Corrosion protection properties of vanadium films formed on zinc surfaces

摘要

Vanadium films were prepared on zinc surfaces by using a solution containing vanadate.Corrosion protection properties of vanadium-treated (V-treated),chromium-treated (Cr-treated),and untreated zinc surfaces in contact with a 3.5 wt.% NaCl solution were studied using potentiodynamic polarization,electrochemical impedance spectroscopy (EIS),and neutral salt spray (NSS) tests.According to these results,the V-treated layer significantly improved the corrosion resistance of zinc surfaces.In comparison with the Cr-treated layer,the V-treated layer exhibited a better corrosion resistance.The composition of the V-treated layer was studied using X-ray photoelectron spectroscopy (XPS).XPS measurements indicated that the vanadium layer formed on zinc surfaces and the vanadium-rich coating was a hydrated oxide with a composition of V2O5,VO2,and its hydrates such as V2O5·nH2O and VO(OH)2.