Modification of the Electrochemical and Corrosion Behavior of Stainless Steels with an Electroactive Coating

Electroactive polyaniline coatings have been deposited on ferritic stainless steels. The coatings appear to be deposited over the passive metal oxide film but can undergo electron transfer with the metal. Polyaniline immobilized on the alloys imparts a form of anodic protection which stabilizes the materials in mineral acids. Electrochemical and SEM characterization results are presented, and effects of coating application techniques are discussed. Oscillations in the open‐circuit voltage occur in solutions containing a high enough concentration of chloride ion to initiate pitting at potentials dictated by the coating. Inhibition of localized corrosion may also be obtainable for favorable systems.