The NLF series of steels are reduced activation ferritic-martensitic (RAFM) steels that are a par... more The NLF series of steels are reduced activation ferritic-martensitic (RAFM) steels that are a part of the Japanese program to produce a suitable reduced activation ferritic-martensitic steel for the ITER project. Published reports on the NLF steels after about 35 dpa at 400°C by Kurishita et al., indicate that these steels have similar strength and better ductility than other RAFM steels such as the JLF steels and F82H irradiated at 400°C to similar doses. The tensile properties of NLF steels irradiated at $400°C to doses as high as 67 dpa are presented here. Tensile tests were conducted at a strain rate of 5 · 10 À4 s À1 at 25, 400°C, and 500°C. Variations in irradiation temperature in the range of 390-430°C had a relatively small, but definite effect on the tensile properties for tests conducted at 25, 400, and 500°C. The strongest hardening is observed for specimens irradiated at 390°C, and very little hardening is observed for specimens irradiated at 430°C. Strain rate jump tests were performed on NLF-0 and NLF-1 at 400°C after irradiation to 52 dpa. The rate sensitivity, m, is quite low, 0.003-0.005 and does not appear to be affected by irradiation at 52 dpa for an irradiation temperature of 430°C.
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Papers by A. Kimura