THE EFFECT OF TITANIUM ADDITION ON MICROSTRUCTURAL EVOLUTION IN AUSTENITIC STEEL IRRADIATED WITH FAST-NEUTRONS IN FFTF

Austenitic model alloys were irradiated with fast neutrons in FFTF (Fast Flux Test Facility) to investigate fundamental mechanisms of microstructural evolution in simple austenitic steels under relatively high dose irradiation. Irradiations were performed in MOTA (Material Open Test Assembly) at 693, 793 and 873 K. Void swelling was reduced by the addition of minor elements such as titanium and carbon to a simple Fe-Cr-Ni ternary alloy at all the tested temperatures. In the titanium bearing alloys, very small cavities were detected on dislocation lines and MC precipitates. Fine dislocation loops were observed in the matrix of the irradiated materials and their size and density were not found to be affected by the solute additions.