2016 Fiscal Year Final Research Report
Creation of nano-crystal-grains layer and Residual stress by the cutting and rubbing process in a notch of specimen
| Project/Area Number |
26420035
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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 | Oita National College of Technology |
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Principal Investigator |
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| Co-Investigator(Renkei-kenkyūsha) |
TODAKA Yoshikazu 豊橋技術科学大学, 大学院工学研究科・機械工学系, 教授 (50345956)
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| Research Collaborator |
OOYAMA Hideto
TAKAHASHI Kenichi
SATOH Takuma
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | 摩擦加工 / 微細結晶粒 / 回転曲げ疲労強度 / 強ひずみ加工 / 残留応力 / 応力集中 / V溝切欠き / ナノ結晶 |
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| Outline of Final Research Achievements |
In order to strengthen a actual machine part, research for strengthening a stress-concentration portion was carried out by using the circumferential V-notched specimen of heat treated SCM5435 steel. The cutting and rubbing processing produced the hard surface-layer with a fine microstructure at the helical-groove bottom. The layer had about 10 μm thickness and Vickers hardness value of 820 (2.7 times of non-processed surface). And the compressive residual stress is over 2000MPa. Rotating bending fatigue limit stress of the processed notched specimens was enhanced to 1.68 times of notched specimen which has not been processed. Although the specimen hardness was sharply dropped to HV of 400 at 0.1mm beneath the surface, the stress distribution of a helical-groove bottom declines rapidly from the maximum surface similarly. From this the effect of strengthening by cutting and rubbing processing is more efficient to a notched specimen than to a plain specimen.
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| Free Research Field |
金属疲労
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