Effect of pre-oxidation and corrosion potential on electronic properties of passive films on Ni-Cr-Fe alloys in pure water at 288 °C

The effect of pre-oxidation and corrosion potential on electronic properties of passive films on Ni-Cr-Fe alloys in pure water at 288°C was studied. It was observed that the corrosion potential was increased stepwise by purging a gas mixture of nitrogen⁺ oxygen and pure oxygen content of 32 ppm in the reservoir water. The measured corrosion potential was converted to the standard hydrogen electrode (SHE) scale after temperature corrections. The variation of electrical resistance of the passive film with corrosion potential, when the cyclic chemical-polarization was carried out from a higher potential to a lower potential and back to higher potential, was also shown.