1988 Fiscal Year Final Research Report Summary
High Temperature Fretting Fatigue of Turbine Steels Under Variable Loading Simulating Practical Operation
| Project/Area Number |
62550053
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械材料工学
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
MUTOH Yoshiharu Associate Professor of Nagaoka University of Technology, 工学部, 助教授 (00107137)
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| Co-Investigator(Kenkyū-buntansha) |
OKAZAKI Masakazu Associate Professor of Nagaoka University of Technology, 工学部, 助教授 (00134974)
TANAKA Kohichi Professor of Nagaoka University of Technology, 工学部, 教授 (90143817)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Fatigue / Fretting Fatigue / Variable Loading / Elevated Temperature / Shot Peening / Fracture Mechanics / Life Prediction / 蒸気タービン用鋼 |
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| Research Abstract |
The reduction of fatigue life by fretting was significant at both room and elevated temperatures. The improvement of fretting fatigue strength due to formation of glaze oxide film at elevated temperatures was not found in steam turbine steels used here. The S/N curves, where fretting fatigue life under block loading simulating practical load was arrauged using the wquivalent stress based on the modified miner's rule, were identical with those under constant amplitude loading at both room and elevated temperatures. This results indicate the effectiveness of the modified miner's rule to fretting fatigue under variable amplitude lading at elevated temperatures. the S-N curves, where fretting fatigue life under random loading was arranged using the rms-value of stress amplitudes, were almost identical with those under constant amplitude loading.
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