The passive corrosion rate of Alloy C-22 is exceptionally low in a wide range of aqueous solutions, temperatures and electrochemical potentials. Alloy C-22 contains approximately 22% chromium (Cr) by weight; thus, it forms a Cr-rich passive film in most environments. A study of the composition, thickness and other properties of the passive film was undertaken to better understand the role of the protective oxide in preventing corrosion. In general the oxide film is expected to be a function of solution pH, temperature and applied electrochemical potential. In this work we focus on the oxide films that form at pH=8.