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Название Efficient strip cooling to meet requirements of advanced steel grades
Автор S. Kramer, A. Sprock, Ch. Hassel
Информация об авторе

SMS Siemag AG (Hilchenbach, Germany):

Krämer S., Head of Hot Rolling Mills Dept.


SMS Siemag AG (Düsseldorf, Germany):

Sprock A., Dr., Referent for Technical Development, e-mail: august.sprock@sms-siemag.com
Hassel Ch., Dr., Central Development Dept.


The demands made on hot-rolled materials have become considerably more stringent over the last few years. On the one hand, models are needed that can provide quantitative statements on the microstructure and thus enable the mechanical properties to be ascertained. On the other hand, for the mechanical equipment of the cooling section, the above properties indicate a heightened demand for water, which needs to be made available in accordance with the required cooling rate. This paper will present improved mechanical equipment, the description of material behaviour in the form of a model and the necessary cooling strategies, with a view to enabling the production of materials which can satisfy future requirements. Resource-effi cient laminar cooling for a hot strip mill at Svenskt Stål (SSAB) in Sweden is displayed and illustration of the cooling rate (CR) as a function of the thickness provided by various operators is presented. Schematic representation of the influence of the cooling rate (CR) and the coiling temperature on the microstructure is analyzed. Attainable cooling rates of diff erent SMS cooling systems for a strip thickness d = 20 mm with TWater = 35 °C are observed and comparison of a calculated CCT diagram and an experimentally determined CCT diagram for material Ck15 are considered. Progression of Gibbs energy for pure iron and of total enthalpy as a function of the temperature for Ck15 is concluded.

Ключевые слова Hot strip rolling, laminar cooling, steel grades, mechanical equipment, microstructure, thickness, continuous cooling transformation (CCT) diagram, enthalpy
Библиографический список

1. Streisselberger, A.; Schwinn, V.; Kirsch, J.: Process developments in TMCP to produce heavy plates in high strength steel grades, 2nd Intern. Conf. on Thermomechanical Processing of Steels (TMP 2004), 15.–17. Juni 2004, Lüttich, Belgien.
2. Ouchi, C.: ISIJ Intern. 41 (2001) Nr. 6, S. 542/53.
3. Ultra-fast cooling in the hot strip mill, Phase 2, ECSC Steel, 7215-PD/018 (98-T3.03d).
4. Mesplont, C.: Grain refi nement and high precipitation hardening by combining microalloying and accelerated cooling, Rev. de Mét. 103 (2006) Nr. 5, S. 238/46.
5. Tomida, T.; Imai, N.; Yoshida, M.; Fukushima, S.: Effect of ultra-fast cooling after rolling in stable austenite region on grain refinement of CMn-Steel, Mat. Sci. Forum, Vol. 539-543 (2007), S. 4708/13.
6. Jongenburger, C. P. et al.: Harvesting metallurgical knowledge for commercial yield, 2nd Intern. Conf. on Thermomechanical Processing of Steels (TMP 2004), 15.–17. Juni 2004, Lüttich, Belgien.
7. Miettinen, J.: Prediction of austenite decomposition and heat release during cooling of low-alloyed steels, TKK-V–B107, ISBN 951 22 2623 5, 1995.
8. Enomoto, M.: ISIJ Intern. 32 (1992) Nr. 3, S. 297/305.
9. Dinsdale, A. T.: Calphad 15 (1991) Nr. 4, S. 317/425.
10. Kozeschnik, E.: Matcalc Sample Database, Version 1.15, 2010.

Language of full-text русский
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