| Project/Area Number |
15560167
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | Utsunomiya University |
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Principal Investigator |
NARAZAKI Michiharu Utsunomiya University, Faculty of Engineering, Associate Professor (00091950)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2005: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2004: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2003: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | HEAT TREATMENT / QUENCH DISTORTION / QUENCH CRACKING / RESIDUAL STRESS / OPTIMIZATION / SIMULATION / 鋼熱処理 / 液体ナトリウム / 冷却特性 / 熱伝達率 |
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| Research Abstract |
The quenching experiment of steel cylinder and steel disc was executed to improve the prediction accuracy of the phase transformation, distortion and stress during sodium quenching. Analytical accuracy was verified by comparing measured results with the result simulated with the heat-treatment process analysis code. It was confirmed that these measurement values and analytical values of cooling curves, hardness, distortion of steel specimens calculated by two heat-treatment process analysis codes (GRANTAS, DEFORM-HT), showed a good agreement. The simulation result of sodium quenching process showed that hard martensite layer near the surface of steel parts created by uniform rapid cooling on whole surface of steel parts in the first cooling stage results in uniform surface hardness, lower distortion, no cracking. In addition, the cooling rate in the lower temperature region (lower than Ms point) can be controlled by sodium quenching. Moreover, it was confirmed that the compressive residual stress was generated to surfaces of parts by uniform and rapid quenching. The quenching experiment and the simulation of quenching process of nonaxisymmetric shaped parts such as the steel axes with a key groove etc. was are executed. It was confirmed that sodium quenching is effective for practical use to control of the distortion and the cracking by hardening the complex shaped steel parts.
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