The liquidus temperature, crystallization behavior, and viscosity of calcium–aluminate (CA)-based mold flux systems are investigated by differential thermal analysis, quench tests, and viscosity measurements to understand the impact of SrO, B 2O 3, F, and Li 2O on the flux properties. For mixtures with a CaO/Al 2O 3 (wt%) ratio of 1, the liquidus temperature of 1443 K and a viscosity of 0.37 Pa s are achieved with the addition of 6.5 wt% B 2O 3. Substitution of CaO for 8.3 wt% SrO in the B 2O 3-free compositions increases a liquidus temperature from 1547 to 1559 K, and 2.6 wt% increases the viscosity from 0.35 to 0.41 Pa s, indicating that low amount SrO is not beneficial in adjusting slag properties of CA mold flux. A fluorine content of up to 6.1 wt% decreases the melting temperature from 1547 to 1509 K and inhibits crystallization while promoting volatilization in the liquid state. Li 2O (2.3 wt%) effectively enhances the glass-forming ability of the CA mold flux and decreases both the liquidus temperature from 1571 to 1509 K and the viscosity of the system from 0.43 to 0.28 Pa s. This study deepens the knowledge on CA flux systems, which could be useful for their effective design.
Bibliographical notePublisher Copyright:
© 2021 The Authors. Steel Research International published by Wiley-VCH GmbH