A STUDY OF THE ROLLING LOAD CALCULATION MODELS FOR FLAT COLD ROLLING PROCESS
DOI:
https://doi.org/10.26512/ripe.v2i23.21052Palavras-chave:
Rolling load. Cold rolling. Friction hill. Noncircular arc.Resumo
In order to keep the rolling products free of defects, the calculation and constant assessment of the rolling load and torque are required. Many theories for rolling load calculation were developed and among them the most used nowadays still are the Bland and Ford ’s (1948) model and Alexander’s (1971) model in order to achieve a better online control for reversible and tandem cold rolling mills. In this work those models were implemented in a numerical calculation software. The elastic roll’s deformation was taken into account using the Hitchcock´s formula for the deformed roll radius in an iterative way. Those models state that the friction hill (or normal pressure) in the contact arc keeps circular after the elastic deformation. This hypothesis is analysed with a third offline model for calculating the rolling load, named Noncirc (Shigaki et al., 2015), that considers the real roll elastic deformation (not circular anymore). Two cold rolling cases were considered and the friction coefficient was varied in order to evaluate the influence of this parameter on the calculated rolling load/width, the contact arc length and profile and pressure distribution over the contact arc. It was found that both models present imprecise results for both cases analysed, as the thickness is very low and the strip is very work hardened. The noncircular model shows higher loads and larger arc of contacts, but has the drawback of being offline.
Downloads
Referências
Abdelkhalek, S., Montmitonnet, P., Legrand, N. & Buessler, P., 2011. Coupled approach for flatness prediction in cold rolling of thin strip. International Journal of Mechanical Sciences, v. 53, n. 9, p. 661-675.
Alexander, J. M., 1971. On the Theory of Rolling. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences (1934-1990), v. 326, n. 1567, p. 535-563.
Bland, D. R. & Ford, H., 1948. The calculation of roll-force and torque in cold strip rolling with tensions. Proceedings of the Institution of Mechanical Engineers, v. 159, p. 144.
Chen, S., Li, W. & Liu, X., 2014. Calculation of rolling pressure distribution and force based on improved Karman equation for hot strip mill. International Journal of Mechanical Sciences, v. 89, p. 256-263.
Dbouk, T., Montmitonnet, P., Suzuki, N., Takahama, Y. , Legrand, N. & Matsumoto, H., 2014. Advanced roll bite models for cold and temper rolling processes, La Metalurgia Italiana, v. 4, pp. 39-49.
Ford, H., Ellis, F. & Bland, D. R., 1951. Cold rolling with strip tension, Part I. A new approximate method of calculation and a comparison with other methods. Journal of the Iron and Steel Institute, v. 168, p. 57.
Freshwater, I. J., 1996. Simplified theories of flat rolling””I. The calculation of roll pressure, roll force and roll torque. International Journal of Mechanical Sciences, v. 38, n. 6, p. 633-648.
Grimble, M. J., Fuller, M. A. & Bryant, G. F., 1978. A noncircular arc roll force model for cold rolling. International Journal for Numerical Methods in Engineering, v. 12, p. 643-663.
Helman, H. & Cetlin, P. R., 2005. Fundamentos da conformação mecânica dos metais. 2 ed. São Paulo: Artliber Editora.
Krimpelstaetter, K., Hohenbichler, G., Finstermann, G. & Zeman, K., 2007. New noncircular arc skin pass model. Ironmaking e Steelmaking, v. 34, n. 4, p. 295-302.
Lenard, J. G., 2014. Primer on Flat Rolling. Elsevier Science. 2nd edition.
Montmitonnet, P., 2006. Hot and cold strip rolling processes. Computer Methods in Applied Mechanics and Engineering, v. 195, n. 48-49, p. 6604-6625.
Orowan, E., 1943. The calculation of roll pressure in hot and cold flat rolling. Proceedings of the Institution of Mechanical Engineers, v. 150, p. 140.
Pietrzyk, M. & Lenard, J. G., 1991. Thermal-Mechanical Modelling of the Flat Rolling Process. Springer. Verlag Berlin Heidelberg
Roberts, W. L., 1978. Cold Rolling of Steel. Taylor e Francis.
Shigaki, Y., Nakhoul, R. & Montmitonnet, P., 2015. Numerical treatments of slipping/no-slip zones in cold rolling of thin sheets with heavy roll deformation. Lubricants, v. 3, n. 2, p. 113.
Siebel, E., 1925. Kraft und materialflub bei der bildsamen formanderung. Stahl Eisen, v. 45, n. 37, p. 1563.
Sims, R. B., 1945. The calculation of the roll force and torque in hot rolling mills. Proceedings of the Institution of Mechanical Engineers, v. 168, p. 191-200.
Von Karman, T., 1925. Bietrag zur theorie des walzvorganges. Zeitschrift für Angewandte Mathematik und Mechanik, v. 5, p. 1563.
Wiklund, O. & Sandberg, F., 2002. Chapter 15 - Modelling and Control of Temper Rolling and Skin Pass Rolling, In Metal Forming Science and Practice, edited by J.G. Lenard,, Elsevier Science Ltd, Oxford, Pages 313-343, ISBN 9780080440248, http://dx.doi.org/10.1016/B978-008044024-8/50015-1.
Yang, Y. Y., Linkens, D. A. & Talamantes-Silva, J., 2004. Roll load prediction - Data collection, analysis and neural network modelling. Journal of Materials Processing Technology, v. 152, n. 3, p. 304-315.
Downloads
Publicado
Como Citar
Edição
Seção
Licença
Autores que publicam nesta revista concordam com os seguintes termos:
Autores mantém os direitos autorais e concedem à revista o direito de primeira publicação, sendo o trabalho simultaneamente licenciado sob a Creative Commons Attribution License o que permite o compartilhamento do trabalho com reconhecimento da autoria do trabalho e publicação inicial nesta revista.
Autores têm autorização para assumir contratos adicionais separadamente, para distribuição não-exclusiva da versão do trabalho publicada nesta revista (ex: publicar em repositório institucional ou como capítulo de livro), com reconhecimento de autoria e publicação inicial nesta revista.
Autores têm permissão e são estimulados a publicar e distribuir seu trabalho online (ex: em repositórios institucionais ou na sua página pessoal) a qualquer ponto antes ou durante o processo editorial, já que isso pode gerar alterações produtivas, bem como aumentar o impacto e a citação do trabalho publicado.
