Prediction of fatigue life of high-heat-load components made of oxygen-free copper by comparing with Glidcop

Following a successful study on the prediction of fatigue life of high-heat-load components made of Glidcop, the thermal limitation of oxygen-free copper (OFC), which is used more commonly than Glidcop, has been studied. In addition to its general mechanical properties, the low-cycle-fatigue (LCF) and creep properties of OFC were investigated in detail and compared with those of Glidcop. The breaking mode of OFC, which was observed to be completely different from that of Glidcop in a fatigue fracture experiment, clarified the importance of considering the creep–fatigue interaction. An additional LCF test with compressive strain holding was conducted so that the creep–fatigue life diagram for out-of-phase thermal fatigue could be obtained on the basis of the strain-range partitioning method. The life predicted from elasto-plastic creep analysis agreed well with that determined from the void ratio estimated in the fatigue fracture experiment.

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Verification of the Prediction Methods of Strain Range in Notched Specimens Made of Mod.9Cr-1Mo

ASME 2010 Pressure Vessels and Piping Conference: Volume 1 ◽

10.1115/pvp2010-25489 ◽

2010 ◽

Cited By ~ 1

Author(s):

Masanori Ando ◽

Yuichi Hirose ◽

Shingo Date ◽

Sota Watanabe ◽

Yasuhiro Enuma ◽

...

Keyword(s):

Fatigue Life ◽

Elevated Temperature ◽

Low Cycle Fatigue ◽

Strain Range ◽

Fatigue Tests ◽

Estimation Methods ◽

Prediction Methods ◽

Test Machine ◽

Notched Specimens ◽

Creep Fatigue

Several innovative prediction methods of strain range have been developed in order to apply to the Generation IV plants. In a component design at elevated temperature, ‘strain range’ is used to calculate the fatigue and creep-fatigue damage. Therefore, prediction of ‘strain range’ is one of the most important issues to evaluate the components’ integrity during these lifetimes. To verify the strain prediction method of discontinues structures at evaluated temperature, low cycle fatigue tests were carried out with notched specimens. All the specimens were made of Mod.9Cr-1Mo, because it is a candidate material for a primary and secondary heat transports system components of JSFR (Japanese Sodium Fast Reactor). Deformation control fatigue tests and thermal fatigue tests were performed by ordinary uni-axial push-pull test machine and equipment generating the thermal gradient in the notched plate by induction heating. Stress concentration level was changed by varying the notch radius in the both kind of tests. Crack initiation and propagation process during the fatigue test were observed by the digital micro-scope and replica method. Elastic and inelastic FEAs were also carried out to estimate the ‘strain range’ for the prediction of fatigue life. Then the ranges of several strain predictions and estimations were compared with the test results. These predictions were based on the sophisticated technique to estimate the ‘strain range’ from elastic FEA. Stress reduction locus (SRL) method, simple elastic follow-up method, Neuber’s rule method and the methods supplied by elevated temperature design standards were applied. Through these results, the applicability and conservativeness of these strain prediction and estimation methods, which is the basis of the creep-fatigue life prediction, is discussed.

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Fatigue life prediction for high-heat-load components made of GlidCop by elastic-plastic analysis

Journal of Synchrotron Radiation ◽

10.1107/s090904950706565x ◽

2008 ◽

Vol 15 (2) ◽

pp. 144-150 ◽

Cited By ~ 14

Author(s):

Sunao Takahashi ◽

Mutsumi Sano ◽

Tetsuro Mochizuki ◽

Atsuo Watanabe ◽

Hideo Kitamura

Keyword(s):

Fatigue Life ◽

Heat Load ◽

Life Prediction ◽

High Heat ◽

Fatigue Life Prediction ◽

Elastic Plastic ◽

Plastic Analysis ◽

High Heat Load

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Influence of Hold-Time and Temperature on the Low-Cycle Fatigue of Incoloy 800

Journal of Engineering for Industry ◽

10.1115/1.3428273 ◽

1972 ◽

Vol 94 (3) ◽

pp. 930-934 ◽

Cited By ~ 7

Author(s):

C. E. Jaske ◽

H. Mindlin ◽

J. S. Perrin

Keyword(s):

Fatigue Life ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Compressive Strain ◽

Hold Time ◽

Strain Range ◽

Cyclic Fatigue ◽

Cycle Fatigue ◽

Incoloy 800 ◽

Strain Cycling

A study has been conducted to determine the low-cycle fatigue behavior of solution-annealed Incoloy 800 bar at temperatures from 800–1400 deg F. The experimental work included evaluation of specimens under both continuous, completely reversed strain cycling and under strain cycling with hold time periods at the strain limits. At 1000, 1200, and 1400 deg F, it was found that 10-min hold-times at the tensile strain limit during every cycle significantly reduced the cyclic fatigue life compared to continuous cycling. However, there was little reduction in cyclic fatigue life when 10-min hold-times were introduced at the compressive strain limits or at both the tensile and compressive limits. The ratio of hold-time cyclic fatigue life to no-hold-time cyclic fatigue life decreased as the length of hold time increased (at constant total strain range) and as the magnitude of strain range decreased (at constant hold-time length).

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Plastic Strain of GlidCop for Materials of High Heat Load Components

Materials Science Forum ◽

10.4028/www.scientific.net/msf.772.123 ◽

2013 ◽

Vol 772 ◽

pp. 123-127 ◽

Cited By ~ 1

Author(s):

Mutsumi Sano ◽

Sunao Takahashi ◽

Atsuo Watanabe ◽

Hideo Kitamura ◽

Ayumi Shiro ◽

...

Keyword(s):

Fatigue Life ◽

Plastic Strain ◽

Heat Load ◽

High Heat ◽

Analytic Solutions ◽

X Ray Diffraction ◽

X Ray ◽

Plastic Analysis ◽

High Heat Load ◽

Number Of Cycles

We investigated the plastic strain of GlidCopTM, copper that is dispersion strengthened with aluminum oxide, by X-ray diffraction using synchrotron radiation. The purpose of this study is to verify the accuracy of the elastic-plastic analysis, which has been employed to predict the fatigue life of GlidCop. As a result, the plastic strain was estimated to be 0.7- 1.3% at any number of cycles, which is slightly smaller than the analytic solutions.

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Verification of the Estimation Methods of Strain Range in Notched Specimens Made of Mod.9Cr-1Mo Steel

Journal of Pressure Vessel Technology ◽

10.1115/1.4006902 ◽

2012 ◽

Vol 134 (6) ◽

Cited By ~ 3

Author(s):

Masanori Ando ◽

Yuichi Hirose ◽

Shingo Date ◽

Sota Watanabe ◽

Yasuhiro Enuma ◽

...

Keyword(s):

Fatigue Life ◽

Elevated Temperature ◽

Low Cycle Fatigue ◽

Strain Range ◽

Fatigue Tests ◽

Estimation Methods ◽

Test Machine ◽

Component Reliability ◽

Notched Specimens ◽

Creep Fatigue

Several methods of estimating strain range at a structural discontinuity have been developed in order to assess component reliability. In a component design at elevated temperature, estimation of strain range is required to evaluate the fatigue and creep-fatigue damage. Therefore, estimation of strain range is one of the most important issues when evaluating the integrity of a component during its lifetimes. To verify the methods of estimating strain range for discontinuous structures, low cycle fatigue tests were carried out with notched specimens. All the specimens were made of Mod.9Cr-1Mo steel, because it is a candidate material for a primary and secondary heat transport system components of Japan Sodium-cooled Fast Reactor (JSFR). Displacement control fatigue tests and thermal fatigue tests were performed by ordinary uniaxial push–pull test machine and equipment generating the thermal gradient in the notched plate by induction heating. Several notch radii were employed to vary the stress concentration level in both kinds of tests. Crack initiation and propagation process during the tests were observed by a digital microscope and the replica method to define the failure cycles. Elastic and inelastic finite element analyses were also performed to estimate strain range for predicting fatigue life. Then, these predictions were compared with the test results. Several methods such as stress redistribution locus (SRL) method, simple elastic follow-up (SEF) method, Neuber's law, and the procedures employed by elevated temperature design codes were applied. Through these comparisons, the applicability and conservativeness of these strain range estimation methods, which is the basis of the fatigue and creep-fatigue life prediction, are discussed.

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Fatigue Life Prediction Strategies for High-Heat-Load Components

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.452-453.789 ◽

2010 ◽

Vol 452-453 ◽

pp. 789-792

Author(s):

W.L. Xiao ◽

H.B. Chen ◽

J.F. Jin

Keyword(s):

Fatigue Life ◽

Heat Load ◽

Life Prediction ◽

High Heat ◽

Multiaxial Fatigue ◽

Fatigue Life Prediction ◽

Critical Plane ◽

Critical Plane Approach ◽

High Heat Load ◽

Strain Model

High-heat-load components such as photon shutters and masks made of Glidcop Al-15 are subjected to intense thermal cycles from the X-ray beams at the third generation light sources. This paper presents thermal fatigue life prediction results of high-heat-load components at the beam line front end of Shanghai Synchrotron Radiation Facility (SSRF) under different power conditions. Used in this analysis are four typical multiaxial fatigue life prediction models, i.e. the maximum principal strain model, equivalent vonMises strain model, maximum shear strain model and critical plane approach. Detailed comparisons among them were implemented from various aspects including applicable conditions, physical meanings and resultant veracities. Critical plane approach was finally determined to be more appropriate method for dealing with multiaxial fatigue of high-heat-load components. To obtain the multiaxial stress-strain fields, nonlinear finite element analysis (FEA) was performed with commercial software ANSYS.

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