Magnitogorsk Iron & Steel Works (Magnitogorsk, Russia):

Moshkunov V. V., Cand. Eng., Engineer Technologist, E-mail: Moshkunov.vv@mmk.ru
Prokhorov S. V., Chief Metallurgist
Kazakov A. S., Leading Specialist
Rabadzhi D. V., Head of Basic Oxygen Shop

Chair of Iron and Steel Metallurgy, Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia):

Didovich S. V., Post-Graduate
Stolyarov A. M., Dr. Eng., Prof.

The new continuous casting machine manufactured by SMS Siemag AG in the basic oxygen shop of Magnitogorsk Iron & Steel Works in January 2010, allows to provide soft reduction of a slab billet during continuous casting. Testing of the designed technology of slab soft reduction has accompanied with signifi cant improvement of billet structure in axial area. This paper describes investigations using the eff ecy of “artifi cial swelling” of a slab billet, undertaken for che cking correspondence of information about actual length of liquid metal cup calculated by computer via dynamical sistem of billet secondary cooling. The conducted experiments showed that this actual length exceeds its calculated value and the maximal diff erence is observed in 300 mm thick slab casting. The required corrections that should be made in calculation algorithm are formulated. The value of setting coeffi cient has been decreased from 0.82 to 0.7, it also led to lowe ring of slab surface temperature by 50–60 ºC and transition of physical boundaries of crystallization in average by 1.5 m. For further quali ty improvement, it was suggested to correct speed of withdrawal of cast billet according to the developed technique; two most frequent cases of slab casting with 300 mm thickness, made of tube steels with 1.2– 1.7% of Mn and two variants of carbon content: less than 0.08% and 0.08–0.15%. The corrected soft reduction technology has been successfully tested and analyzed on 124 samples. Therefore, axial porosity and axial chemical heterogeneity of continuously cast billets have been improved comparing with designed technology be 23 and 38 times respectively.

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2. Moshkunov V. V., Stolyarov A. M., Kazakov A. S. Vestnik Magnitogorskogo Gosudarstvennogo Tekhnicheskogo Universiteta imeni G. I. Nosova — Bulletin of G. I. Nosov Magnitogorsk State Technical University. 2012. No. 1 (37). pp. 24–26.

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