Niobium Solubility in Austenite in the Presence of Niobium Carbides, Nitrides and Carbonitrides

Abstract:

Niobium is added to carbon steels in small amounts (< 0.1weight %), thus being called a microalloying element, to increase mechanical strength and toughness. When added to steel, niobium is partly soluble in the matrix and another part combines with carbon and nitrogen forming a family of Nb_xC_yN_z precipitates (niobium carbides, nitrides or carbonitrides), where the values ​​of x, y, z depend on the temperature and the chemical composition of the steel. The solubility equations for niobium in austenite available in the literature only provide the niobium content that could be solubilized at a given temperature. But when niobium is added above the solubility limit, the excess niobium will not only form the Nb_xC_yN_z family of precipitates. This is what the proposed model calculates. The proposed model is easy to apply and provided results are very close to those determined experimentally by different researchers, who used different techniques such as atom probe, or matrix dissolution with precipitate filtration, for example. Although the proposed model has been used to calculate niobium in solution in austenite, the same can be applied to any other precipitate, such as carbides, nitrides or carbonitrides of vanadium and titanium, for example.

• Periodical: Defect and Diffusion Forum (Volume 439)
• Pages: 35-52
• DOI: https://doi.org/10.4028/p-MKHv3P
• Online since: February 2025
• Authors: Paulo Roberto Mei*
• Keywords: Carbon Steel, Carbonitrides, Microalloyed Steel, Niobium, Solubility

References

[1] P. R. Mei. Effects of niobium microaddition on carbon steels. Defect and Diffusion Forum, 420 (2022) 101-117

DOI: 10.4028/p-5kc1x5

[2] ASM. Selected values of the thermodynamic properties of binary alloys, ASM, USA, 1973, p.846.

[3] Metals Handbook, v. 8, ASM, USA, 1973.

[4] H. Nordberg, B. Aronsson. Solubility of niobium carbide in austenite, JISI. 206 (1968) 1263-1266.

[5] F. D. Kazinczi et al. Some properties of niobium treated mild steel. Jerkontorets Annaler, Stockholm, 147 (1963) 408. In: Columbium as a micro-alloying element in steels and its effect on welding technology. T. M. Nore'n. Washington, DC, U. S. Department of Commerce, Office of Technical Services. August 30, 1963, 53 p. https://apps.dtic.mil/sti/pdfs/AD0424983.pdf

[6] T. Mori et al. Thermodynamic properties of niobium carbides and nitrides in steels. Tetsu to Hagane. 54 (1968) 763-776. https://www.jstage.jst.go.jp/article/tetsutohagane1955/ 54/7/54_7_763/_pdf/-char/en

DOI: 10.2355/tetsutohagane1955.54.7_763

[7] K. Narita. Physical chemistry of the groups IVA (Ti, Zr), Va (V, Nb, Ta) and the rare earth elements in steel. Trans. ISI Japan. 15 (1975) 145 -152. https://www.jstage.jst.go.jp/article/ isijinternational1966/15/3/15_145/_pdf/-char/en

DOI: 10.2355/isijinternational1966.15.145

[8] V. K. Lakshmanan, J. S. Kirkaldy. Solubility product for niobium carbide in austenite. Metallurgical Transactions A. 15 (1984) 541-544 https://link.springer.com/content/pdf/

DOI: 10.1007/bf02644978

[9] E. J. Palmiere, C. I. Garcia, A. J. De Ardo. Compositional and microstructural changes which attend reheating and grain coarsening in steels containing niobium. Metall. Mater. Trans. A. 25 (1994) 277–286

DOI: 10.1007/BF02647973

[10] W. Stuckens. Pure cementite and W, V, Nb, and Ta substituted cementites. Ann. Chim. 8 (1963) 229-249.

[11] W. Stuckens and A. Michel. Variations in the stoichiometry of pure cementite. Comp. Rend. 253 (1961) 2358-2360.

[12] Handbook of Chemistry and Physics. 58ª ed., CRC Press, USA, 1977, p. F-215.

[13] P.C. Liu et al. The significance of Nb interface segregation in governing pearlitic refinement in high carbon steels, Materials Letters. 279 (2020) 128520

DOI: 10.1016/j.matlet.2020.128520

[14] R. C. Hudd et al. A method for calculating the solubility and composition of carbonitride precipitates in steel with particular reference to niobium carbonitride. JISI. 209 (1971) 121-125.

[15] S. Koyama et al. Effects of Mn, Si, Cr, and Ni on the solution and precipitation of niobium carbide in iron austenite. J. Japan Inst. Metals. 35 (1971) 1089-1094.

DOI: 10.2320/jinstmet1952.35.11_1089

[16] D. C. Houghton et al. Characterization of carbonitrides in Ti bearing HSLA steel. Int. Symp. Niobium 81, San Francisco, USA, Nov. 8-11, 1981.

[17] S. R. Keown and W.G. Wilson. In: Thermomechanical processing of microalloyed austenite. TMS-AIME, Warrendale, PA, 1981, p.343–56.

[18] K. J. Irvine et al. Grain refined C-Mn steels. JISI. 205 (1967) 161-182.

[19] P. Mandry and W. Dornelas. Solubilité des précipités de niobium dans l'austénite dans le cas d'aciers de construction à bas carbone et contenant de très faibles quantités de niobium. Compt. Rendus, Acad. Sci. Paris, Série C. 263 (1966) 1118-1121.

DOI: 10.1051/metal/196966070563

[20] T. Mori et al. Thermodynamic behaviors of niobium carbide-nitride and sulfide in steel. Tetsu to Hagane. 51 (1965) 2031-2033

DOI: 10.2355/tetsutohagane1955.51.11_2025

[21] D. Webster, J. H. Woodhead. Effect of 0.03 % Nb on the ferrite grain size of mild steel. JISI. 202 (1964) 987-994.

[22] G. L. Fisher, R.H. Geils. The effect of columbium on the alpha-gamma transformation in a low alloy Ni-Cu steel. Trans. Met. Soc. AIME. 245 (1969) 2405-2412.

[23] W. B. Morrinson. The influence of small niobium additions on the properties of carbon-manganese steels. JISI. 201 (1963) 317-325.

[24] A. Brownrigg, R. Boelen. The effect of Nb on hardenability of C-Mn-Si-Al steels. Intern. Inst. of Welding (I.I.W. Publ. Sess. Met. Technol. Conference); Sidney, Australia, 1976, Serie A, Sess. 8-6.

[25] S. Kanazawa et al. On the behavior of precipitates in the Nb-Mo heat-treated high strength steel having 80 kg/mm2 tensile strength. Trans. Japan Inst. Metals. 8 (1967) 113-119. https://www.jim.or.jp/journal/e/pdf3/8/02/113.pdf

DOI: 10.2320/matertrans1960.8.113

[26] M.H. Thomas, G. M. Michael. The influence of Nb and Nb(C,N) precipitation on the formation of proeutectoid ferrite in low alloy Steel. Intern. Conf. on Solid-Solid Phase Transformation, Proc., Carnegie Mellon Univ., Pittsburgh, Pennsylvania, Sep. 1982.

[27] J. M. Gray, R. B. G., Yeo. Columbium carbonitride precipitation in low-alloy steels with particular emphasis on precipitate-row formation. Trans. ASM. 61 (1968) 255-269.

[28] M. Tanino, K. Aoki. The Precipitation behavior and the strengthening effect of NbC during tempering and during continuous cooling. Trans. I.S.I. Japan. 8 (1968) 337-345. https://www.jstage.jst.go.jp/article/isijinternational1966/8/5/8_337/_article/-char/en

DOI: 10.2355/isijinternational1966.8.337

[29] R. M. Brito, H. J. Kestenbach. On the dispersion hardening potential of interphase precipitation in micro-alloyed niobium steel. J Mater. Sci. 16 (1981) 1257–1263. https://doi.org/10.1007/ BF01033840

DOI: 10.1007/bf01033840

[30] A. le Bon, J. Rofes-Vernis, C. Rossard. Recrystallization and precipitation during hot working of a Nb-Bearing HSLA Steel, Metal Science. 9 (1975) 36-40

DOI: 10.1179/030634575790444919

[31] J. J. Jonas, I. Weiss. Effect of precipitation on recrystallization in microalloyed steels. Material Science. 13 (1979) 238-245

DOI: 10.1179/msc.1979.13.3-4.238

[32] I. Weiss, J. J. Jonas. Interaction between recrystallization and precipitation during the high temperature deformation of HSLA steels. Metall. Mater. Trans. A. 10 (1979) 831–840

DOI: 10.1007/BF02658301

[33] I. Weiss, J. J. Jonas. Dynamic precipitation and coarsening of niobium carbonitrides during the hot compression of HSLA steels. Metall. Mater. Trans. A. 11 (1980) 403–410

DOI: 10.1007/BF02654564

[34] Ray, A. and Bhadeshia, H.K.D.H. Niobium in microalloyed rail steels. In: HSLA Steels 2015, Microalloying 2015 & Offshore Engineering Steels 2015, TMS

DOI: 10.1007/978-3-319-48767-0_3

[35] M.J. Luton et al. Interaction between deformation, recrystallization and precipitation in niobium steels. Metall. Mater. Trans. A. 11 (1980) 411-420

DOI: 10.1007/BF02654565

[36] L. Z. Meyer. Metallkd, Bd. 58 (1967) 334. In: L. Meyer. International Journal of Materials Research. 58 (1967) 396-401

[37] Klinkenberg, C., Trute, S. and Bleck, W. Niobium in engineering steels for automotive applications. Steel Research International. 77 (2206) 698-703. https://doi.org/10.1002/ srin.200606450

DOI: 10.1002/srin.200606450

[38] R. Coladas et al. The influence of niobium on the austenite processing of medium and high carbon steels. In: The hot deformation of austenite, Symposium. Ballance, J. B., Ed., New York, 1976, p.341.

[39] X. Chen et al. Effects of Mo, Cr and Nb on microstructure and mechanical properties of heat affected zone for Nb-bearing X80 pipeline steels. Materials and Design. 53 (2014) 888–901

DOI: 10.1016/j.matdes.2013.07.037

[40] K. Hausmann et al. The influence of Nb on transformation behavior and mechanical properties of TRIP-assisted bainitic-ferritic sheet steels. Materials Science and Engineering A. 588, (2013) 142-150

DOI: 10.1016/j.msea.2013.08.023

[41] H. Hu et al. The effects of Nb and Mo addition on transformation and properties in low carbon bainitic steels. Materials and Design. 84 (2015) 95-99

DOI: 10.1016/j.matdes.2015.06.133

[42] Z. LI et al. Microstructure evolution during continuous cooling in niobium microalloyed high carbon steels. Metals and Materials International. 20 (2014) 801-806

DOI: 10.1007/s12540-014-5001-2

[43] P. C. Liu et al. The significance of Nb interface segregation in governing pearlitic refinement in high carbon steels. Materials Letters. 279 (2020) 128520

DOI: 10.1016/j.matlet.2020.128520

[44] D. J. Minicucci et al. Development of niobium microalloyed steel for railway wheel with pearlitic bainitic microstructure. Materials Research. 22 (2019)

DOI: 10.1590/1980-5373-MR-2019-0324

[45] P. P. Senthil et al. Influence of niobium microalloying on the microstructure and mechanical properties of high carbon nano bainitic steel. Procedia Structural Integrity. 14 (2019) 729–737

DOI: 10.1016/j.prostr.2019.05.091

[46] A. B. Rezende et al. Wear behavior of bainitic and pearlitic microstructures from microalloyed railway wheel steel. Wear. 456–457 (2020) 203377

DOI: 10.1016/j.wear.2020.203377

[47] A. B. Rezende et al. Effect of niobium and molybdenum addition on the wear resistance and the rolling contact fatigue of railway wheels. Wear. 466–467 (2020) 203571

DOI: 10.1016/j.wear.2020.203571

[48] Y. Wang et al. Influence of Nb on microstructure and property of low-carbon Mn series air-cooled bainitic steel. Journal of Iron and Steel Research International. 17 (2010) 49–53

DOI: 10.1016/S1006-706X(10)60044-1

[49] M.A. Altuna et al. Precipitation of Nb in ferrite after austenite conditioning. Part II: strengthening contribution in High-Strength Low-Alloy (HSLA) steels. Metall. Mater. Trans. A.  43 (2012) 4571-4586

DOI: 10.1007/s11661-012-1270-x

[50] S. Shanmugam et al. Microstructure of high strength niobium-containing pipeline steel. Materials Science and Engineering A. 441 (2006) 215–229

DOI: 10.1016/j.msea.2006.08.017

[51] B. Wang, J. Lian. Effect of microstructure on low-temperature toughness of a low carbon Nb–V–Ti microalloyed pipeline steel. Materials Science and Engineering A. 592 (2014) 50-56

DOI: 10.1016/j.msea.2013.10.089

[52] C. Chattopadhyay et al. Improved wear resistance of medium carbon microalloyed bainitic steels. Wear. 289 (2012) 168-179

DOI: 10.1016/j.wear.2012.03.005