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Adjustment of Roll Gap for the Dimension Accuracy of Bar in Hot Bar Rolling Process  

Kim, Dong-Hwan (ERC for Net Shape Die & Manufacturing, Busan National University)
Kim, Byung-Min (ERC for Net Shape Die & Manufacturing, Busan National University)
Lee, Youngseog (Plate, Rod & Welding Group at Technical Research Laboratories, Pohang Iron and Steel Corp.(POSCO))
Publication Information
International Journal of Precision Engineering and Manufacturing / v.4, no.1, 2003 , pp. 56-62 More about this Journal
Abstract
The objective of this study is to adjust the roll gap for the dimension accuracy of bar in hot bar rolling process considering roll wear. In this study hot bar rolling processes for round and oval passes have been investigated. In order to predict the roll wear, the wear model is reformulated as an incremental form and then wear depth of roll is calculated at each deformation step on contact area using the results of finite element analysis, such as relative sliding velocity and normal pressure at contact area. Archard's wear model was applied to predict the roll wear. To know the effects of thermal softening of DCI (Ductile Cast Iron) roll material according to operating conditions, high temperature micro hardness test is executed and a new wear model has been proposed by considering the thermal softening of DCI roll expressed in terms of the main tempering curve. The new technique developed in this study for adjusting roll gap can give more systematically and economically feasible means to improve the dimension accuracy of bar with full usefulness and generality.
Keywords
Roll wear; Hot rod rolling; Thermal softening; Roll gap; Neural network;
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  • Reference
1 Archard, J. E, 'Contacts and rubbing of flat surface,' J. of APPL. Phys., Vol. 24, p. 981, 1953   DOI
2 Kim, D.H., Kim, D.J. and Kim, B.M., 'The application of neural network and statistical method to process design in metal forming process,' International Journal of Advanced Manufacturing Technology, Vol. 15, pp. 886-894, 1999   DOI   ScienceOn
3 Liou, M. J. and Hasio, H. S., 'Prediction of die wear in high speed hot upset forging,' ERC/NSDM Report, No. 99-33, OSU, 1989
4 Kim, D.H., Ko, D.C. and Kim, B.M., 'Application of artificial neural network and taguchi method to preform design in metal forming considering workability,' International Journal of Machine Tools and Manufacture, Volume 39, Issue 5, pp. 771-785, May 1999   DOI   ScienceOn
5 Holm, R., 'Electric contacts,' Almqvist and wiksells, strokholm, p. 203, 1946
6 Ohnuki, A., 'Wear and deterioration of rolling roll and procedure of anti-wear,' J of Japan Soc. Lubr. Eng., Vol. 32, pp. 621-626, 1987
7 Williams, R.V. and Boxall, G.M., 'Roll surface deterioration in hot strip mills,' J. of The Iron and Steel Institute, pp. 369-377, Apr., 1965
8 Lee, Y., Choi, S. and Kim, Y.H., 'Mathematical model and experimental validation of surface profile of a workepiece in round-oval-round pass sequence,' J. Mater. Proc. Tech., Vol. 81, pp. 87-96, 2000
9 Minami, A. and Saiki, H., 'Effect of surface hardening by nitriding on thermal softening and deterioration of dies in warm and hot forging,' Advanced Tech. Plasticity, pp. 389-392, 1996
10 Hansen, P. H. and Bay, P. H., 'A flexible computer based system for prediction of wear distribution in forming rolls,' Advanced technology of plasticity, Vol. 1, pp. 19-26, 1990
11 Sachs, G., et.al., 'Roll wear in finishing trains of hot strip mills,' Iron and Steel Engineer, Vol, 38, pp. 71-92, 1961
12 Kim, T. H., Kim, B. M. and Choi, J. C., 'Prediction of die wear in the wire in the wire drawing process,' J. of Mat. Pro. Tech., Vol. 65, pp. 11-17, 1997
13 Shigeru Shida, 'Emprical formula of flow-stress of carbon steels - Resistance to deformation of carbon steels,' J. Japan Society for Technology of Plasticity, Vol. 10, No. 103, pp. 610-617, 1989
14 Kim, D.H., Kim, D.J., Kirn, H.G., Kim, B.M. and Choi, J.C., 'Process design of a hot forged product using the artificial neural network and the statistical design of experiments,' J. KSPE, Vol. 15, No. 9, pp. 15-24, 1998
15 Alexander Geleji, Bildsame Fromung der Metalle in Rechnung und Versuch, Akademie-Verlag Gmbh, Berlin, 1960
16 Kim, D.H., Kim, B.M. Lee, Y., Yoo, S.J. and Choo, W.Y., 'Prediction of roll wear using three-dimensional wear program for the hot rollingprocess.' Proceedings, Rolling 2001, Jeju, pp. 90-99, 2001
17 Park, J. W., Lee, H.C., and Lee, S., 'Composition, microstructure, hardness, and wear properties of high-speed steel rolls,' Metall. Mater. Trans. A, Vol. 30 A, pp. 399-409,1999   DOI   ScienceOn
18 Lundberg, S. E., 'A new high-temperature test rig for optimization of materials for hot-rolling rolls,' J. of Mat. Pro. Tech., Vol. 36, pp. 273-301, 1993   DOI   ScienceOn