Download or read book EVOLUTION STRUCTURALE D ALLIAGES FERRITIQUES SOUS IRRADIATION written by MARIELLE.. AKAMATSU JOUSSET and published by . This book was released on 1994 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: NOUS AVONS ETUDIE L'EVOLUTION, SOUS L'EFFET DE L'IRRADIATION, DE LA MICROSTRUCTURE ET DES PROPRIETES MECANIQUES D'ALLIAGES FERRITIQUES MODELE (FE-CU) ET D'ACIERS DE CUVE DE REACTEUR NUCLEAIRE A EAU PRESSURISEE (CHOOZ A). TROIS TRAITEMENTS DE PRECIPITATION SONT COMPARES: VIEILLISSEMENT THERMIQUE A 500C, IRRADIATION AUX ELECTRONS (3MEV, 290C) ET IRRADIATION AUX NEUTRONS (290C). L'UTILISATION CONJOINTE DE LA SONDE ATOMIQUE ET DE LA DIFFUSION DES NEUTRONS AUX PETITS ANGLES A PERMIS D'OBTENIR LES CARACTERISTIQUES (TAILLE, DENSITE NUMERIQUE, COMPOSITION) DES PRECIPITES FORMES A L'ECHELLE NANOMETRIQUE, EN FONCTION DU TEMPS OU DE LA FLUENCE. DANS LES ALLIAGES FE-CU (0 A 1,4% POIDS) IRRADIES, LES PRECIPITES NE SONT PAS CONSTITUES DE CUIVRE PUR (COMME LE PREVOIRAIT LE DIAGRAMME DE PHASE), MAIS CONTIENNENT UNE FORTE PROPORTION DE FER ET DE LACUNES. LES MESURES DE DURETE SOUS FAIBLE CHARGE MONTRENT UN NET DURCISSEMENT DU A CES PRECIPITES. LES IRRADIATIONS CONDUISENT A UN DURCISSEMENT SUPERIEUR A CELUI DU AU VIEILLISSEMENT THERMIQUE, DU FAIT DE LA CREATION DE NOMBREUX DEFAUTS PONCTUELS. NOUS AVONS ESSAYE D'ANALYSER NOS RESULTATS DANS LES TERMES DU MODELE DURCISSEMENT PAR EFFET DE MODULE DE RUSSEL ET BROWN. NOS TENTATIVES D'EVALUATION NON DESTRUCTIVE PAR MESURE DU BRUIT BARKHAUSEN REVELENT SIMPLEMENT QUE LES PRECIPITES FORMES PAR IRRADIATION SONT VRAISEMBLABLEMENT TROP PETITS POUR ETRE DETECTES. DANS L'ACIER DE CUVE, L'IRRADIATION AUX NEUTRONS EN SERVICE A CONDUIT A LA FORMATION DE NUAGES D'ATOMES DE NI, MN, SI ET CU AU SEIN DE LA MATRICE DE FER

Download or read book Meso structure in Materials written by Omourtague Dimitrov and published by . This book was released on 1997 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pr visions de l volution microstructurale sous irradiation d alliages ferritiques par simulations num riques l chelle atomique written by Raoul Ngayam Happy and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, we have improved a diffusion model for point defects (vacancies and self-interstitials) by introducing hetero-interstitials. The model has been used to simulate by Kinetic Monte Carlo (KMC) the formation of solute rich clusters that are observed experimentally in irradiated ferritic model alloys of type Fe – CuMnNiSiP – C.Electronic structure calculations have been used to characterize the interactions between self-interstitials and all solute atoms, and also carbon. P interacts with vacancies and strongly with self-interstitials. Mn also interacts with self-interstitials to form mixed dumbbells. C, with occupies octahedral sites, interacts strongly with vacancies and less with self-interstitials. Binding and migration energies, as well as others atomic scale properties, obtained by ab initio calculations, have been used as parameters for the KMC code. Firstly, these parameters have been optimized over isochronal annealing experiments, in the literature, of binary alloys that have been electron-irradiated. Isochronal annealing simulations, by reproducing experimental results, have allowed us to link each mechanism to a single evolution of the resistivity during annealing. Moreover, solubility limits of all the elements have been determined by Metropolis Monte Carlo. Secondly, we have simulated the evolution at 300 °C of the microstructure under irradiation of different alloys of increasing complexity: pure Fe, binary alloys, ternaries, quaternaries, and finally complex alloys which compositions are close to those of pressure vessel steels. The results show that the model globally reproduces all the experimental tendencies, what has led us to propose mechanisms to explain the behaviours observed.

Download or read book Understanding and Mitigating Ageing in Nuclear Power Plants written by Philip G Tipping and published by Elsevier. This book was released on 2010-10-26 with total page 953 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant life management (PLiM) is a methodology focussed on the safety-first management of nuclear power plants over their entire lifetime. It incorporates and builds upon the usual periodic safety reviews and licence renewals as part of an overall framework designed to assist plant operators and regulators in assessing the operating conditions of a nuclear power plant, and establishing the technical and economic requirements for safe, long-term operation. Understanding and mitigating ageing in nuclear power plants critically reviews the fundamental ageing-degradation mechanisms of materials used in nuclear power plant structures, systems and components (SSC), along with their relevant analysis and mitigation paths, as well as reactor-type specific PLiM practices. Obsolescence and other less obvious ageing-related aspects in nuclear power plant operation are also examined in depth. Part one introduces the reader to the role of nuclear power in the global energy mix, and the importance and relevance of plant life management for the safety regulation and economics of nuclear power plants. Key ageing degradation mechanisms and their effects in nuclear power plant systems, structures and components are reviewed in part two, along with routes taken to characterise and analyse the ageing of materials and to mitigate or eliminate ageing degradation effects. Part three reviews analysis, monitoring and modelling techniques applicable to the study of nuclear power plant materials, as well as the application of advanced systems, structures and components in nuclear power plants. Finally, Part IV reviews the particular ageing degradation issues, plant designs, and application of plant life management (PLiM) practices in a range of commercial nuclear reactor types. With its distinguished international team of contributors, Understanding and mitigating ageing in nuclear power plants is a standard reference for all nuclear plant designers, operators, and nuclear safety and materials professionals and researchers. Introduces the reader to the role of nuclear power in the global energy mix Reviews the fundamental ageing-degradation mechanisms of materials used in nuclear power plant structures, systems and components (SSC) Examines topics including elimination of ageing effects, plant design, and the application of plant life management (PLiM) practices in a range of commercial nuclear reactor types

Download or read book Simulations num riques l chelle atomique de l volution microstructurale sous irradiation d alliages ferritiques written by Edwige Vincent and published by . This book was released on 2006 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dans ce travail, nous avons développé un modèle de diffusion des défauts ponctuels (lacunes et interstitiels) permettant de simuler par Monte Carlo cinétique (MCC) la formation d'amas riches en solutés observés expérimentalement dans des alliages modèles de type FeCuNiMnSi irradiés ainsi que dans l'acier de cuve. Des calculs de structure électronique nous ont permis de caractériser les interactions existant entre les défauts ponctuels et les différents atomes de solutés. Chacun des solutés établit des liaisons attractives avec la lacune. Le Mn, quant à lui, élément ayant le moins d'affinité avec la lacune, établit des liaisons plus favorables avec l'interstitiel. Les énergies de liaison, de migration ainsi que d'autres propriétés à l'échelle atomique, déterminées par calculs ab initio, nous ont conduits à un jeu de paramètres pour le code de MCC. Dans un premier temps, ces paramètres ont été optimisés sur des expériences de recuit thermique réalisées sur l'alliage binaire FeCu et sur des alliages complexes, décrites dans la littérature. Les simulations de recuit thermique montrent qu'en présence de lacunes, tous les solutés migrent et forment des amas, en respectant les tendances observées expérimentalement. Pour simuler l'évolution de la microstructure sous irradiation, nous avons, dans un second temps, introduit les interstitiels dans le code de MCC. Leur présence rend plus efficace le transport du Mn. Les premières simulations d'irradiation par des électrons et des neutrons montrent que le modèle reproduit dans l'ensemble des résultats qualitativement en accord avec les tendances observées expérimentalement.

Download or read book INIS Atomindex written by and published by . This book was released on 1988 with total page 794 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book EVOLUTION STRUCTURALE ET DEFAUTS D IRRADIATION DANS LE COMPOSE INTERMETALLIQUE NI 3AL written by XINC.. ZHANG and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: L'EVOLUTION STRUCTURALE EN FONCTION DE LA TEMPERATURE, LES EFFETS DE L'IRRADIATION PAR DES ELECTRONS ET L'INFLUENCE DE L'ECART A LA STOECHIOMETRIE SUR CES PHENOMENES ONT ETE ETUDIES DANS LE COMPOSE INTERMETALLIQUE NI#3AL, QUI REPRESENTE UN MODELE DE LA PHASE DURCISSANTE DES SUPERALLIAGES A BASE DE NICKEL. DES ALLIAGES MONOPHASES DE TENEUR EN AL COMPRISE ENTRE 24,5 ET 26,4 AT% ONT ETE ETUDIES. DES VARIATIONS REVERSIBLES DE RESISTIVITE ELECTRIQUE MESUREE A 4,2 K, DONT L'AMPLITUDE EST MAXIMALE A LA STOECHIOMETRIE, ONT ETE OBSERVEES LORS DES RECUITS ISOCHRONES ET ONT ETE ATTRIBUEES A UNE EVOLUTION DU DEGRE D'ORDRE A GRANDE DISTANCE DE CES MATERIAUX. LA CINETIQUE DE MISE EN ORDRE A ETE ETUDIEE LORS DE RECUITS ISOTHERMES. LES ALLIAGES NI#3AL ET UN METAL DE REFERENCE (NI) ONT ETE IRRADIES SIMULTANEMENT A 4,6 K PAR DES ELECTRONS DE 3 MEV. SI L'ON ADMET QUE LA CREATION DE DEFAUTS EST LE PHENOMENE PREPONDERANT, ON PEUT DETERMINER LA RESISTIVITE DE LA PAIRE DE FRENKEL (1,15.10##2.CM P.U.C) ET LE VOLUME DE RECOMBINAISON. SI AU CONTRAIRE, ON SUPPOSE QUE LA RESISTIVITE DE LA PAIRE DE FRENKEL EST LA MEME QUE CELLE D'UN ALLIAGE DESORDONNE, ON PEUT OBTENIR LE RAPPORT ENTRE LE NOMBRE DE REMPLACEMENTS ET LE NOMBRE DE DEPLACEMENTS ATOMIQUES (13). LE SPECTRE DE RESTAURATION DANS NI#3AL EST QUALITATIVEMENT SIMILAIRE A CELUI OBTENU DANS LES METAUX PURS; CEPENDANT UNE RESTAURATION SUPERIEURE A 100% INDIQUE QU'UNE MISE EN ORDRE SE PRODUIT AU COURS DES RECUITS. NOUS AVONS DETERMINE LES DOMAINES DE TEMPERATURES OU LES DIFFERENTS DEFAUTS MIGRENT ET S'ELIMINENT

Download or read book Stabilit sous irradiation de particules d oxydes finement dispers es dans des alliages ferritiques written by Isabelle Monnet and published by . This book was released on 1999 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les aciers ferrito-martensitiques renforcés par dispersion d'oxydes sont envisagés dans le cadre d'applications nucléaires à forte fluence et haute température, comme le gainage du combustible des réacteurs à Neutrons Rapides. La matrice cubique centrée assure une bonne résistance au gonflement et la dispersion d'oxydes améliore les propriétés mécaniques hors pile à haute température. Une gaine en DY (Fe-13Cr-1,5Mo+TiO 2+Y2 O3) a été irradié dans le réacteur expérimental Phénix. Les oxydes se sont dissout sous irradiation. Les observations microstructurales indiquent que l'évolution des oxydes dépend de la dose et consiste en quatre phénomènes : - les interfaces oxydes/matrice deviennent irrégulières, - les petits oxydes (

Download or read book Journal de physique written by and published by . This book was released on 2001 with total page 986 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book EVOLUTION DE LA MICROSTRUCTURE ET DES PROPRIETES MECANIQUES D ALLIAGES NI AL TI PAR VIEILLISSEMENT THERMIQUE ET SOUS IRRADIATION written by NABIL.. NJAH and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ON A ETUDIE L'EVOLUTION MICROSTRUCTURALE ET SES CONSEQUENCES SUR LES PROPRIETES MECANIQUES DANS DES ALLIAGES BIPHASES NIALTI AU COURS DES TRAITEMENTS DE VIEILLISSEMENT THERMIQUE OU SOUS IRRADIATION AUX ELECTRONS. CES MATERIAUX REPRODUISENT LA STRUCTURE - DES SUPER-ALLIAGES A BASE DE NICKEL. LES RESULTATS MONTRENT QUE LA VITESSE DE COALESCENCE DES PARTICULES AUGMENTE AVEC LA FONCTION VOLUMIQUE DE CELLES-CI ET AVEC LE RAPPORT TI/AL. LA VARIATION DE LA LIMITE ELASTIQUE AVEC LA TAILLE DES PRECIPITES REVELE DEUX REGIMES: AUX PETITES TAILLES, LA LIMITE ELASTIQUE EST INDEPENDANTE DE LA TAILLE; ELLE EST PROBABLEMENT CONTROLEE PAR LE CISAILLEMENT DES PARTICULES . POUR DES TAILLES PLUS GRANDES, LA LIMITE ELASTIQUE DIMINUE; ELLE EST CONTROLEE PAR LE CONTOURNEMENT DES PARTICULES PAR LES DISLOCATIONS. AU COURS DE L'IRRADIATION DANS LE DOMAINE DE TEMPERATURE 180 K-400 K DANS UN MICROSCOPE ELECTRONIQUE A HAUTE TENSION, LA PHASE SE DESORDONNE; LA CINETIQUE DE CETTE MISE EN DESORDRE A ETE DETERMINEE. L'IRRADIATION AUX ELECTRONS AUX FAIBLES DOSES ENTRAINE UNE LEGERE DIMINUTION DE LA LIMITE ELASTIQUE DANS LE DOMAINE DE TAILLE CORRESPONDANT AU CISAILLEMENT DES PARTICULES, ET A UN LEGER DURCISSEMENT QUAND LA DEFORMATION SE FAIT PAR GLISSEMENT DES DISLOCATIONS DANS LA PHASE

Download or read book Mod lisation Num rique de L volution Nanostructurale D aciers Ferritiques Sous Irradiation written by Monica Chiapetto and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We developed object kinetic Monte Carlo (OKMC) models that proved able to predict the nanostructure evolution under neutron irradiation in both RPV and F/M steels. These were modelled, respectively, in terms of Fe-C-MnNi and Fe-C-Cr alloys, but the model was also validated against data obtained on a real RPV steel coming from the surveillance programme of the Ringhals Swedish nuclear power plant. The effects of the substitutional solutes of interest were introduced in our OKMC model under the simplifying assumptions of ''grey alloy'' scheme, i.e. they were not explicitly introduced in the model, which therefore cannot describe their redistribution under irradiation, but their effect was translated into modified parameters for the mobility of defect clusters. The possible origin of low temperature radiation hardening (and subsequent embrittlement) was also investigated and the models strongly supported the hypothesis that solute clusters segregate on immobile interstitial loops, which act therefore as heterogeneous nucleation sites for the formation of the NiSiPCr- and MnNi-enriched cluster populations experimentally, as observed with atom probe tomography in, respectively, F/M and RPV steels. In other words, the so-called matrix damage would be intimately associated with solute atom clusters and precipitates which increase their stability and reduce their mobility: their ultimate effect is reflected in an alteration of the macroscopic mechanical properties of the investigated alloys. Throughout all our work the obtained results have been systematically validated on existing experimental data, in a process of continuous improvement of the physical hypotheses adopted.

Download or read book Sodium cooled Nuclear Reactors written by Jean-François Parisot and published by . This book was released on 2016 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1980 with total page 1038 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Duplex Stainless Steels written by Iris Alvarez-Armas and published by John Wiley & Sons. This book was released on 2013-01-16 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Duplex Stainless Steels (DSSs) are chromium-nickel-molybdenum-iron alloys that are usually in proportions optimized for equalizing the volume fractions of austenite and ferrite. Due to their ferritic-austenitic microstructure, they possess a higher mechanical strength and a better corrosion resistance than standard austenitic steels. This type of steel is now increasing its application and market field due to its very good properties and relatively low cost. This book is a review of the most recent progress achieved in the last 10 years on microstructure, corrosion resistance and mechanical strength properties, as well as applications, due to the development of new grades. Special attention will be given to fatigue and fracture behavior and to proposed models to account for mechanical behavior. Each subject will be developed in chapters written by experts recognized around the international industrial and scientific communities. The use of duplex stainless steels has grown rapidly in the last 10 years, particularly in the oil and gas industry, chemical tankers, pulp and paper as well as the chemical industry. In all these examples, topics like welding, corrosion resistance and mechanical strength properties (mainly in the fatigue domain) are crucial. Therefore, the update of welding and corrosion properties and the introduction of topics like texture effects, fatigue and fracture strength properties, and mechanical behavior modeling give this book specific focus and character.

Download or read book Dictionary of Building and Civil Engineering written by Don Montague and published by Taylor & Francis. This book was released on 1996 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dual-language dictionary lists over 20,000 specialist terms in both French and English, covering architecture, building, engineering and property terms. It meets the needs of all building professionals working on projects overseas. It has been comprehensively researched and compiled to provide an invaluable reference source in an increasingly European marketplace.

Download or read book Integrity of Reactor Pressure Vessels in Nuclear Power Plants written by and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication is intended to assist nuclear utilities in optimizing the service life of nuclear power plants. It reviews the latest research on the effects of neutron irradiation on the steels and welds of reactor pressure vessels within light water cooled and moderated reactors.

Download or read book Modelling Aqueous Corrosion written by Kenneth R. Threthewey and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: All significant studies agree that aqueous corrosion continues to cost nations dearly in almost every area of technological endeavour. Over the past ten years, microcomputers have facilitated an explosion in the power of modelling as a technique in science and engineering. In corrosion they have enabled better understanding of polarization curves, they have transformed the scope of electrochemical impedance measurements and they have placed a large range of electrochemistry at the fingertips of the corrosion scientist. This book focuses on the models, rather than the computing, which have been made possible during the past decade. Aimed at all those with an interest in corrosion and its control, the book draws together the range of new modelling strands, suggests new avenues of approach and generates further momentum for improvements to corrosion management, whether by increased understanding of atomistic processes or by control of large plant.