Effects of Charged Hydrogen on Oxidation Behavior of Alloy 690 in High Temperature Water Environments

The oxide films formed on non-charged and hydrogen-charged Alloy 690 specimens exposed to 290 °C pure water environment with different dissolved oxygen concentrations were characterized. It was found that the oxide film formed on the hydrogen-charged specimen was thicker than that on the noncharged specimen. Local protruding oxides were observed on the hydrogen-charged Alloy 690 but not on the non-charged specimen. The Ni and Fe contents of local protrusion on the hydrogen-charged specimen were higher than those on the noncharged specimen.