Advanced Ni-based gas turbine disks are expected to operate at higher service temperatures in aggressive environments for longer time durations. Exposures of Ni-based alloys to alkaline-metal salts and sulfur compounds at elevated temperatures can lead to hot corrosion fatigue crack growth in engine disks. Type II hot corrosion involves the formation and growth of corrosion pits in Ni-based alloys at a temperature range of 650 °C to 750 °C. Once formed, these corrosion pits can serve as stress concentration sites where fatigue cracks can initiate and propagate to failure under subsequent cyclic loading. In this paper, a probabilistic methodology is developed for predicting the corrosion fatigue crack growth life of gas turbine engine disks made from a powder-metallurgy Ni-based superalloy (ME3). The key features of the approach include: (1) a pit growth model that describes the depth and width of corrosion pits as a function of exposure time, (2) a cycle-dependent crack growth model for treating fatigue, and (3) a time-dependent crack growth model for treating corrosion. This set of deterministic models is implemented into a probabilistic life-prediction code called DARWIN. Application of this approach is demonstrated for predicting corrosion fatigue crack growth life in a gas turbine disk based on the ME3 properties from the literature. The results of this study are used to assess the conditions that control the transition of a corrosion pit to a fatigue crack and to identify the pertinent material parameters influencing corrosion fatigue life and disk reliability.

References

1.
Sidhu
,
T. S.
,
Prakash
,
S.
, and
Agrawal
,
R. D.
,
2006
, “
Hot Corrosion and Performance of Nickel-Based Coatings
,”
Curr. Sci.
,
90
(
1
), pp.
41
47
.
2.
Chiang
,
K. T.
,
Pettit
,
F. S.
, and
Meier
,
G. H.
,
1983
, “
Low Temperature Hot Corrosion
,” NACE-6, pp.
519
530
.
3.
Rapp
,
R.
,
2002
, “
Hot Corrosion of Materials: A Fluxing Mechanism?
,”
Corros. Sci.
,
44
, pp.
209
221
.10.1016/S0010-938X(01)00057-9
4.
Leyens
,
C.
,
Wright
,
I. G.
, and
Pint
,
B. A.
,
1999
, “
Hot Corrosion of Nickel-Based Alloys in Biomass-Derived Fuel Simulated Atmosphere
,”
Elevated Temperature Coatings: Science and Technology III
,
J. M.
Hampikian
and
N. B.
Dahotre
, eds.,
TMS
,
Warrendale, PA
, pp.
79
90
.
5.
Gabb
,
T. P.
,
Telesman
,
J.
,
Hazel
,
B.
, and
Mourer
,
D. P.
,
2010
, “
The Effects of Hot Corrosion Pits on the Fatigue Resistance of a Disk Superalloy
,”
J. Mater. Eng. Perform.
,
19
(
1
), pp.
77
89
.10.1007/s11665-009-9399-5
6.
Franklin
,
D. B.
and
Nelson
,
E. E.
,
1981
, “
Corrosion Fatigue of Inconel 718 and Incoloy 903
,” NASA Marshall Space Flight Center, AL, NASA Report No. TM-82426.
7.
Groh
,
J. R.
and
Duvelius
,
R. W.
,
2001
, “
Influence of Corrosion Pitting on Alloy 718 Fatigue Capability
,”
Superalloys 718, 625, 706 and Various Derivatives
,
L. A.
Loria
, ed.,
TMS
,
Warrendale, PA
, pp.
583
592
.
8.
Encinas-Oropesa
,
A.
,
Drew
,
G. L.
,
Hardy
,
M. C.
,
Leggett
,
A. J.
,
Nicholls
,
J. R.
, and
Simms
,
N. J.
,
2008
, “
Effects of Oxidation and Hot Corrosion in a Nickel Disc Alloy
,”
Superalloy 2008
,
R. C.
Reed
,
K. A.
Green
,
P.
Caron
,
T. P.
Gabb
,
M. G.
Fahrmann
,
E. S.
Huron
, and
S. A.
Woodard
, eds.,
TMS
,
Warrendale, PA
, pp.
609
618
.
9.
Gabb
,
T. P.
,
Telesman
,
J.
,
Kantzos
,
P. T.
,
Smith
,
J. W.
, and
Browning
,
P. F.
,
2004
,
Effects of High Temperature Exposures on Fatigue Life of Disk Superalloys
,
K. A.
Green
,
T. M.
Pollock
,
H.
Harada
,
T. E.
Howson
,
R. C.
Reed
,
J. J.
Schirra
, and
S.
Walston
, eds.,
TMS
,
Warrendale, PA
, pp.
269
274
.
10.
Sriraman
,
M. R.
and
Pidaparti
,
R. M.
,
2010
, “
Crack Initiation Life of Materials Under Combined Pitting Corrosion and Cyclic Loading
,”
J. Mater. Eng. Perform.
,
19
(
1
), pp.
7
12
.10.1007/s11665-009-9379-9
11.
Harlow
,
D. G.
and
Wei
,
R. P.
,
1994
, “
Probability Approach for Prediction of Corrosion and Corrosion Fatigue Life
,”
AIAA J.
,
32
, pp.
2073
2079
.10.2514/3.12254
12.
Dolley
,
E. J.
,
Lee
,
B.
, and
Wei
,
R. P.
,
2000
, “
The Effect of Pitting Corrosion on Fatigue Life
,”
Fatigue Fract. Eng. Mater. Struct.
,
23
, pp.
555
560
.10.1046/j.1460-2695.2000.00323.x
13.
Chen
,
G. S.
,
Gao
,
M.
,
Harlow
,
D. G.
, and
Wei
,
R. P.
,
1994
, “
Corrosion and Corrosion Fatigue of Airframe Aluminum Alloys
,”
NASA Conf. Publ.
3274
, pp.
157
173
.
14.
Wang
,
Q. Y.
,
Pidaparti
,
R. M.
, and
Palakal
,
M. J.
,
2001
, “
Comparative Study of Corrosion-Fatigue in Aircraft Materials
,”
AIAA J.
,
39
(
2
), pp.
325
330
.10.2514/2.1308
15.
Gabb
,
T. P.
,
Telesman
,
J.
,
Kantzos
,
P. T.
, and
O'Connor
,
K.
,
2002
, “
Characterization of the Temperature Capabilities of Advanced Disk Alloy ME3
,” NASA Glenn Research Center, NASA Report No. TM-2002-211796.
16.
Gao
,
Y.
,
Kumar
,
M.
,
Nalla
,
R. K.
, and
Ritchie
,
R. O.
,
2005
, “
High-Cycle Fatigue of Nickel-Based Superalloy ME# at Ambient and Elevated Temperatures: Role of Grain Boundary Engineering
,”
Metall. Mater. Trans. A
,
36A
, pp.
3325
3333
.10.1007/s11661-005-0007-5
17.
Southwest Research Institute
,
2011
, “DARWIN® User's Guide,” San Antonio, TX.
18.
Wu
,
Y. T.
,
Enright
,
M. P.
, and
Millwater
,
H. R.
,
2002
, “
Probabilistic Methods for Design Assessment of Reliability With Inspection
,”
AIAA J.
,
40
(
5
), (2002), pp.
937
946
.10.2514/3.15143
19.
Ishihara
,
S.
,
Saka
,
S.
,
Nan
,
Z. Y.
,
Goshima
,
T.
, and
Sunada
,
S.
,
2006
, “
Prediction of Corrosion Fatigue Lives of Aluminum Alloy on the Basis of Corrosion Pit Growth Law
,”
Fatigue Fract. Eng. Mater. Struct.
,
29
, pp.
472
480
.10.1111/j.1460-2695.2006.01018.x
20.
Balsone
,
S. J.
,
1985
, “
The Effect of Stress and Hot Corrosion on Nickel-Base Superalloys
,” M.S. thesis, Air Force Institute of Technology, Wright-Patterson AFB, Dayton, OH.
21.
Lindley
,
T. C.
,
McIntyre
,
P.
, and
Trant
,
P. J.
,
1982
, “
Fatigue Crack Initiation at Corrosion Pits
,”
Met. Technol. (London)
,
9
, pp.
135
142
.10.1179/030716982803286403
22.
Peterson
,
R. E.
,
1974
,
Stress Concentration Factors
,
John Wiley and Sons
,
New York
.
23.
Kitagawa
,
H.
and
Takahashi
,
S.
1976
, “
Applicability of Fracture Mechanics to Very Small Cracks or the Cracks in the Early Stage
,”
2nd International Conference on Mechanical Behavior of Materials (ICM-2), Boston, MA, August 16–20, American Society for Metals
,
Metals Park, OH
, pp.
627
631
.
24.
Wei
,
R. P.
and
Landes
,
J. D.
,
1969
, “
Correlation Between Sustained-Load and Fatigue Crack Growth in High-Strength Steels
,”
Mater. Res. Stand.
,
44
(
46
), pp.
25
27
.
You do not currently have access to this content.