The high efficiency of Ce addition in grain refinement of δ-ferrite in a cast Fe–4 wt.%Si alloy was verified. In order to further understand the solute effect of Ce on the grain refinement of δ-ferrite, the conventional directional solidification technique, which enabled to freeze the solid–liquid interface to room temperature, was used to investigate the interfacial morphology and solute redistribution in the liquid at the front of the interface, together with thermodynamic calculation of the equilibrium partition coefficients of Ce and Si in Fe–4 wt.%Si–Ce system using the Equilib module and the FsStel database in FactSage software system. Metallographic examination using a laser scanning confocal microscope showed a transition of the solid–liquid interface from planar to cellular in the Fe–4 wt.%Si alloy after adding 0.0260 wt.% Ce during the directional solidification experiment. Further, electron probe microanalysis revealed an enhanced segregation of Si solute in the liquid at the front of the solid–liquid interface due to the Ce addition. This solute segregation is considered as the cause of planar to cellular interface transition, which resulted from the creation of constitutional supercooling zone. Thermodynamic calculation indicated that Ce also segregated at the solid–liquid interface and the Ce addition had negligible effect on the equilibrium partition coefficient of Si. It is reasonable to consider that the contribution of Ce to the grain refinement of δ-ferrite in the cast Fe–4 wt.%Si alloy as a solute was marginal.

证明了在铸造Fe–4 wt。％Si合金中δ族铁素体晶粒细化中添加Ce的高效率。为了进一步了解Ce对δ铁素体晶粒细化的溶质影响，使用常规的定向凝固技术将固液界面冻结到室温，研究了Ce的界面形态和溶质的重新分布。界面前端的液体，以及使用FactSage软件系统中的Equilib模块和FsStel数据库，对Fe–4 wt。％Si–Ce系统中Ce和Si的平衡分配系数进行热力学计算。使用激光扫描共聚焦显微镜进行的金相检查显示，在添加0.0260 wt％的Fe-4 wt。％Si合金后，固液界面从平面过渡到蜂窝。在定向凝固实验中的％Ce。此外，电子探针显微分析显示，由于添加了Ce，固溶体界面前部液体中的Si溶质偏析增强。这种溶质的分离被认为是平面到细胞界面过渡的原因，这是由构成过冷区的产生引起的。热力学计算表明，铈也偏析在固液界面上，而铈的添加对硅的平衡分配系数的影响可忽略不计。有理由认为，Ce对铸造的Fe–4 wt。％Si合金中的δ-铁素体晶粒细化的溶质贡献很小。电子探针显微分析显示，由于添加了Ce，固溶体界面前部液体中Si溶质的偏析增强。这种溶质的分离被认为是平面到细胞界面过渡的原因，这是由构成过冷区的产生引起的。热力学计算表明，铈也偏析在固液界面上，而铈的添加对硅的平衡分配系数的影响可忽略不计。有理由认为，Ce对铸造的Fe–4 wt。％Si合金中的δ-铁素体晶粒细化的溶质贡献很小。电子探针显微分析显示，由于添加了Ce，固溶体界面前部液体中Si溶质的偏析增强。这种溶质的分离被认为是平面到细胞界面过渡的原因，这是由构成过冷区的产生引起的。热力学计算表明，铈也偏析在固液界面上，而铈的添加对硅的平衡分配系数的影响可忽略不计。有理由认为，Ce对铸造的Fe–4 wt。％Si合金中的δ-铁素体晶粒细化的溶质贡献很小。这是由于建立了宪法过冷区。热力学计算表明，铈也偏析在固液界面上，而铈的添加对硅的平衡分配系数的影响可忽略不计。有理由认为，Ce对铸造的Fe–4 wt。％Si合金中的δ-铁素体晶粒细化的溶质贡献很小。这是由于建立了宪法过冷区。热力学计算表明，铈也偏析在固液界面上，而铈的添加对硅的平衡分配系数的影响可忽略不计。有理由认为，Ce对铸造的Fe–4 wt。％Si合金中的δ-铁素体晶粒细化的溶质贡献很小。