Abstract
The effect of oxide film structure obtained by thermal treated in air on minimal corrosion release of Type 304 stainless steel in a high temperature pure water was investigated in order to clarify a cause for existing of an optimum temperature range to inhibit metal dissolution. The oxidation treatments up to ca. 600K were effective to increase the polarization resistance, and the oxide film primarily consisted of a uniform duplex oxide layer of α-Fe2O3 in outer and iron-chromium spinel type oxide in inner layer. A lot of nodular oxides, however, were formed by the oxidation treatments more than ca. 800K, the polarization resistance decreased with the increase and the growth of the nodules, and which consisted of only α-Fe2O3 from the surface to the oxide-metal interface.
