Breakout of a slab as the result of changes in the thermophysical properties of continuously cast steel |
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Authors: | F. Kavicka J. Dobrovska K. Stransky B. Sekanina J. Stetina T. Mauder M. Masarik |
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Affiliation: | 1. Brno University of Technology, , Brno, CZ, 616 69 Czech Republic;2. VSB‐Technical University of Ostrava, , Ostrava, CZ, 708 33 Czech Republic;3. EVRAZ VITKOVICE STEEL, , Ostrava, CZ, 709 00 Czech Republic |
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Abstract: | The so‐called secondary cooling zone is an important part of the continuous casting machine. In this zone, a breakout may occur because of an increase of the local and temperature heterogeneity of steel, resulting from an increase of the stress caused by bending of the slab and by high local concentration of nonmetallic slag inclusions. Changes of the chemical composition of steel during continuous casting are particularly dangerous. In the event that two melts are cast one after another, that is, if the melt of steel with chemical composition A ends and is immediately followed by the steel B, it may automatically stop the continuous casting machine, and an atypical breakout may take place. It has happened during continuous casting of the slab, 250 × 1530 mm in the area of straightening, 20 min after flying change of tundish. In the present paper, by employing the dimensional analysis, eight dimensionless numbers are derived. If the values of these dimensionless numbers for two followed steels significantly differ, the atypical breakout may take place. |
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Keywords: | breakout chemical and temperature heterogeneity continuous casting dimensionless number steel slab |
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