Fracture toughness test results of precracked Charpy specimens of irradiated 73 W weld material

This work investigates the use of precracked Charpy specimens to predict fracture toughness behaviour of reactor pressure vessel steels. Fracture toughness measurements were performed on the 73 W weld material previously tested by Oak Ridge National Laboratories (ORNL). Charpy-size specimens were tested in three-point bend and compared with the original data obtained on large compact tension (CT) samples. Fracture toughness tests were performed in both unirradiated and irradiated (T_irrad≈288 °C and Φ≈1.5 10¹⁹ n/cm², E>IMeV) conditions. Most of the Charpy size samples were reconstituted from broken CT specimens. Fracture toughness data obtained using Charpy size samples are in good agreement with results from large CT samples. Moreover, the various temperature shifts measured by the Charpy impact test data are in agreement with the fracture toughness shifts. Reconstitution results in a decrease of the upper shelf energy but has little effect on the other transition parameters.