| Project/Area Number |
16K05976
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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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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
武富 紳也 佐賀大学, 理工学部, 准教授 (20608096)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 水素脆化 / 格子欠陥 / 変形機構 / 材料強度 / 計算力学 / 第一原理計算 / 炭素 / 拡散 / 機械材料・材料力学 / 金属物性 / 計算物理 / 分子動力学 |
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| Outline of Final Research Achievements |
The initial atomic structures for all analyses were defined based on statistical thermodynamics. We revealed the interaction energy between carbon atoms and hydrogen atoms in lattice, near grain boundaries, and on free surfaces. The hydrogen desorption curves from vacancy clusters with different size, dislocations, and grain boundaries were also calculated. Furthermore, we obtained the binding energy of an atomic vacancy with vacancy clusters, and clarified the necessary vacancy concentration to let grow vacancy clusters by absorbing atomic vacancy and the influence of vacancy-cluster size on dissociation temperature of an atomic vacancy from vacancy clusters.
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| Academic Significance and Societal Importance of the Research Achievements |
水素によって材料強度が劣化する水素脆化の研究は，その重要性から継続的に行われてきたが，単純な材料系に対しても脆化メカニズムに関する統一的な見解は得られてこなかった．本研究では，材料の実際の使用環境に対応付けた条件設定を行い，水素原子の格子欠陥への影響を切り分けて解析した．得られた計算結果と実験的に得られている知見を総合することで，空孔数が数個の空孔クラスター（複空孔）が低合金鋼の脆化に強く関与していることを明らかにした．水素環境での鋼材の安全利用や，新しい材料の開発に繋がる成果である．
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