The effects of acetate ions on electrochemical behaviour of brass in chloride solutions

The corrosion behaviour of brass (67% Cu, 33% Zn) was investigated in chloride solutions, in the presence of acetate ions. For this aim, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements were utilized. The pH of solution was adjusted to 8.5. It was shown that, CH3COO− ions could inhibit anodic dissolution of brass in aggressive chloride media. The effect of temperature was also studied in a range between 298 and 328 K. The inhibition effect of acetate ions was resulted from complex formations (between acetate ions and corrosion products) which physically adsorbed on the surface. The inhibition efficiency decreased with the temperature. The results obtained at different temperatures were used to evaluate various thermodynamical properties.