Mechanisms of Stress Corrosion Cracking of Irradiated Austenitic Chromium-Nickel Steels Used for WWER and PWR Vessel Internals

摘要

Specimens made of irradiated austenitic chromium-nickel 321, 316 and 304 stainless steels used for the internals of WWER-type and PWR-type reactors were tested for stress corrosion cracking (SCC). The specimens were irradiated to 4-150 dpa in different neutron energy spectra. The autoclave tests under different loading conditions were conducted in simulated WWER primary water environment at 290-315 degrees C. The effects of neutron dose and energy spectrum on the susceptibility of these steels to SCC were analyzed. The dominant SCC mechanisms for different austenitic steels have been identified. Comparison of the effect of different loading conditions on SCC resistance was made.