Triazoles as corrosion inhibitor for brass in sea water environment

The inhibitive effect of triazoles on brass in 3% NaCl has been investigated by means of weight loss, electrochemical polarisation and impedance methods. The present investigation also deals with the mechanism of dezincification of commercial brass. All the triazoles derivatives, namely, Amino-methyl mercapto triazoles (AMMT), Amino Ethyl mercapto triazole (AEMT) and Amino propyl mercapto triazole (APMT) gave inhibition efficiencies in the order APMT (94.5) > AEMT (93.6) > AMMT (91.5). All the inhibitors were found to be mixed inhibitors. Nyquist plots showed warburg impedance i.e. the reaction was diffusion control. The inhibition efficiencies of the triazoles did not drop in dynamic flow conditions. Solution analysis showed selective dissolution of zinc as compared with copper. The dissolution of Zinc decreased in the presence of triazoles, to 0.35 mg/l.