INTERACTION BETWEEN THE DEFORMATION AND THE IRRADIATION DEFECT CLUSTERS IN AUSTENITIC STEELS

The response of the irradiation-induced microstructure to deformation was examined in a model alloy (Fe/18wt%Cr/14wt%Ni) irradiated at about 1 dpa with 700 keV Kr2+ ions at temperatures varying from 523 to 873 K. Different microstructures are observed: from a high density of blac k dots to large isolated loops. When the microstructure consists of la rge loops, after strain the main fraction of loops becomes unfaulted a nd the glide is localised in planes. We observe the agglomeration of p erfect loops by glide and helical screw dislocations. Only a few examp les of pinning have been scarcely detected. We analyse configurations of perfect loops which tend to come together. In a 20% cold-worked 316 L stainless steel irradiated by Kr2+ ions at 623 K we observe the evol ution of the dislocation cells from 1 to 5 dpa. No initial network rem ains at 5 dpa and small loops appear.