The low-cycle-fatigue (LCF) behaviour of superalloys has been examined with particular emphasis on their early stage strength changes and their response to complex cycling. Using steels and a titanium alloy as comparators, it has been possible to establish some general guidelines regarding their LCF performance. In the normal testing domain (700–1000°C) a high yield strain results in predominantly elastic conditions and cyclic stability. Under strain controlled dwell testing superalloys are fatigue dominated and generally more sensitive to compressive hold periods, whereas under stress control shortest lifetimes result from tensile dwells. Environmental influences are strong especially at temperatures where oxides remain brittle, but at high temperatures (>900°C) overaging effects may be beneficial. During thermal–mechanical cycling in-phase testing appears most deleterious.
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References
1.
LEESEG. E. and BILLR. G.: Proc. AGARD Conf. No. 393 on ‘Damage tolerance concepts for critical engine components’, San Antonio, Tex., Apr. 1985, AGARD, Paper 15.
2.
WELLSC. H. and SULLIVANc. P.: STP 459, ‘Fatigue at high temperature’, (ed. CoffinL. F.), 59; 1969, Philadelphia, Pa, The American Society for Testing and Materials.
3.
MARCHIONNIM., RANUCCID., and PICCOE.: ‘High temperature alloys for gas turbines’, (ed. R. Brunetaud et al.), 791; 1982, Dordrecht, Reidel.
4.
ANTOLOVICHS. A. and ROSAE.: Mater. Sci. Eng.,1981, 47, 47.
5.
ELLISONE. G., PLUMBRIDGEW. J., and DEANM. S.: ‘Turbine blade material behaviour and life prediction’, Report No. 84/12, Department of Mechanical Engineering, University of Bristol, 1984.
6.
de ABREUE. and ANTUNESV. T.: PhD thesis, Cranfield Institute of Technology, 1979.
7.
ELLISONE. G. and PATTERSONA. J. F.: Proc. Inst. Mech. Eng.,1976, 190, 321.
8.
PLUMBRIDGEW. J., DALSKIM. E., and CASTLEP.: Fatigue Eng. Mater. Struct.,1980, 3, 177.
9.
PLUMBRIDGEW. J. and STANLEYM.: Int. J. Fatigue, 1986, 8, 209.
10.
RAOK. B. S., SCHIFFERSH., and SCHUSTERH.: Proc. Int. Conf. on ‘High temperature alloys: their exploitable potential’, Petten, Oct. 1985, Bond voor Materialenkennis.
11.
RANTINGG., RANUCCID., and PICCOE.: Mater. Sci. Eng.,1983, 58, 127.
12.
WHITLOWG. A., JOHNSONR. L., PRIDEMOREW. H., and ALLENJ. M.: J. Eng. Mater. Technol.,1984, 106, 43.
13.
LORDD. C. and COFFINL. F.: Metall. Trans.,1973, 4A, 1647.
14.
HYZAKJ. M. and BERNSTEINH. L.: Proc. AGARD Conf. CP 243 on ‘Characterisation of low-cycle high-temperature fatigue by the strain v. range partitioning method’, Aalborg, Apr. 1978, AGARD, Paper 11, p. 1.
15.
COFFINL. F.: Metall. Trans.,1975, 2, 3105.
16.
PLUMBRIDGEW. J., PRIESTR. H., and ELLISONE. G.: ‘Mechanical behaviour of materials’, (eds K. J. Miller and R. F. Smith), Vol. 2, 129; 1979, Oxford, Pergamon.
OSTERGRENW. J.: in ‘Creep—fatigue interaction’, (ed. CurranR. M.), 179; 1976, New York, American Society for Mechanical Engineers.
19.
slimC. I.‘High-temperature low-cycle fatigue mechanisms for a nickel-base and copper-base alloy’, Report NASA-CR 3543,Lewis Research Center, Cleveland, Ohio, 1982.
20.
MILLIGANW. W. and BtuR. C.: ‘Low-cycle-fatigue behaviour of conventionally cast MAR-M200 at 1000°C’, Report NASA TM-83769, Lewis Research Center, Cleveland, Ohio, 1984.
21.
PRIESTR. H. and ELLISONE. G.: Mater. Sci. Eng.,1981, 49, 7.
22.
PLUMBRIDGEW. J. and STANLEYM.: in Proc. Int. Conf. on ‘Fatigue of engineering materials and structures’, Sheffield, 1986, Institute of Mechanical Engineers, 377-386.
23.
BERNSTEINH. L.: STP 770, ‘Low cycle fatigue and life predictions’, (ed. C. Amzallag et al.), 105; 1982, Philadelphia, Pa., The American Society for Testing and Materials.
24.
SANDORB. I.: ‘Fundamentals of cyclic stress and strain’, 106; 1972, University of Wisconsin Press.
25.
DAYM. F. and THOMASG. B.: Met. Sci.,1979, 13, 26.
26.
McMALIONC. J. and COFFINL. F.: Metall. Trans.,1970, 1A, 3443.
27.
ANTOLOVICHS. D., BOMASP., and STRUDELJ. L.: Metall. Trans.,1979, 10A, 1859.
28.
ANTOLOVICHS. D., ROSAE., and A. PINEAL’: Mater. Sci. Eng.,1981, 47, 47.
29.
REUCIIETJ. and REMYL.: Metall. Trans.,1983, 14A, 1441.
30.
COFFINL. F.: Metall. Trans.,1972, 3A, 1777.
31.
HANTINGG., RANUCCID., PICCOE., and STROCCHIP. M.: Int. J. Fatigue, 1984, 6, 95.
32.
NAZMYM. Y.: Mater. Sci. Eng.,1982, 55, 231.
33.
NAZMYM. Y.: Scripta Metall., 1982, 16, 1329.
34.
MANSONS. S., HALFORDG. R., and OLDRIEVER. E.: ‘Relation of cyclic loading pattern to microstructural fracture in creep-fatigue’, Report NASA-TM 83473, Lewis Research Center, Cleveland, Ohio, 1984.
35.
BRINKMANC. R., J. P. STRIZAK, NI. K. BOOKER, and JASKEC. E.:J. Nucl. Mater.,1976, 62, 181.
36.
RAOK. B. S., VALSANH., SANDHYAR., RAYS. K., MANNANS. L., and RODRIGUEZP.: Int. J. Fatigue, 1985, 7, 141.
37.
SAMLELSSONA., LARSSONL. E., and LUNDBERGL.: Final Report, COST 50, Project 52, 1981, Round II.
38.
HUFFH. and KONIGG. W.: Proc. AGARD Conf. No. 393 on ‘Damage tolerance concepts for critical engine components’, San Antonio, Tex., Apr. 1985, AGARD, Paper 19.
39.
MARCHANDN. and PELLOUXR. M.: Thermal-mechanical fatigue crack growth in Inconel X750’, Report NASA CR-174740, MIT, 1984.
40.
RAUC. A., GEMMAA. E., and LEVERANTG. R.: STP 520, ‘Fatigue at elevated temperatures, (ed. CardenA. E. et al.), 166;1973, Philadelphia, Pa, The American Society for Testing and Materials.
