Fracture toughness predictions for a reactor pressure vessel steel in the initial and highly embrittled states with the Master Curve approach and a probabilistic model

Predictions of the temperature dependence of cleavage fracture toughness are performed on the basis of the Master Curve approach and a probabilistic model for a 2Cr-Ni-Mo-V reactor pressure vessel steel in the initial (as-produced) state and in the highly embrittled state. Calculations of the K-IC(T) curve are carried out with both approaches on the basis of fracture toughness test results from pre-cracked Charpy specimens at some (one) temperature. The K-IC(T) curves for the initial state calculated with the Master Curve approach and the probabilistic model are compared and show good agreement. Cleavage fracture toughness values for the embrittled 2Cr-Ni-Mo-V steel are obtained by testing 2T-CT specimens over a wide temperature range. The calculated K-IC(T) curves of the embrittled steel are compared with the test results from the 2T-CT specimens. It is shown that, for the embrittled steel, the K-IC(T) curve predicted with the Master Curve approach does not fit adequately into the experimental data, whereas the agreement of the test results and the K-IC(T) curve calculated with the probabilistic model is good. (C) 2002 Elsevier Science Ltd. All rights reserved.