Cu-Zn alloys known as brasses possess attractive properties such as great corrosion and biofouling resistance. They have extensive applications in water treatment and desalination units in oil and petrochemical industries and power plants. However, brasses are susceptible to dezincification. This paper addresses the effectiveness of 1% tin (Sn) as alloying element on preventing the corrosion of 70Cu-30Zn brass in sulfide polluted 3.5% NaCl solution. The corrosion behavior of brass at 50 and 200 ppm of Na S 2 was studied by AC and DC electrochemical techniques including potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The EIS measurements showed a decrease in charge transfer resistance and an increase in double layer capacitance values with increase in Na S 2 concentration suggesting a slight increase in alloy corrosion rate. This confirmed the observations made in the potentiodynamic polarizations studies. Moreover, tin reduces the corrosion rate by forming 2 SnO as protecting layer rather than forming Cu S 2 film on brass surface.

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