Effects of neutron irradiation on microstructure and mechanical propertiesof pure iron

Tensile specimens of pure iron were irradiated with fission neutrons (i) at 320 K to displacement dose levels of 7.5 x 10(-3), 7.5 x 10(-2) and 3.75 x 10(-1) dpa (NRT) and (ii) at 523 K to dose levels of 7.5 x 10(-2) and 2.25 x 10(-1) dpa (NRT). Both unirradiated and irradiated specimens were tensil e tested at the irradiation temperatures. Microstructures of the as-irradia ted and irradiated and tensile tested specimens were investigated by transm ission electron microscopy. Fracture surfaces of tensile tested specimens i n unirradiated and irradiated conditions were examined in a scanning electr on microscope. Results of these investigations are reported and discussed p articularly in terms of the role of interstitial clusters (produced directl y in the cascades) and their transport via one-dimensional glide. It is sug gested that the formation and interaction of 'cleared' channels may play a significant role in determining the deformation and fracture behaviour of t he irradiated pure iron. (C) 1999 Elsevier Science B.V. All rights reserved .