STABILITY OF LEAD-BRASS ALLOYS IN ACIDIC CHLORIDE AND SULFATE-SOLUTIONS

The electrochemical behavior of two lead-brass alloys with different lead (Pb) contents was investigated in acidic chloride (Cl-) and sulfate (SO4-) solutions under open-circuit and potentiostatic conditions using electrochemical impedance spectroscopy (EIS). Behavior of the alloy was compared to that of its constituent elements under the same conditions. The effect of Pb content on stability of the alloy was studied. In both electrolytes, the electrode impedance (Z) drifted toward higher values and then decreased This behavior was attributed to the adsorption of anions on the electrode surface. After long immersion times, film breakdown occurred. Increasing Pb content in the alloy modified its characteristics and increased its corrosion resistance, as indicated by the increased impedance and polarization resistance values in both electrolytes.