The microstructure and tensile properties of Fe-Cr alloys after neutron irradiation at 400 C to 5.5-7.1 dpa

Room temperature tensile properties, void swelling and microstructural changes in Fe-Cr alloys (0,2,6,12 and 18 at.%Cr) have been studied following irradiation at 400 C in the BR-10 fast reactor to doses in the range 5.5-7.1 dpa. Swelling of 3%,0.03% and 0.1% was found in Fe, Fe-2Cr and Fe-12Cr alloys, respectively. No voids were observed in Fe-6Cr and Fe-18Cr alloys. In Fe, Fe-2Cr and Fe-6Cr dislocation loops lie in {100} habit planes and have a left angle 100 right angle Burgers vector, while in Fe-12Cr and Fe-18Cr alloys a mixed population of loops with a left angle 100 right angle and a/2 left angle 111 right angle Burgers vectors have been observed. The strength of irradiated alloys increases and ductility decreases with increasing Cr content. Fe-18Cr alloy revealed a severe embrittlement after irradiation. (orig.)