Abstract
High melting point inclusions , such as spinel, alumina and Al2O3 rich calcium-aluminates, have a strong tendency to agglomerate on the tundish stopper rod and Submerged Entry Nozzle (SEN) during the steel casting process, and eventually to cause SEN clogging . Calcium treatment by wire injection during steel refining during Ladle Metallurgy (LM) is commonly used to modify these troublesome inclusions to lower melting point inclusions. However, too much Ca injection (Ca over-treatment) can cause operational issue (e.g. slide gate plate erosion), as well as increase Ca cost. Therefore, it is desirable to add an appropriate amount of Ca to avoid either under- or over-treatment. Based on inclusion analysis with an ASPEX® computer controlled scanning electron microscope (ASPEX) instrument, Al2O3 and Al2O3 rich calcium-aluminates were identified as a major cause of SEN clogging at ArcelorMittal Dofasco Electric Arc Furnace (EAF) steelmaking stream. A Ca treatment index was developed to improve the inclusion modification. The improved inclusion control has reduced SEN clogging and enhanced steel quality.
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Acknowledgements
The authors would like to thank L. Sun, L. Stewart and other members of Product Characterization Group, Global R&D Hamilton, for their contributions in inclusion analysis. The authors would also like to thank ArcelorMittal Dofasco EAF steelmaking management and operators for their support and contributions to the success of this project. Our special thanks to B. Farrand for his discussions and advice during the project and preparation of this manuscript.
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© 2017 The Minerals, Metals & Materials Society
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Sun, S., Waterfall, S., Strobl, N., Liao, D., Holdridge, D. (2017). Inclusion Control with Ca Treatment to Improve Castability of Low Carbon Aluminum-Killed Steel. In: Hwang, JY., et al. 8th International Symposium on High-Temperature Metallurgical Processing. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-319-51340-9_34
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DOI: https://doi.org/10.1007/978-3-319-51340-9_34
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