New Mold Slag Compositions for the Continuous Casting of Soft Steels

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung

Abstract

Several fluorine-free mold slag compositions have already been established in the literature. In all cases, the formation of a crystalline phase exhibiting behavior similar to that of cuspidine is emphasized to control horizontal heat transfer without influencing the lubrication performance for the casting of peritectic steel grades. In contrast, for casting soft steels, glassy solidification of the slag is required. Herein, different slag compositions involving the selected oxides are developed with the help of FactSage calculations. Mixtures of pure raw materials are melted at 1673 K and quenched to 295 K. It is observed that B2O3 increases the glass-forming ability of the slags. To obtain the glassy phase, the composition must satisfy the conditions (CaO+MgO)/(Al2O3+SiO2)<0.9 and (CaO+MgO)<30wt%. For TiO2 content <10 wt%, glassy solidification is detected after quenching to room temperature. However, this phenomenon-is not observed for slags with TiO2 content >15 wt%. Moreover, the addition of alumina and alkali oxides enhances crystallization. Based on these findings, promising mold slag compositions are designed and characterized in the laboratory using a furnace crystallization test, mineralogical investigations, and the single/double hot thermocouple technique. From the investigated mixtures, three compositions are suggested for use in continuous casting processes.
OriginalspracheEnglisch
Seiten (von - bis)1-7
Seitenumfang7
FachzeitschriftSteel research international
Jahrgang2022
Ausgabenummer93
Frühes Online-Datum24 Mai 2021
DOIs
PublikationsstatusVeröffentlicht - 2021

Bibliographische Notiz

Funding Information:
The authors gratefully acknowledge the funding support of the K1‐MET GmbH Metallurgical Competence Center. The research program of the K1‐MET Competence Center is supported by COMET (Competence Center for Excellent Technologies), the Austrian program for competence centers. COMET is funded by the Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology, the Federal Ministry for Digital and Economic Affairs, the Federal States of Upper Austria, Tyrol, and Styria, as well as the Styrian Business Promotion Agency (SFG). Furthermore, the authors thank the Upper Austrian Research GmbH for the continuous support. In addition to the public funding from COMET, partial financing came from the industrial partners RHI Magnesita, voestalpine Stahl, and voestalpine Stahl Donawitz and the scientific partner Montanuniversität Leoben.

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

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