Some fundamental aspects of thermally activated processes involved in stress corrosion cracking in high temperature aqueous environments

Complex mechano-chemical interactions at material/solution interfaces under elevated temperatures are involved in the stress corrosion cracking (SCC) of structural materials in light water reactor environments. Elucidating the thermally activated processes of SCC is of great importance for the mechanistic understanding and quantitative predictions. Steady state stress corrosion crack growth rates have been measured and used to calculate apparent activation energies under various test conditions. The observed apparent activation energies have been analyzed, based on the concept that multiple sub-processes with different thermally activated rate-controlling steps contribute simultaneously to the SCC crack growth.