Corrosion and Corrosion Inhibition of Aluminum Alloys A5052 and A5754 in Sulfuric Acid Solutions by Some Inorganic Inhibitors

Abstract

AbstractThe corrosion of aluminum alloys (A5052 and 5754) in sulfuric acid solutions was investigated using potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), and energy-dispersive X-ray (EDX) methods. For comparison, the corrosion of pure aluminum in sulfuric acid was examined potentiodynamically. The data reveal that increasing sulfuric acid concentrations and solution temperature enhance the corrosion rate of aluminum alloys. The two aluminum alloys exhibit higher corrosion resistance than pure aluminum. Moreover, A5052 involves more corrosion resistance than A5754. The effect of WO2−4and MoO2−4anions as inorganic inhibitors on the corrosion of aluminum alloys in 0.3 M H2SO4solution has also been studied. Results show that the presence of either WO2−4or MoO2−4anions in the acid solution decreases the corrosion of aluminum alloys. The Langmuir isotherm is found to be an accurate isotherm describing the adsorption of these oxyanions on the alloys surface.