Investigation of the Erosion Mechanism of the Mold Flux Containing Rare Earth Oxide on the Submerged Entry Nozzle Affected by an External Electric Field

Abstract

Considering the change and unpredictability of the mold flux containing rare earth oxides, the impact of controlling the erosion behavior of the mold flux containing rare earth oxide on the submerged entry nozzle is thoroughly investigated herein by applying an electric field. The extracted results show that the rare earth is reduced, and Ce 3þ ions and compounds are formed. Under the control of electrochemical reaction in the negative enforced electric field, a stable and dense protective film with a multilayer structure is formed on the surface of the electrode. The existence of this film can effectively prevent the erosion of the submerged entry nozzle. In addition, the phase composition of the mold flux is not affected by the externally applied electric field. The implementation of the external electric field is anticipated to be used as a new method for the highquality and high-efficiency continuous casting production of rare earth steel.

Interface Wetting and Reaction Behavior between Mold Flux and Submerged Entry Nozzle under an External Electric Field

“…This was because the mold flux used in the continuous casting often added a certain amount of carbonaceous substances (like graphite) as a melting rate regulator and antioxidant, which was not relevant for the corrosion of the slag-line. [24,25] After the premelting was completed, the mold flux was cut and polished into a cuboid specimen according to the equipment requirements (3.5 Â 3.5 Â 4.0 mm).…”

“…of the electric field, a stable and highly viscous protective layer can be formed on the surface of the slag-line materials to resist the alternate scouring and corrosion of the mold flux and molten steel. [23][24][25] However, in actual continuous casting, whether the protective layer can stably form and adhere to the surface of the slag-line is directly related to the wettability and interface reaction between the mold flux and the slag-line materials. Moreover, the applied electric field also affects the interfacial reaction, wetting process, and wettability between the mold flux and the slag-line materials.…”