Radiation-induced Segregation and Void Swelling in 304 Stainless Steel

. Void swelling and radiation-induced segregation have been measured in 304 stainless steel. Samples were irradiated in the outer regions of the EBR-11reactor where displacement rates of 2.OX10-8and 6.6 xl 0-8dpds are comparable to those in pressurized water reactor components. Samples were inadiated at temperatures from 371-390°C to total doses of up to 20 dpa. Void swelling reached a maximum of 2 0/0 at 20 dpa. Nickel enrichment and chromium dep~etion of up to of 20 at% and 12 atO/Orespectively were measured. Both void swelling and radiation-induced segregation were dependent on dose rate, increasing as the dose rate decreased. Grain boundary compositions were measured both near and in areas free of precipitates. The presence of a precipitate significantly changes the grain boundary compositions near the precipitate.