Download or read book Experimental study and simulation of cyclic softening of tempered martensite ferritic steels written by Pierre-François Giroux and published by . This book was released on 2011 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inscrit au sein d'un grand projet aboutissant à la mise en œuvre des réacteurs nucléaires de génération IV, ce travail de thèse porte sur l'étude des aciers martensitiques revenus à 9 % de chrome. Actuellement utilisés pour des applications à haute température, notamment dans les centrales thermiques, ils présentent en fatigue et en fatigue-fluage un phénomène d'adoucissement mécanique et des évolutions microstructurales particulièrement prononcées : disparition de nombreux joints de sous-grains, baisse de la densité de dislocations, apparition et/ou grossissement de précipités et de nouvelles phases. Les objectifs principaux de cette thèse sont (i) d'établir expérimentalement une corrélation entre l'adoucissement mécanique des aciers à 9 % de chrome constaté en fatigue à 550 °C et l'évolution de leur microstructure au cours de ce type de sollicitation et (ii) de modéliser les mécanismes physiques de déformation afin de prédire le comportement mécanique de ces aciers sous chargement cyclique. Une étude des propriétés mécaniques en traction monotone et sous sollicitations cycliques à 550 °C a été conduite sur un acier de Grade 92 (9Cr-0,5Mo-1,8W-V-Nb). L'expertise des éprouvettes de traction suggère que l'adoucissement du matériau est principalement lié à une augmentation de la taille moyenne des sous-grains de plus de 15 % par rapport à l'état initial. L'étude de l'évolution de la contrainte macroscopique durant les essais cycliques montre que l'adoucissement du matériau est dû à la diminution de l'écrouissage cinématique. Les observations effectuées au MET montrent une augmentation de la taille moyenne des sous-grains comprise entre 65 et 95 % et une diminution de la densité de dislocations de plus de 50 % dans le matériau après les essais de fatigue, par rapport à l'état initial. Un modèle auto-cohérent à champs moyens fondé sur l'élastoviscoplasticité polycristalline, prédisant le comportement mécanique macroscopique du matériau et l'évolution microstructurale au cours de la déformation est proposé. En décrivant les mécanismes de déformation à partir d'observations microstructurales, le modèle utilise seulement deux paramètres ajustables (énergie et volume d'activation) liés aux mécanismes de déformation viscoplastique. Les valeurs de l'ensemble des autres paramètres sont fixées grâce à des mesures expérimentales ou des calculs issus de la littérature. Le modèle prédit correctement l'adoucissement macroscopique et donne une bonne tendance des évolutions microstructurales au cours de la déformation. L'étude paramétrique montre une bonne stabilité des prédictions dès lors que les paramètres expérimentaux varient dans un intervalle de mesure physiquement acceptable. Enfin, quelques perspectives d'amélioration du modèle sont testées et des essais de torsion cyclique avec et sans contrainte moyenne sont simulés.

Download or read book Advances in Mechanics of High Temperature Materials written by Konstantin Naumenko and published by Springer. This book was released on 2019-07-09 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a collection of contributions on advanced approaches to the mechanics of materials and mechanics of structures for high-temperature applications, such as power plant components, engines and turbochargers. The contributions highlight advanced constitutive models for high-temperature materials, as well as new approaches to the efficient modeling and analysis of engineering structures operating in high-temperature environments.

Download or read book Evolution of Microstructure during Long term Creep of a Tempered Martensite Ferritic Steel written by Ali Aghajani Bazazi and published by Cuvillier Verlag. This book was released on 2009-12-08 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tempered martensite ferritic steels are used for critical components in fossil fired power plants that operate in the creep range. The materials contain a high density of dislocations and precipitates form on all types of internal interfaces, the majority of which represent subgrain boundaries. Most previous studies suffer from either only relating to short term creep experiments or from being incomplete in not considering all relevant elements of the microstructure. No systematic effort was made to investigate the evolution of microstructures under conditions of long term creep. In the present study the evolution of the microstructure of a 12% Cr tempered martensite ferritic steel was investigated under conditions of long term aging and creep. Transmission electron microscopy (TEM) and electron back scattered diffraction (EBSD) techniques were used to characterize materials from interrupted creep tests (0.5%, 1%, 1.6% and rupture at 11.9%; creep conditions: 550°C, 120 MPa, rupture time: 139 971 h). It is shown that subgrains coarsen, that the close correlation between carbides and subgrain boundaries loosens during long term creep, and that the frequency of small angle boundaries increases. In addition, the evolution of dislocation densities during long term aging and creep was studied using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM). During aging the dislocation density remains constant, while during long term creep the dislocation density continuously decreases. All these elementary deformation processes have already been discussed in short term creep studies. The present study shows that they also govern long term creep, however, during long term creep, precipitation and coarsening reactions occur which are not observed during short term creep. Cr rich M23C6, VX carbides and Laves phase were identified as the major precipitates in the microstructure of the 12% Chromium tempered martensite ferritic steel. Their chemical compositions, sizes, volume fractions and number densities were evaluated in all interrupted specimens. M23C6 particles coarsen and establish their equilibrium concentration after 51072 hours. VX particles are stable. The Laves phase particles do not reach thermodynamic equilibrium as they form and grow during long term creep. This is due to Silicon which is found in the Laves phase particles and which diffuses slowly in the steel matrix.

Download or read book Structural Materials for Generation IV Nuclear Reactors written by Pascal Yvon and published by Woodhead Publishing. This book was released on 2016-08-27 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt: Operating at a high level of fuel efficiency, safety, proliferation-resistance, sustainability and cost, generation IV nuclear reactors promise enhanced features to an energy resource which is already seen as an outstanding source of reliable base load power. The performance and reliability of materials when subjected to the higher neutron doses and extremely corrosive higher temperature environments that will be found in generation IV nuclear reactors are essential areas of study, as key considerations for the successful development of generation IV reactors are suitable structural materials for both in-core and out-of-core applications. Structural Materials for Generation IV Nuclear Reactors explores the current state-of-the art in these areas. Part One reviews the materials, requirements and challenges in generation IV systems. Part Two presents the core materials with chapters on irradiation resistant austenitic steels, ODS/FM steels and refractory metals amongst others. Part Three looks at out-of-core materials. Structural Materials for Generation IV Nuclear Reactors is an essential reference text for professional scientists, engineers and postgraduate researchers involved in the development of generation IV nuclear reactors. - Introduces the higher neutron doses and extremely corrosive higher temperature environments that will be found in generation IV nuclear reactors and implications for structural materials - Contains chapters on the key core and out-of-core materials, from steels to advanced micro-laminates - Written by an expert in that particular area

Download or read book Metals Abstracts written by and published by . This book was released on 1998 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 1116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Creep Resistant Steels written by Fujio Abe and published by Elsevier. This book was released on 2008-03-14 with total page 701 pages. Available in PDF, EPUB and Kindle. Book excerpt: Creep-resistant steels are widely used in the petroleum, chemical and power generation industries. Creep-resistant steels must be reliable over very long periods of time at high temperatures and in severe environments. Understanding and improving long-term creep strength is essential for safe operation of plant and equipment. This book provides an authoritative summary of key research in this important area.The first part of the book describes the specifications and manufacture of creep-resistant steels. Part two covers the behaviour of creep-resistant steels and methods for strengthening them. The final group of chapters analyses applications in such areas as turbines and nuclear reactors.With its distinguished editors and international team of contributors, Creep-resistant steels is a valuable reference for the power generation, petrochemical and other industries which use high strength steels at elevated temperatures. - Describes the specifications and manufacture of creep-resistant steels - Strengthening methods are discussed in detail - Different applications are analysed including turbines and nuclear reactors

Download or read book Introduction to the Physical Metallurgy of Welding written by Kenneth Easterling and published by Elsevier. This book was released on 2013-09-17 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to the Physical Metallurgy of Welding deals primarily with the welding of steels, which reflects the larger volume of literature on this material; however, many of the principles discussed can also be applied to other alloys. The book is divided into four chapters, in which the middle two deal with the microstructure and properties of the welded joint, such as the weld metal and the heat-affected zone. The first chapter is designed to provide a wider introduction to the many process variables of fusion welding, particularly those that may influence microstructure and properties, while the final chapter is concerned with cracking and fracture in welds. A comprehensive case study of the Alexander Kielland North Sea accommodation platform disaster is also discussed at the end. The text is written for undergraduate or postgraduate courses in departments of metallurgy, materials science, or engineering materials. The book will also serve as a useful revision text for engineers concerned with welding problems in industry.

Download or read book Bainite and Martensite written by Carlos Garcia-Mateo and published by MDPI. This book was released on 2020-05-27 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructures of both martensite and bainite, although sharing some common features, depict a plethora of subtle differences that made them unique when studied in further detail. Tailoring the final properties of a microstructure based on one or the other as well as in combination with others and exploring more sophisticated concepts, such as Q&P and nanostructured bainite, are the topics which are the focus of research around the world. In understanding the key microstructural parameters controlling the final properties as well as definition of adequate process parameters to attain the desired microstructures requires that a proper understanding of the mechanism ruling their transformation and a detailed characterization first be acheived. The development of new and powerful scientific techniques and equipment (EBSD, APT, HRTEM, etc.) allow us to gain fundamental insights that help to establish some of the principles by which those microstructures are known. The developments accompanying such findings lead to further developments and intensive research providing the required metallurgical support.

Download or read book Structural Alloys for Nuclear Energy Applications written by Robert Odette and published by Newnes. This book was released on 2019-08-15 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-performance alloys that can withstand operation in hazardous nuclear environments are critical to presentday in-service reactor support and maintenance and are foundational for reactor concepts of the future. With commercial nuclear energy vendors and operators facing the retirement of staff during the coming decades, much of the scholarly knowledge of nuclear materials pursuant to appropriate, impactful, and safe usage is at risk. Led by the multi-award winning editorial team of G. Robert Odette (UCSB) and Steven J. Zinkle (UTK/ORNL) and with contributions from leaders of each alloy discipline, Structural Alloys for Nuclear Energy Applications aids the next generation of researchers and industry staff developing and maintaining steels, nickel-base alloys, zirconium alloys, and other structural alloys in nuclear energy applications. This authoritative reference is a critical acquisition for institutions and individuals seeking state-of-the-art knowledge aided by the editors' unique personal insight from decades of frontline research, engineering and management. - Focuses on in-service irradiation, thermal, mechanical, and chemical performance capabilities. - Covers the use of steels and other structural alloys in current fission technology, leading edge Generation-IV fission reactors, and future fusion power reactors. - Provides a critical and comprehensive review of the state-of-the-art experimental knowledge base of reactor materials, for applications ranging from engineering safety and lifetime assessments to supporting the development of advanced computational models.

Download or read book Failure Analysis of Heat Treated Steel Components written by Lauralice de Campos Franceschini Canale and published by ASM International. This book was released on 2008 with total page 651 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts Index written by and published by . This book was released on 1996 with total page 1622 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bainite in Steels written by H.K.D.H. Bhadeshia and published by CRC Press. This book was released on 2019-04-15 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the third edition of the book, much expanded to include and incorporate important developments in the subject over the last fifteen years. The book represents a comprehensive treatise on all aspects of the bainite transformation, from the choreography of atoms during the phase change to length scales that are typical of engineering applications. The alloy design that emerges from this explains the role of solute additions, and the pernicious effects of impurities such as hydrogen. The picture presented is self-consistent and therefore is able to guide the reader on the exploitation of theory to the design of some of the most exciting steels, including the world’s first bulk nanostructured metal.

Download or read book The Engineering Index Annual written by and published by . This book was released on 1988 with total page 2282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its creation in 1884, Engineering Index has covered virtually every major engineering innovation from around the world. It serves as the historical record of virtually every major engineering innovation of the 20th century. Recent content is a vital resource for current awareness, new production information, technological forecasting and competitive intelligence. The world?s most comprehensive interdisciplinary engineering database, Engineering Index contains over 10.7 million records. Each year, over 500,000 new abstracts are added from over 5,000 scholarly journals, trade magazines, and conference proceedings. Coverage spans over 175 engineering disciplines from over 80 countries. Updated weekly.

Download or read book Manufacturing and Application of Stainless Steels written by Andrea Di Schino and published by MDPI. This book was released on 2020-04-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stainless steels represent a quite interesting material family, both from a scientific and commercial point of view, following to their excellent combination in terms of strength and ductility together with corrosion resistance. Thanks to such properties, stainless steels have been indispensable for the technological progress during the last century and their annual consumption increased faster than other materials. They find application in all these fields requiring good corrosion resistance together with ability to be worked into complex geometries. Despite to their diffusion as a consolidated materials, many research fields are active regarding the possibility to increase stainless steels mechanical properties and corrosion resistance by grain refinement or by alloying by interstitial elements. At the same time innovations are coming from the manufacturing process of such a family of materials, also including the possibility to manufacture them starting from metals powder for 3D printing. The Special Issue scope embraces interdisciplinary work covering physical metallurgy and processes, reporting about experimental and theoretical progress concerning microstructural evolution during processing, microstructure-properties relations, applications including automotive, energy and structural.

Download or read book HSLA Steels 2015 Microalloying 2015 Offshore Engineering Steels 2015 written by The Chinese Society for Metals and published by Springer. This book was released on 2017-03-22 with total page 1147 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a collection of papers presented at the joint conference of the 7th International Conference on High Strength Low Alloy Steels (HSLA Steels 2015), the International Conference on Microalloying 2015 (Microalloying 2015), and the International Conference on Offshore Engineering Steels 2015 (OES 2015). The papers focus on the exchange of the latest scientific and technological progresses on HSLA steels, microalloying steels, and offshore engineering steels over the past decades. The contributions are intended to strengthen cooperation between universities and research institutes, and iron and steel companies and users, and promote the further development in the fields all over the world.

Download or read book Steels Processing Structure and Performance Second Edition written by George Krauss and published by ASM International. This book was released on 2015-03-01 with total page 705 pages. Available in PDF, EPUB and Kindle. Book excerpt: George Krauss, University Emeritus Professor, Colorado School of Mines and author of the best-selling ASM book Steels: Processing, Structure, and Performance, discusses some of the important additions and updates to the new second edition.