Study of chromate coatings by means of electrode impedance measurements

Abstract

The corrosion resistance of chromate layers on zinc sheet was studied by electrode impedance measurements in 0.1 mol/1 NaClO₄ solutions. A correlation was found to exist between the inhomogeneity and corrosion protection of the chromate layers and impedance data measured at different spots of the specimen. The results of impedance measurements and humidity tests agreed within the experimental error.