Prediction of fracture toughness of reactor pressure-vessel steels on the basis of the 'master curve' approach and probabilistic model

摘要

On the basis of a probabilistic model and "Master Curve" approach we perform prediction of the brittle fracture-toughness temperature dependence of 15Kh2NMFA reactor pressure-vessel steel in the initial and high-embriffled states. Calculations of the K{sub}(IC)(T) curve have been carried out using these approaches on the basis of the results of fracture toughness testing of precracked Charpy specimens at some (single) temperature. The K{sub}(IC)(T) curves for the initial state calculated with the Master Curve approach and the probabilistic model are compared and their good agreement is shown. Experimental values of the fracture toughness have been obtained for the embrittled 15Kh2NMFA steel through testing compact-tension 2T-CT specimens over a wide temperature range. We compared the calculated K{sub}(IC) (T) curves for the embriffled steel with the corresponding test results. It is shown that the K{sub}(IC) (T) curve for the embrittled steel calculated in accordance with the Master curve approach does not describe the experimental data adequately At the same time, the agreement of the experimental data on fracture toughness and the K{sub}(IC)(T) curves calculated by the probabilistic model is good.