Corrosion Resistance of Galvannealed Steel

Abstract

Galvannealed steel is an iron-zinc alloy coated steel produced by a diffusion process. The corrosion potentials and corrosion current of the various iron-zinc alloy phases present in the coating were measured in a neutral salt solution by employing coulometric and linear polarization techniques. In laboratory accelerated corrosion tests, painted galvannealed steel performed significantly better than painted hot-dipped or electrogalvanized steel with respect to underfilm corrosion. This was explained in terms of electrochemical measurement results.