Mechanics and mechanisms of stress corrosion cracking and quantitative prediction of SCC growth rate

The secular distortion of nuclear power plants is a key factor for life extension and safety points of view. Establishment of reliable systems for repair and maintenance is essential to solute the problem. Stress corrosion cracking (SCC) is one of leading factors to affect degradation of the nuclear plants. For improving the availability factor of the plants, the organic combination of prediction of crack initiation, evaluation of crack growth rate and non-destructive testing is essential. In this review paper, the mechanism of SCC growth rate in austenitic steels and its modeling are summarized based on the recent studies. The status and future on quantitative prediction of the crack growth rate are discussed from the several points of view. In particular, prediction studies for unexperienced phenomena developed by NRC of USA, and approaches of connecting continuum mechanics prediction with physical phenomena of atomic levels developed in Europe are expected to get results. (A. Hishinuma)