EIS and XPS study of the corrosion of carbon steel in inhibited natural seawater

Electrochemical and surface analytical techniques were used to study the corrosion behaviour of a carbon steel in inhibited seawater. Linear polarization resistance and Tafel polarization measurements showed the effect of inhibitor injection on the corrosion rate of carbon steel in natural seawater. A 90% reduction in the corrosion rate was observed for the steel under investigation. In situ electrochemical impedance spectroscopy (EIS) measurements indicated that the inhibiting film formed in seawater was stable and no pitting corrosion was observed. Surface analysis of steel samples by XPS revealed conclusively that the inhibiting film was three-dimensional in nature because the steel surface was essentially buried under it. Copyright © 1999 John Wiley & Sons, Ltd.