Evaluation Of Fracture Toughness Master Curve Shifts For Jmtr Irradiated F82h Using Small Specimens

Small to ultra-small 1/3 size pre-cracked Charpy and 1.65 x 1.65 x 9 min deformation and fracture minibeam (DFMB) specimens of the F82H 1EA heat were irradiated to 0.02 and 0. 12 dpa at 290 degrees C in the Japanese Materials Test Reactor. Nominal cleavage transition temperature shifts, based on the measured toughness, K-Jm(T), data (Delta T-m) as well as reference temperature shifts (Delta T-0) found after size-adjusting the K-Jm(T) data yielded Delta T-m/0 approximate to 27 +/- 10 and 44 +/- 10 at the two doses, respectively. Using measured yield stress changes (Delta sigma(y)), the C-0 = Delta T-0/Delta sigma(y) = 0. 58 +/- 0.14 at 0. 12 dpa, is in good agreement with data in the literature. The dynamic transition temperature shift, Delta T-d, derived from DFMB tests, was approximate to 30 +/- 20 degrees C at 0.1 dpa, also in good agreement with the estimated Delta T-0 shifts. The Delta T-d and Delta T-0 are also in excellent agreement with a Delta T-0 = C-0 Delta sigma(y) (dpa, T-i) hardening-shift model, where the Delta sigma(y) (dpa, T-i) was found by fitting a large database of tensile properties. C 2007 Elsevier B.V. All rights reserved.