Correlation between Corrosion Films and Corrosion-Related Defects Formed on 316 Stainless Steel at High Temperatures in Pressurized Water

The correlation between corrosion films and corrosion-related defects formed on 316 austenitic stainless steel exposed to 300 °C/10 MPa water for 50 h, 100 h, 200 h and 500 h was characterized by x-ray absorption spectroscopy, grazing incidence x-ray diffraction, scanning electron microscopy/energy-dispersive x-ray spectroscopy and positron annihilation spectroscopy. The corrosion results showed that the oxide films formed were composed of hematite (Fe₂O₃/Cr₂O₃) and spinel (FeCr₂O₄). At the initial corrosion stage, the deposition of these oxide films was accompanied by the formation of abundant corrosion-related defects. As the corrosion duration increased, the formation of more spinel in the oxide films led to a decrease in the density of corrosion-related defects.