Effect of Cerium on Interfacial Wetting Behavior, Heat Transfer Characteristics, and Solidification Microstructure in Subrapid Solidified Nonoriented Silicon Steel via Droplet Solidification Technique

This study investigates the effects of Ce (0–150 ppm) on the subrapid solidification process of 2.5 wt.% Si nonoriented silicon steel using a droplet solidification technique that simulates the strip casting process, with particular focus on interfacial wetting behavior, heat transfer characteristics, naturally deposited films, and solidification microstructure. The results demonstrate that increasing Ce content from 0 to 150 ppm leads to a significant reduction in interfacial tension from 1545 to 1221 mN/m and a corresponding decrease in contact angle from 127° to 105°, while simultaneously enhancing the maximum heat flux from 7.5 to 11.7 MW/m 2 . It indicates that Ce effectively reduces the interfacial tension between molten steel and cooling substrate, thereby improving both interfacial wettability and heat transfer performance. Furthermore, the strong deoxidizing capability of Ce leads to a remarkable reduction in SiO 2 content within the naturally deposited films formed on the substrate surface. In addition, Ce and its associated inclusions perform dual functions by promoting heterogeneous nucleation and enhancing interfacial heat transfer, which collectively contribute to substantial refinement of the solidified microstructure in Ce‐containing silicon steels.