The process of activation and repassivation of metal surfaces must be understood to improve the performance of alloys under corrosive wear. The transient current response acquired from a scratch test can be used to analyze the wear processes as a result of surface deformation and electrochemical reactions. The purpose of this technical note is to report the differences in the transient current response acquired for a cold-worked and an annealed vacuum-processed (VP) iron in a 0.2M KOH electrolyte.
The mechanisms involved during the activation (dissolution) and passivation of iron have been proposed and discussed by several authors.1-9 Most of these mechanisms assume the presence of an FeOH film adsorbed on the surface, even though the direct evidence of the presence of FeOH is still lacking. The corrosion of Fe in alkaline is less understood than in acidic solutions.1,10 The scratch technique has been used to study the transient...
