| Project/Area Number |
25249099
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Kyushu University |
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Principal Investigator |
Tsuzaki Kaneaki 九州大学, 工学(系)研究科(研究院), 教授 (40179990)
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| Co-Investigator(Kenkyū-buntansha) |
SAWAGUCHI Takahiro 物質・材料研究機構, 主席研究員 (30354161)
KOYAMA Motomichi 九州大学, 大学院工学研究院, 助教 (20722705)
MATSUNAGA Hisao 九州大学, 大学院工学研究院, 准教授 (80346816)
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| Co-Investigator(Renkei-kenkyūsha) |
NOGUCHI Hiroshi 九州大学, 大学院工学研究院, 教授 (80164680)
HIGASHIDA Kenji 九州大学, 大学院工学研究院, 教授 (70156561)
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥45,370,000 (Direct Cost: ¥34,900,000、Indirect Cost: ¥10,470,000)
Fiscal Year 2015: ¥13,780,000 (Direct Cost: ¥10,600,000、Indirect Cost: ¥3,180,000)
Fiscal Year 2014: ¥14,040,000 (Direct Cost: ¥10,800,000、Indirect Cost: ¥3,240,000)
Fiscal Year 2013: ¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000)
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| Keywords | 高Mnオーステナイト鋼 / 疲労変形 / 低サイクル疲労 / 疲労き裂進展 / マルテンサイト変態 / 鉄鋼材料 / 耐震性 / 震災復興 / High-Mn steel / 破壊 / 機械的性質 / ミクロ組織 |
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| Outline of Final Research Achievements |
In order to determine the optimal alloy composition, we investigate the low-cycle fatigue properties of seven Fe-30Mn-(6-x)Si-xAl alloys with x=0 to 6. The alloys are prepared by induction melting. Cylindrical fatigue specimens with a diameter of 8 mm are machined from the annealed alloys after hot forging and rolling. The specimens are subjected to axial-strain-controlled low-cycle fatigue tests in air at a constant total strain range of 2.0 %. The volume fractions of the constituent phases are determined using X-ray diffraction analyses, and the deformation microstructures are observed using scanning electron microscopy, electron backscatter diffraction (SEM-EBSD) and transmission electron microscopy (TEM). We have found that the Fe-30Mn-4Si-2Al alloy with FCC-HCP martensitic transformation shows the best fatigue life of more than 8,000 cycles. It is interesting to note that the alloy has an intermediate value of SFE (stacking fault energy) among the present seven alloys.
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