<span style="FONT-FAMILY: 宋体">铸锭宏观组织和偏析的数值仿真</span>-中国材料进展

文章信息/Info

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

摘要:: 自 1960s Flemings 时代起人们经过半个世纪的努力已对铸锭内铸态组织和宏观偏析形成的物理机理有了定性或半定量的认识，但还是难以对其进行定量预测，主要原因是其与各种多相流现象有关，例凝固糊状区枝晶间的对流，等轴晶区晶粒沉积等。当然这些多相流现象是与凝固过程热力学和扩散动力学以及宏观铸态组织形成过程相耦合的。近 20 年多相计算流体动力学的发展及其在凝固领域的应用为解决上述问题提供了有效手段。本报告将首先对这方面的进展作一个简要综述，然后通过具体事例重点展示其在铸锭铸态组织和宏观偏析形成过程动态数值仿真的应用前景，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.