Inhibition de la corrosion de l'alliage d'aluminium 6063 au moyen de composés inorganiques dans une solution de chlorure de sodium à 3 %

Abstract

Some inorganic compounds have been tested as corrosion inhibitors for 6063 aluminium alloy in 3% NaCl by electrochemical and metalographic methods. The compounds were MoO42–, CrO42–, NO2– oxo-anions and Li+ and Mg2+ metallic cations. Results obtained show that these compounds inhibited corrosion of 6063 aluminium alloy, and that the Li+ cations were the best inhibitors. The difference between pitting potential and corrosion potential increase by increasing the concentration of Li+. The maximum inhibition efficiency (E% = 85%) was attained at 5 × 10–3 M. Increasing temperature from 25 to 55°C improve corrosion resistance of 6063 aluminium alloy in the absence of Li+. However, in the presence of these cations, E% decreased at elevated temperature.Key words: corrosion, inhibition, inorganic compounds, 6063 aluminium alloy, 3% NaCl.