Abstract

Turbine disks in some advanced engine applications may be exposed to temperatures above 700°C for extended periods of time, approaching 1000 h. These exposures could affect near-surface composition and microstructure through formation of damaged and often embrittled layers. The creation of such damaged layers could significantly affect local mechanical properties. Powder metal disk superalloys LSHR and ME3 were exposed at temperatures of 704, 760, and 815°C for times up to 2020 h, and the types and depths of environmental attacked were measured. Fatigue tests were performed for selected cases at 704 and 760°C, to determine the impacts of these exposures on properties. Fatigue resistance was reduced up to 98 % in both superalloys for some exposure conditions. The changes in surface composition and phases, depths of these changed layers, failure responses, and failure initiation modes were compared.

References

1.
Furrer
,
D.
and
Fecht
,
H.
, “
Ni-Based Superalloys for Turbine Discs
,”
J. Metals
, Vol.
51
, No.
1
,
1999
, pp.
14
17
.
2.
Antolovich
,
S. D.
,
Domas
,
P.
and
Strudel
,
J. L.
, “
Low Cycle Fatigue of René 80 as Affected by Prior Exposure
,”
Met. Trans. A
, Vol.
10A
,
1979
, pp.
1859
1868
. https://doi.org/10.1007/BF02811730
3.
Gabb
,
T. P.
,
Telesman
,
J.
,
Kantzos
,
P. T.
and
Smith
,
J. W.
, “
Effects of High Temperature Exposures on Fatigue Life of Disk Superalloys
,”
Superalloys 2004: Proceedings of the 10th International Symposium on Superalloys
,
K. A.
Green
,
H.
Harada
,
T. E.
Howson
,
T. M.
Pollock
,
R. C.
Reed
,
J. J.
Schirra
and
S.
Walston
, Eds.,
The Minerals, Metals, and Materials Society (TMS)
,
Warrendale, PA
,
2004
, pp.
269
274
.
4.
Chang
,
D. R.
,
Krueger
,
D. D.
and
Sprague
,
R. A.
, “
Superalloy Powder Processing, Properties and Turbine Disk Applications
,”
Superalloys 1984: Proceedings of the 5th International Symposium on Superalloys
,
M.
Gell
,
C. S.
Kortovich
,
R. H.
Bricknell
,
W. B.
Kent
and
J. F.
Radavich
, Eds.,
TMS
,
Warrendale, PA
,
1984
, pp.
245
273
.
5.
Woodford
,
D. A.
, “
Gas Phase Embrittlement and Time Dependent Cracking of Nickel Based Superalloys
,”
Energy Materials: Mater. Sci. Eng. Energ. Syst
, Vol.
1
, No.
1
, March
2006
, pp.
59
79
. https://doi.org/10.1179/174892306X99679
6.
Encinas-Oropesa
,
A.
,
Drew
,
G. L.
,
Hardy
,
M. C.
,
Leggett
,
A. J.
,
Nicholls
,
J. R.
and
Simms
,
N. J.
, “
Effects of Oxidation and Hot Corrosion in a Nickel Disc Alloy
,”
Superalloys 2008: Proceedings of the 11th International Symposium on Superalloys
,
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
,
2008
, pp.
609
618
.
7.
Sudbrack
,
C.
,
Draper
,
S.
,
Gorman
,
T.
,
Telesman
,
J.
,
Gabb
,
T.
and
Hull
,
D.
, “
Oxidation and the Effects of High Temperature Exposures on Notched Fatigue Life of an Advanced Powder Metallurgy Disk Superalloy
,”
Superalloys 2012: Proceedings of the 12th International Symposium on Superalloys
,
E. S.
Huron
,
R. C.
Reed
,
M. C.
Hardy
,
M. J.
Mills
,
R. E.
Montero
,
P. D.
Portella
and
J.
Telesman
, Eds.,
TMS
,
Warrendale, PA
,
2012
, pp.
863
872
.
8.
ASTM E466-2007
:
Standard Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic Materials
,
Annual Book of ASTM Standards
,
ASTM International
,
West Conshohocken, PA
,
2007
.
9.
Gabb
,
T. P.
,
Gayda
,
J.
,
Telesman
,
J.
and
Kantzos
,
P. T.
, “
Thermal and Mechanical Property Characterization of the Advanced Disk Alloy LSHR
,”
NASA/TM-2005-213645
,
National Aeronautics and Space Administration
,
Washington, D.C.
,
2005
.
10.
Telesman
,
J.
,
Gabb
,
T.
,
Yamada
,
Y.
,
Ghosn
,
L.
,
Hornbach
,
D.
and
Jayaraman
,
N.
, “
Dwell Notch Low Cycle Fatigue Behavior of a Powder Metallurgy Nickel Disk Alloy
,”
Superalloys 2012: Proceedings of the 12th International Symposium on Superalloys
,
E. S.
Huron
,
R. C.
Reed
,
M. C.
Hardy
,
M. J.
Mills
,
R. E.
Montero
,
P. D.
Portella
and
J.
Telesman
, Eds.,
TMS
,
Warrendale, PA
,
2012
, pp.
853
862
.
11.
ASTM E112-2010
:
Standard Test Methods for Determining Average Grain Size
,
Annual Book of ASTM Standards
,
ASTM International
,
West Conshohocken, PA
,
2010
.
12.
Gabb
,
T. P.
,
Garg
,
A.
,
Ellis
,
D. L.
and
O'Connor
,
K. M.
, “
Detailed Microstructural Characterization of the Disk Alloy ME3
,”
NASA/TM-2004-213066
,
National Aeronautics and Space Administration
,
Washington, D.C.
,
2004
.
13.
Jou
,
H.
,
Olson
,
G.
,
Gabb
,
T.
,
Garg
,
A.
and
Miller
,
D.
, “
Characterization and Computational Modeling of Minor Precipitate Phases in Alloy LSHR
,”
Superalloys 2012: Proceedings of the 12th International Symposium on Superalloys
,
E. S.
Huron
,
R. C.
Reed
,
M. C.
Hardy
,
M. J.
Mills
,
R. E.
Montero
,
P. D.
Portella
and
J.
Telesman
, Eds.,
TMS
,
Warrendale, PA
,
2012
, pp.
893
902
.
14.
Qiu
,
Y. Y.
, “
Coarsening Kinetics of γ′ Precipitates in Ni-Al and Ni-Al-Mo Alloys
,”
J. Mater. Sci.
, Vol.
31
,
1996
, pp.
4311
4319
. https://doi.org/10.1007/BF00356455
15.
Gabb
,
T. P.
,
Sudbrack
,
C. K.
,
Draper
,
S. L.
,
MacKay
,
R. A.
and
Telesman
,
J.
, “
Effects of Long Term Exposures on PM Disk Superalloys
,”
NASA/TM-2013-216614
,
National Aeronautics and Space Administration
,
Washington, D.C.
, Dec.
2013
.
16.
Decker
,
R. F.
, “
Strengthening Mechanisms in Nickel-Base Superalloys
,”
Proceedings on Symposium: Steel-Strengthening Mechanisms
,
Zurich, Switzerland
,
Climax Molybdenum Company
, May 5–6,
1969
, pp.
147
170
.
This content is only available via PDF.
You do not currently have access to this content.