Kinetics of Internal Oxidation of Mn-Steel Alloys
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Internal oxidation of three Mn-steel alloys with 1.7, 3.5 and 7.0 wt% Mn concentration at 950 °C in a gas mixture composed of nitrogen, hydrogen and water vapor with a dew point of +10°C was evaluated. For these alloys, the kinetics of internal oxidation are diffusion-controlled and obey parabolic growth rate law. The diffusion coefficient of oxygen and manganese determined from the observed internal oxidation kinetics are 3.35 × 10−7 and 4.14 × 10−12 cm2/s at 950 °C, respectively. The formed internal oxide precipitates are mainly composed of MnO. The solubility product of MnO in an austenitic iron matrix is estimated to be (7.66 ± 0.18) × 10−9 mol fraction2 at 950 °C. The numerical simulation of concentration depth profiles of precipitated oxygen is in agreement with depth profiles determined with image analysis and X-ray microanalysis. Validity of the numerical simulation in case of the phase transformation was also tested. When a 1.7 wt% Mn-steel alloy is oxidized at 850 °C (instead of 950 °C) with a dew point of +12 °C partial phase transformation from austenite to ferrite takes place due to the Mn depletion. The associated precipitated oxygen concentration depth profile can be predicted accurately with numerical simulation.
KeywordsInternal oxidation Modelling Kinetics Diffusion coefficient of oxygen Diffusion coefficient of manganese MnO solubility product
This research was carried out under project number M22.7.11439 in the framework of the Research Program of the Materials innovation institute (M2i, www.m2i.nl). Financial support from International Zinc Association (IZA, www.zinc.org) is gratefully acknowledged. The authors are indebted to Dr. W. Melfo, Dr. H. Bolt and Dr. M. Zuiderwijk of Tata Steel (IJmuiden, The Netherlands) for valuable discussions and providing the Mn steel alloys. The authors are also indebted to Ing. J. C. Brouwer for technical support and assistance with experiments.
- 1.G. M. Song, W. G. Sloof, T. Vystavel and J. Th. M. De Hosson, Materials Science Forum 539–543, 1104 (2007).Google Scholar
- 2.G. M. Song,T. Vystavel, N. van der Pers, J. Th. M. De Hosson and W. G. Sloof, ActaMaterialia 60, 2973 (2012).Google Scholar
- 3.G. Zimbitas and W. G. Sloof, Materials Science Forum 696, 82 (2011).Google Scholar
- 4.M. Shibata, JEOL News 39, 28 (2004).Google Scholar
- 5.J. T. Armstrong, Quantitative elemental analysis of individual microparticles with electron beam instruments, in Electron Probe Quantitation, K. F. J. Heinrich and D. E. Newbury (Editors) (Plenum Press, New York, 1991), p. 261.Google Scholar
- 6.ImageJ, image processing and analysis in Java, available from: http://rsbweb.nih.gov/ij/.
- 7.A. S. M. Handbook, Metallography and Microstructures, vol. 9 (Materials Park, OH, ASM International, 1992), pp. 124–133.Google Scholar
- 8.W. M. Haynes (ed.), CRC Handbook of Chemistry and Physics, 93rd ed. (Internet version 2013), (CRC Press/Taylor and Francis, Boca Raton, FL, 2012-2013), p. 4–75.Google Scholar
- 9.C. Wagner, Zeitschriftfür Elektrochemie 63, 772 (1959).Google Scholar
- 10.R. A. Rapp, ActaMetallurgica 9, 730 (1961).Google Scholar
- 11.R. A. Rapp, Corrosion 21, 382 (1965).Google Scholar
- 12.A. Fick, Annalen der Physik 170, 59 (1855).Google Scholar
- 13.J. Crank, The Mathematics of Diffusion (Clarendon Press, Oxford, 1975).Google Scholar
- 14.D. Huin, P. Flauder and J.-B. Leblond, Oxidation of Metals 64, 131 (2005).Google Scholar
- 15.E. Feulvarch, J. M. Bergheau and J. B. Leblond, International Journal for Numerical Methods in Engineering 78, 1492 (2009).Google Scholar
- 16.J. H. Swisher and E. T. Turkdogan, Transactions of the Metallurgical Society of AIME 239, 426 (1967).Google Scholar
- 17.K. Nohara and K. Hirano, Transactions of the Iron and Steel Institute of Japan MetalsSuppl. 11, 1267 (1971).Google Scholar
- 18.H. Oikawa, Tetsu-To-Hagane 68, 1982 (1489).Google Scholar
- 19.V. A. Lashgari, C. Kwakernaak and W. G. Sloof, Oxidation of Metals 81, 435 (2014).Google Scholar
- 21.C. Wagner, Journal of the Electrochemical Society 99, 369 (1952).Google Scholar
- 22.R. H. Tien and E. T. Turkdogan, Metal Science 9, 233 (1975).Google Scholar
- 23.Thermo-Calc Software, available from: http://www.thermocalc.com/.
- 24.O. Kubaschewski, C. B. Alcock and P. J. Spencer, Materials Thermo-Chemistry (Pergamon Press, 1993).Google Scholar
- 25.A. S. M. Handbook, Alloy Phase Diagrams, vol. 3 (ASM International, Materials Park, OH, 1992).Google Scholar