2020 Fiscal Year Research-status Report
Development of a novel multi-directional thermomechanical process to optimize the microstructure of Oxide-Dispersion-Strengthened (ODS) ferritic steel
| Project/Area Number |
20K14445
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| Research Institution | National Institute for Fusion Science |
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Principal Investigator |
申 晶潔 核融合科学研究所, ヘリカル研究部, 助教 (80824747)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 12Cr ODS steel / Recrystallization / Tensile properties / Microstructure / Oxide particles |
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| Outline of Annual Research Achievements |
In fiscal year 2020, recrystallization of 12Cr ODS steel was achieved by the new thermomechanical process, namely, multi-directional cold rolling with a thickness reduction of 90% and subsequent annealing at 1000 ℃ and 1100 ℃. It was found that both size and number density of oxide particles were not obviously changed after annealing. Tensile tests in the temperature range between room temperature and 700 ℃ were carried out. In addition, dog-bone shape tensile specimens and 0.2 mm thick disks with a diameter of 3 mm were prepared for neutron irradiation at Belgian Reactor 2 (BR2) via collaborative research with Oarai Center, Institute for Materials Research, Tohoku University.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
As the proposed schedule of this study, microstructure of recrystallized 12Cr ODS steel was characterized, and tensile properties in the range of room temperature - 700 ℃ were evaluated in FY 2020. Specimens for the creep test are preparing. Creep test machines need maintenance and machine time will be arranged for the recrystallized specimens.
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| Strategy for Future Research Activity |
Based on the schedule of this study, creep properties of recrystallized specimens are planned to be evaluated. Regarding the creep test, it is time-consuming, and creep test machines inevitably need a lot of maintenance. Moreover, in order to investigate the irradiation resistance and the stability of oxide particles under irradiation, high energy ion irradiation experiments at both room temperature and high temperatures will be performed via joint usage/research with other universities and/or institutes.
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| Causes of Carryover |
Some specimens were made using other budget before this budget came. Tensile test holder was not necessary to change in this fiscal year. Besides, due to the COVID-19 pandemic, the domestic and international conferences were held online so that the registration fee became cheaper and there was no need for travel expenses.
This amount of budget would be used in the next fiscal year for machining specimens and ion irradiation experiments.
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