The effect of low dose irradiation on the impact fracture energy and tensile properties of pure iron and two ferritic martensitic steels

Two batches of subsize V-notched impact bend specimens and subsize tensile specimens have been irradiated in the Saphir test reactor of the Paul Scherrer Institute (PSI). The first batch of specimen has been irradiated at 250 degrees C to a dose of 2.65 x 10(19) n/cm(2) (0.042 dpa) and the second batch has been irradiated at 400 degrees C to a dose of 8.12 x 10(19) n/cm2 (0.13 dpa). Three different materials in three different microstructures were irradiated: pure iron and two ferritic steels, the alloy MANET 2 and a low activation composition CETA. The results of the impact tests and of the corresponding tensile tests are presented. Despite the very low neutron dose, a significant shift of the ductile to brittle transition temperature (DBTT) is observed. The influence of the test temperature on the impact energy is discussed for the irradiated and unirradiated conditions, with special emphasis on the microstructure. (C) 1998 Elsevier Science B.V. All rights reserved.