1 School of Material and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China; 2 Inner Mongolia Autonomous Region Key Laboratory of Advanced Metal Materials, Baotou 014010, Inner Mongolia, China; 3 School of Mechanical and Mining Engineering, The University of Queensland, Brisbane QLD 4072, Australia; 4 Testing Center, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China; 5 Analytical Applications Center SHIMADZU (China) Co., Ltd., Shanghai 200233, China
Effect of Ce on solute redistribution in liquid ahead of solid–liquid interface during solidification of Fe–4 wt.%Si alloy
1 School of Material and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China; 2 Inner Mongolia Autonomous Region Key Laboratory of Advanced Metal Materials, Baotou 014010, Inner Mongolia, China; 3 School of Mechanical and Mining Engineering, The University of Queensland, Brisbane QLD 4072, Australia; 4 Testing Center, Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China; 5 Analytical Applications Center SHIMADZU (China) Co., Ltd., Shanghai 200233, China
摘要 The high efficiency of Ce addition in grain refinement of d-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 d-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 ofthe equilibrium partition coefficients of Ce and Si in Fe–4 wt.%Si–Ce system using the Equilib module and the FsSteld at a base 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 micro analysis revealed an enhanced segregation of Sisolute 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 super cooling 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 d-ferrite in the cast Fe–4 wt.%Si alloy as a solute was marginal.
Abstract：The high efficiency of Ce addition in grain refinement of d-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 d-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 ofthe equilibrium partition coefficients of Ce and Si in Fe–4 wt.%Si–Ce system using the Equilib module and the FsSteld at a base 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 micro analysis revealed an enhanced segregation of Sisolute 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 super cooling 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 d-ferrite in the cast Fe–4 wt.%Si alloy as a solute was marginal.
Yun-ping Ji,Ming-xing Zhang,Yuan Hou, et al. Effect of Ce on solute redistribution in liquid ahead of solid–liquid interface during solidification of Fe–4 wt.%Si alloy[J]. Journal of Iron and Steel Research International, 2021, 28(10): 1251-1258.
2021, Vol. 28 
