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Research Papers: Gas Turbines: Manufacturing, Materials, and Metallurgy

Development of a Tool for Temperature Estimation From Microstructural Condition of a Nicoraly+Re Coating Applied on the Surface of Gas Turbine Hot Components

[+] Author and Article Information
Claudia Calcagno

Ansaldo Energia,
Corso Perrone 118,
Genoa 16161, Italy

Contributed by the Manufacturing Materials and Metallurgy Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received June 27, 2013; final manuscript received July 25, 2013; published online October 21, 2013. Editor: David Wisler.

J. Eng. Gas Turbines Power 136(1), 012101 (Oct 21, 2013) (7 pages) Paper No: GTP-13-1191; doi: 10.1115/1.4025264 History: Received June 27, 2013; Revised July 25, 2013; Accepted July 28, 2013

The hot gas path components of gas turbines have to withstand to severe conditions in terms of high temperature oxidation, hot corrosion, and creep-fatigue phenomena. The evaluation of components residual life is an important matter for gas turbines producers and the estimation of service temperatures is a key tool for this evaluation. The most diffused methods to estimate service temperatures of gas turbines blades and vanes in Ni based superalloys are related to the microstructural evolution of the dispersed intermetallic phase γ′, Ni3Al. The aim of this work has been the determination of a tool to estimate service temperature on the basis of the microstructural evolutions of a NiCoCrAlY+Re coating. In order to obtain a deep characterization of the coating after exposure at different durations and temperatures, an extensive experimental test program has been planned. Samples of Ni based superalloys, covered by the investigated coating, have been aged in chamber furnaces in the temperature range 700 °C–1000 °C with durations up to 20,000 h. The microstructure of this coating is characterized by β phase, NiAl, which is the Al reservoir, embedded in the matrix, that is constituted by γ′ phase at low temperature and by γ phase over 900 °C. Moreover, electron back scattered diffraction and X-ray diffraction measurements on samples have revealed three classes of secondary phases: the first one has been identified as σ-Cr2Re3, the second one as Cr carbide-Cr23C6 and the third one as α-Cr. σ phase is very abundant at the lower temperatures while it disappears after long exposures at temperatures higher than 900 °C. The σ phase composition is different at different temperatures and the Re content in particular increases with the temperature. Starting from the σ phase composition determined at different temperatures, a tool has been constructed that relates the service temperature to the Re content in the same phase. The new tool has been applied to the analyses of different components. The results of the new method have been compared to those ones obtained with the method based on γ′ features, developed in the past through huge experimental campaigns. The agreement between the two methods is generally good, they can be used in a complementary way due to the fact that the γ′ one seems to be more suitable for high temperature ranges (T > 900 °C) where it gives a reliable estimation, while the σ method is more suitable in the temperature range 700 °C–900 °C.

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References

Reed, R. C., 2006, The Superalloys, Fundamentals and Applications, Cambridge University Press, Cambridge, UK, pp. 33–216.
Mughrabi, H., 2009, “Microstructural Aspects of High Temperature Deformation of Monocrystalline Nickel Base Superalloys: Some Open Problems,” Mater. Sci. Technol., 25(2), pp. 191–204. [CrossRef]
Baldan, A., 2002, “Review: Progress in Ostwald Ripening Theories and Their Applications to γ′-Precipitates in Nickel-Base Superalloy: Part II—Ni-Base Superalloys,” J. Mater. Sci., 37, pp. 2379–2405. [CrossRef]
Roy, I., Balikci, E., Ibekwe, S., and Raman, A., 2005, “Precipitate Growth Activation Energy Requirements in the Duplex Size γ′ Distribution in the Superalloy IN738LC,” J. Mater. Sci., 40, pp. 6207–6215. [CrossRef]
Balikci, E. and Raman, A., 2008, “The Relationship Between Activation Energy and Precipitate Size for Precipitate Agglomeration,” J. Mater. Sci., 43, pp. 927–932. [CrossRef]
Mammoliti, F., Mastromatteo, F., Giannozzi, M., Iozzelli, F., and Lucci, D., 2004, “The Coarsening Kinetic of γ′ Particle in Nickel-Based Superalloys During Aging at High Temperature,” ASME Paper No. GT2006-90137. [CrossRef]
Moshtaghin, S., and Asgari, S., 2003, “Growth Kinetics of γ′ Phase Precipitates in Superalloy IN738LC During Long Term Aging,” Mater. Des., 24, pp. 325–330. [CrossRef]
Stevens, R. A., and Flewitt, P.E.J., 1979, “The Effect of γ′ Precipitate Coarsening During Isothermal Aging and Creep of Nickel-Base Superalloy IN738,” Mater. Sci. Eng., 37, pp. 237–247. [CrossRef]
Aurrecoechea, J., and Brentnall, W., 1990, “Operating Temperature Estimation and Life Assessment of Turbine Blade Airfoils,” Gas Turbine Aeroengine Congress and Exposition, Brussels, Belgium, Belgium, June 11–14, ASME Paper No. 90-GT-23.
Vacchieri, E., Bonadei, A., Delogu, G., Cordano, E., Corcoruto, S., and Poggio, E., 2008, “Operating Temperature Estimation Based on Microstructure Evolution of Ni-Base Superalloys for GT Blades/Vanes,” The Future of Gas Turbine Technology 4th International Conference, Brussels, Belgium, October 15–16.
Poggio, E., Corcoruto, S., and Vacchieri, E., 2009, “Microstructural Degradation of a Cast Ni-Based Superalloy After Creep, LCF, and TMF Tests,” ECCC Creep Conference, Zurich, April 21–23.
Krukovskii, P. G., and Tadlya, K. A., 2007, “Method for Estimation of the Average Local Working Temperature and the Residual Resource of Metal Coatings of Gas Turbine Blades,” J. Eng. Phys. Thermophys., 80(3), pp. 440–447. [CrossRef]
Krukovsky, P., Kolarik, V., Tadlya, K., Rybnikov, A., Kryukov, I., Mojaiskaya, N., and Juez-Lorenzo, M., 2004, “Lifetime Prediction for MCrAlY Coatings by Means of Inverse Problem Solution (IPS),” Surf. Coat. Technol., 177–178, pp. 32–36. [CrossRef]
Achar, D.R.G., Munoz-Arroyo, R., Singheiser, L., and Quadakkers, W. J., 2004, “Modelling of Phase Equilibria in MCrAlY Coating Systems,” Surf. Coat. Technol., 187, pp. 272–283. [CrossRef]
Ellison, K. A., Daleo, J. A., and Hussain, K., 2004 “A New Method of Metal Temperature Estimation for Service-Run Blades and Vanes,” 10th International Symposium on Superalloys, Champion, PA, September 19–23, pp. 759–768, http://www.tms.org/superalloys/10.7449/2004/Superalloys_2004_759_768.pdf
Dahl, K. V., and Hald, J., 2006, “Estimation of Metal Temperature of MCrAlY Coated IN738 Components Based on Interdiffusion Behaviour,” Energy Mater., 1, pp. 106–115. [CrossRef]
Czech, N., Schmitz, W. F., and Stamm, W., 1995, “Microstructural Analysis of the Role of Rhenium in Advanced MCrAlY Coatings,” Surf. Coat. Technol., 76-77, pp. 28–33. [CrossRef]
Beele, W., Czech, N., Quadakkers, W. J., and Stamm, W., 1997, “Long-Term Oxidation Tests on a Re-Containing MCrAlY Coating,” Surf. Coat. Technol., 94–95, pp. 41–45. [CrossRef]
Täck, U., 2004, “The Influence of Cobalt and Rhenium on the Behaviour of MCrAlY Coatings,” Ph.D. thesis, Tech. Univ. Frieberg, Germany.
Toscano, J., Gil, A., Hüttel, T., Wessel, E., Naumenko, D., Singheiser, L., and Quadakkers, W. J., 2007, “Temperature Dependence of Phase Relationships in Different Types of MCrAlY-Coatings,” Surf. Coat. Technol., 202, pp. 603–607. [CrossRef]
Huang, L., Sun, X. F., Guan, H. R., and Hu, Z. Q., 2006, “Improvement of the Oxidation Resistance of NiCrAlY Coatings by the Addition of Rhenium,” Surf. Coat. Technol., 201, pp. 1421–1425. [CrossRef]
Liu, Xu, Huang, L., Bao, Z. B., Wei, H., Sun, X. F., Guan, H. R., and Hu, Z. Q., 2009, “Oxidation Behavior of Graded NiCrAlYRe Coatings at 900, 1000, and 1100 °C,” Oxid. Met., 71, pp. 125–142. [CrossRef]
Phillips, M. A., and Gleeson, B., 1998, “Beneficial Effects of Rhenium Additions on the Cyclic-Oxidation Resistance of β-NiAl + α-Cr Alloys,” Oxid. Met., 50(5/6), pp. 399–429. [CrossRef]
Czech, N., Schmitz, W. F., and Stamm, W., 1994, “Improvement of MCrAlY Coatings by Addition of Rhenium,” Surf. Coat. Technol., 68–69, pp. 17–21. [CrossRef]
Barbareschi, E., Bonadei, A., Costa, A., Guarnone, P., and Vacchieri, E., 2010, “Assessment of a Residual Life Evaluation Tool for Gas Turbine Blades and Vanes Based on Microstructural Evolution of a NiCoCrAlY+Re Coating,” 9th Liege Conference: Materials for Advanced Power Engineering Liège, Belgium, September 27–29.
Costa, A., Bonadei, A., Vacchieri, E., Cirilli, F., Di Donato, A., and Tassa, O., “Thermodynamic and Diffusive Model for NiCoCrAlY+Re Coatings Applied on Gas Turbine Hot Gas Path Components,” 25th International Conference on Surface Modification Technologies (SMT25), Trollhattan, Sweden, June 20–22.
Baufeld, B., and Schmucker, M., 2005, Microstructural Evolution of a NiCoCrAlY Coating on an IN100 Substrate,” Surf. Coat. Technol., 199, pp. 49–56. [CrossRef]
Yang, Y.-M., Liao, H., and Coddet, C., 2002, “Simulation and Application of a HVOF Process for MCrAlY Thermal Spraying,” J. Therm. Spray Technol., 11(1), pp. 36–43. [CrossRef]
Zhao, L., Parco, M., and Lugscheider, E., “High Velocity Oxy-Fuel Thermal Spraying of a NiCoCrAlY Alloy,” Surf. Coat. Technol., 179, pp. 272–278. [CrossRef]
Lugscheider, E., Herbst, C., and Zhao, L., “Parameter Studies on High-Velocity Oxy-Fuel Spraying of MCrAlY Coatings,” Surf. Coat. Technol., 108–109, pp. 16–23. [CrossRef]
Brandl, W., Toma, D., Kruger, J., Grabke, H. J., and Matthaus, G., 1997, “The Oxidation Behaviour of HVOF Thermal-Sprayed MCrAlY Coatings,” Surf. Coat. Technol., 93–95, pp. 21–26. [CrossRef]
Saeidi, S., Voisey, K. T., and McCartney, D. G., 2009, “The Effect of Heat Treatment on the Oxidation Behavior of HVOF and VPS CoNiCrAlY Coatings,” J. Therm. Spray Technol., 18(2), pp. 209–216. [CrossRef]
Brandl, W., Toma, D., and Grabke, H. J., 1998, “The Characteristics of Alumina Scales Formed on HVOF-Sprayed MCrAlY Coatings,” Surf. Coat. Technol., 108–109, pp. 10–15. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Microstructure of as delivered SiCoat2453 applied by (a) VPS and (b) HVOF

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Fig. 2

Phase identification in the VPS SiCoat2453 on PWA1483SX

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Fig. 3

α-Cr phase inside some β grains with fine and globular morphology in HVOF coating on René 80

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Fig. 4

EBSD of the whole HVOF coating, exposed to 900  °C for 10,000 h: (a) BSE signal; (b) image quality + inverse pole figure; (c) image quality + phase map

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Fig. 5

Microstructure of a HVOF coating exposed at low temperature which shows the presence of high and low Re Cr carbide

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Fig. 6

EBSD Map at high magnification of the VPS coating on Renè80 exposed to 900 °C for 1000 h: (a) BSE signal; (b) image quality + inverse pole figure; (c) image quality + phase map

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Fig. 7

Phase stability as a function of temperature by thermodynamic calculation of the coating composition

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Fig. 8

Normalized Re content (Re content at temperature T / maximum Re content at maximum stable temperature) as a function of temperature in σ phase in tested coupons

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Fig. 9

First stage blade from an Ansaldo GT AE94.3A2 after service

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Fig. 10

Microstructural condition of the metallic coating with its phases and the base material γ′ phase at the leading and trailing edge in the 50% height section of the first stage blade of Ansaldo GT AE94.3A2 after service

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