Abstract
In order to predict the metallurgical structure of the quenched part by numerical simulation, one needs the boundary condition at the part-bath interface. This last, generally of the third kind, is deduced from measurement of temperature and heat flux density of the surface of work piece. The main goal of this work is the understanding of the heat transfers mechanisms that control the cooling speed according to the size of the work piece. We developed an original device of measurement which allowed temperature and local heat flux estimating at the part-bath interface during quenching process. Experimental results have updated the prevalence of one heat transfer mode according to the more or less thermal resistive character of the quenched part. This prevalence is linked to the mean Biot number Bi m . When Bi m < <1, heat conduction inside the work piece does not have a significant role in the cooling: the part is practically isothermal. The cooling is primarily ensured by boiling and more particularly by film boiling. Consequently the profile of cooling velocity is quasi uniform in the part. This situation favours a uniform metallurgic transformation in all the part and the absence of in temperature gradients avoids the differentials of dilation which are at the origin of residual stress fields. Conversely, when Bi m > > 1, the part has a large thermal resistance such as the temperature of the bath is quickly imposed on its surface. Then, cooling is primarily ensured by convection. In this case, the part bulk is the seat of large thermal gradients which induce a strong distribution of cooling velocity. The latter is at the origin of some differences in metallurgical structure and of a residual stress field within the part. In the intermediate value range, 0.1 < Bi m < 10, boiling and convection ensure successively the cooling, but in the boiling there is a prevalence of nucleate boiling mode which determines the reached maximum value of cooling speed located always in the close vicinity of the part-bath interface.
Similar content being viewed by others
References
Azim AE (1996) Modélisation par approche numérique inverse des processus thermiques et métallurgiques couplés mis en jeu dans le traitement thermique des aciers, PhD Thesis, El-Jadida (Marroco)
Chevrier JC (1973) Conduction transitoire de la chaleur dans un solide soumis à un transfert diphasique ; application aux contraintes thermiques, PhD Thesis Nancy (France)
Singh JP, Tree Y, Hasselman DPH (1981) Effect of bath and specimen temperature on the thermal stress resistance of brittle ceramics subjected to thermal quenching. JMS 16:2109–2118
Legendre B (1997) Le transfert thermique pendant la trempe: apport du choc thermique des céramiques, Ph.D. thesis, Caen
Lee WJ, Kim Y, Case ED (1993) The effect of quenching media on the heat transfer coefficient of polycristalline alumina. JMS 28–8:2079–2083
Pickles CSJ, Field JE (1996) The laboratory simulation of thermal shock failure. J. Phys. D.: Appl. Phys. 29:436–441
Osman AM, Beck JV (1990) Investigation of transient heat transfer coefficients in quenching experiments. Journal of Heat Transfer 112(4):843–848
Nukiyama S (1934) The maximum and minimum values of the heat flux transmitted from metal to boiling water under atmospheric pressure. J. Jap. Soc. Mech. Eng 37:367–374 English translation in Int. J. Heat Mass Transfer, vol. 9, p. 1419-1433, 1966
Gilles J, Bourouga B, Sorin A (2002) Mise au point d’une méthodologie expérimentale en vue de caractériser le coefficient de transfert pièce-bain de trempe. In: Proc. SFT 2002, Elsevier, Vittel, 351–356
Gilles J, Bourouga B, Bardon JP (2002) Estimation of the part-bath heat transfer coefficient during a quenching operation of aluminium workpiece. Proc. IHTC 12, Elsevier, Grenoble vol. 4, 765–770
Gilles J, Bourouga B, Sorin A (2002) Quenching operation of aluminium alloys: measurements and numerical simulations. Proc. 5th Int. ESAFORM, M. Pietrzyk, Kraków 651–654
Gilles J, Bourouga B, Sorin A (2004) Quenching operation of aluminum alloys: Measurements and numerical simulations. Rev. Met N°9:695–703
Gilles J (2004) Experimental study of the thermal aspects related to a quenching operation. Phd thesis of Nantes University
Beck JV, Blackwell B, St. Clair CR (1985) Inverse heat conduction. Ill posed problems. book Wiley Interscience, New York
Bourouga B, Goizet V, Bardon JP (2000) Theoritical aspects of the instumentation of a weak inertia parietal thermal sensor. Int. J. Thermal Sciences 39:96–109
Sorin A, Bourouga B, Gilles J, Dupont A (2002) Etude numérique du caractère intrusif de l’instrumentation pariétale par thermocouple, SFT 2002, Vittel (France), pp. 617–622
Acknowledgements
We gratefully acknowledge all the members of the SIMULFORGE program.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bourouga, B., Gilles, J. Roles of heat transfer modes on transient cooling by quenching process. Int J Mater Form 3, 77–88 (2010). https://doi.org/10.1007/s12289-009-0645-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12289-009-0645-z