Abstract
Coatings of 80Ni-20Cr and 50Ni-50Cr on a 9Cr-1Mo steel substrate were produced by high-velocity oxy-fuel (HVOF) spraying to protect the steel against steam oxidation in ultrasupercritical (USC) boilers. The oxidation studies on the coated specimens showed good protection against the scale growth on the steel substrate. Both the 80Ni-20Cr and 50Ni-50Cr coatings formed a thin protective oxide film on the coating surface. The 80Ni-20Cr coating showed Fe diffusion from the substrate to the coating and nickel diffusion from the coating to the substrate during the oxidation process. In the case of 50Ni-50Cr coatings, the diffusion process was reduced, but a continuous layer of chromium carbide was observed at the coating/substrate interface during the oxidation. The adhesive/cohesive strength of these coatings was evaluated on aged specimens at 750 °C by using a simple tensile test. The results of the as-coated 80Ni-20Cr specimens showed an adhesive-strength value of 68 MPa. On extended aging, the strength of the coating increased beyond the detection limit of the resin. The nickel diffusion from the coating to the substrate and the iron diffusion from the substrate to the coating caused the increased adhesive strength. In the case of 50Ni-50Cr, the as-coated specimens showed an average adhesive strength of 76 MPa and showed a decreasing trend on the aged specimens. The formation of chromium carbide at the interface caused inferior values in the adhesive/cohesive strength of the 50Ni-50Cr coatings. The chromium carbide formed on the coating/substrate interface was identified as M23C6-type carbide.
Similar content being viewed by others
References
W. Kaysser: Surface Eng., 2001, vol. 17, pp. 305–11.
C. Cheng, G.H. Meier, R.A. Perkins, and W.T. Bekker: in Materials for Coal Gasification R.W. Bekker, ed., ASM INTERNATIONAL, Metals Park, OH, 1988, pp. 159–69.
R. Burgel and I. Kvernes: in High Temperature Alloys for Gas Turbine and Other Applications 1986, Conf. Proc., Dordrecht, D. Reidel Publishing Co., 1986, W. Betz ed., 1986, pp. 327–56.
R. Viswanathan and W. Bekker: J. Mater. Eng. Performance, 2001, vol. 10, pp. 81–95.
F. Abe, H. Okada, S. Wanikawa, M. Tabuchi, T. Itagaki, K. Kimura, and K. Yamaguchi: 1st Int. Conf. on Advances in Structural Steels, Tsukuba, Japan, May 22–24, 2002.
M. Taneike, F. Abe, and K. Sawada: Nature, 2003, vol. 424, pp. 294–96.
H. Kutsumi, S. Muneki, T. Itagaki, and F. Abe: J. Jpn. Inst. Met., 2002, vol. 66, pp. 997–1003.
T. Sundararajan, S. Kuroda, T. Itagaki, and F. Abe: Iron Steel Inst. Jpn. Int., 2003, vol. 43, pp. 95–103.
T. Sundararajan, S. Kuroda, T. Itagaki, and F. Abe: Iron Steel Inst. Jpn. Int., 2003, vol. 43, pp. 104–11.
T. Sundararajan, S. Kuroda, K. Nishida, T. Itagaki, and F. Abe: Iron Steel Inst. Jpn. Int., 2004, vol. 44, pp. 139–44.
T. Sundararajan, S. Kuroda, T. Itagaki, and F. Abe: in Thermal Spray 2003: Advancing the Science & Applying the Technology, C. Moreau and B. Marple, eds., ASM INTERNATIONAL, Materials Park, OH, 2003, pp. 495–502.
Adhesion or Cohesive Strength of Flame Sprayed Coatings ASTM C-633, ASTM, Philadelphia PA, 2002, vol. 03.01, pp. 739–41.
T. Sundararajan, S. Kuroda, and F. Abe: Mater Trans., 2004, vol. 45 (4), 1299.
S.R.J. Saunders and J.R. Nicholls: Mater. Sci. Technol., 1988, vol. 5, pp. 780–98.
M. Mayuzumi, J. Ohta, and T. Arai: Corrosion, 1998, vol. 54, pp. 271–80.
F.H. Stott, F.I. Wei, and C.A. Enahoro: Werkstoffe Korr., 1989, vol. 40, pp. 198–205.
E.A. Brandes and G.B. Brook: Smithells Metals Hand Book, Butterworths-Heinemann, Oxford, 1992, pp. 13:1–13:311.
J.J. Barnes, J.G. Goedjen, and D.A. Shores: Oxid. Met., 1989, vol. 32, pp. 449–69.
Hand Book of Chemistry and Physics, 83rd ed., D.R. Lide, ed., CRC Press, London, 2002–2003, pp. 12:219–12:232.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sundararajan, T., Kuroda, S. & Abe, F. Effect of thermal spray on the microstructure and adhesive strength of high-velocity oxy-fuel-sprayed Ni-Cr coatings on 9Cr-1Mo steel. Metall Mater Trans A 35, 3187–3199 (2004). https://doi.org/10.1007/s11661-004-0063-2
Received:
Issue Date:
DOI: https://doi.org/10.1007/s11661-004-0063-2