EFFECT OF SULFIDE IONS ON THE CORROSION BEHAVIOR OF MILD-STEEL IN ACETATE BUFFER

The corrosion behaviour of mild steel was investigated in acidic acetate buffer solutions using impedance and potential measurements. It was found that there are two dissolution rates resulting from the duplex nature of the formed oxides. The dissolution rates were found to depend on the dissolving acetate buffer solution pH and the dissolution temperature. In all cases, the film thickness was found to decrease with time of corrosin according to the relation C(m)-1 = (C(m)0)-1 - k(d)t1/2. It was found that addition of sulfide ions increases the dissolution rate and increases the rate of hydrogen evolution reaction hut does not affect the mechanism of cathodic process. The role of sulfide ions on the corrosion behaviour of steel in acetate buffer solutions is revealed by the complex plane impedance analysis.