Formulation of the Stress Corrosion Crack Growth Rates Based on the Theoretical Strain Rate Model for Light Water Reactors

Abstract The stress corrosion cracking (SCC) growth rate in a light water reactor environment is usually expressed in the form of a power law of the stress intensity factor, K. However, the power law of K was originally introduced with reference to the Paris law in fatigue crack growth and it is not based on SCC growth theory. Based on the theoretical equation for the strain rate ahead of the crack tip of a growing crack, it is appropriate to express the SCC growth rate in the form of a power law of log(K/K0). On the other hand, the conventional equation in the form of a power law of K is based on the strain distribution ahead of the stationary crack and it is not theoretically appropriate for growing cracks. This study developed a formulation method for SCC growth rate based on SCC growth theory and the theoretical equation of strain distribution ahead of the crack tip. And it confirmed the applicability of the proposed formulation method for several types of materials.