2014 №02 (01) DOI of Article
2014 №02 (03)

The Paton Welding Journal 2014 #02
The Paton Welding Journal, 2014, #2, 12-23 pages



RC «Pratt&Whitney-Paton». 68 Gorky Str., Kiev, Ukraine. E-mail:
In modern gas-turbine units increase of gas working temperature leads to shortening of blade service life. For this reason their repair becomes a priority. Retailoring of single-crystal blade tip by hardfacing is a rather complicated task. In order to select suitable filler material, thermal cycling tests of samples of deposited welds on CMSX-4 alloy with a single-crystal structure have been performed. Evolution of the structure under the conditions of high-temperature cyclic oxidation is considered. Selection of filler material, which ensures high temperature resistance and stability of weld metal structure, was optimized. These requirements are satisfied by Co-Ni-based material, which was earlier tried out and proved to be very good in complex technology of repair of a blade from ZMI-3U alloy. The technology includes airfoil tip retailoring by hardfacing with subsequent deposition on the item surface of a high-temperature metal coating by electron beam deposition to ensure the required service properties of the item. 18 Ref., 4 Tables, 10 Figures.
Keywords: single-crystal alloy, hardfacing, dendritic growth, stray grains, raft structure, heat-affected zone, cyclic oxidation, oxidation resistance, coating, spinel, yttrium oxide
Received:                25.10.13
Published:               28.02.14
1. Shukin, S., Annerfeldt, M., Bjorkman, M. (2008) Siemens SGT-800 industrial gas turbine enhanced to 47 MW. In: Proc. of ASME Turbo Expo 2008 on Power for Land, Sea and Air (June 9-13, 2008, Germany), 1-6.
2. Wilson, B.C., Hickman, J.A., Fuchs, G.E. (2003) The effect of solution heat treatment on a single-crystal Ni-based superalloy. JOM, 3, 35-40.
3. Wortman, D.J., Duderstadt, E.C., Nelson, W.A. (1990) Bond coat development for thermal barrier coating. Transact. of ASME. J. Eng. Gas Turbines Power, 12(10), 527-530.
4. Belyavin, A.F., Fedotov, D.A., Kurenkova, V.V. et al. (2013) Restoration of single-crystal blades using argon-arc surfacing and deposition of thermal-barrier coating. Pt 1. Sovr. Elektrometallurgiya, 1, 49-57.
5. Anderson, T.D., DuPont, J.N. (2010) Stray grain formation and solidification cracking susceptibility of single crystal Ni-base superalloy CMSX-4. Met. and Materials Transact. A, 41(1), 181-195.
6. Shalin, R.E., Svetlov, I.L., Kachanov, E.B. et al. (1997) Single crystals of nickel heat-resistant alloys. Moscow: Mashinostroenie.
7. Sieborgen, D., Brehm, H., Wunderlich, F. et al. (2001) Temperature dependence of lattice parameter, misfit and thermal expansion coefficient of matrix, gВ-phase and superalloy. Z. Metallkd, 92, 58-61.
8. Caron, P., Lavigne, O. (2011) Recent studies at ONERA on superalloys for single crystal turbine blades. J. AerospaceLab., Issue 3, 11, 1-14.
9. Kablov, E.N. (2001) Cast blades of gas turbine engines. Moscow: MISiS.
10. Tikhomirova, E.A., Azizov, T.N., Sidokhin, E.F. (2012) On thermal fatigue of heat-resistant alloys. Aviats. Materialy i Tekhnologii, 3, 3-5.
11. Kolomytsev, P.T. (1979) Heat-resistant diffusion coatings. Moscow: Metallurgiya.
12. Jackson, R.D. (2009) The effect of bond coat oxidation on the microstructure and endurance of two thermal barrier coating systems: Dis.
13. Toscano, J. (2008) Influence of composition and processing on the oxidation behavior of MCrAlY-coatings for TBC applications. Energy & Environment, 28, 187.
14. Nikitin, V.N. (1987) Corrosion and protection of gas turbine blades. Leningrad: Mashinostroenie.
15. Tien, I.K., Rand, W.H. (1972) The effect of active element addition in void formation during oxidation. Ser Metal, 1, 55-57.
16. Michels, H.T. (1976) The effect of dispersed reactive metal oxides on the oxidation resistance of nickel-20% chromium alloys. Met. Transact., 3, 379-388.
17. Malashenko, V.S., Shelkovoj, A.N., Grabin, V.V. et al. (2000) Life of condensation thermal barrier coatings in current heat-resistant nickel alloy. Problemy Spetselektrometallurgii, 1, 23-24.
18. Liu, J. (2007) Mechanism of lifetime improvement in thermal barrier coatings with Hf or Y modification of CMSX-4 superalloy substrates: Dis.