Development of electrochemical surface treatment for improvement of localized corrosion resistance of zirconium in chloride environment

An electrochemical surface treatment technique was developed in this study to improve the localized corrosion resistance of zirconium in a chloride ion environment. A combination of anodic and cathodic polarization cycles was applied to induce the selective dissolution of the inclusions that could potentially initiate the localized corrosion of zirconium. Shallow dips were observed on the specimen surface after the treatment, thereby indicating the dissolution of the inclusions. The electrochemical treatments via galvanostatic anodic polarization and potentiostatic cathodic polarization in concentrated phosphate-buffered saline resulted in a high pitting potential of greater than 2 V in a simulated body fluid. This indicated that the devised technique realized a significant increase in the localized corrosion resistance of the treated Zr. (author)