{"title":"Prediction of low cycle fatigue life for neutron-irradiated and nonirradiated RAFM steels using their tensile properties","authors":"Hussein Zahran , Aleksandr Zinovev , Dmitry Terentyev , Giacomo Aiello , Magd Abdel Wahab","doi":"10.1016/j.ijfatigue.2024.108589","DOIUrl":null,"url":null,"abstract":"<div><p>Reduced Activation Ferritic-Martensitic (RAFM) steels are the candidate structural steels for In-Vessel Components of fusion reactors. Since the operation of a tokamak-type fusion reactor is cyclic by its nature, thermomechanical fatigue will be one of the limiting factors defining the life of the plasma-facing components exposed to neutron irradiation. The assessment of fatigue life requires considerable efforts in terms of low cycle fatigue experiments, which is extremely complicated on neutron-irradiated specimens inside the hot cell environment. Performing tensile tests is instead much faster, technically easier and more cost effective than performing fatigue tests especially on neutron-activated specimens. Therefore, a method for predicting fatigue life based on the tensile properties would be an important asset to assess the design of IVC when experimental data on fatigue are not available. Here, several fatigue life prediction methods based on Universal Slopes Equation were assessed based on the fatigue test results of RAFM steels in the irradiated and non-irradiated conditions to choose the best method. Analysis of the available fatigue database showed an effect of test medium and specimen size on the fatigue life. This effect was quantified and added to the selected method by means of scaling factors. The chosen method with the scaling factors was able to predict the fatigue life of irradiated and non-irradiated RAFM steels with an accuracy of 95% within the sleeve of factor three. The modified equations were then used to predict the fatigue life of irradiated RAFM steels at irradiation doses for which the fatigue data is not available.</p></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"190 ","pages":"Article 108589"},"PeriodicalIF":5.7000,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Fatigue","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0142112324004481","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Reduced Activation Ferritic-Martensitic (RAFM) steels are the candidate structural steels for In-Vessel Components of fusion reactors. Since the operation of a tokamak-type fusion reactor is cyclic by its nature, thermomechanical fatigue will be one of the limiting factors defining the life of the plasma-facing components exposed to neutron irradiation. The assessment of fatigue life requires considerable efforts in terms of low cycle fatigue experiments, which is extremely complicated on neutron-irradiated specimens inside the hot cell environment. Performing tensile tests is instead much faster, technically easier and more cost effective than performing fatigue tests especially on neutron-activated specimens. Therefore, a method for predicting fatigue life based on the tensile properties would be an important asset to assess the design of IVC when experimental data on fatigue are not available. Here, several fatigue life prediction methods based on Universal Slopes Equation were assessed based on the fatigue test results of RAFM steels in the irradiated and non-irradiated conditions to choose the best method. Analysis of the available fatigue database showed an effect of test medium and specimen size on the fatigue life. This effect was quantified and added to the selected method by means of scaling factors. The chosen method with the scaling factors was able to predict the fatigue life of irradiated and non-irradiated RAFM steels with an accuracy of 95% within the sleeve of factor three. The modified equations were then used to predict the fatigue life of irradiated RAFM steels at irradiation doses for which the fatigue data is not available.
期刊介绍:
Typical subjects discussed in International Journal of Fatigue address:
Novel fatigue testing and characterization methods (new kinds of fatigue tests, critical evaluation of existing methods, in situ measurement of fatigue degradation, non-contact field measurements)
Multiaxial fatigue and complex loading effects of materials and structures, exploring state-of-the-art concepts in degradation under cyclic loading
Fatigue in the very high cycle regime, including failure mode transitions from surface to subsurface, effects of surface treatment, processing, and loading conditions
Modeling (including degradation processes and related driving forces, multiscale/multi-resolution methods, computational hierarchical and concurrent methods for coupled component and material responses, novel methods for notch root analysis, fracture mechanics, damage mechanics, crack growth kinetics, life prediction and durability, and prediction of stochastic fatigue behavior reflecting microstructure and service conditions)
Models for early stages of fatigue crack formation and growth that explicitly consider microstructure and relevant materials science aspects
Understanding the influence or manufacturing and processing route on fatigue degradation, and embedding this understanding in more predictive schemes for mitigation and design against fatigue
Prognosis and damage state awareness (including sensors, monitoring, methodology, interactive control, accelerated methods, data interpretation)
Applications of technologies associated with fatigue and their implications for structural integrity and reliability. This includes issues related to design, operation and maintenance, i.e., life cycle engineering
Smart materials and structures that can sense and mitigate fatigue degradation
Fatigue of devices and structures at small scales, including effects of process route and surfaces/interfaces.