Abstract
A new approach for controlling microstructure development during hot working processes is proposed. This approach is based on optimal control theory and involves state-space type models for describing the material behavior and the mechanics of the process. The effect of process control parameters such as strain, strain rate, and temperature on important microstructural features can be systematically formulated and then solved as an optimal control problem. This method has been applied to the optimization of grain size and process parameters such as die geometry and ram velocity during the extrusion of plain carbon steel. Experimental results of this investigation show good agreement with those predicted in the design stage.
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References
D.E. Kirk: Optimal Control Theory: An Introduction, Prentice-Hall Inc., Englewood Cliffs, NJ, 1970, pp. 29–46 and pp. 184–309.
P.M. DeRusso, R.J. Roy, and C.M. Close: State Variables for Engineers, John Wiley and Sons, New York, NY, 1965.
W.G. Frazier, E.A. Medina, J.C. Malas, and R.D. Irwin: JMEP, 1997, vol. 6 (2), pp. 153–60.
R.D. Irwin, R.D. Glenn, W.G. Frazier, D.A. Lawrence, and R.F. Follett: AIAA J. Guidance, Control, Dynamics, 1995, vol. 18 (2), pp. 214–21.
J.J. Jonas, C.M. Sellars, and McG. Tegart: Metall. Rev., 1969, vol. 14 (1), 1969, pp. 1–24.
P.L. Orsetti Rossi and C.M. Sellars: Acta Mater., 1997, vol. 45 (1), pp. 137–48.
H.J. McQueen and J.J. Jonas: Treatise on Materials Science and Technology, Vol. 6, Plastic Deformation of Materials, Academic Press, New York, NY, 1975, pp. 393–493.
W. Roberts: in Deformation, Processing and Structure, G. Krauss, ed., ASM INTERNATIONAL, Metals Park, OH, 1984, pp. 109–84.
W. Roberts: Process Control in Steel Industry, MEFOS, Luleå, Sweden, 1986, vol. 2, pp. 551–77.
J.C. Malas: Ph.D. Dissertation, Ohio University Athens, OH, 1991.
J.C. Malas and V. Seetharaman: JOM, 1992, vol. 44 (6), pp. 8–13.
H.J. Frost and M.F. Ashby: Deformation Mechanism Maps; The Plasticity and Creep of Metals and Ceramics, Pergamon Press, Oxford, United Kingdom, 1982.
R. Raj: Metall. Trans. A, 1981, vol. 12A, pp. 1089–97.
Y.V.R.K. Prasad, H.L. Gegel, S.M. Doraivelu, J.C. Malas, J.T. Morgan, K.A. Lark, and D.R. Barker: Metall. Trans. A, 1984, vol. 15A, pp. 1883–92.
W.G. Frazier: Robust Control Techniques for Hot Deformation Processes, Contributive Research and Development, vol. 228, Systran Corp., Dayton, OH, Final Report, Task 178, Contract No. F33615-90-C5944, Mar. 1995.
H. Yada: Proc. Int. Symp. Accelerated Cooling of Rolled Steels, Conf. of Metallurgists, CIM, Winnipeg, MB, Canada, Aug. 24–26, 1987, G.E. Ruddle and A.F. Crawley, eds., Pergamon Press, Toronto, 1987, pp. 105–20.
C. Devadas, I.V. Samarasekara, and E.B. Hawbolt: Metall. Trans. A, 1991, vol. 22A, pp. 335–49.
A. Kumar, K.P. Rao, E.B. Hawbolt, and I.V. Samarasekara: Univ. of British Columbia, Vancouver, B.C., unpublished research, 1987.
George F. Vander Voort: in Metallography, Principles and Practice, McGraw-Hill Book Co., New York, NY, 1994, p. 410.
Antares Software User Manual, UES, Inc., Dayton, OH, 1995.
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Malas, J.C., Frazier, W.G., Medina, E.A. et al. Optimization of microstructure development during hot working using control theory. Metall Mater Trans A 28, 1921–1930 (1997). https://doi.org/10.1007/s11661-997-0122-6
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DOI: https://doi.org/10.1007/s11661-997-0122-6