On the localised corrosion of carbon steel induced by the in-situ local damage of porous corrosion products

Abstract

The effect of in-situ local damage of uniform porous corrosion products on the localised corrosion of carbon steel is investigated using the wire beam electrode technique (WBE) combined with morphology characterisation and electrochemical tests. The WBE measurements demonstrate that the localised corrosion is enhanced by the in-situ local removal of porous corrosion products, supported by the morphology characterisation and electrochemical tests. The enhanced localised corrosion does not originate from the damaged wire in WBE where the corrosion products are removed but from the other undamaged wires, which is reported for the first time. A mechanism is proposed that the intensive anodic polarisation effect of the damaged wire on the undamaged wires could account for the enhanced localised corrosion, which is due to the protective corrosion products newly formed on the damaged surface and the increase in the potential of damaged wire.