Investigation on Fatigue Behavior of Zircaloy -4 Alloy in Room Temperature and 380°C Condition

2005 ◽  
Vol 297-300 ◽  
pp. 1005-1012
Author(s):  
Wei Ming Sun ◽  
Kangda Zhang ◽  
Xing Ren
Keyword(s):  
Nuclear Power ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Research Result ◽  
Fatigue Property ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Test Results ◽  
Design Data ◽  
Fatigue Design

Zr-4 alloy is the material of nuclear fuel shell in nuclear power plant’s PWR. This paper presents this material’s general mechanical property and fatigue behavior that are tested in accordance with ASTM in room temperature and 380°C condition. The test results show that there is no cyclic hardening or cyclic softening phenomena for Zr-4 alloy applied by cyclic loading in room temperature condition. The fatigue design curve is obtained by processing fatigue test results with adopting ASME Sec.Ⅲ based on the test results of strain fatigue property. The research result shows the fatigue design data at different temperature may be corrected by elastic modulus with room temperature curve. This paper’s result may be used in PWR component design.

Low-Cycle Fatigue Behavior of Small Slice Specimens of Zircaloy-4 at Elevated Temperature

2006 ◽  
Vol 324-325 ◽  
pp. 1241-1244 ◽  
Author(s):  
Li Xun Cai ◽  
Yu Ming Ye
Keyword(s):  
Elevated Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Uniaxial Strain ◽  
Transverse Strain ◽  
Test Results ◽  
Element Analysis

A series of strain fatigue tests were carried out on small bugle-like slice-specimens of Zr-4 alloy at 20 and 400. According to Elastic and Plastic Finite Element Analysis and assumption of local damage equivalence, a strain formula was given to transform transverse strain of the specimen to uniaxial strain. Based on the test results of the alloy and the strain transform formula, M-C (Manson-Coffin) models to be used for estimating uniaxial fatigue life of Zr-4 alloy were obtained. The results show that, the alloy mainly behaves as cyclic softening at 20 and as cyclic hardening at 400, and the elevated temperature can lead serious additional fatigue damage of the alloy and the effect of the elevated temperature impairs gradually with increasing of amplitude strain. A conclusion is helpful that prediction life by using M-C model based on traditional strain transform equation is quite conservative when uniaxial strain amplitude is less than 0.5%.

Low Cycle Fatigue Behavior of a New Type of Zircaloy Material

2011 ◽  
Vol 80-81 ◽  
pp. 788-791
Author(s):  
Wei Wei Yu ◽  
Fei Xue ◽  
Xin Ming Meng ◽  
Lei Lin
Keyword(s):  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Strain Range ◽  
Cyclic Hardening ◽  
Cycle Fatigue ◽  
Fatigue Lifetime ◽  
Softening Behavior ◽  
New Type

To investigate the property of a new type of Zircaloy material, a low cycle fatigue (LCF) test has been performed at room temperature (RT) and 375°C. Results show that the new alloy generally displays cyclic hardening followed by a continuous softening behavior. Fatigue lifetime curves as a function of strain range imply that the new alloy has a nearly same lifetime than that of Zr-4 at RT, and superior than that at 375°C.

Experimental Study on the Fatigue Properties and Reliability for the Steel of Elastic Oil Sump

2013 ◽  
Vol 300-301 ◽  
pp. 1377-1380
Author(s):  
Bin Li ◽  
Zong De Liu ◽  
Peng Duan
Keyword(s):  
Large Scale ◽  
Stress Ratio ◽  
Cyclic Stress ◽  
Probabilistic Methods ◽  
Life Assessment ◽  
Fatigue Properties ◽  
Test Results ◽  
Design Data ◽  
Cyclic Stress Ratio ◽  
Fatigue Design

The elastic oil sump is commonly used as support parts in large-scale thrust bearing. It often operates under fluctuating load conditions during service. So, fatigue analysis of the material of the elastic oil sump is of great significance. In order to obtain the fatigue design data of the material of the elastic oil sump, the systematic tests on uniaxial tension-compression fatigue at room temperature are made. The fatigue limits and the fatigue life curves of the steel of the elastic oil sump are determined at different cyclic stress ratio. The P-S-N equations are calculated by the probabilistic methods. The test results provide a theoretical basis for the safety of life assessment of the elastic oil sump.

Effect of Temperature on the Cyclic Stress Amplitude of ENiCrFe-1 Ni-Based Alloy Electrode and its Mechanism

2021 ◽  
Vol 1035 ◽  
pp. 259-263
Author(s):  
Qun Bing Zhang ◽  
Jian Xun Zhang ◽  
Wen Lan Wei
Keyword(s):  
Stress Amplitude ◽  
Base Alloy ◽  
Fatigue Behavior ◽  
Reference Value ◽  
Cyclic Hardening ◽  
Cyclic Stress ◽  
Cyclic Softening ◽  
Structural Safety ◽  
Alloy Electrode ◽  
Effect Of Temperature

Ni-based alloy welding material has been widely used in the welding and post-welding repair of high-temperature materials. The effect of temperature on the cyclic stress amplitude of ENiCrFe-1 Ni-base alloy electrode was studied under the same strain condition. The results showed that when the temperature was lower than 400 °C, it presented the characteristics of cyclic hardening and then cyclic softening. When the temperature was higher than 500 °C, it presented the characteristics of cyclic hardening and then cyclic stability. The main reason is that with the temperature increase, the dislocation structure changed more and more stable. The results not only enrich the internal mechanism of fatigue behavior of nickel-based alloy welding materials, but also have important reference value for improving the structural safety of welded joints.

Elevated Temperature Fatigue Behavior of 2 1/4 Cr-1 Mo Steel

1975 ◽  
Vol 97 (4) ◽  
pp. 252-257 ◽  
Author(s):  
C. R. Brinkman ◽  
M. K. Booker ◽  
J. P. Strizak ◽  
W. R. Corwin
Keyword(s):  
Elevated Temperature ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Fatigue Tests ◽  
Annealed Condition ◽  
Temperature Range ◽  
Hardening And Softening

Results are reported for a number of load and strain controlled fatigue tests conducted over the temperature range of room temperature to 1000°F (538°C). Cyclic hardening and softening characteristics for a single heat of 2 1/4 Cr-1 Mo steel in the isothermally annealed condition are discussed. Comparisons of the data generated in this effort are made with data available from the literature and from these compilations possible ASME design fatigue curves were prepared covering continuous high and low cycle behavior over the temperature range of room temperature to 1100°F (593°C). Equations for these design curves are also given.

scholarly journals Effects of Microstructures on Fatigue Behavior of an Al-Mg-Sc Alloy at an Elevated Temperature

2012 ◽  
Vol 706-709 ◽  
pp. 426-430 ◽  
Author(s):  
Chihiro Watanabe ◽  
Ryoichi Monzen
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Small Particles ◽  
Factors Affecting ◽  
Slip Bands ◽  
Large Particles ◽  
Fatigue Characteristics ◽  
The Relationship

Polycrystalline Al-1wt%Mg-0.27wt%Sc alloys bearing Al3Sc particles with different average sizes of 4 and 11nm in diameter have been cyclically deformed at 423K under various constant stress amplitudes, and the relationship between fatigue characteristics and microstructure of the alloy has been investigated. The specimen bearing 11 nm particles exhibited a cyclic hardening to saturation, while in specimens with the small particles a cyclic softening was observed after initial hardening. In the specimen with large particles, dislocations were uniformly distributed under all applied stress amplitudes, whereas the specimens bearing small particles, in which cyclic softening occurred exhibited clearly developed slip bands. The cyclic softening for the latter specimen was explained by particle shearing within the strongly strained slip bands. The width of precipitate free zones (PFZs) has been found to be one of the factors affecting the fatigue life of the specimens at 423K. The two-step aging decreases the width of PFZs, resulting in increase in the fatigue life.

Experimental Study on Fatigue Behavior of 35CrMo Steel after Torsional Prestrain

2013 ◽  
Vol 690-693 ◽  
pp. 1718-1722 ◽  
Author(s):  
Shi Yue Wang ◽  
Zhi Yu Wu ◽  
Xi Jie Yang ◽  
Zhao Ying Ren
Keyword(s):  
High Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hysteresis Loops ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Sem Analysis ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
35Crmo Steel ◽  
Scanning Electron

Low cycle and high cycle fatigue tests of 35CrMo steel at different pretorsional angles were conducted and cyclic hardening and softening curves, hysteresis loops and S-N curves were obtained of 35CrMo steel after the torsional prestrain. Scanning electron microscopy (SEM) analysis was also made of the fatigue fracture. The results show that: 35CrMo steel features obvious cyclic softening with basically the same law and degree at different torsional prestrains. The area surrounded by the stress-strain hysteresis loop decreases with the increment of the pretorsional angle; the torsional prestain reduces the fatigue life of the materials.

Fatigue Behavior of Extruded Mg-Al-Ca-Mn Alloy with T6 Treatment at Elevated Temperature

2014 ◽  
Vol 627 ◽  
pp. 417-420 ◽  
Author(s):  
Yukio Miyashita ◽  
Hugo Inzunza ◽  
Adrian Elizondo ◽  
Yoshiyuki Murayama ◽  
Yuichi Otsuka ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Fatigue Strength ◽  
Fatigue Test ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Fatigue Property ◽  
Propagation Behavior ◽  
Replication Technique

Fatigue behavior of Mg-Al-Ca-Mn alloy with T6 treatment was studied at room temperature and 150°C by conduction rotating bending fatigue test. Fatigue strength at high temperature was lower than that at room temperature in the alloys with and without heat treatment. However, degradation of fatigue strength at high temperature in the T6 treated alloy was not significant compared to the as-extruded alloy. Fatigue crack initiation and propagation behavior was observed with replication technique by conducting interrupted fatigue test at room temperature and 150°C. Multiple cracking was significantly observed at 150°C in both as-received and T6 treated alloys. Change in grain size and randomization of crystal orientation due to the heat treatment could affect the fatigue property.

Low-Cycle Fatigue Behavior of an Al-Mg-Si Alloy with and without a Small Addition of Sc

2010 ◽  
Vol 654-656 ◽  
pp. 938-941 ◽  
Author(s):  
Chihiro Watanabe ◽  
Ryoichi Monzen
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Cyclic Softening ◽  
Strengthening Effect ◽  
Cycle Fatigue ◽  
Slip Bands ◽  
Transmission Electron ◽  
Peak Aging ◽  
Bearing Alloy

Low-cycle fatigue behavior of a wrought Al-0.8wt%Mg-0.7wt%Si alloy with and without 0.27wt%Sc has been investigated at room temperature under constant plastic-strain amplitudes. After peak-aging treatments, both the alloys had fine lath-shaped β' precipitates. In the Sc-containing alloy, spherical Al3Sc precipitates of about 11 nm in diameter were co-existed. The alloy with Sc exhibited cyclic hardening to saturation, while the alloy without Sc showed clear cyclic softening after initial hardening. Transmission electron microscopy observation revealed that slip band structures were developed in the Sc-free alloy. Within the slip bands, shearing of the β' precipitates by moving dislocations was often observed. The cyclic softening in the alloy without Sc can then be explained by a loss of precipitation strengthening effect through the precipitation destruction within strongly-strained slip bands. In the Sc-bearing alloy, owing to the existence of non-shearable Al3Sc precipitates, dislocations were uniformly distributed, resulting in the absence of the cyclic softening.

High Cycle Fatigue Properties of Modified 9Cr-1Mo Steel at Elevated Temperatures

2012 ◽  
Author(s):  
Yoshiaki Matsumori ◽  
Jumpei Nemoto ◽  
Yuji Ichikawa ◽  
Isamu Nonaka ◽  
Hideo Miura
Keyword(s):  
Fatigue Strength ◽  
Fatigue Limit ◽  
Room Temperature ◽  
Structural Reliability ◽  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Fatigue Behavior ◽  
Cyclic Softening ◽  
Fatigue Properties ◽  
Cycle Fatigue

Since high-cycle fatigue loads is applied to the pipes in various energy and chemical plants due to the vibration and frequent temperature change of fluid in the pipes, the high-cycle fatigue behavior of the alloys used for pipes should be understood quantitatively in the structural reliability design of the pipes. The purpose of this study, therefore, is to clarify the high-cycle fatigue strength and fracture mechanism of the modified 9Cr-1Mo steel at temperatures higher than 400°C. This material is one of the effective candidates for the pipes in fast breeder demonstration reactor systems. A rotating bending fatigue test was applied to samples at 50 Hz in air. The stress waveform was sinusoidal and the stress ratio was fixed at −1. The fatigue limit was observed at room temperature and it was about 420 MPa. This value was lower than the 0.2% proof stress of this alloy by about 60 MPa. This decrease can be attributed to the cyclic softening of this material. The limited cycles at knee point was about 8×105 cycles. All fracture was initiated from a single surface crack and no inclusion-induced fracture was observed in the fracture surface by SEM. Thus, the high-cycle fatigue design based on the fatigue limit may be applicable to the modified 9Cr-1Mo steel at room temperature. The fatigue limit of about 350 MPa was also observed at 400°C, and it appeared at about 107 cycles, while it appeared at around 106 cycles at room temperature. Thus, it was confirmed that the fatigue strength of this alloy decrease with temperature. However, the fatigue limit didn’t appear at 550°C up to 108 cycles. The fatigue limit may disappear in this alloy at 550°C. It is very important, therefore, to evaluate the ultra-high cycle fatigue strength of this alloy at temperatures higher than 400°C.

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