Corrosion Inhibition of Aluminum-Zinc Alloy in Hydrochloric Acid Solutions

Abstract

Abstract Corrosion rates and inhibitor efficiencies in hydrochloric acid solutions have been determined for aluminum-zinc alloy containing 4.5–6.5 percent zinc. Percent efficiencies of the various inhibitors were in the ranges: acridine 80–98, thiourea 86–95, nicotinic acid 80–97, strychnine 64–94 and quinine hydro-chloride 58–95. Polarization studies with thiourea, strychnine and quinine hydrochloride showed that anode polarization is negligible, whereas cathode polarization is considerable. The Tafel plot is valid in this case. Dissolution of the metal is electrochemical in character. With these inhibitors the corrosion process appears to be essentially under cathodic control. 5.8.2, 6.4.2, 4.3.2