亚共晶灰铸铁非平衡凝固过程的微观数值模拟

根据亚共晶灰铸铁非平衡凝固过程的特点，提出了数值模拟其凝固组织的一套方法，其中主要包括奥氏体枝晶生长过程体积分数的计算以及晶粒接触因素的处理，该方法以样杯中浇注的试验块的对象进行实验验证，模拟得到的冷却曲线、奥氏体分及人晶团密度均与实测结果取得了较好的一致。

Micro-Modeling of Non-EquilibriumSolidification Process of Hypoeutectic Gray Iron

To our best knowledge, there exist only micro-modeling results on equilibrium solidification process of hypoeutectic gray iron in the open literature. But in industrial production the solidification process of hypoeutectic gray iron is always non-equilibrium. We propose a method in section 2 through section 5 for micro-modeling of the non-equilibrium solidification process of hypoeutectic gray iron; the method contains the calculation of volume fraction of dendritic austenite (section 2) and the treatment of grain impingement (section 5). In section 6 we give experimental results. Fig.1 shows good agreement of solid cooling curve (calculated by our micro-modeling method) with dotted cooling curve (test results).Table 1 shows the good agreement of calculated results with test results for ΔT (max undercooling), N (eutectic cell density), and fs(γ) (dendritic austenite fraction).