Original Article

Effect of slag composition on crystallization and melting properties during electroslag remelting process

¹ School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, Liaoning, PR China
² Tianjin Pipe Corporation, Tianjing 300300, PR China
³ Liaoning Institute of Science and Technology, Benxi 117004, Liaoning Province, PR China

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
^** e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
^*** e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 10 November 2025
Accepted: 2 January 2026

Abstract

This study investigates the continuous cooling crystallization behavior and melting properties of CaF₂-CaO-Al₂O₃-MgO quaternary slags and CaF₂-CaO-Al₂O₃-MgO-B₂O₃ quinary slags during electroslag remelting. Experimental methods include X-Ray diffraction for phase analysis, scanning electron microscope for microstructure observation, the rotating cylinder method for viscosity measurement, and the hemispherical method for melting temperature determination, aiming to clarify the intrinsic relationship between slag composition and properties and provide a basis for ESR slag optimization and process control. Results show that in the quinary slag, as B₂O₃ content decreases (from 3.0% to 1.2%), precipitated Ca₁₂Al₁₄O₃₃ crystals transform from elongated strips to large blocks. When B₂O₃ content is below 2.1% (B3-B4), Ca₃B₂O₃ crystals no longer precipitate, confirming B₂O₃’s refining effect. B₂O₃ reduces both slags’ melting temperature, which decreases continuously with composition changes. The quaternary slag’s viscosity decreases, while the quinary slag’s viscosity remains stable, as B₂O₃ regulates polymerization to offset viscosity fluctuations from other components.