OPTIMIZATION OF PARTIAL STAINLESS STEEL MELT OXIDATION IN THE EAF

1,2 BAJŽELJ Anže
Co-authors:
1,2 BURJA Jaka
Institutions:
1 Institute of Metals and Technology, Ljubljana, Slovenia, EU, anze.bajzelj@imt.si, jaka.burja@imt.si
2 University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Materials and Metallurgy, Ljubljana, Slovenia, EU
Conference:
33rd International Conference on Metallurgy and Materials, Orea Congress Hotel Brno, Czech Republic, EU, May 22 - 24, 2024
Proceedings:
Proceedings 33rd International Conference on Metallurgy and Materials
Pages:
19-24
ISBN:
978-80-88365-21-1
ISSN:
2694-9296
Published:
26th June 2024
Proceedings of the conference have been sent to Web of Science and Scopus for evaluation and potential indexing.
Metrics:
92 views / 61 downloads
Abstract

Stainless steel production typically follows the duplex process, beginning with the electric arc furnace (EAF) and proceeding to the vacuum oxygen decarburizer (VOD) or argon oxygen decarburizer (AOD). The EAF's role is to melt the charge and heat it up for further processing, reducing tap-to-tap times through partial oxidation. However, this partial oxidation in the EAF leads to chromium losses as oxygen interacts with the high chromium steel melt. To address this issue, parameters affecting chromium burn-off have been identified and presented. A primary challenge in EAF steel production with elevated chromium content is to lower carbon levels while maximizing chromium yield in the melt. Unlike VOD and AOD processes, which permit low carbon and high chromium levels through vacuum or argon blowing, the EAF provides limited protection, mainly through silicon. At higher temperatures, carbon oxidation predominates, hence it is important to limit oxygen input into the system in the initial stages, while “protecting” the chromium with silicon. During the oxidation phase of the steel melt, carbon content decreases; however, attention must be paid to ensure that the concentration is not too low, as this increases chromium activity in the melt, leading to more intense oxidation. A practical model, derived from thermodynamic calculations, has been developed to guide carbon, chromium, and other element oxidation during scrap melting. This model, validated through industrial trials, aids in optimizing steel melt oxidation to minimize chromium losses effectively.

Keywords: EAF, stainless steel scrap, carbon oxidation, chromium oxidation, thermodynamics

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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