MODELING AND QUANTITATIVE PREDICTION OF ENVIRONMENTALLY ASSISTED CRACKING BASED UPON A DEFORMATION-OXIDATION MECHANISM

摘要

In order to provide a quantitative tool for predicting EAC growth rates for austenitic alloys such as austenitic stainless steels, Alloys 600 and 182 in simulated LWR environments, a model based upon the synergistic effects of deformation and oxidation at the crack tip has been proposed. In this paper, the effects of hardening, variation of K with crack growth and oxidation kinetics on EAC growth rate are described with special emphasis on field applications. The results imply recent cracking incidences in BWR core shroud and Primary Loop Recirculation (PLR) piping and PWR Vessel Penetrations (VP). In particular, the significance of oxide analysis at the crack tip and also of a kinetic approach to oxidation under stress or strain condition is described. Potential future directions for mitigation of such cracking are discussed.