Effects of Irradiation Fluence and Creep on Fracture Toughness of 347/348 Stainless Steel

摘要

The postirradiation fracture toughness of Type 347/348 stainless steel was investigated using 5.08-mm thick three-point bend specimens tested at 427 exp 0 C. The J/sub Ic/ values were determined using the single-specimen unloading compliance technique in accordance with ASTM E 813-81. Equivalent values of plane strain fracture toughness, K/sub Ic/, were computed from experimentally determined J/sub Ic/ values for several fluence levels ranging from 2.3 to 4.8 x 10 exp 22 n/cm exp 2 (E > 1.0 MeV) and for irradiation creep of 0.0, 0.6, 1.1, and 1.8%. The test matrix involved four variables: fluence, creep, helium content, and heat-to-heat variation. Results show that an interpolated trend exists, i.e., K/sub Ic/ decreases with increasing combinations of fluence, creep, and helium content. These results also suggest that irradiation creep has less effect on reducing K/sub Ic/ than has been suggested previously. (ERA citation 09:043841)