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

Complex chemo-mechanical interactions at material/solution interfaces at elevated temperatures are involved in stress corrosion cracking (SCC) of structural materials in light water reactor (LWR) environments. Recent experimental results show that SCC growth of several key austenitic alloys in simulated LWR environments is thermally activated. Elucidating the thermally activated processes of SCC is of great importance for the mechanistic understanding and the quantitative prediction. Subprocesses involved in SCC propagation such as active oxidation, film recovery, and passivation as well as their rate-controlling steps such as electron transfer and mass transport in the aqueous solution or through the solid phase are analyzed, with emphasis on their responses to the environmental temperature