This paper studies the accuracy of a technique which is capable of predicting and modeling a wide range of creep life in Ni-based superalloys. The θ-projection method was applied to characterize the creep behavior of the Ni-based superalloy IN-792 at 800 °C. Constant load creep tests have been carried out over a wide range of loads at the constant operating temperature. Creep curves were fitted using either 4-θ or 6-θ equation by the use of a nonlinear least-square technique. The results showed that both 4- and 6-θ projection parameters revealed a good linearity as a function of stress. Comparison of experimental creep curves with those predicted using both of the utilized θ-projection techniques showed that the techniques fit the experimental data at high strain values very well while the 6-θ approach describes much better the creep curves at low strain region.

References

References
1.
Wilshire
,
B.
,
2002
, “Observations, Theories, and Predictions of High-Temperature Creep Behavior,”
Metall. Mater. Trans. A
,
33
(2), pp.
241
248
.10.1007/s11661-002-0086-5
2.
Koul
,
A. K.
,
Castillo
,
R.
, and
Willett
,
K.
,
1984
, “Creep Life Predictions in Nickel-Based Superalloys,”
Mater. Sci. Eng. A
,
66
(2), pp.
213
226
.10.1016/0025-5416(84)90182-4
3.
Burt
,
H.
, and
Wilshire
,
B.
,
2006
, “Theoretical and Practical Implications of Creep Curve Shape Analyses for 7010 and 7075,”
Metall. Mater. Trans. A
,
37
(3), pp.
1005
1015
.10.1007/s11661-006-0073-3
4.
Brown
,
S. G. R.
,
Evans
,
R. W.
, and
Wilshire
,
B.
,
1986
, "Creep Strain and Creep Life Prediction for the Cast Nickel-Based Superalloy IN-100,"
Mater. Sci. Eng. A
,
84
, pp.
147
156
.10.1016/0025-5416(86)90232-6
5.
Kim
,
W. G.
,
Yin
,
S. N.
,
Kim
,
Y. W.
, and
Chang
,
J. H.
,
2008
, “Creep Characterization of a Ni-Based Hastelloy-X Alloy by Using Theta Projection Method,”
Eng. Fract. Mech.
,
75
(17), pp.
4985
4995
.10.1016/j.engfracmech.2008.06.017
6.
Evans
,
M.
,
2000
, “Predicting Times to Low Strain for a 1CrMoV Rotor Steel Using a 6-θ Projection Technique,”
J. Mater. Sci.
,
35
(12), pp.
2937
2948
.10.1023/A:1004770525118
7.
Evans
,
M.
,
2001
, “The θ Projection Method and Small Creep Strain Interpolations in a Commercial Titanium Alloy,”
J. Mater. Sci.
,
36
(12), pp.
2875
2884
.10.1023/A:1017946218860
8.
Evans
,
R. W.
, and
Wilshire
,
B.
,
1985
,
Creep of Metals and Alloys
,
Institute of Metals
,
London
.
9.
Evans
,
M.
, and
Wang
,
D.
,
2008
, “The Small Punch Creep Test: Some Results From a Numerical Model,”
J. Mater. Sci.
,
43
(6), pp.
1825
1835
.10.1007/s10853-007-2388-x
10.
Koul
,
A. K.
,
1982
, “Larson-Miller Parameter and Its Modified Version,”
Scr. Metall.
,
16
(8), pp.
947
952
.10.1016/0036-9748(82)90131-4
11.
Koul
,
A. K.
, and
Castillo
,
R.
,
1991
, “A Critical Assessment of the θ Projection Concept for Creep Life Prediction of Nickel-Based Superalloy Components,”
Mater. Sci. Eng. A
,
138
(2), pp.
213
219
.10.1016/0921-5093(91)90690-O
12.
Wolf
,
H.
,
Mathew
,
M. D.
,
Mannan
,
S. L.
, and
Rodriguez
,
P.
,
1992
, “Prediction of Creep Parameters of Type 316 Stainless Steel Under Service Conditions Using the π-Projection Concept,”
Mater. Sci. Eng. A
,
159
(2), pp.
199
204
.10.1016/0921-5093(92)90290-H
13.
Evans
,
M.
,
2002
, “Sensitivity of the Theta Projection Technique to the Functional Form of the Theta Interpolation/Extrapolation Function,”
J. Mater. Sci.
,
37
(14), pp.
2871
2884
.10.1023/A:1016031907086
14.
Brown
,
S. G. R.
,
Evans
,
R. W.
, and
Wilshire
,
B.
,
1986
, “Exponential Descriptions of Normal Creep Curves,”
Scr. Metall.
,
20
(6), pp.
855
860
.10.1016/0036-9748(86)90454-0
15.
Brown
,
S. G. R.
,
Evans
,
R. W.
, and
Wilshire
,
B.
,
1986
, “A Comparison of Extrapolation Techniques for Long-Term Creep Strain and Creep Life Prediction Based on Equations Designed to Represent Creep Curve Shape,”
Int. J. Pressure Vessels Piping
,
24
(3), pp.
251
268
.10.1016/0308-0161(86)90125-0
16.
Evans
,
R. W.
,
2000
, “The θ Projection Method and Low Creep Ductility Materials,”
Mater. Sci. Technol.
,
16
(1), pp.
6
8
.10.1179/026708300773002609
17.
Caron
,
P.
, and
Khan
,
T.
,
1983
, “Improvement of Creep Strength in a Nickel-Base Single-Crystal Superalloy by Heat Treatment,”
Mater. Sci. Eng.
,
61
(2), pp.
173
184
.10.1016/0025-5416(83)90199-4
18.
Nix
,
W. D.
, and
Gibling
,
J. C.
,
1983
,
Mechanisms of Time Dependent Flow and Fracture
,
The American Society for Metals
,
Metals Park
.
19.
Nix
,
W. D.
, and
Ilschner
,
B.
,
1980
, “
Mechanisms Controlling Creep of Single Phase Metals & Alloys
,”
Proceedings 5th International Conference on the Strength of Metals and Alloys (ICSMA 5), Aachen, Germany, August 27–31, 1979
,
P.
Haasen
,
V.
Gerold
,
G.
Kostorz
, eds., Pergamon Press, New York, Vol.
3
, p.
1503
.
20.
Nathal
,
M. V.
,
MacKay
,
R. A.
, and
Miner
,
R. V.
,
1989
, “Influence of Precipitate Morphology on Intermediate Temperature Creep Properties of a Nickel-Base Superalloy Single Crystal,”
Metall. Trans. A
,
20
(1), pp.
133
141
.10.1007/BF02647500
21.
Baldan
,
A.
,
1991
, “Rejuvenation Procedures to Recover Creep Properties of Nickel-Base Superalloys by Heat Treatment and Hot Isostatic Pressing Techniques,”
J. Mater. Sci.
,
26
(13), pp.
3409
3421
.10.1007/BF00557126
22.
Perry
,
A. J.
,
1974
, “Cavitation in Creep,”
J. Mater. Sci.
,
9
(6), pp.
1016
1039
.10.1007/BF00570398
23.
Dennison
,
J. P.
, and
Wilshire
,
B.
,
1962
, “Observations on the Influence of Impurities on the Creep and Fracture Behavior of Nickel at 500 and 600 °C,”
J. Inst. Met.
,
91
, pp.
343
352
.
24.
Williams
,
K. R.
, and
Wilshire
,
B.
,
1977
, “Effects of Microstructural Instability on the Creep and Fracture Behaviour of Ferritic Steels,”
Mater. Sci. Eng.
,
28
(2), pp.
289
296
.10.1016/0025-5416(77)90183-5
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