Abstract
Stress corrosion cracking (SCC) tests under controlled potentials were conducted on plastically stressed C-rings of Alloy-800 to evaluate the effect of thermal treatments (at 500 to 850 C) on SCC of Alloy-800 steam generator tubing. The tests were conducted in a caustic solution at 300 C; such alkaline environments may sometimes form in crevices in nuclear steam generators. The results are presented in the form of a time-temperature-SCC diagram.
Thermal treatments generally inhibited the SCC of Alloy-800, and the improvement was substantial in a few cases. Application of anodic potential and increasing stress generally accelerated SCC.
Abstract
Stress corrosion cracking (SCC) tests were carried out on specimens of Monel 400, Inconel 600, and Sanicro 30 steam generator tubing in solutions containing 10 to 500 g NaOH/kg H2O at 300 C for times up to 600 days. Applied stress and sodium hydroxide concentration had a significant effect on the (SCC) resistance of the three materials.
Abstract
Nuclear grade production tubing of Alloy 600 was evaluated for stress corrosion cracking (SCC) susceptibility in high purity water at 365, 345, 325, and 290 C. Reverse tube U-bend specimens provided crack initiation data and constant extension rate tests were employed to determine the crack velocities experienced in the crack propagation stage. Initial results indicate that a linear extrapolation of data received from high temperature tests can be used to predict the service life of steam generator tubing that has been plastically deformed or is continually deforming by “denting.”
Laboratorial technique for fabrication of outer diameter stress corrosion cracking on steam generator tubing