Development of Electrochemical Surface Treatment for Improvement of Localized Corrosion Resistance of Zirconium in Chloride Environment

Abstract

An electrochemical surface treatment technique to improve the localized corrosion resistance of zirconium in chloride ion environment has been developed. The combination of anodic and cathodic polarization cycles was applied to induce selective dissolution of the inclusions that initiated localized corrosion on zirconium. Shallow-shaped traces were observed on the specimen surface after the treatment, indicating the dissolution of the inclusions. The treatment with constant anodic current and constant cathodic potential in a concentrated phosphate-buffered saline resulted in the high pitting potential over 2 V in a physiological saline. Thus, the localized corrosion resistance of the treated Zr was significantly improved by this technique.