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研究生: 張弘儒
Chang, Hung-Ju
論文名稱: 金屬線條之連續鑄造模式分析
Modeling Analysis of metal wire rods in continuous casting
指導教授: 黃文星
Hwang, Weng. Sing.
學位類別: 碩士
Master
系所名稱: 工學院 - 材料科學及工程學系
Department of Materials Science and Engineering
論文出版年: 2005
畢業學年度: 93
語文別: 中文
論文頁數: 98
中文關鍵詞: 凝固模式精細金屬連續鑄造
外文關鍵詞: Solidifying Model, Fine Metal, Continuous casting
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  •   在精細金屬線條的連鑄過程中,影響鑄件品質的因素很多,所以有必要對不同的操作條件作影響評估。針對此目標,本研究建立一穩態的數學模式來模擬精細金屬之連鑄過程的熱傳行為,物理模型包含石墨模與模內以固定鑄造速度移動之金屬材料。數值方法是使用有限差分法,以等效比熱-熱焓法來處理凝固時潛熱釋放的問題,於電腦程式之建立中,使用史蒂芬問題來驗證凝固模式之數值計算的正確性。本文依此建立的模式,針對不同之鑄造條件(鑄造速度、冷卻效應、金屬材料等),來作分析比較,並將溫度計算結果代入套裝軟體ANSYS,來做熱應力分析。由計算結果發現鑄造速度越快,沿軸向之溫度下降會越減緩,而且液體轉變成固體的深度會越深。冷卻速率越大,最後拉出石墨模的金屬線條的溫度會越低,但金屬線條上端的溫度梯度還是一樣的,到了金屬線條中後端溫度才有改變。至於金屬部份,以純銀的出口溫度最低,而純銅的液體轉變成固體的深度會最淺。

     In the continuous casting process of metal wire rod, many factors influence the casting quality, so it is necessary to evaluate the effects of different operation conditions. To achieve this object, a mathematical model of steady state was built in this paper to simulate the heat transfer of the continuous casting of metal wire rod. The physical model includes graphite mold and the metal in the mold with a constant casting speed. The numerical method is the finite difference method and the effective specific heat/enthalpy method is used to handle the release of latent heat during solidification. The accuracy of the computer program was verified by testing the Stefan problem. With the proposed model, different working conditions (different casting speeds, cooling effects and materials) were analyzed. The computing results of the temperature field were put into the commercial package ANSYS to do the analysis of thermal stress. From the computing results, it can be found that the increase of casting speed makes the decrease of temperature along the axial direction slower and the depth of liquid/solid interface larger. The bigger cooling rate makes the outlet temperature of metal from the graphite mold lower. For copper, silver and gold metals, silver has the lowest outlet temperature and copper has the smallest depth of solid/liquid interface.

    目錄 摘要 I Abstract II 目錄 III 圖目錄 VI 表目錄 VIII 符號說明 IX 第一章 緒論 I 1-1 研究背景 1 1-1-1金屬線材 1 1-1-2真空連續鑄造製程 2 1-2 文獻回顧 4 1-3 研究目的 5 第二章 理論分析 13 2-1 物理模型 13 2-2 基本假設 13 2-3統御方程式 14 2-4起始條件與邊界條件 15 2-4-1初始條件 15 2-4-2邊界條件 15 第三章 數值方法 21 3-1 差分方程式與解法 21 3-2 潛熱效應之計算方法 23 3-2-1 等效比熱法 (Effective specific heat method) 24 3-2-2 熱焓法 (Enthalpy method) 24 3-2-3 等效比熱-熱焓法 (Effective specific heat - Enthalpy method) 25 3-3 處理界面的方法 27 3-3-1. 完全緊密接觸 27 3-3-2. 非完全緊密接觸 29 3-4 求解流程與收斂條件 30 第四章 測試與討論 43 4-0 史蒂芬問題 43 4-1 ㄧ維的熱傳模式之數值測試 44 4-2 潛熱效應測試 44 4-2-1 凝固模式 46 4-2-2 測試結果討論 47 4-3 單純軸對稱與含液固相變化軸對稱的熱傳模式之測試 48 4-3-1 單純軸對稱熱傳模式之測試 48 4-3-2 液固相變化軸對稱的熱傳模式之測試 48 4-4 金屬與石墨模間之界面熱傳係數之測試 49 第五章 結果與討論 65 5-1 加入石墨模計算的溫度分布圖與實驗驗證 65 5-2 不同的鑄造速度 67 5-3 不同界面熱傳係數的計算結果 67 5-3-1 界面熱傳係數(heff)的大小 68 5-3-2 界面熱傳係數(heff)分佈的趨勢 68 5-4 不同材料的計算結果 69 第六章 結論 93 參考文獻 95

    參考文獻
    1. J. S. Hsiao, "An Efficient Algorithm for Finite Difference Analysis of Heat Transfer with Melting and Solidification," Numerical Heat Transfer, Vol. 8, pp. 653-666, 1985.
    2. J. A. Dantzig, “Modeling Liquid-Solid Phase Changes with Melt Convection”, International Journal of Numerical Methods in Engineering V28, n8, pp. 1769-1785, August 1989.
    3. 張建宏,”多晶矽薄膜製程之研究” 國立成功大學工程科學研究所碩士論文,2002。
    4. J. P. Holman, “ Heat transfer,” 9th edition, Mcgraw-Hill company, New York, USA, 2002.
    5. M. Uoti, M. Immonen, and K. Harkki, “Theoretical and Experimental Study of Vertical Continuous Casting of Copper.”
    6. R. Wilson, “A Practical Approach to Continuous Casting of Copper-Based Alloys and Precious Metals,” IOM Communication Ltd., London, UK, 2000.
    7. 何永和,”連鑄模中操作條件影響鋼液清淨度的數值模擬及驗證” 國立成功大學材料科學及工程學系博士論文,1998。
    8. D.A. Anderson, J. C. Tannehill, and R.H. Pletcher, Computational Fluid Mechanics and Heat Trandfer, Hemisphere, Washington D.C.,U.S.A.,1984
    9. S. Louhenkilpi, E. Laitinen, and R. Nieminen, “Real-Time simulation of heat Transfer in Continuous Casting”, Metallurgical Transactins B, Vol. 24B, 1993, PP. 685-693.
    10. C. H Kuo, M. J. Lu, and Y. H. Chung, “Optimization of Air-Water Mist Cooling of Slab During Continuous Casting Process”, China steel Technical Report. No. 5, 1991, pp. 74-83.
    11. H. C. Huang, Y. H. Chung, K. J. Lin, and Y. P. Chen, “A Continuous Casting Model of Air-Mist Cooling for Slab”, Symposium Proceedings on Transport Phenomena and Applications, Taipei, 1990, pp. 197-202.
    12. S. K. Choudhary, D. Mazumdar, and A. Ghosh, “Mathematical Modeling of Heat Transfer Phenomena in Continuous Casting of Steel”, ISIJ International, Vol. 33, No. 7, 1993, pp. 764-774.
    13. S. Lougenkilpi, “Modelling of Heat Transfer in Continuous Casting”, Materials Science Forum, Vol. 414-415, 2003, pp. 445-454.
    14. B. Q. Li, P. N. Anualebechi, “A Micro/Macro Model for Fluid Flow Evolution and Microstructure Formation in Solidification Process”, Int. J. Heat. Mass. Transfer. Vol. 38, No. 13, 1995, pp.2367-2381.
    15. J. M. Rodriguez, A. Esteva, S. Meza, “A Note on the Control of the Solidification Front in the Continusous Casting of Copper tubes”, Journal of Materials Processing Technology 96, 1996, pp. 42-47.

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