Research Associate, Himeji Institute of Technology, Himeji,
Professor, Research Institute for Strength and Fracture of Materials, Faculty of Engineering, Tohoku University, Sendai,
A new evaluation procedure for the critical fracture toughness (KIc, KId) from Charpy-V impact absorbed energy is presented. The strain-rate/temperature effect on the cleavage-controlled fracture toughness transition is first explained by applying the concept of a stress-dependent rate process for fracture initiation. The expression described in terms of the Charpy-V energy ratio, Cv-us/Cv, for fracture toughness under a constant strain rate is newly derived. The feasibility of the new procedure for evaluating the irradiation embrittlement of reactor pressure vessel steel, such as SA533B-1, is here verified utilizing the data for both unirradiated and irradiated materials in the literature. Another method for the determination of coefficients in the new expression from the Cv-fitting curve is also presented.
Paper ID: JTE10319J