Application of scanning Kelvin probe to study the corrosion protection of chromated hot-dip galvanized steel

Abstract

The scanning Kelvin probe has been used to study the inhibition mechanisms and the efficiency of chromating of hot-dip galvanized steel. Our results show that chromate coatings influence the cathodic partial reaction, i.e. oxygen reduction. The beneficial influence of phosphates on the inhibition efficiency of chromate coatings is also evidenced. Scanning Kelvin probe allows to evaluate the quality (efficiency and homogeneity) of the chromating. Finally we can observe that the protective properties of chromating in a lightly corrosive environment are kept. © WILEY-VCH Verlag GmbH, 2001.