Stress corrosion behavior of scratched Alloy 690TT steam generator tube in chlorine-containing high-temperature pressurized water

摘要

Alloy 690TT tube samples with six different scratch depths are prepared for immersion test in high-temperature pressurized water containing chloride ions (Cl-) at 300 degrees C. An immersion test with a duration of 1000 h shows that the scratched area with higher scratch depth has higher stress corrosion cracking sensitivity. In chloride-containing solution, Cl- erodes preferentially into the scratched area through the weak sites such as slip bands and deformed grain boundaries, and this process is continuously promoted with the assistance of higher residual strain in this area.