Possibilities of S-EMS utilization for the improvement of central segregation in continuously cast billets in conditions of TŽ

• Autorzy: Cibulka J , Bocek D. , Huczala T. , Cupek R.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The aim of the paper is to investigate practical possibilities of the strand stirrer (S-EMS) for the improvement of inner quality and central segregation in high carbon billets. An optimal S-EMS setting was proposed for the billet caster producing billets 150x150 mm. Design/methodology/approach: Impact of different S-EMS settings on central segregation and inner quality of as-cast billets was investigated. A set of longitudinal and transverse samples were analysed including evaluation of baumann prints and central segregation by means of LECO method. Samples of wires for segregation survey in rolled products were picked up as well. Findings: It was observed that application of the strand stirrer (S-EMS) is capable to suppress central segregation. However, its impact is visible just to a certain stirring level. Subsequent increasing of stirring intensity does not cause further improvement of segregation in the analyzed central part. On the contrary, stronger white band can be seen in the solidification line. Moreover, concentration gradient between the central part and surrounding ring of negative central segregation is lowered. These two effects can play a significant role in the evaluation of segregation level in rolled wires. Research limitations/implications: Analysis of central segregation in a lower size than used 6 mm. Practical implications: Optimal S-EMS setting seems to be 300 A/14 Hz. Originality/value: Impact of S-EMS setting on changes in central segregation of as-cast billets, relationship between central segregation level in wires and cast structure.

Słowa kluczowe

EN

continuous casting; electromagnetic stirring; segregation

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2012
• Tom: Vol. 55, nr 2
• Strony: 638--643
• Opis fizyczny: Bibliogr. 10 poz., rys., tab.

Twórcy

autor

Cibulka J

• Třinecké Železárny, a.s., Průmyslová 1000, 739 70 Třinec, Czech Republic

autor

Bocek D.

• Třinecké Železárny, a.s., Průmyslová 1000, 739 70 Třinec, Czech Republic

autor

Huczala T.

• Třinecké Železárny, a.s., Průmyslová 1000, 739 70 Třinec, Czech Republic

autor

Cupek R.

• Třinecké Železárny, a.s., Průmyslová 1000, 739 70 Třinec, Czech Republic

Bibliografia

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• [2] BK SPEC GA-03-063:1996, Segregation.
• [3] M. Diserens, T. Hätönen, E. Ristimaki, M. Tukiainen, Experiences on continuously cast billets influenced by electromagnetic stirring below mould, Scandinavian Journal of Metallurgy 10 (1981) 19-23
• [4] K.H. Spitzer, K. Schwerdtheger, The magnetic field of inductors used for rotation stirring in the continuous casting of steel. I&SM 57 (1990) 57-71.
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• [6] S. Unstreich, Electromagnetic stirring for continuous casting, Part 2, La Revue de Metallurgie 4 (2003) 395-408.
• [7] S. Unstreich, stirring for continuous casting, Part 2, La Revue de Metallurgie 11 (2003) 1043-1061.
• [8] K.S. Oh, Y.W. Chank, Macrosegregation behavior in continuously cast high carbon steel blooms and billets at the final stage of solidification in combination stirring, ISIJ International 7 (1995) 866-875.
• [9] J. Moreault, L. Beitelman, Metallurgical performance of single and dual-coil EMS with submerged pour casting of high carbon steel billets, Proceedings of the XXXVIII International Steelmaking Seminar, Belo Horizonte, 2007.
• [10] S.K. Choudhary, S. Ganguly, Morphology and segregation in continuously cast high carbon steel billets, ISIJ International 12 (2007) 1759-1766.