Behavior of electrogalvanized steel pre-treated with Cr(III)-based baths and exposed to 0.5 M Na2SO4 solution

Abstract

As Cr (VI) compounds used to formulate conversion layers provide enhanced anticorrosive protection to zinc coatings, but they are produced using hazardous chemicals, the development of ''green'' technologies is a paramount purpose. Consequently, the corrosion behavior of zinc coatings subjected to a Cr3+ based passivating treatment, with and without sealing, was studied through EIS measurements in 0.5 M Na2SO4 solution. The analyses of the experimental data allowed inferring that the Cr3+-based conversion treatment with an adequate sealer provides good corrosion resistance and, coupled to an adequate painting system, could be a suitable alternative to traditional chromate coatings.