Effect of solid solution carbon on stress corrosion cracking of Alloy 600 in a primary water at 360 °C

The effect of solid solution carbon in Alloy 600 steam generator tube materials on the stress corrosion cracking behavior was evaluated using microstructure controlled materials with a carbide-free and similar grain size structure in a hydrogenated primary water at 360 °C. Stress corrosion cracking tests were performed using a slow strain rate tensile test method for specimens with a hump in the middle of the gauge length. The time to failure and maximum load of Alloy 600 containing 0.04% carbon increased by about a factor of two relative to those of Alloy 600 containing 0.01% carbon. The role of solid solution carbon was discussed with respect to the interaction between carbon and dislocation during the deformation process.