R-AND-D OF LOW-ACTIVATION FERRITIC STEELS FOR FUSION IN JAPANESE UNIVERSITIES

Following the brief review of the R&D of low activation ferritic steel s in Japanese universities, the status of 9Cr-2W type ferritic steels development is presented. The main emphasis is on mechanical property changes by fast neutron irradiation in FFTF. Bend test, tensile test, CVN test and in-reactor creep results are provided including some data about low activation ferritic steels with Or variation from 2.25 to 1 2%. The 9Cr-2W ferritic steel, denoted as JLF-1, showed excellent mech anical properties under fast neutron irradiation as high as 60 dpa. As potential materials for DEMO and beyond, innovative oxide dispersion strengthened (ODS) quasi-amorphous low activation ferritic steels are introduced. The baseline properties, microstructural evolution under i on irradiation and the recent progress of new processes are provided.