Electrochemical investigation on steel corrosion in iron-rich clay

The iron-rich clay mineral, such as the red soil, is found corrosive toward pipeline steel, which may partly attribute to the active Fe oxide constituents residing in the clay. Surface charge and electrokinetic properties of the red clay mineral were characterized and related to corrosion behavior of X80 steel in the soil. Results show that surface charge of the Fe-rich clay mineral is variable according to pH. Active clay minerals, especially Fe oxides, distinctly influence corrosion process of the steel. The dynamic redox cycle of Fe oxides promotes and sustains corrosion of the steel in contact with iron-rich clay environments.