Abstract

MAHMOUD, S.S.. Hydrochloric Acid Corrosion Inhibition of Zn-Al-Cu Alloy by Methyl-Substituted Piperidines. Port. Electrochim. Acta [online]. 2008, vol.26, n.3, pp.245-256. ISSN 0872-1904.

The corrosion behavior of Zn-Al-Cu alloy was investigated in HCl solution in absence and in presence of different concentrations of inhibitors. The techniques of measurements were: weight loss, linear polarization and galvanic static polarization. It was found that the corrosion rate of this alloy was higher than that of zinc or aluminum. The inhibitors used were: heterocyclic piperidine (PP), 2- methyl piperidine (2mp), 3-methyl piperidine (3mp) and 4- methyl piperidine (4mp). These inhibitors are mixed type and their inhibition efficiency, I%, increases according to the order: 2mp < 3mp < pp < 4mp. The values of activation energy of corrosion were determined in absence and in presence of inhibitors. It was found that the presence of these inhibitors increases the values of activation energy. The adsorption of these inhibitors on the surface of the alloy follows Frumkin’s  isotherm.

Keywords : hydrochloric acid; corrosion inhibition; Zn-Al-Cu alloy; methyl-substituted piperidines.

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