Investigation of corrosion behavior of Al-alloys system Al-Mg-Cu in aqueous solutions of NaCl and Na2SO4: And review of the efficiency of inhibitors Na2CO3, NaNO2 and Na2HPO4

Corrosion inhibitors are substances which, added to a small amount of aggressive media, can considerable reduce the corrosion rate of metals. The proper selection of inhibitors is a very important fact, if we know that some inhibitor slows down corrosion for a particular composition of solution /metal interface. This paper presents impact of inorganic inhibitors NaNO2, Na2CO3 and Na2HPO4 in 0.5 M Na2SO4 solution, in which the comparative results of the effects of these inhibitors in 0.51 M NaCl and 0.5 M Na2SO4 are analyzed. The effect of inhibitors is reflected in the increase of polarization resistance and decrease in the corrosion current density, in different degree depending on the type of inhibitor, the aggressive solution and the type of alloy.