| Project/Area Number |
18K03841
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 18010:Mechanics of materials and materials-related
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| Research Institution | Kumamoto University |
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Principal Investigator |
Kawashima Fumiko 熊本大学, 大学院先端科学研究部(工), 准教授 (70506849)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2020: ¥260,000 (Direct Cost: ¥200,000、Indirect Cost: ¥60,000)
Fiscal Year 2019: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2018: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
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| Keywords | クリープ / TypeIV / 改良9Cr-1Mo鋼 / 余寿命評価 / ボイド / 最大主応力 / 応力多軸度 / ボイド発生速度 / ボイド成長速度 / creep / Mod.9Cr-1Mo steel / Triaxial Factor / void |
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| Outline of Final Research Achievements |
The creep tests with simulated FGHAZ of the Mod.9Cr-1Mo steel were conducted and samples with Type IV creep damage were gotten. Test specimens were notched bars. The test temperature was 650C. The maximum principal stress and stress triaxiality factors of the creep test were A)79MPa、2.9、B) 73MPa、21.9、and C)79MPa、3.3. The change of distribution of voids’ radius were observed and void’s initiate rate, f, growth rate of void’s radius, h, and start time of void’s initiation, t1, were evaluated.
The results were as follows; under the same TF of 2.9, the maximum principal stress of 79MPa gave larger f and h than that of 73MPa. Under the same stress of 79MPa, TF of 2.9 gave larger h than TF of 3.5, but f on both conditions were almost the same. All t1 on three conditions were almost zero.
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| Academic Significance and Societal Importance of the Research Achievements |
改良9Cr-1Mo鋼は火力発電所の高温化・高効率化に寄与するが、TypeIVクリープ損傷による破断により発電停止したことがある。破断の予想は困難であった。その理由は、第一に発電中の温度応力の正確な把握が難しく、第二に同じ温度応力条件であっても微小成分などが異なればクリープ寿命には10倍程度の差があり、第三にTypeIV損傷と応力と応力多軸度の定量的関係の評価法がなかったためである。
本研究では評価対象の定期検査結果に基づき定量評価を行ため、上記の課題を解決できる。本研究は耐熱鋼の火力発電所における安全な使用に寄与し、電力の安定供給、省エネルギー化、脱炭素化に役立つ。
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