Metallurgical Model Fitted to Experimental Data Using a Genetic Algorithm

Abstract:

The hot stamping process is an established process in the automotive industry to satisfy challenges concerning security aspects and lightweight construction. Now, innovative processes have arisen which consist in heating locally the tools and thus adjust local final mechanical properties of the parts. To simulate accurately this so called tailored tempering process, a coupling between thermal and metallurgical phenomena must be considered as the metallurgical transformations lead to a source term in the heat equation and the thermal evolution drives the transformation. To improve the model, a genetic algorithm optimizes the metallurgical model parameters to fit both the CCT and TTT diagrams, taking in account the cooling rate dependence. This method for creating a metallurgical data file, that is directly usable by the industrial software and that fits the TTT diagram and the final constituent proportions of the different constituents, is presented. This method, tested on hypothetical experimental data, is then validated and results are presented. Moreover, the principle of this work can be adapted to various softwares that industries use.

• Periodical: Key Engineering Materials (Volumes 504-506)
• Pages: 1079-1084
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.504-506.1079
• Online since: February 2012
• Authors: Alexandre Blaise, Brahim Bourouga, Christine Dessain
• Keywords: Genetic Algorithm (GA), Heat Treatment, Hot Stamping, Metallurgy

References

[1] B. Abdulhay, B. Bourouga, C. Dessain, G. Brun, J.Wilsius , Development of estimation procedure of contact heat transfer coefficient at the part-tool interface in hot stamping process, International Journal of Heat Transfer Engineering HTE, Volume 32, Issue 6, August/September 2010.

DOI: 10.1080/01457632.2010.506362

[2] B. Abdulhay, B. Bourouga, C. Dessain, G. Brun, J.Wilsius, Experimental study of heat transfer in hot stamping process, Proc. 12th International ESAFORM Conference on Material Forming. April 27-29 2009, University of Twente, Netherland.

DOI: 10.1007/s12289-009-0457-1

[3] F. FERNANDES, S. DENIS, A. SIMON, Prévision de l'évolution thermique et structurale des aciers au cours de leur refroidissement continu, Mémoires et Etudes Scientifiques Revue de Métallurgie, July-Agust (1986)

DOI: 10.1051/metal/197774120665

[4] F. FERNANDES Modélisation et calcul de l'évolution de la température et de la microstructure au cours du refroidissement des aciers. Doctorate thesis, INPL, Nancy, 1985.

DOI: 10.1051/metal/191714090607

[5] D. FARIAS Traitement thermique laser de l'acier XC42 et modélisation des transformations de phases en cycles thermiques rapides au chauffage et au refroidissement. Doctorate thesis, INPL, Nancy, 1991.

DOI: 10.1051/metal/197976070478

[6] S. DENIS, D. FARIAS, A. SIMON Mathematical model coupling phase transformations and temperature evolutions in steel. ISIJ International Vol 32(1992) n3, pp.316-325.

DOI: 10.2355/isijinternational.32.316