scholarly journals Component Assessment Data Requirements from Creep-Fatigue Tests

2012 ◽  
pp. 3-3-20 ◽  
Author(s):  
S. R. Holdsworth
Keyword(s):  
Fatigue Tests ◽  
Assessment Data ◽  
Creep Fatigue ◽  
Data Requirements

scholarly journals Component Assessment Data Requirements from Creep-Fatigue Tests

2011 ◽  
Vol 8 (3) ◽  
pp. 103583 ◽  
Author(s):  
S. R. Holdsworth ◽  
A. Saxena ◽  
B. Dogan ◽  
S. W. Dean
Keyword(s):  
Fatigue Tests ◽  
Assessment Data ◽  
Creep Fatigue ◽  
Data Requirements

Progress of EASICS Validation Experiments and Code Comparison of R5, RCC-MRX and ASME III Division V

2021 ◽  
Author(s):  
Peter James ◽  
David Coon ◽  
Colin Austin ◽  
Nicholas Underwood ◽  
Caroline Meek ◽  
...  
Keyword(s):  
High Temperature ◽  
Fatigue Tests ◽  
Guidance Document ◽  
High Temperature Creep ◽  
Temperature Creep ◽  
R Ratio ◽  
Creep Fatigue ◽  
The Uk ◽  
The Impact ◽  
Relevant Component

Abstract The “Establishing AMR Structural Integrity Codes and Standards for UK GDA” (EASICS) project was established in 2019 to help support the acceptance of Advanced Modular Reactors, or AMRs, which are typically based on high temperature Generation IV reactors. The EASICS project is aiming to provide guidance on the requirements for codes and standards for the design of AMRs for use in the UK, to ensure that state-of-the art knowledge will be brought to bear on developing the required design and assessment methodologies. The EASICS project started in July 2019 and is looking to complete by December 2021. To support this aim, the work presented in this paper provides an overview of two interacting aspects of the programme. The first is to perform validation tests for high temperature creep-fatigue assessments of a plant relevant component. The second aspect is to use these results, to provide a comparison of internationally recognised approaches for the assessment of high temperature (creep regime) components. This approach will be repeated for two other case scenarios deemed to be plant relevant components. This paper builds upon the initial overview paper presented at the 2020 conference providing an update on progress. One of the cases presented herein, described as the Thin Walled Welded Pipe Test uses specialist testing of a plant relevant component under high temperature loading conditions is underway with some initial results available. The validation testing includes both fatigue tests and creep-fatigue tests on 316H welded thin section tubes. The tubes have been subjected to strain-controlled tension/compression (R-ratio of −1), with some including a displacement controlled dwell. The tests are being conducted at 525°C. An update to the progress of these tests is included herein. To help enhance interaction with the code bodies, and to understand the impact of differences in the approaches, comparative assessments have been performed when adopting R5, ASME Section III Div 5 and RCC-MRx. One comparison will be based around the tests detailed above (tube test). A further assessment comparison will consider the Evasion mock-up tests provided by CEA (sodium based thermal shock tests). The third assessment case is loosely based around a plant relevant assessment within one of the UK Advanced Gas Reactors (AGRs). This paper provides an overview of the results from all these cases using R5, ASME Section III Div 5 and RCC-MRx. The subsequent discussions covers results, differences and potential impact to the codes which will all help to inform a guidance document to support assessing AMRs within a UK regulatory framework.

Experimental Investigation on the Creep and Low Cycle Fatigue Behaviors of a Serviced Turbine Blade

2019 ◽  
Author(s):  
Zhenlei Li ◽  
Duoqi Shi ◽  
Xiaoguang Yang ◽  
Nina Li
Keyword(s):  
Turbine Blade ◽  
Low Cycle Fatigue ◽  
Test System ◽  
Fatigue Tests ◽  
Test Results ◽  
Cycle Fatigue ◽  
Hold Period ◽  
Low Pressure Turbine ◽  
Creep Fatigue ◽  
Crack Initiation Life

Abstract This paper experimentally investigated the creep and fatigue behaviors of a low-pressure turbine (LPT) blade with 600 hours of service using a novel test system. Pure low cycle fatigue (LCF), pure creep and creep-fatigue interaction (CFI) experiments on the full-scale serviced blades were conducted respectively. Test results showed that the increasing of deformation amplitude was divided into three stages under both pure LCF and creep-fatigue loadings. The deformation of each blade increased rapidly until failure when the test cycle exceeded the 80% of their overall life under the pure LCF and CFI condition. The hold period in creep-fatigue tests shortens the first stage of whole life and has no influence on the proportion of crack initiation life to overall life. The fractures in pure LCF, pure creep and creep-fatigue tests emerged transgranular, intergranular and both transgranular and intergranular behaviors respectively. The crack initiated and propagated in a specific zone of the blade under all the experimental loadings, which limited its creep-fatigue resistance. At last, the remaining life of turbine blade was estimated conservatively by introducing the safety limit into a statistical method.

Void Growth Simulation of a Steam Turbine Casing Material Under Creep and Creep-Fatigue Loading

2007 ◽  
Author(s):  
Takashi Ogata
Keyword(s):  
Growth Rate ◽  
Cyclic Loading ◽  
Void Growth ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Growth Behavior ◽  
Growth Simulation ◽  
Creep Fatigue ◽  
Turbine Casing ◽  
Damaged Materials

High temperature components in thermal power plants are subjected to creep and creep-fatigue loading where creep voids initiate and grow on grain boundaries. Development of a quantitative evaluation method of the void growth is important for reliable maintenance of these components. In this study, creep and creep-fatigue tests were carried out at 600 °C on a 1Cr-Mo-V casting steel. Creep damaged materials were produced by interrupting the creep tests and microstructure of the damaged materials were observed carefully by a scanning microscope. The creep-fatigue tests were also conducted in a scanning electron microscope, and continuous observation of void growth behavior during the tests was made. From the observations, spherical shape voids initiate and grow up to their length of 2μm on grain boundaries at initial stage of damage, and then these voids change their shape to crack-like to grow until their length reaches around 10μm under both the creep and the creep-fatigue conditions. Under the same stress level, the void growth rate in the creep-fatigue condition was faster than that in the creep condition indicating acceleration of void growth rate by cyclic loading. Previously proposed void growth simulation model, in which the void growth was controlled by diffusion and power law creep, was modified to express acceleration of the void growth by the cyclic loading. Void growth behavior within a certain area under both the creep and the creep-fatigue condition were simulated by the modified program. Predicted void growth behaviors agreed with observed ones. The void growth behavior of an actual turbine casing was also simulated and void growth behavior was discussed based on the result.

Research on Application of Supported Vector Machine to Creep-Fatigue Lifetime Prediction of P91 Steel

2012 ◽  
Vol 616-618 ◽  
pp. 1787-1796 ◽  
Author(s):  
Dong Mei Ji
Keyword(s):  
Goal Function ◽  
Fatigue Property ◽  
Fatigue Tests ◽  
Control Methods ◽  
Prediction Ability ◽  
Fatigue Lifetime ◽  
P91 Steel ◽  
Creep Fatigue ◽  
Training Error ◽  
Research On Application

Creep-fatigue tests were carried out to study creep-fatigue property of P91 steel in many references. There are two kinds of loading control methods. One is controlled by stress, and the other is controlled by strain. In this study the creep-fatigue test data loading controlled by stress are summarized. Based on these data Supported Vector Machine(SVM) method is used to build up the models to predict the creep-fatigue lifetime of P91 steel. The results show SVM method can be used to predict the creep-fatigue life of P91 steel, and the value of insensitive factor is very important. When the value of insensitive factor is small and the training error of the model is small too, but the prediction ability decreases. On the contrary when insensitive factor is increased, the training error will become large, and the prediction ability will increase. So during the training, mean square error should not be regarded as the unique goal function.

Creep-Fatigue Properties of the Candidate Materials of 700°C-USC Boiler

2007 ◽  
Author(s):  
Keiji Kubushiro ◽  
Hiroki Yoshizawa ◽  
Takuya Itou ◽  
Hirokatsu Nakagawa
Keyword(s):  
Hold Time ◽  
Strain Range ◽  
Small Strain ◽  
Fatigue Tests ◽  
Holding Time ◽  
Experimental Results ◽  
Fatigue Properties ◽  
Alloy 617 ◽  
Creep Fatigue ◽  
Cycles To Failure

Creep-fatigue properties of candidate materials of 700°C-USC boiler are investigated. The candidate materials are Alloy 230, Alloy 263, Alloy 617 and HR6W. Creep-fatigue tests were conducted at 700°C and the effect of both strain range and hold time were studied. Experimental results showed that at 1.0% strain range, cycles to failure with 60 min strain holding is about 10% of that without strain holding, but at 0.7% strain range, cycles to failure with 60 min strain holding decreases down to about 1% of without strain holding. It appears that cycles to failure is decreased by increasing strain holding time at all tested strain ranges, and the effect of holding time is emphasized at small strain range. These phenomena depend on the kind of alloys.

Life Estimation of SUS304 Steel Subjected to Nonproportionally Combined Push-Pull and Cyclic Torsion at 973K

2007 ◽  
Vol 345-346 ◽  
pp. 323-326 ◽  
Author(s):  
Katsuyuki Tokimasa
Keyword(s):  
Strain Range ◽  
Inelastic Strain ◽  
Fatigue Tests ◽  
Critical Plane ◽  
Plane Model ◽  
Life Estimation ◽  
Cyclic Torsion ◽  
Creep Fatigue ◽  
Thin Walled ◽  
Tubular Specimens

The present paper summarizes the fully reversed strain-controlled creep-fatigue tests conducted on thin-walled tubular specimens of SUS304 austenitic stainless steel at 973K in air under push-pull, cyclic torsion, in-phase straining and 90deg out-of-phase straining of push-pull and cyclic torsion. It is shown that, as the results of analysis of the experimental data by the strain-range partitioning methodand the critical plane model parameter, a new inelastic-strain based parameter was proposed for life estimation of SUS304 subject to nonproportionally combined push-pull and cyclic torsion by the strain-range partitioning method.

scholarly journals Determination of the Creep-Fatigue Interaction Diagram for Alloy 617

2016 ◽  
Author(s):  
J. K. Wright ◽  
L. J. Carroll ◽  
T.-L. Sham ◽  
N. J. Lybeck ◽  
R. N. Wright
Keyword(s):  
Fatigue Testing ◽  
Hold Time ◽  
Strain Range ◽  
Fatigue Tests ◽  
Alloy 617 ◽  
Interaction Diagram ◽  
Creep Fatigue ◽  
Intermediate Heat Exchanger ◽  
Cycles To Failure

Alloy 617 is the leading candidate material for an intermediate heat exchanger for the very high temperature reactor (VHTR). As part of evaluating the behavior of this material in the expected service conditions, creep–fatigue testing was performed. The cycles to failure decreased compared to fatigue values when a hold time was added at peak tensile strain. At 850°C, increasing the tensile hold duration continued to degrade the creep–fatigue resistance, at least to the investigated strain–controlled hold time of up to 60 minutes at the 0.3% strain range and 240 minutes at the 1.0% strain range. At 950°C, the creep–fatigue cycles to failure are not further reduced with increasing hold duration, indicating saturation occurs at relatively short hold times. The creep and fatigue damage fractions have been calculated and plotted on a creep–fatigue interaction D–diagram. Test data from creep–fatigue tests at 800 and 1000°C on an additional heat of Alloy 617 are also plotted on the D–diagram.

Study on Life Prediction Method for Creep-Fatigue Interaction at Elevated Temperature

2007 ◽  
Vol 353-358 ◽  
pp. 190-194
Author(s):  
Nian Jin Chen ◽  
Zeng Liang Gao ◽  
Wei Zhang ◽  
Yue Bao Le
Keyword(s):  
Elevated Temperature ◽  
Prediction Model ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Hold Time ◽  
Prediction Method ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Creep Fatigue ◽  
316L Austenitic Stainless Steel

The law of low-cycle fatigue with hold time at elevated temperature is investigated in this paper. A new life prediction model for the situation of fatigue and creep interaction is developed, based on the damage due to fatigue and creep. In order to verify the prediction model, strain-controlled low-cycle fatigue tests at temperature 693K, 823K and 873K and fatigue tests with various hold time at temperature 823K and 873K for 316L austenitic stainless steel were carried out. Good agreement is found between the predictions and experimental results.

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