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

The electrochemical behavior of two lead-brass alloys with different l ead (Pb) contents was investigated in acidic chloride (Cl-) and sulfat e (SO4-) solutions under open-circuit and potentiostatic conditions us ing electrochemical impedance spectroscopy (EIS). Behavior of the allo y was compared to that of its constituent elements under the same cond itions. The effect of Pb content on stability of the alloy was studied . In both electrolytes, the electrode impedance (Z) drifted toward hig her values and then decreased This behavior was attributed to the adso rption 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 indicat ed by the increased impedance and polarization resistance values in bo th electrolytes.