Abstract A new laboratory technique for obtaining a fresh metal surface is presented and has been used to investigate corrosion rates on stainless steel under open-circuit conditions. The fresh surface mixed potential decay at the cessation of abrading in aerated chloride solutions of varying pH and anion concentration was followed for 30s. The potential changed to more positive values, established by a surface covered with a passivating oxide film. Film thickening on stainless steel was logarithmic with respect to time, independent of concentration, dependent on the electrode surface roughness and solution pH.