文章信息/Info

Title:

Modelling As-Cast Structure and Macrosegregation in Ingot Casting

作者:

吳孟懷1; 2;  Kharicha A1; 2;  Ludwig A2

Author(s):

Wu M1; 2;  Kharicha A1; 2;  Ludwig A2

1． Christian-Doppler Laboratory for Advanced Process Simulation of Solidification & Melting, University of Leoben, A-8700 Leoben, Austria
2．Department of Metallurgy, University of Leoben, A-8700 Leoben, Austria

關鍵詞:

凝固;  鑄錠;  宏觀偏析; 鑄態(tài)組織;  數值仿真

DOI:

10.7502/j.issn.1674-3962.2015.09.02

文獻標志碼:

A

摘要:

自 1960s Flemings 時代起人們經過半個世紀的努力已對鑄錠內鑄態(tài)組織和宏觀偏析形成的物理機理有了定性或半定量的認識，但還是難以對其進行定量預測，主要原因是其與各種多相流現象有關，例凝固糊狀區(qū)枝晶間的對流，等軸晶區(qū)晶粒沉積等。當然這些多相流現象是與凝固過程熱力學和擴散動力學以及宏觀鑄態(tài)組織形成過程相耦合的。近 20 年多相計算流體動力學的發(fā)展及其在凝固領域的應用為解決上述問題提供了有效手段。本報告將首先對這方面的進展作一個簡要綜述，然后通過具體事例重點展示其在鑄錠鑄態(tài)組織和宏觀偏析形成過程動態(tài)數值仿真的應用前景，指出目前成在的某些局限性。

Abstract:

Since 1960s the formation mechanisms of the as-cast structure and macrosegregation during solidification of steel ingots were systematically studied by Flemings and other researchers, and understanding to this issue was significantly achieved, but there is still no mathematical model which can quantitatively predict them. Reason is due to the complexity of the involved multiphase flow phenomena, e.g. interdendritic flow in the mush, sedimentation of free moving (equiaxed) crystals, etc..All these multiphase flow phenomena are coupled with the solidification thermodynamics and diffusion kinetics, affecting the formation of as-cast structure. The development of multiphase computational fluid mechanics (MCFD) and its application in the study of solidification in last two decades provide a new tool for solving the above problem. This report is going to give a brief review of the progress in this area. Some examples are presented to demonstrate the potential and limitations of this tool for the calculation of the as-cast structure and macrosegregation in ingot castings.