Modeling of the Divorced Eutectic Solidification of Spheroidal Graphite Cast Iron
Modeling of the Divorced Eutectic Solidification of Spheroidal Graphite Cast Iron
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DOI：
10.4028/www.scientific.net/kem.457.324
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发表时间：
2010-12
期刊：
影响因子：
--
通讯作者：
Honglei Zhao;M. Zhu;D. Stefanescu
中科院分区：
文献类型：
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作者：
Honglei Zhao;M. Zhu;D. Stefanescu
方解石-球状石墨（SG）共晶的凝固是最复杂的并且因此最难通过计算建模来描述的液-固转变之一。这是因为铁-碳平衡相图是不对称图，其预测在相对低的凝固速度下，可能在共晶组合物的铸件中产生初生奥氏体。此外，共晶的两相凝固为离异共晶，只有奥氏体与共晶液体接触。本文提出了一种用元胞自动机技术实现球墨铸铁共晶凝固组织演变可视化的计算模型。该模型是早期的朱Stefanescu模型的初级相凝固的扩展，并包括在液体中的初级SG，初生奥氏体和碳扩散通过固体奥氏体壳控制的石墨-石墨共晶的生长。该模型输出了球墨铸铁共晶凝固过程中组织演变的真实图像。
The solidification of the austenite-spheroidal graphite (SG) eutectic is one of the most complex and therefore most difficult liquid-to-solid transformations to describe through computational modeling. This is because the iron-carbon equilibrium phase diagram is an asymmetric diagram that predicts that at relatively low solidification velocities it is possible to produce primary austenite in a casting of eutectic composition. In addition, the two phases of the eutectic solidify as a divorced eutectic, with only the austenite being in contact with the eutectic liquid. The paper proposes a computational model for the eutectic solidification of SG iron with visualization of the microstructure evolution using a cellular automaton technique. The model is an extension of the earlier Zhu-Stefanescu model for primary phase solidification and includes the growth of primary SG in the liquid, of primary austenite and of the austenite-graphite eutectic controlled by carbon diffusion through the solid austenite shell. The model outputs realistic images of the microstructure evolution from the beginning to the end of eutectic solidification of SG cast iron.