Kinetic Predication for the Composition of 30CrNiMo8 Steel during Welded Billet Electrode Electroslag Remelting Process

Electroslag remelting (ESR) is critical for high‐quality steel production, yet welded billet electrodes with inter‐billet gaps alter current density and electrode specific surface area, posing new challenges to process control. This study aims to establish a model for predicting slag‐steel‐inclusion reactions in the welded‐electrode ESR process. The model adopts the effective equilibrium reaction zone approach and penetration theory‐based mass transfer kinetics and is verified through industrial ESR experiments on 30CrNiMo8 steel. The reaction area, contact time, and steel‐slag mass transfer coefficients in the electrode tip, steel droplets, and steel/slag interface are clarified specifically for welded billet electrodes ESR process. It is demonstrated that the reaction between [Si] and (Al 2 O 3 ) s drives the dynamic evolution of aluminum and silicon in the ingot. The liquid film zone contributes 72% to total desulfurization, which is around 30% higher than a traditional ESR process with a single electrode. The optimized initial slag composition of 52.3 wt% CaF 2 + 22.3 wt% CaO + 22.4 wt% Al 2 O 3 + 3 wt% SiO 2 meets the sulfur content and Al/Si fluctuation control requirements for 30CrNiMo8 steel. This model exhibits high prediction accuracy, providing valuable guidance for the design of industrial slag systems in the ESR process of high‐quality steel.