The electrochemical behaviour of brass in NaHSO₃ solution without and with Cl^-

The electrochemical behaviour of brass in NaHSO₃ solution without and with Cl^- was investigated by potentiodynamic polarization and cyclic voltammetry techniques. The results indicated brass dissolution was accelerated with HSO₃^- concentration increasing. And the first stable region in polarization curves was attributed to adsorbed layers, while the other to the formation of copper oxides. In the mixed solution containing HSO₃^- and Cl^-, when the potential is under -0.2 V_SCE, HSO₃^-, the dominant factor influencing the corrosion behaviour of brass, inclines to make brass stable; while Cl^- becomes the leading aspect above -0.2 V_SCE by destroying protective layers.