Effect of hydrogen peroxide on the dezincification of brass in acidified sodium sulfate solution under free corrosion conditions

The dissolution of brass in acidified sodium sulfate solution containing different concentrations of H2O2 (01% m/v) was investigated under free corrosion conditions. The effect of temperature on the dissolution of brass was also addressed. Testing solution was analyzed for Zn+2 and Cu+2 using Inductively Coupled Plazma (ICP) technique. Surface characterization of brass surface was performed after each experiment. The increase of H2O2 concentration leads to the increase of the concentration of zinc and copper ions. These increases become more obvious at 0.5% m/v H2O2 while large increases are noticed at 1% m/v H2O2. Dissolution of brass was also enhanced by the increase of temperature. Strong dezincification of brass was obtained after prolonged testing (72 h). This strong dezincification was supported by SEM and XPS investigations. The extent of selective dissolution of zinc was expressed in the form of a dezincification factor (Z) i.e.: Dezincification factor (z) = [CZn/Ccu]soiution / [CZn/CCu]alloy].