CINÉTICA DA DISSOLUÇÃO DE PRECIPITADOS DURANTE O REAQUECIMENTO DE PLACAS DE AÇO MICROLIGADO
DISSOLUTION KINETICS OF PRECIPITATES DURING MICROALLOYED STEEL SLAB REHEATING
Gorni, Antonio Augusto
http://dx.doi.org/10.4322/tmm.2011.004
Tecnol. Metal. Mater. Min., vol.8, n1, p.19-23, 2011
Resumo
Desenvolveu-se um modelo matemático para determinar a cinética de solubilização de elementos microligantes durante o reaquecimento de placas de aço para a laminação a quente. O modelo permite verificar que, sob condições práticas de reaquecimento de placas, precipitados eutéticos com tamanho superior a 250 nm não serão completamente dissolvidos, reduzindo o teor de Nb solubilizado na austenita. Também verifica-se que a eficiência da solubilização varia em função de pequenas oscilações na composição química de aços microligados, fato que é particularmente importante nas chamadas "marcas de skid" (regiões mais frias) das placas reaquecidas.
Palavras-chave
Solubilização, Cinética, Aço microligado, Modelo matemático
Abstract
This work describes a mathematical model for the calculation of the solution kinetics of microalloying elements during steel slab reheating previous to hot rolling. That model shows that, under the industrial practical conditions of slab reheating, eutectoid precipitates with size greater than 250 nm are not completely dissolved, decreasing the free Nb content in austenite. It is also verified that the solution efficiency varies according to small oscillations in chemical composition of the microalloyed steels, a situation that is particularly important in the so called "skid marks" (colder regions) in the reheated slabs.
Keywords
Solution, Kinetics, Microalloyed steel, Mathematical model
Referências
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2 CHAKRABARTI, D. et al. Development of bimodal grain structures in nb-containing high-strength low-alloy steels during slab reheating. Metallurgical and Materials Transactions A, v. 39A, n. 8, p. 1963-77, Aug. 2008. http://dx.doi.org/10.1007/s11661-008-9535-0
3 BORGGREN, U. et al. A model for particle dissolution and precipitation in HSLA steels. Advanced Materials Research, v. 15-17, p. 714-9, 2007. http://dx.doi.org/10.4028/www.scientific.net/AMR.15-17.714
4 GALLEGO, J. et al. Carbonitretos eutéticos em aços microligados comerciais. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS – CBECIMAT, 19., 2002, Natal. Anais... São Paulo: Metallum, 2002. p. 2380-6.
5 ANDERSEN, I.; GRONG, O. Analytical modelling of grain growth in metals and alloys in the presence of growing and dissolving precipitates – I. Normal grain growth. Acta Metallurgica et Materialia, v. 43, n. 7, p. 2673-88, July 1995. http://dx.doi.org/10.1016/0956-7151(94)00488-4
6 GORNI, A. A. Spreadsheet applications in materials science. In: FILBY, G. (Ed.) Spreadsheets in science and engineering. Berlin: Springer, 1997. p. 229-60.
7 PIETTE, M.; PERDRIX, C. An integrated model for microstructural evolution in the hot strip mill and tensile properties prediction of plain and microalloyed C-Mn Hot Strip. Materials Science Forum, v. 284-286, p. 361-8, 1998. http://dx.doi.org/10.4028/www.scientific.net/MSF.284-286.361
8 HUIN, D. et al. Microstructural modelling for NbTi micro-alloying adjustement on hot rolled HSLA steels. In: INTERNATIONAL CONFERENCE ON THERMOMECHANICAL PROCESSING OF STEELS – TMP 2008, Padua. Proceedings. Padua: Associazione Italiana di Metallurgia, 2008.
2 CHAKRABARTI, D. et al. Development of bimodal grain structures in nb-containing high-strength low-alloy steels during slab reheating. Metallurgical and Materials Transactions A, v. 39A, n. 8, p. 1963-77, Aug. 2008. http://dx.doi.org/10.1007/s11661-008-9535-0
3 BORGGREN, U. et al. A model for particle dissolution and precipitation in HSLA steels. Advanced Materials Research, v. 15-17, p. 714-9, 2007. http://dx.doi.org/10.4028/www.scientific.net/AMR.15-17.714
4 GALLEGO, J. et al. Carbonitretos eutéticos em aços microligados comerciais. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS – CBECIMAT, 19., 2002, Natal. Anais... São Paulo: Metallum, 2002. p. 2380-6.
5 ANDERSEN, I.; GRONG, O. Analytical modelling of grain growth in metals and alloys in the presence of growing and dissolving precipitates – I. Normal grain growth. Acta Metallurgica et Materialia, v. 43, n. 7, p. 2673-88, July 1995. http://dx.doi.org/10.1016/0956-7151(94)00488-4
6 GORNI, A. A. Spreadsheet applications in materials science. In: FILBY, G. (Ed.) Spreadsheets in science and engineering. Berlin: Springer, 1997. p. 229-60.
7 PIETTE, M.; PERDRIX, C. An integrated model for microstructural evolution in the hot strip mill and tensile properties prediction of plain and microalloyed C-Mn Hot Strip. Materials Science Forum, v. 284-286, p. 361-8, 1998. http://dx.doi.org/10.4028/www.scientific.net/MSF.284-286.361
8 HUIN, D. et al. Microstructural modelling for NbTi micro-alloying adjustement on hot rolled HSLA steels. In: INTERNATIONAL CONFERENCE ON THERMOMECHANICAL PROCESSING OF STEELS – TMP 2008, Padua. Proceedings. Padua: Associazione Italiana di Metallurgia, 2008.
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