| Project/Area Number |
04650633
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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 |
金属加工(含鋳造)
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| Research Institution | Kagoshima University |
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Principal Investigator |
NAKANISHI Kenji Kagoshima University, Engineering, Professor, 工学部, 教授 (80041549)
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| Co-Investigator(Kenkyū-buntansha) |
KAMITANI Shunpei Kagoshima University, Engineering, Associate Professor, 工学部, 助教授 (40204622)
FUKUI Yasuyoshi Kagoshima University, Engineering, Associate Professor, 工学部, 助教授 (00117540)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Metal Forming Process / Flow Curves at Room Temp. / Flow Curves at High Temp. / Flow Curve Prediction / Analysis of Deformation Mechanism / Work-Hardening Rate Equations / Aluminum Alloy / Low Carbon Steel / 変形抵抗値推算 / 塑性加工シミュレーション / ステンレス鋼 |
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| Research Abstract |
Detailed analysis and forming simulation are proceeded to achieve successful and optimized metalforming processes. Those analysis and simulation require the constitutive equation representing flow stresses of a forming material with regard to deformation pass involving strain variation, strain-rate variaion and temperature variation in a deformation process. Experimental results reveal that many metallic materials show remarkable strain-rate dependence of flow stress at warm and hot deformation temperature. Head investigator proposed previously the work-hardening rate equations for predicting the flow curves of Copper deformed at varying strain-rate and at varying temperature. The method was adopted to the flow curve prediction of Aluminum (1100-0), Aluminum alloy (6063AA), Stainless steel (SUS304) and 0.39C low carbon steel in the present investigation. Then, the work-hardening rate equations involving some material constants could be determined for the above materials and the computer program of flow curve prediction was constructed. The program is available to predict the flow curves at temperatures in temperature range, room temperature-0.9Tm (Tm : Melting point K), for Alumninum, Aluminum alloy and Stainless steel, and at around room temperature for 0.39C Steel (Spheroidized carbides structure) and at above 800 ﾟC for 0.39C steel (Austenite structure). The above computer program was employed to evaluate the effective stress distribution in the deformation zone of Aluminum alloy billet in plane strain hot extrusion using some non-symmetric dies. Then, the effective stress distribytions in extrusion were predicted with taking into account effects of strain-rate distribution, strain distribution and temperature distribution (involving temperature rise due to plastic working energy). The results show variation of effective strain-rate on effective stress is quite remarkable and significant in the hot forming processes.
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