2017 Fiscal Year Final Research Report
Deformation Twinning and Related Change in Mechanical Properties in Stainless Steel Processed by Low ECAP Passes
| Project/Area Number |
15K06510
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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 |
Material processing/Microstructural control engineering
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| Research Institution | Osaka City University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
内田 真 大阪市立大学, 大学院工学研究科, 講師 (90432624)
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Keywords | ステンレス鋼 / 強ひずみ加工 / 引張変形 / 疲労 / 双晶 |
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| Outline of Final Research Achievements |
Austenitic stainless steel was processed by equal-channel angular pressing (ECAP) for one and two passes, using a die heated at 423K. To increase deformation twin density, some two-pass samples were annealed insertionally before the second pass. In addition, some samples including one-pass samples were post-annealed after the last ECAP pass, to homogenize a heavily-deformed structure. The insertional annealing at 600 degree Celsius resulted in increase in twinned area up to 47 %, and the tensile strength of this two-pass sample attained to be 1160MPa. For the one-pass samples, by the post-annealing at 600 degree Celsius, the fatigue strength under a high-cycle condition improved and the fatigue softening under a low-cycle condition was moderated. The as-ECAPed two-pass sample showed a high fatigue strength and a small fatigue softening, and no significant influence of the heat treatments on fatigue performance was recognized for the two-pass samples.
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| Free Research Field |
材料工学
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