| Project/Area Number |
23560109
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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 | Tokuyama College of Technology |
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Principal Investigator |
NISHIMURA Futoshi 徳山工業高等専門学校, 機械電気工学科, 教授 (70189314)
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| Co-Investigator(Kenkyū-buntansha) |
MORINO Kazuhiro 呉工業高等専門学校, その他部局等, その他 (90099870)
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| Project Period (FY) |
2011 – 2013
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| Project Status |
Completed (Fiscal Year 2013)
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| Budget Amount *help |
¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000)
Fiscal Year 2013: ¥260,000 (Direct Cost: ¥200,000、Indirect Cost: ¥60,000)
Fiscal Year 2012: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2011: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
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| Keywords | 球状黒鉛鋳鉄 / ラジカル窒化 / 高サイクル疲労 / 疲労強度 / 耐摩耗性 / 疲労 / 残留応力 / 硬さ / 摩耗特性 |
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| Research Abstract |
Spheroidal graphite cast iron has high strength and high toughness in the static property. However, it is well known that the fatigue strength is not so great. On the other hand, surface treatment that hardens surface and generates the compressive residual stress is an effective method to relay the crack initiation.
In this study, radical nitriding, one of superior surface treatment methods, was applied to ferritic spheroidal graphite cast iron and the effect of nitriding on the mechanical property (hardness, wear resistance and fatigue strength) were investigated in comparison with as cast one. Fatigue strength was increased by nitriding. Fracture started from microshrinkages or abnormal graphites in the same manner as that of as cast iron. The cause of these results was the hardened layer and the compressive residual stress, which suppressed the initiation of the surface crack.
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