At the high operating temperatures experienced within a gas turbine, creep damage is a major life-limiting factor. This is especially true for components which are highly stressed and closest to the hot gas inlet end of the machine, such as the rotating blades in this area. The ability to recover the creep properties of used gas turbine components might enable their service lives to be increased considerably. Thereby, maintenance costs could be reduced. Previous research into the feasibility of reconditioning crept superalloys by heat treatment will be reviewed and perceived limitations identified. The current work will add to knowledge on the effects of conventional recovery techniques and will explore potential new heat treatment regimes. The experimental and analytical methods to be used will be both described and supported by preliminary results.
Issue Section:
Gas Turbines: Manufacturing, Materials, and Metallurgy
Keywords:
heat treatment,
creep fracture,
gas turbines,
metallurgy,
manufacture,
superalloys,
nickel alloys
1.
Davies
, P. W.
, Dennison
, J. P.
, and Evans
, H. E.
, 1966
, “Recovery of Properties of a Nickel-Based High-Temperature Alloy after Creep at 750°C
,” J. Inst. Met.
, 94
, pp. 270
–275
.2.
Davies
, P. W.
, Dennison
, J. P.
, and Evans
, H. E.
, 1967
, “The Kinetics of the Recovery of Creep Properties During Annealing of Nimonic 80A After Creep at 750°C
,” J. Inst. Met.
, 95
, pp. 231
–234
.3.
Hart
, R. V.
, and Gayter
, H.
, 1968
, “Recovery of Mechanical Properties in Nickel Alloys by Re-Heat-Treatment
,” J. Inst. Met.
, 96
, pp. 338
–344
.4.
Davies
, P. W.
, Dennison
, J. P.
, and Sidey
, D.
, 1973
, “The Recovery of Mechanical Properties of Nimonic 105 by Heat-Treatment After High-Temperature Creep
,” J. Inst. Met.
, 101
, pp. 153
–161
.5.
Cina, B., and Myron, S., 1976, “Means for Extending the Secondary Creep Life of Nickel-Base Superalloys,” Second International Conference on Mechanical Behavior of Materials, Federation of Materials Societies, Boston, pp. 2025–2030.
6.
Davies
, P. W.
, and Dennison
, J. P.
, 1975
, “The Use of Heat-Treatment to Recover the Creep Properties of Nimonic 115 After High-Temperature Creep
,” Met. Sci. J.
, 9
, pp. 319
–323
.7.
Dennison
, J. P.
, Holmes
, P. D.
, and Wilshire
, B.
, 1978
, “The Creep and Fracture of the Cast Nickel-Based Superalloy IN 100
,” Mater. Sci. Eng.
, 33
, pp. 35
–47
.8.
Stevens, R. A., and Flewitt, P. E. J., 1979, “Regenerative Heat Treatments for the Extension of the Creep Life of Superalloy IN 738,” Proceedings of the Fifth International Conference on Strength of Metals and Alloys, Vol. 1, Aachen, Germany, Pergamon, New York, pp. 27–31.
9.
Ross, M. D., Bennett, G. T., and Stewart, D. C., 1979, “Rejuvenation of Turbine Blade Material by Thermal Treatment,” Pratt and Witney Aircraft Report AD-A077527.
10.
McLean, M., and Tipler, H. R., 1984, “Assessment of Damage Accumulation and Property Regeneration by Hot Isostatic Pressing and Heat Treatment of Laboratory-Tested and Service-Exposed IN 738LC,” Proceedings of the Fifth International Symposium on Superalloys, Gell, M., et al., eds. Metals Society of AIME, pp. 73–82.
11.
Koul, A. K., Immarigeon, J.-P., Castillo, R., Lowden, P., and Liburdi, J., 1988, Rejuvenation of Service-Exposed IN 738 Turbine Blades, “Superalloy’s 1988, S. Reichman et al., eds., The Metallurgical Society, Champion, PA, pp. 755–764.
12.
Baldan
, A.
, 1992
, “Recovery of the Creep Resistance of a Conventionally Cast Nickel-Base Superalloy
,” J. Mater. Sci. Lett.
, 11
, pp. 1319
–1321
.13.
Girdwood
, R. B.
, and Evans
, R. W.
, 1996
, “Recovery of Creep Properties of the Nickel-Base Superalloy Nimonic 105
,” Int. J. Pressure Vessels Piping
, 66
, pp. 141
–153
.14.
Stevens
, R. A.
, and Flewitt
, P. E. J.
, 1979
, “The Role of Hydrostatic Pressure on the Sintering of Creep Cavities in a Nickel-2 Percent Chromium Alloy
,” Acta Metall.
, 27
, pp. 67
–77
.15.
Wroe
, R.
, and Rowley
, A. T.
, 1996
, “Evidence for a Non-Thermal Microwave Effect in the Sintering of Partially Stabilised Zirconia
,” J. Mater. Sci.
, 31
, pp. 2019
–2926
.16.
Bruce
, R. W.
, 1988
, “New Frontiers in the Use of Microwave Energy: Power and Metrology
,” Mater. Res. Soc. Symp.
124
, pp. 3
–15
.17.
Zavalishin
, Y. K.
, Masalov
, Y. A.
, and Postnikov
, S. N.
, 1995
, “Pulsed Magnetic Field Treatment (PMFT Method)
,” Surf. Eng. Appl. Electrochem.
, 2
, pp. 65
–74
.18.
Hochman
, R. F.
, Tselesin
, N.
, and Drits
, V.
, 1988
, “Magnetic Fields: Fertile Ground for Metals Processing
,” Adv. Mater. Proc.
, 8
, pp. 36
–41
.19.
Evans, R. W., and Wilshire, B., Creep of Metals and Alloys, The Institute of Metals, London.
20.
Nabarro, F. R. N., and de Villiers, H. L., 1995, The Physics of Creep, Taylor and Francis, London.
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