Abstract

A testing method under creep-fatigue interaction conditions has been proposed as the ASTM standard E2714-09. In accordance with the ASTM standard, round bar smooth specimens have been recommended as a testing specimen. Additionally, creep-fatigue crack initiation and growth life are usually defined as the attainment of a specific rate of decrease in the maximum tensile stress or the modulus of elasticity ratios. However, these criterions of crack initiation and growth life on ASTM standard are not characterized in terms of physical crack size. In this study, the creep-fatigue crack initiation and growth tests for P92 were conducted using circular notched round bar specimens. An attempt is made to measure the crack length during the tests by the direct current potential drop method, which results in the establishment of a high accuracy crack length measurement. Additionally, the life of creep-fatigue crack growth was characterized by linear cumulative damage law combined with the Q*concept which has been proposed as fracture parameter to describe the life of creep crack growth.

Issue Section:
Research Papers
Keywords:
P92, creep-fatigue, crack initiation life, crack growth life, circular notched round bar specimen, linear cumulative damage law, Q* concept

References

1.
Fujita
,
T.
, “
Advances in Heat Resistant Steels for Fossil Power
,”
Mater. Jpn.
, Vol.
40
,
2001
, pp.
938
–
942
.
Google Scholar
Crossref
Search ADS
 
2.
Fujita
,
T.
, “
Materials for Future Power Plants
,”
Adv. Mater. Process
, Vol.
157
(
6
),
2000
, pp.
55
–
59
.
3.
ASTM E2714-09
,
2009
, “
Standard Test Method for Creep-Fatigue Testing
,”
Annual Book of ASTM Standards
, Vol.
03.01
,
ASTM International
,
West Conshohocken, PA
.
4.
Peterson
,
R. E.
,
Stress Concentration Design Factors
,
Wiley
,
New York
,
1953
, p. 33.
5.
Sugiura
,
R.
,
Yokobori
,
A. T.
, Jr.,
Tabuchi
,
M.
,
Fuji
,
A.
,
Adachi
,
T.
, “
Characterization of Structural Embrittlement of Creep Crack Growth for W-Added 12 %Cr Ferritic Heat-Resistant Steel Related to the Multi-axial Stress
,”
J. Eng. Mater. Technol., Trans. ASME
, Vol.
131
,
2009
, pp.
1
–
9
. https://doi.org/10.1115/1.3026544
Google Scholar
Crossref
Search ADS
 
6.
H. H.
 
Johnson
, “
Calibrating the Electric Potential Method for Studying Slow Crack Growth
,”
Mater. Res. Stand.
, Vol.
5
,
1965
, pp.
442
–
445
.
7.
Schwalbe
,
K. H.
 and
Hellman
,
D.
, “
Application of the Electrical Potential Method to Crack Length Measurements Using Johnson’s Formula
,”
J. Test. Eval.
, Vol.
9
(
4
),
1980
, pp.
218
–
220
.
8.
Adachi
,
T.
,
Yokobori
,
A. T.
, Jr.,
Tabuchi
,
M.
,
Fuji
,
A.
,
Yokobori
,
T.
, and
Nikbin
,
K.
,
2004
, “
The Proposal of Q* Parameter and Derivation of the Law of Creep Crack Growth Life for a Round Bar Specimen with a Circular Notch for Cr-Mo-V Steel
,”
Mater. High Temp.
, Vol.
21
(
2
), pp.
95
–
100
. https://doi.org/10.3184/096034004782749962
Google Scholar
Crossref
Search ADS
 
9.
Yokobori
,
A.T.
, Jr.,
Yokobori
,
T.
, and
Takasu
,
N.
, “
Effects of Frequency, Stress Rising Time and Stress Hold Time on Corrosion Fatigue Crack Behavior of Low Alloy Cr-Mo Steel
,”
Corrosion Cracking
,
V. S.
 
Goel
, Ed.,
American Society of Metals
,
1986
, pp.
1
–
9
.
10.
Yokobori
,
A. T.
 Jr.,
Kaji
,
Y.
, and
Kuriyama
,
T.
, “
Damage Progression Behavior under High Temperature Creep and Fatigue Conditions
,”
Advances in Fracture Research, Proceedings of ICF10
, in the content of Special Lecture of CD, Honolulu,
Elsevier Science
,
2001
.
11.
Taira
,
S.
, “
On Creep in Structures
,”
Proceedings of IUTAM Collection
,
Springer
,
Berlin
,
1962
, p. 96.
12.
ASME
Boiler and Pressure Vessel Code Case N-47.
13.
Lemaitre
,
J.
 and
Plumtree
,
A.
, “Application of Damage Concepts to Predict Creep-Damage Failures,”
J. Eng. Mater. Technol., Trans ASME
, Vol.
101
,
1979
, pp.
284
–
292
. https://doi.org/10.1115/1.3443689
Crossref
Search ADS
 
14.
Bui-Quoc
,
T.
 and
Biron
,
A.
, “A Phenomenological Approach for the Analysis of Combined Fatigue and Creep,”
Nucl. Eng. Des.
, Vol.
71
,
1982
, pp.
89
–
102
. https://doi.org/10.1016/0029-5493(82)90172-8
Crossref
Search ADS
 
15.
Yokobori
,
A. T.
, Jr. and
Yokobori
,
T.
, “
New Concept to Crack Growth at High Temperature Creep and Creep-Fatigue
,” in
Proceedings of ICF7, Advances in Fracture Research
,
K.
 
Salama
,
K.
 
Ravi-chandar
,
D.M.R.
 
Taplin
, and
P.
 
Rama Rao
, Eds.,
Pergamon
,
New York
,
1989
, Vol.
2
, pp.
1723
–
1735
.
Google Scholar
Crossref
Search ADS
 
16.
Yokobori
,
A. T.
, Jr.,
Uesugi
,
T.
,
Yokobori
,
T.
,
Fuji
,
A.
,
Kitagawa
,
M.
,
Yamaya
,
I.
,
Tabuchi
,
M.
, and
Yagi
,
K.
, “
Estimation of Creep Crack Growth Rate in IN-100 Based on the Q* Parameter Concept
,”
J. Mater. Sci.
, Vol.
33
,
1998
, pp.
1555
–
1562
. https://doi.org/10.1023/A:1017511703462
Google Scholar
Crossref
Search ADS
 
17.
Sugiura
,
R.
,
Yokobori
,
A. T.
, Jr.,
Sato
,
K.
,
Tabuchi
,
M.
,
Yatomi
,
M.
,
Kobayashi
,
K.
, and
Nikbin
,
K.
,
Strength, Fracture and Complexity
,
2011
(in press).
18.
ASME
, Boiler and Pressure Vessel Code, Section III,
2005
.
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