Corrosion inhibition of sage extract on tinplate in 3% NaCl

The use of sage (Salvia officinalis, L.) as a corrosion inhibitor for tinplate in 3 % sodium chloride solution has been evaluated by using electrochemical impedance spectroscopy techniques (EIS) at 25 °C. Inhibitor concentrations of sage extract were included within the range between 0 and 500 ppm. EIS techniques have shown that sage extract could serve as an effective inhibitor (90.2 %) for the corrosion of tinplate in 3 % in concentration of 200 ppm, at temperature 25 °C. These results confirm that sage extract exhibits good inhibitive performance for tinplate in a 3 % NaCl solution, and that it is more efficient at inhibiting the corrosion of tinplate at 200 ppm concentration than in higher concentrations of sage extract. The passivating film properties of the tinplate were improved by the presence of polyphenols in the sage extracts.