Strategy for characterizing fracture toughness in the ductile to brittle transition regime

A tentative method is proposed for treating the scatter and size effects of fracture toughness of ferritic steels in the ductile-to-brittle transition regime. The method is aimed at the determination of the probability function for initiation of fast growing cleavage cracks under the plane strain condition. The practical relevance of this method has been checked with toughness data sets obtained from various CT-specimen sizes and CCT-specimens of a pressure vessel tested at two different temperatures in the transition regime. (orig.)