Download or read book Phosphorus Segregation and Intergranular Embrittlement in Thermally Aged and Neutron Irradiated Reactor Pressure Vessel Steels written by Masahide Suzuki and published by . This book was released on 2007 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study on phosphorus (P) segregation at grain boundaries and intergranular embrittlement of reactor pressure vessel steels due to thermal aging and neutron irradiation has been performed for A533B steel plates and weld metals doped with different bulk levels of P. The initial P concentration at grain boundaries of these materials determined by scanning Auger microscopy ranged from 9 to 33 %. The materials thermally aged at temperatures ranging from 450 to 550°C for up to 10000 h exhibited increases in P concentration described by the McLean's equation. A linear correlation was obtained between P concentration and Charpy 41 J transition temperature (T41J). Fracture toughness tests in the ductile-to-brittle transition temperature region have been conducted by the Master Curve method using 1T-CT specimens. The material subject to intergranular embrittlement exhibited the dual fracture toughness distributions typically observed in inhomogeneous materials. This was probably due to two types of initiation of cleavage and intergranular fracture. The lower tail analysis based on the Master Curve method enabled conservative fracture toughness estimates by fitting the lower fracture toughness arising from intergranular fracture. The relation between median KJc values estimated from the lower tail analysis and temperature appeared to follow the Master Curve. For neutron irradiated materials up to a fluence of 6.9×1019 n/cm2 (E>1 MeV) at 290°C by the Japan Materials Testing Reactor, an increase in grain boundary P segregation associated with decrease in carbon segregation was observed with increasing fluence. Relative significant hardening was recognized for the material with high bulk P content. Shifts in the reference temperature T0 and T41J were comparable for the thermally aged and irradiated materials.
Download or read book Review of Phosphorus Segregation and Intergranular Embrittlement in Reactor Pressure Vessel Steels written by WL. Server and published by . This book was released on 2001 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a systematic review of the behavior of phosphorus (P), highlighting the implications of P segregation to grain boundaries under neutron irradiation. The review focuses on Mn-Mo-Ni steels employed in US pressurized water reactors (PWRs), and other PWRs worldwide. Segregation of P to grain boundaries in reactor pressure vessel (RPV) steels can occur during fabrication (especially during the slow cooling stage of a post-weld heat treatment), and as a result of in-service exposure to high operating temperature and irradiation. This segregation of P to grain boundaries can promote a change in the brittle fracture mode from transgranular (TGF) to intergranular (IGF), and a degradation in the mechanical properties. In US RPV steels, most data are on thermal aging of the heat-affected zone (HAZ). Studies in coarse-grained HAZ have shown that the embrittlement arising from segregation of P to grain boundaries is approximately linearly related to the proportion of the brittle fracture that is IGF, and/or the P concentration at the grain boundary. Data are sparse on the effect of irradiation at 288°C on P segregation, and on the contribution of IGF to the total shift in the 41J transition temperature, T41J. In general, the bulk P content appears to be less than about 0.028 wt% P, with base metals having lower levels than weldments. In addition, the consequences of vessel annealing are considered at temperatures around 475°C. It is certain that the annealing treatment will have the consequence of reducing the irradiation hardening, but may significantly increase the grain boundary phosphorus coverage and the likelihood of IGF.
Download or read book Effects of Radiation on Materials written by R. K. Nanstad and published by ASTM International. This book was released on 1999 with total page 1135 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temper Embrittlement Irradiation Induced Phosphorus Segregation and Implications for Post Irradiation Annealing of Reactor Pressure Vessels written by CA. English and published by . This book was released on 1999 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three steels designated JPB, JPC and JPG from the IAEA Phase 3 Programme containing two copper and phosphorus levels were pre- and post-irradiation Charpy and hardness tested in the as-received (AR), 1200°C/0.5h heat treated (HT) and heat treated and 450°C/2000h aged (HTA) conditions. The HT condition, was designed to simulate coarse grained heat-affected zones (HAZ's) and showed a marked sensitivity to thermal ageing in all three alloys. Embrittlement after thermal ageing was greater in the higher phosphorus alloys JPB and JPG. Charpy shifts due to thermal ageing of between 118 and 209°C were observed and accompanied by pronounced intergranular fracture, due to phosphorus segregation. The irradiation embrittlement response was complex. The low copper alloys, JPC and JPB, in the HT and HTA condition exhibited significant irradiation induced Charpy shift but very low or even negative hardness changes indicating non-hardening embrittlement. The higher copper alloy, JPG, also exhibited irradiation hardening in line with its copper content. Fractographic and microchemical studies indicated irradiation induced phosphorus segregation and a transition from cleavage to intergranular failure at grain boundary phosphorus concentrations above a critical level. The enhanced grain boundary phosphorus level increased with dose in agreement with a kinetic segregation model developed at Harwell.
Download or read book Irradiation Embrittlement of Reactor Pressure Vessels RPVs in Nuclear Power Plants written by Naoki Soneda and published by Elsevier. This book was released on 2014-09-01 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reactor Pressure Vessels (RPVs) contain the fuel and therefore the reaction at the heart of nuclear power plants. They are a life-determining structural component: if they suffer serious damage, the continued operation of the plant is in jeopardy. This book critically reviews irradiation embrittlement, the main degradation mechanism affecting RPV steels, and mitigation routes for managing the RPV lifetime. Part I reviews RPV design and fabrication in different countries, with an emphasis on the materials required, their important properties, and manufacturing technologies. Part II then considers RVP embrittlement in operational nuclear power plants using different reactors. Chapters are devoted to embrittlement in light-water reactors, including WWER-type reactors and Magnox reactors. Finally, Part III presents techniques for studying embrittlement, including irradiation simulation techniques, microstructural characterisation techniques, and probabilistic fracture mechanics. Irradiation Embrittlement of Reactor Pressure Vessels (RPVs) in Nuclear Power Plants provides a thorough review of an issue that is central to the safety of nuclear power generation. The book includes contributions from an international team of experts, and will be a useful resource for nuclear plant operators and managers, relevant regulatory and safety bodies, nuclear metallurgists and other academics in this field - Discusses reactor pressure vessel (RPV) design and the effect irradiation embrittlement can have, the main degradation mechanism affecting RPVs - Examines embrittlement processes in RPVs in different reactor types, as well as techniques for studying RPV embrittlement
Download or read book Grain Boundary Phosphorus Segregation Under Irradiation and Thermal Aging and Its Effect on the Ductile to Brittle Transition written by S. Song and published by . This book was released on 2001 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Embrittlement of low-alloy steel components used in the nuclear power industry is classified into hardening embrittlement and non-hardening embrittlement. Hardening embrittlement stems from precipitation of carbides or copper-rich compounds. Non-hardening embrittlement results mainly from grain boundary segregation of phosphorus. To examine the non-hardening embrittlement in 2.25Cr 1Mo steel, phosphorus intergranular segregation in samples subjected to neutron irradiation and thermal aging at 270°C and 400°C is determined by modelling and transmission electron microscopy. The ductile-to-brittle transition temperature for the steel is determined by means of small punch testing with 3 mm diameter disc specimens. It is indicated that there is a reasonable agreement between the behavior of intergranular phosphorus segregation and shifts in the ductile-to-brittle transition temperature. Measured and predicted phosphorus intergranular segregation in a range of pressure vessel steels is also discussed.
Download or read book Investigation of Temper Embrittlement in Reactor Pressure Vessel Steels Following Thermal Aging Irradiation and Thermal Annealing written by MA. Sokolov and published by . This book was released on 2001 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Heavy-Section Steel Irradiation Program at Oak Ridge National Laboratory includes a task to investigate the propensity for temper embrittlement in coarse grain regions of heat-affected zones in prototypic reactor pressure vessel (RPV) steel weldments as a consequence of irradiation and thermal annealing. For the present studies, five prototypic RPV steels with specifications of A302 grade B, A302 grade B (modified), A533 grade B class 1, and A508 class 2 were given two different austenitization treatments and various thermal aging treatments. Thermal aging treatments were conducted at 399, 425, 454 and 490°C for times of 168 and 2000 h. Charpy V-notch impact toughness vs temperature curves were developed for each condition with ductile-brittle transition temperatures used as the basis for comparing the effects of the various heat treatments. Very high austenitization heat treatment produced extremely large grains which exhibited a very high propensity for temper embrittlement following thermal aging. Intergranular fracture was the predominant mode of failure in many of the materials and Auger analysis confirmed significant segregation of phosphorus at the grain boundaries. Lower temperature austenitization treatment performed in a super Gleeble to simulate prototypic coarse grain microstructures in submerged-arc weldments produced the expected grain size with varying propensity for temper embrittlement dependent on the material as well as on the thermal aging temperature and time. Although the lower temperature treatment resulted in decreased propensity for temper embrittlement, the results did provide motivation for the investigation of the potential for phosphorus segregation as a consequence of neutron irradiation and post-irradiation thermal annealing at 454°C. One of the A 302 grade B (modified) steels was given the Gleeble treatment, irradiated at 288°C to about 0.8 x 1019n/cm (>1 MeV) and given a thermal annealing treatment at 454°C for 168 h. Charpy impact testing was conducted on the material in both the irradiated and irradiated/annealed conditions, as well as in the as-received condition. The results show that, although the material exhibited a relatively small Charpy impact 41-J temperature shift, the heat-affected zone-simulated material did exhibit significant intergranular fracture in the post-irradiation annealed condition.
Download or read book Review of Phosphorus Segregation and Intergranular Embrittlement in Reactor Pressure Vessel Steels PWRMRP 19 written by S. Rosinski and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation and Thermally Induced Phosphorus Inter Granular Segregation in Pressure Vessel Steels written by Z. Lu and published by . This book was released on 2005 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: A survey of neutron- and thermally-induced phosphorus inter-granular segregation behavior in C-Mn welds, LWR plates, LWR HAZ materials, and VVER steels is described in this paper. The materials were irradiated up to doses of 0.13 dpa (fast neutron energy > 1 MeV), with dose rates ranging from 1.75 × 10−8 dpa/s to 10−12 dpa/s, at temperatures between 190°C and 400°C. Irradiation-induced P inter-granular segregation has been found in LWR and VVER materials at high doses (generally 10-130 mdpa) but is absent in all Magnox C-Mn submerged-arc welds at lower doses (1.5-13 mdpa). The dose sensitivity of the irradiation-induced P monolayer coverage depends on the material examined, being highest for VVER plates and weld, lower for the LWR materials, and zero for the C-Mn welds. There are high initial P segregations (arising from pre-heat-treatment) in C-Mn weld and LWR HAZ materials and low initial P segregation in LWR and VVER steels. Comparisons of the experimental data with model predictions are made. The amount of phosphorus segregation is shown via site competition models to be related to free carbon concentration. The model results show a good agreement with experimental measurements.
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 The Modelling of Irradiation Enhanced Phosphorus Segregation in Neutron Irradiated Reactor Pressure Vessel Submerged Arc Welds written by CJ. Bolton and published by . This book was released on 1996 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent results on neutron-irradiated RPV submerged-arc welds have revealed grain boundary segregation of phosphorus during irradiation, which may lead to intergranular fracture. However, the experimental database is insufficient to define the dependence of the process on variables such as dose, dose-rate and temperature. This paper describes work in which two existing models of phosphorus segregation, under thermal or irradiation conditions, have been developed to obtain predictions of these dependencies.
Download or read book Comprehensive Nuclear Materials written by and published by Elsevier. This book was released on 2020-07-22 with total page 4871 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials in a nuclear environment are exposed to extreme conditions of radiation, temperature and/or corrosion, and in many cases the combination of these makes the material behavior very different from conventional materials. This is evident for the four major technological challenges the nuclear technology domain is facing currently: (i) long-term operation of existing Generation II nuclear power plants, (ii) the design of the next generation reactors (Generation IV), (iii) the construction of the ITER fusion reactor in Cadarache (France), (iv) and the intermediate and final disposal of nuclear waste. In order to address these challenges, engineers and designers need to know the properties of a wide variety of materials under these conditions and to understand the underlying processes affecting changes in their behavior, in order to assess their performance and to determine the limits of operation. Comprehensive Nuclear Materials, Second Edition, Seven Volume Set provides broad ranging, validated summaries of all the major topics in the field of nuclear material research for fission as well as fusion reactor systems. Attention is given to the fundamental scientific aspects of nuclear materials: fuel and structural materials for fission reactors, waste materials, and materials for fusion reactors. The articles are written at a level that allows undergraduate students to understand the material, while providing active researchers with a ready reference resource of information. Most of the chapters from the first Edition have been revised and updated and a significant number of new topics are covered in completely new material. During the ten years between the two editions, the challenge for applications of nuclear materials has been significantly impacted by world events, public awareness, and technological innovation. Materials play a key role as enablers of new technologies, and we trust that this new edition of Comprehensive Nuclear Materials has captured the key recent developments. Critically reviews the major classes and functions of materials, supporting the selection, assessment, validation and engineering of materials in extreme nuclear environments Comprehensive resource for up-to-date and authoritative information which is not always available elsewhere, even in journals Provides an in-depth treatment of materials modeling and simulation, with a specific focus on nuclear issues Serves as an excellent entry point for students and researchers new to the field
Download or read book Influence of Phosphorus on Thermal and Neutron Embrittlement of Pressure Vessel Steels written by H. Horowitz and published by . This book was released on 1993 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: In conjunction with an international study coordinated by the International Atomic Energy Agency (IAEA), a review was made of three Japanese model steels with different phosphorus and copper contents irradiated at 5.1019 n • cm-2 (E > 1 MeV) to explain the influence of phosphorus on the thermal and neutron embrittlement of steels.
Download or read book Irradiation Induced Grain Boundary Solute Segregation and Its Effect on Ductile to Brittle Transition Temperature in Reactor Pressure Vessel Steels written by Masatake Yamaguchi and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study on grain-boundary segregation and embrittlement in terms of the Charpy ductile-to-brittle transition temperature (DBTT) has been performed for the neutron-irradiated A533B steels with typical contents of impurities of Japanese reactor pressure vessel ones. The neutron irradiation was conducted at 563 K to a fluence of 1.3 x 1024n/m2 (E>1 MeV) using material testing reactors. The neutron irradiation induced the P and Ni segregation and the reduction in C in some cases at grain-boundaries. The increase in the P segregation at high fluence (>5 x 10 23n/m2, E>1 MeV) was less than 0.1 in monolayer coverage for the steels with the bulk content of P not exceeding 0.02 wt%. The hardening more strongly affected the DBTT shift than the P segregation for those steels. The reduction in segregated C that enhances the grain-boundary cohesion by neutron fluence is not large enough to cause the DBTT shift.
Download or read book Characterization of Phosphorus Segregation in Neutron irradiated Pressure Vessel Steels by Atom Probe Ion Microscopy written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of Neutron Irradiation Induced Grain Boundary Embrittlement by Phosphorous Segregation in a Reactor Pressure Vessel Steel written by A. Kimura and published by . This book was released on 2005 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The materials used were two sorts of reactor pressure vessel steels (RPVSs), which contain different amounts of impurity phosphorous (P) and copper (Cu). The specimens for Charpy V-notch impact tests and Auger electron spectroscopy (AES) were irradiated in the Japan Materials Test Reactor (JMTR) at 290°C up to fluences of 6 × 1021 and 1 × 1024 n/m2 using a multi-division temperature control capsule which enables removal of a part of the sub-capsules during operation of the reactor.
Download or read book Effects of Radiation on Materials written by Todd R. Allen and published by ASTM International. This book was released on 2006 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt:
