Corrosion inhibition of zinc by aqueous vanadate species

This study presents a characterization of the degree and mechanism of corrosion inhibition of Zn by vanadate inhibitors. Acombination of open circuit potential measurements, anodic and cathodic polarization, and Raman spectroscopy were used to compare corrosion inhibition of Zn exposed to or pre-treated with a dilute ∼pH 6.3 NaVO₃+NaCl solution, which likely contained predominantly tetrahedrally coordinated vanadate species, relative to controls. The presence of vanadate caused a decrease in corrosion current density of up to two orders of magnitude due to overall mixed anodic and cathodic inhibition associated with the formation and/or stabilization of adherent surface films.