2020 Fiscal Year Final Research Report
Establishment of Numerical Method of Local Plastic Strain by Nanoscale Marking
Project/Area Number |
18K04751
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 26040:Structural materials and functional materials-related
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Research Institution | Kyushu University |
Principal Investigator |
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Co-Investigator(Kenkyū-buntansha) |
田中 將己 九州大学, 工学研究院, 教授 (40452809)
奥山 彫夢 九州大学, 工学研究院, 学術研究員 (50804655)
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Project Period (FY) |
2018-04-01 – 2021-03-31
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Keywords | 転位論 / 力学物性 / 集合組織 / 変形微視組織 |
Outline of Final Research Achievements |
In dual-phase steels used in line pipes for laying deep-sea bottoms, the effect of the plastic inhomogeneity on the yield stress drop with load reversal was investigated, and the peculiar phenomenon of strain recovery in the local deformation region was found when the loading direction was reversed. On the other hand, in dual-phase steels for automotive applications, it was found that martensite, which contributes to strengthening, contributes to work hardening not only in the elastic deformation region but also after the onset of plastic deformation. The effect tended to saturate early in deformation when the volume fraction of martensite increased.
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Free Research Field |
結晶性材料における力学物性に及ぼす内部組織の影響および内部組織の形成過程
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Academic Significance and Societal Importance of the Research Achievements |
学術的には,材料の内部組織を複相化することで,どのように変形の不均一が助長され,それが材料の力学特性の向上に如何に寄与するかについて多くの知見が得られた. また,実用的には,ラインパイプに使われる複相鉄鋼材料の荷重逆転による降伏応力低下のメカニズムが解明され,自動車用複相鋼における強化組織の役割が明確化されたことにより,新たな材料開発指針を得るとともに,TRIP鋼などの他の材料種への知見の応用が示唆された.
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