J. Mater. Sci. Technol. ›› 2009, Vol. 25 ›› Issue (04): 561-568.

• Articles • 上一篇    下一篇

Fe-0.8wt%C合金宏观偏析形成的数值模拟

刘东戎1;李殿中2;桑宝光3   

  1. 1. 沈阳中科院金属所; 哈尔滨理工大学;
    2. 中国科学院金属研究所材料加工模拟研究部
    3. IMR
  • 收稿日期:2008-02-27 修回日期:2008-07-24 出版日期:2009-07-28 发布日期:2009-10-10
  • 通讯作者: 刘东戎
  • 基金资助:

    中国科学院知识创新项目;中国科学院知识创新项目

Numerical Simulation of Macrosegregation for an Fe-0.8 wt pct C Alloy

Dongrong Liu1,2)†, Dianzhong Li1),  Baoguang Sang1)   

  1. 1) Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    2) School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China
  • Received:2008-02-27 Revised:2008-07-24 Online:2009-07-28 Published:2009-10-10
  • Contact: Dongrong Liu
  • Supported by:

    the Innovative Scientific-Research Project of Institute of Metal Research, CAS under grant No. KGCXZ-YW-206
    the Post-Doctor Foundation for China under grant No. 20080431162
    the Foundation of Harbin University of Science and Technology, China under grant No. 20081526

RichHTML

8

PDF (PC)

1327

摘要：

本文模拟了等轴晶Fe-0.8wt%C合金凝固过程中宏观偏析的形成。基于两相体积元平均技术，计算了凝固过程中传热、对流、成分分布、形核和晶粒生长。设计了弱耦合算法求解守恒方程。模拟了冷却速度，形核密度，热对流和溶质对流相对强度改变对宏观偏析形成的影响。计算结果表明，增大冷速有助于成分的均匀化；增大形核密度会减小宏观偏析；热对流和溶质对流之间的相对强度决定通道偏析形成的方向。

关键词: 宏观偏析;通道偏析;热溶对流;Fe-C 合金

Abstract:

Macrosegregation in Fe-0.8 wt pct C alloy solidifying with equiaxed morphology was numerically simulated. Based on a two-phase volumetric averaging approach, heat transfer, melt convection, composition distribution, nucleation and grain evolution on the system scale were described. A weak-coupling numerical procedure was designed to solve conservation equations. Simulations were conducted to study the effects of cooling rate and nuclei density on the macrosegregation pattern. The relative influence of thermal buoyancy- and solutal buoyancy-induced flows on macrosegregation was identified. Calculated results indicate that a higher cooling rate establishes a more homogeneous composition. More uniform solute distributions are formed with increasing nuclei density. In addition, it is noted that the direction of channel segregates depends on the relative strength of thermal and solutal buoyancy forces.

Key words: Macrosegregation, Channel segregation, Thermosolutal convection, Fe-C alloy