bridge, the radius of the capacitive arc was the smallest, and sandy soil had the strongest corrosion effect on X80 steel. Brown-yellow corrosion products (iron oxides, Fe2O3) with uneven thickness were deposited on the surface of the X80 steel. The localized corrosion products appeared as leopard pattern, flocculent clusters, rice grains.