Thermally Grown Oxide Layer on Aluminized Superalloy 690 Substrate and its Stability in Nitrate-Based Environment

Abstract:

Aluminides were formed on Ni-Cr-Fe based superalloy 690 substrates using pack aluminization process at 1273 K in controlled atmosphere. Thermal oxidation of aluminized specimens was carried out at 1273 K for a total period of 4 hours in air. The thermally grown oxide layer was examined using X-ray diffraction (XRD) studies on top surface and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) analysis along the cross-section of the sample. The oxide layer developed on aluminized superalloy 690 substrate consisted of Al₂O₃ layer with a thickness of about 2 μm. The oxidized specimens were exposed in nitrate-based environment (simulated high-level nuclear liquid waste) at 373 K for a total period of 216 hours. A good adherence of aluminide coatings was noticed even after prolonged exposure in nitrate-based solution with a little amount of material dissolution from the edges of the specimens. XRD studies on exposed specimen indicated existence of Al₂O₃ layer on the top surface, which is believed to have resulted in good adherence of aluminide coatings.

• Periodical: Materials Science Forum (Volume 710)
• Pages: 733-738
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.710.733
• Online since: January 2012
• Authors: Rabi Sankar Dutta, Chelakkattu Yusufali, Sanjib Majumdar, Raman Kumar Mishra, Chetan Parkash Kaushik, Rohidas Jagannath Kshirsagar, Ulhas Digambar Kulkarni, Gautam Kumar Dey
• Keywords: Adherence, Alloy 690, Aluminides, Diffusion Barrier Coatings, EDS, SEM, X-Ray Diffraction (XRD)

References

[1] D. Li, Y. Xu, D.Lin, Oxidation behavior of FeAl alloys with and without titanium, J. Mater. Sci. 36 (2001) 979-983.

[2] J. Xia, C.X. Li, H. Dong, Thermal oxidation treatment of B2 iron aluminide for improved wear resistance, Wear 258 (2005) 1804-1812.

DOI: 10.1016/j.wear.2004.12.016

[3] Z. D. Xiang, S. R. Rose, P. K. Datta, Low-temperature formation and oxidation resistance of nickel aluminide/nickel hybrid coatings on alloy steels, Scripta Mater. 59 (2008) 99-102.

DOI: 10.1016/j.scriptamat.2008.02.034

[4] C. Houngniou, S. Chevalier, J. P. Larpin, Synthesis and characterization of pack cemented aluminide coatings on metals, Appl. Surf. Sci. 236 (2004) 256-269.

DOI: 10.1016/j.apsusc.2004.04.026

[5] R. Prescott, M. J. Graham, The oxidation of iron-aluminum alloys, Oxidation of Metals 38 (1992) 73-87.

DOI: 10.1007/bf00665045

[6] M. Yamaguchi, H. Inui, K. Ito, High-temperature structural intermetallics, Acta Mater. 48 (2000) 307-322.

DOI: 10.1016/s1359-6454(99)00301-8

[7] R. S. Sundar, R. G. baligidad, Y. V. R. K. Prasad, D. H. Sastry, Processing of iron aluminides, Mater. Sci. Eng. A 258 (1998) 219-228.

DOI: 10.1016/s0921-5093(98)00937-x

[8] A. M. Hodge, D. C. Dunand, Synthesis of nickel-aluminide foams by pack-aluminization of nickel foams, Intermetallics 9 (2001) 581-589.

DOI: 10.1016/s0966-9795(01)00047-4

[9] Z. D. Xiang, J. S. Burnell-Gray, P. K. Datta, Aluminide coating formation on nickel-base superalloys by pack cementation process, J. Mater. Sci. 36 (2001) 5673-5682.

[10] C. Christoglou, N. Voudouris, G. N. Angelopoulos, Formation and modelling of aluminide coating on iron by a fluidised bed CVD process, Surf. Coat. Technol. 155 (2002) 51-58.

DOI: 10.1016/s0257-8972(02)00044-0

[11] N. Voudouris, C. Christoglou, G. N. Angelopoulos, Formation of aluminide coatings on nickel by a fluidized bed CVD process, Surf. Coat. Technol. 141 (2001) 275-282.

DOI: 10.1016/s0257-8972(01)01193-8

[12] J. A. Hearley, J. A. little, A. J. Sturgeon, The effect of spray parameters on the properties of high velocity oxy-fuel NiAl intermetallic coatings, Surf. Coat. Technol. 123 (2000) 210-218.

DOI: 10.1016/s0257-8972(99)00511-3

[13] L. Levin, A. Ginzburg, L. Klinger, T. Werber, A. Katsman, P. Schaaf, Controlled formation of surface layers by pack aluminization, Surf. Coat. Technol. 106 (1998) 209-213.

DOI: 10.1016/s0257-8972(98)00529-5

[14] R. S. Dutta, S. Majumdar, P. K. Limaye, U. D. Kulkarni, G. K. Dey, Characterization of aluminides formed on superalloy 690 substrate, Trans. IIM 64 (2011) 31-36.

DOI: 10.1007/s12666-011-0006-8

[15] T. F. An, H. R. Guan, X. F. Sun, Z. Q. Hu, Effect of the θ-a-Al2O3 transformation in scales on the oxidation behavior of nickel-base superalloy with an aluminide diffusion coating, Oxidation of Metals 54 (2000) 301-316.

[16] M. W. Brumm, H. J. Grabke, The oxidation behavior of NiAl-I. Phase transformations in the alumina scale during oxidation of NiAl and NiAl-Cr alloys, Corr. Sci. 33 (1992) 1677-1690.

DOI: 10.1016/0010-938x(92)90002-k

[17] G. Liu, M. Li, M. Zhu, Y. Zhou, Transient of alumina oxide scale on b-NiAl coated on M38G alloy at 9500C, Intermetallics 15 (2007) 1285-1290.

DOI: 10.1016/j.intermet.2007.03.010

[18] H. J. Choi, J. Jedlinski, B. Yao, Y. H. Sohn, Transmission electron microscopy observations on the phase composition and microstructure of the oxidation scale grown on as-polished and yttrium-implanted b-NiAl, Surf. Coat. Technol. 205 (2010) 1206-1210.

DOI: 10.1016/j.surfcoat.2010.10.034

[19] I. Vidensky, H. Gan, L. Pegg, in: G. L. Smith, S. K. Sundaram, D. R. Spearing (Eds.), Environmental Issues and Waste Management Technologies, American Ceramic Society, Ohio, 2002, pp.141-150.

[20] S. K. Tiwari, R. K. Sahu, A. K. Pramanick, R. Singh, Development of conversion coating on mild steel prior to sol gel nanostructured Al2O3 coating for enhancement of corrosion resistance, Surf. Coat. Technol. 205 (2011) 4960-4967.

DOI: 10.1016/j.surfcoat.2011.04.087

[21] S. K. Tiwari, T. Mishra, M. K. Gunjan, A. S. Bhattacharyya, T. B. Sigh, R. Singh, Development and characterization of sol-gel silica-alumina composite coatings on AISI 316 L for implant applications, Surf. Coat. Technol. 201 (2007) 7582-7588.

DOI: 10.1016/j.surfcoat.2007.02.026