The mechanisms of corrosion inhibition of hot-dip galvanized steel by vanadyl oxalate: A galvanic corrosion investigation supported by XPS

The mechanisms of corrosion inhibition of hot-dip galvanized steel by vanadyl oxalate were studied using galvanic corrosion approach and XPS. The partial separation of electrode reactions was achieved using a split cell design. Injection of vanadyl oxalate solution to the cathode side of split cells significantly reduced the galvanic current, whereas injection to the anode side had little effect on the galvanic current. V(IV) inhibits oxygen reduction by a mechanism involving V(IV) reduction to V(III) and formation of V(III) layers on the cathode. V(IV) acts as a cathodic inhibitor, due to V(III) layer occupation of active sites for oxygen reduction.