Role of Fe oxides in corrosion of pipeline steel in a red clay soil

Red clay soils show especially corrosive towards metallic materials, but no satisfactory interpretation exists to explain the phenomenon. Soil Fe oxides (goethite, hematite, etc.) appear to play a key role in soil corrosion by functioning as a cathodic depolarizer. A series of experiments were therefore conducted to evaluate the effect of Fe oxides on corrosion of pipeline steel in a red clay soil. The results indicate that corrosivity of the red clay soil greatly relieves after Fe oxides are removed from the soil. A Fe oxide-catalyzed kinetic mechanism is proposed to clarify high corrosivity of red clay soils. (C) 2013 Elsevier Ltd. All rights reserved.