MECHANICAL-PROPERTIES OF NEUTRON-IRRADIATED LOWER ACTIVATED FE-CR-MN ALLOYS

Fe-Cr-Mn steels have been proposed as materials for structural compone nts of the fusion reactor because of their lower radio-activity in com parison with SUS 316 austenitic stainless steels. Therefore, it is req uired to characterize the material with respect to its mechanical prop erties and microstructural changes during neutron irradiation for the doses and temperatures relevant for first wall condition. For these ob jectives, a series of Fe-Cr-Mn-(Al) steels with different compositions have been examined in tensile tests and by electron microscopy after neutron irradiation up to 8 x 10(23) n/m(2) at 473 K. The 0.2% proof s tress, ultimate tensile stress and total elongation were compared befo re and after irradiation. The results indicate that both Fe-10%Cr-(20- 25)%Mn-3%Al and Fe-10%Cr-30%Mn steels show most radiation-resistant.