Collect Available Creep-Fatigue Data and Study Existing Creep-Fatigue Evaluation Procedures for Grade 91 and Hastelloy XR.
Collect Available Creep-Fatigue Data and Study Existing Creep-Fatigue Evaluation Procedures for Grade 91 and Hastelloy XR.

Author:

Publisher:

Published: 2007

Total Pages:

ISBN-13:

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This report describes the results of investigation on Task 5 of DOE/ASME Materials Project based on a contract between ASME Standards Technology, LLC (ASME ST-LLC) and Japan Atomic Energy Agency (JAEA). Task 5 is to collect available creep-fatigue data and study existing creep-fatigue evaluation procedures for Grade 91 steel and Hastelloy XR. Part I of this report is devoted to Grade 91 steel. Existing creep-fatigue data were collected (Appendix A) and analyzed from the viewpoints of establishing a creep-fatigue procedure for VHTR design. A fair amount of creep-fatigue data has been obtained and creep-fatigue phenomena have been clarified to develop design standards mainly for fast breeder reactors. Following this, existing creep-fatigue procedures were studied and it was clarified that the creep-fatigue evaluation procedure of the ASME-NH has a lot of conservatisms and they were analyzed in detail from the viewpoints of the evaluation of creep damage of material. Based on the above studies, suggestions to improve the ASME-NH procedure along with necessary research and development items were presented. Part II of this report is devoted to Hastelloy XR. Existing creep-fatigue data used for development of the high temperature structural design guideline for High Temperature Gas-cooled Reactor (HTGR) were collected. Creep-fatigue evaluation procedure in the design guideline and its application to design of the intermediate heat exchanger (IHX) for High Temperature Engineering Test Reactor (HTTR) was described. Finally, some necessary research and development items in relation to creep-fatigue evaluation for Gen IV and VHTR reactors were presented.

Proceedings of the 8th Pacific Rim International Conference on Advanced Materials and Processing (PRICM-8)
Proceedings of the 8th Pacific Rim International Conference on Advanced Materials and Processing (PRICM-8)

Author: FernD.S. Marquis

Publisher: Springer

Published: 2017-03-21

Total Pages: 3431

ISBN-13: 3319487647

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PRICM-8 features the most prominent and largest-scale interactions in advanced materials and processing in the Pacific Rim region. The conference is unique in its intrinsic nature and architecture which crosses many traditional discipline and cultural boundaries. This is a comprehensive collection of papers from the 15 symposia presented at this event.

Artificial Intelligence: Concepts, Methodologies, Tools, and Applications
Artificial Intelligence: Concepts, Methodologies, Tools, and Applications

Author: Management Association, Information Resources

Publisher: IGI Global

Published: 2016-12-12

Total Pages: 3095

ISBN-13: 152251760X

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Ongoing advancements in modern technology have led to significant developments in artificial intelligence. With the numerous applications available, it becomes imperative to conduct research and make further progress in this field. Artificial Intelligence: Concepts, Methodologies, Tools, and Applications provides a comprehensive overview of the latest breakthroughs and recent progress in artificial intelligence. Highlighting relevant technologies, uses, and techniques across various industries and settings, this publication is a pivotal reference source for researchers, professionals, academics, upper-level students, and practitioners interested in emerging perspectives in the field of artificial intelligence.

Creep-Fatigue Interaction Models for Grade 91 Steel
Creep-Fatigue Interaction Models for Grade 91 Steel

Author: Stefan Holmström

Publisher:

Published: 2014

Total Pages: 26

ISBN-13:

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Different approaches for modelling creep-fatigue (CF) interaction are used on strain controlled creep fatigue data of 9Cr-1Mo-VNb (P91) steel and assessed with the target of finding suitable candidates for use in design rules. The assessed models include time, ductility, and strain energy-based creep-fatigue interaction methods and two simplified models. For the interaction diagram-based models, the challenge of acquiring representative creep damage fractions from the dynamic material response, i.e., cyclic softening with changing relaxation behaviour is addressed. In addition, the interaction diagram approaches are discussed in the light of known (fatigue) material scatter and defining representative cycles for CF data. The performance of the model are presented and also compared against the RCC-MR design code methodology. It is shown that the fitting accuracy of the complex interaction models vary significantly and that modified ductility based models seem to be less susceptible to changes in supporting creep and relaxation models. Successful and also superior prediction of the CF number of cycles to failure for Grade 91 steel was accomplished by simplified methods with much less fitting parameters. The practicality in using interaction diagram methods for design purposes, where simplicity is a key issue, is questioned.

Recommendation for Creep and Creep-fatigue Assessment for P91 Component
Recommendation for Creep and Creep-fatigue Assessment for P91 Component

Author:

Publisher:

Published: 2016

Total Pages: 43

ISBN-13: 9789279571398

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This report is based on the results and experience gained in assessing both public domain and MATTER data, some previously reported in the MATTER deliverable D4.5: "Creep-fatigue interaction rules for P91" and some assessed here. A number of methods, including interaction diagram based methods and simplified methods, have been compared for predicting the creepfatigue life of P91 steel. The effect of cyclic softening on creep properties have been considered in the evaluations presented in this report. The purpose of this report is to give recommendations for creep and creep-fatigue assessment for components made of X10CrMoVNb9-1 (P91) steel. Based on the conclusions of the assessments the following recommendations are given: 1.^The creep properties of P91 steel suffer from cyclic loading and it is recommended that the current RCC-MRx creep strain equations should be modified or replaced by a model that can implement time factors or stress reduction factors to correct for softening. Suitable models have been identified. The softening of P91 potentially causes unconservativeness in significant creep conditions where accumulated strain is a limiting design factor. 2. The interaction diagram models currently applied in design codes are complicated to apply and include several complex modelling challenges. It has been recommended that alternative modelling concepts, such as using simplified models should be considered for use in design codes. The simplified models optimized for P91 have been shown to give good and robust predictions on cycles to failure. 3. Currently available P91 data mainly consists of large strain range and short hold period data, where creep is mainly causing additional strain.^Data with verified creep cavitation damage is limited or totally lacking. It is recommended that more data is generated at low strain ranges and long hold times to improve long term extrapolation robustness. Tensile property data for softened material is also needed to determine the stress range where power-law breakdown behaviour in creep can be expected and to improve the understanding of the long term microstructural evolution in cyclic service.

Design for Creep
Design for Creep

Author: R.K. Penny

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 439

ISBN-13: 9401105618

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Our rationale for the second edition remains the same as for the first edition, which appeared over twenty years ago. This is to offer simplified, useful and easily understood methods for dealing with the creep of components operating under conditions met in practice. When the first edition was written, we could not claim that the methods which were introduced were well-tried. They were somewhat conjectural, although firmly based, but not sufficiently well devel oped. Since that time, the Reference Stress Methods (RSM) introduced in the book have received much scrutiny and development. The best recognition we could have of the original methods is the fact that they are now firmly embedded in codes of practice. Hopefully, we have now gone a long way towards achieving our original objectives. There are major additions to this second edition which should help to justify our claims. These include further clarification regarding Reference Stress Methods in Chapter 4. There are also new topics which depend on RSM in varying degrees: • Creep fracture is covered in Chapter 7, where methods for assessing creep crack initiation and crack growth are fully described. This chapter starts with a review of the basic concepts of fracture mechanics and follows with useful, approximate methods, compatible with the needs of design for creep and the availability of standard data. • Creep/fatigue interactions and environmental effects appear in Chapter 8.