TY - JOUR

T1 - Investigation of calcium-aluminate-based mold flux of different compositions

AU - Marschall, Irmtraud

AU - Harmuth, Harald

N1 - Publisher Copyright: © 2021 The Authors. Steel Research International published by Wiley-VCH GmbH

PY - 2021/6/10

Y1 - 2021/6/10

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85107592600&partnerID=8YFLogxK

U2 - 10.1002/srin.202100187

DO - 10.1002/srin.202100187

M3 - Article

VL - 93.2022

JO - Steel research international

JF - Steel research international

SN - 1611-3683

IS - 3

M1 - 2100187

ER -