Improved probabilistic model for fracture toughness prediction for nuclearpressure vessel steels

An improved probabilistic model for fracture toughness prediction is repres ented which is based on the local criteria for cleavage and ductile fractur e proposed by the authors and an improved approximate solution for the prob lem of the stress-strain state near the crack tip. The main considerations of the previous probabilistic model are also used and some inexact consider ations of the previous model are eliminated. The probabilistic model allows prediction of the dependence of K-IC on temperature for any given probabil ity of brittle fracture, gives a description of the effect of specimen thic kness on K-IC, and allows determination of the scatter band for the brittle -to-ductile transition temperature. Comparison of experimental and calculat ed results as applied to 2.5Cr-Mo-V nuclear pressure vessel steel has been performed. (C) 1998 Elsevier Science Ltd. All rights reserved.