Evaluation of Corrosion Resistance and Passive Film Properties of Industrial Chromium Plating by Immersion Potential Monitoring

Abstract

Improving the corrosion resistance of industrial chromium plating films necessitates stabilization of the chromium passive film and processes such as closing surface cracks. For this study, as a step toward finding a technique to improve the corrosion resistance of chromium plating, we investigated monitoring the immersion potential in hydrochloric acid solution as a method to evaluate the breakdown of the passive film of chrome plating films. The active dissolution time（tEF）of chromium plating films depends on the hydrochloric acid concentration and the measurement temperature. They likely behaved in a first-order chemical reaction manner. This method allowed the polishing and heat treatment of the chromium plating films to affect the stability of the passive films to be assessed. This simple and quick method is useful to evaluate the improvement of the corrosion resistance of industrial chromium plating products.