Evaluation of the corrosion resistance of different galvanized steels treated in a cerium salt solution

Analysis of polarization curves and impedance spectra has shown that the surface chemistry of galvanized steels plays an important role in determining their corrosion behavior. Zn‐Ni samples that were untreated or had been treated in a 10 mM Ce(NO 3 ) 3 solution had the lowest corrosion rates in 0.5 N NaCl. The efficiency of the surface modification process was the highest for electrogalvanized steel. Surface analysis showed that the protective layers on Zn‐Ni and electrogalvanized steel contained mainly cerium oxides/hydroxides, while the layer on hot‐dipped steel consisted mainly of zinc hydroxide.