New Expression Method of SCC Crack Growth Modeling

Abstract

This paper reports a new approach for the modeling of SCC crack growth in nuclear coolant environments. Many SCC tests have been carried out since 70’s. Some of crack growth rate data was observed to be widely scattered. Previous studies have concentrated on the prediction of crack growth rate in a wide range of stress intensity factor. On the review of many laboratory test data, we propose a process of crack growth of SCC is the coupled phenomenon as a result of synergistic state transition between mechanical system that consisted of stress and material, and chemical system that consisted of material and environment. The coupled phenomenon is a two-stage reaction as results of state transitions of material which commonly exists in the both systems. Since in the case of new approach, several critical reactions could exist in the process of SCC crack growth, it could be explained that an observed data in laboratory test was fluctuated.