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HomeDefect and Diffusion ForumDefect and Diffusion Forum Vol. 354Pulse Carburization of Steel – Model of the...

Pulse Carburization of Steel – Model of the Process

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Abstract:

Gas carburizing is a widely used heat treatment process in which carbon is transferred into steel. The hardening reliability involves an active control of mass transfer during the process and this is why understanding diffusion in solids is so essential to model the process. The currently used models are often based on the simplest, one-dimensional form of the diffusion equation in which diffusivity depends on composition. The objective of this work is to develop a model of carbon diffusion in multicomponent alloy subjected to pulse carburizing. The model is based on the Darken method (bi-velocity method) in which the diffusion velocity depends on the diffusion potential gradient and is independent of the choice of the reference frame while the drift velocity is common for the carbon and steel components. Our model allows predicting the kinetics of carbon transfer at various treatment conditions and is applied to the pulse carburizing process at constant temperature. The process is carried out by repeating consecutively a carburization stage, when the carburizing gas is supplied into a carburizing chamber, and a diffusion stage at vacuum conditions, when the carburizing gas is exhausted and only the diffusion of carbon takes place. The numerical calculations are made for varying carburization and diffusion periods and are confirmed by the experimental results. On the basis of the series of computer experiments some findings that are important in designing the carburizing technology are formulated.

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Periodical:

Defect and Diffusion Forum (Volume 354)

Pages:

145-152

DOI:

https://doi.org/10.4028/www.scientific.net/DDF.354.145

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Online since:

June 2014

Authors:

M. Zajusz*, K. Tkacz-Śmiech, K. Dychtoń, Marek Danielewski

Keywords:

Bi-Velocity Method, Diffusion, Pulse Carburizing

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[1] Munts V. A., Baskatov A. P.: Rate of Carburizing of Steel. Metal Science and Heat Treatment 22 (1980) 358÷360.

DOI: 10.1007/bf00693263

[2] Moiseev B. A., Brunzel Y.M., Shvartsman L.A.: Kinetics of Carburizing in an Endothermal Atmosphere. Metal Science and Heat Treatment 21 (1979) 437÷442.

DOI: 10.1007/bf00780479

[3] Goldstein J. I., Moren A. E.: Diffusion Modeling of the Carburization Process. Metallurgical and Materials Transactions A 9 (1978) 1515÷1525.

DOI: 10.1007/bf02661934

[4] Totten G. E. Howes M. A. H.: Steel Heat Treatment Handbook, Marcell Dekker, Inc., New York, 1997.

[5] Agren J.: Revised Expression for the Diffusivity of Carbon in Binary Fe-C Austenite. Scripta Metallurgica 20 (1986) 1507÷1510.

DOI: 10.1016/0036-9748(86)90384-4

[6] Asimow R. M.: Analysis of the Variation of the Diffusion Constant of Carbon in Austenite with Concentration. Transactions of AIME 230 (1964) 611÷613.

[7] Qua J., Peter J. Blaua P. J., Zhangb L., Xuc H.: Effects of multiple treatments of low-temperature colossal supersaturation on tribological characteristics of austenitic stainless steel. Wear 265 (2008) 1909÷1913.

DOI: 10.1016/j.wear.2008.03.011

[8] Christiansen T. L., Somers M. A. J.: Low temperature gaseous surface hardening of stainless steel: the current status. Int. J. Mat. Res. 100 (2009) 1361÷1377.

DOI: 10.3139/146.110202

[9] Bongartz K., Lupton D. F., Schuster H.: A Model to Predict Carburization Profiles in High Temperature Alloys. Metall. Trans. A, 11A (1980) 1883÷1893.

DOI: 10.1007/bf02655105

[10] Bongartz K., Schulten R., Quadakkers W.J. Nickel H.: A Finite Difference Model Describing Carburization in High-Temperature Alloys.. Corrosion 42 (1986) 390÷397.

DOI: 10.5006/1.3584919

[11] Bongartz K., Quadakkers W.J., Schulten R., Nickel H.: A Mathematical Model Describing Carburization in Multielement Alloy System. Metall. Trans. 20A (1989) 1021÷1028.

DOI: 10.1007/bf02650138

[12] Morral J. E., Dupen B. M., Law C. C.: Application of Commercial Computer Codes to Modeling the Carburizing Kinetics of Alloy Steels. Metall. Trans. A, 23A (1992) 2069÷2071.

DOI: 10.1007/bf02647553

[13] Engström A., Höglund L., Ågren J.: Computer Simulation of Diffusion in Multiphase Systems. Mat. Sci. Forum, 163÷165 (1994) 725÷730.

DOI: 10.4028/www.scientific.net/msf.163-165.725

[14] Darken L. S.: Diffusion, Mobility and Their Interrelation through Free Energy in Binary Metallic Systems. Trans. A.I.M.E. 174 (1948) 184-201.

[15] Danielewski M., Wierzba B.: Thermodynamically consistent bi-velocity mass transport phenomenology. Acta Mat. 58 (2010) 6717÷6727.

DOI: 10.1016/j.actamat.2010.08.037

[16] Ryzhov N. M.: Control of Carbon Saturation of the Diffusion Layer in Vacuum Carburizing of Heat-Resistant Steels. Metal Science and heat Treatment 46 (2004) 22÷27.

DOI: 10.1023/b:msat.0000048845.35526.09

[17] Buchholz D., Khan R.U., Bajohr S., Reimert R.: Computational Fluid Dynamics Modeling of Acetylene Pyrolysis for Vacuum Carburizing of Steel. Ind. Eng. Chem. Res. 49 (2010) 1130÷1137.

DOI: 10.1021/ie900996h

[18] Collin R., Gunnarson S., Thulin D.: Mathematical model for predicting carbon concentration profiles. Iron Steel 210 (1972) 785÷789.

[19] Oila A., Bull S. J.: Atomistic simulation of Fe–C austenite. Comp. Mat. Science 45 (2009) 235÷239.

DOI: 10.1016/j.commatsci.2008.09.013

[20] Kula P., Pietrasik R., Dybowski K.: Vacuum carburizing—process optimization. J. Mat. Proc. Tech. 164–165 (2005) 876÷881.

DOI: 10.1016/j.jmatprotec.2005.02.145