Download or read book Thermal Aging Phenomena in Cast Duplex Stainless Steels written by and published by . This book was released on 2015 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We used cast stainless steels (CASSs)for the large components of light water reactor (LWR) power plants such as primary coolant piping and pump casing. The thermal embrittlement of CASS components is one of the most serious concerns related to the extended-term operation of nuclear power plants. Many past researches have concluded that the formation of Cr-rich alpha-phase by Spinodal decomposition of delta-ferrite phase is the primary mechanism for the thermal embrittlement. Cracking mechanism in the thermally-embrittled duplex stainless steels consists of the formation of cleavage at ferrite and its propagation via separation of ferrite-austenite interphase. This article intends to provide an introductory overview on the thermal aging phenomena in LWR-relevant conditions. Firstly, the thermal aging effect on toughness is discussed in terms of the cause of embrittlement and influential parameters. Moreover, an approximate analysis of thermal reaction using Arrhenius equation was carried out to scope the aging temperatures for the accelerated aging experiments to simulate the 60 and 80 years of services. Further, an equilibrium precipitation calculation was performed for model CASS alloys using the CALPHAD program, and the results are used to describe the precipitation behaviors in duplex stainless steels. Our results are also to be used to guide an on-going research aiming to provide knowledge-based conclusive prediction for the integrity of the CASS components of LWR power plants during the service life extended up to and beyond 60 years.
Download or read book The effect of thermal aging on the mechanical properties of cast duplex stainless steels and weld metal written by T. Tanaka and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aging Degradation of Cast Stainless Steels written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water operating conditions. Mechanical property data are presented from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 450, 400, 350, 320, and 290°C. The results indicate that thermal aging increases the tensile strength and decreases the impact energy, J/sub IC/, and tearing modulus of the steels. Also, the ductile-to-brittle transition curve shifts to higher temperatures. The fracture toughness results are consistent with the Charpy-impact data, i.e., the relative reduction in J/sub IC/ is similar to the relative decrease in impact energy. The ferrite content and concentration of C in the steel have a strong effect on the overall process of low-temperature embrittlement. The low-carbon CF-3 steels are the most resistant and Mo-containing CF-8M steels are most susceptible to embrittlement. Weakening of the ferrite/austenite phase boundaries by carbide precipitates has a significant effect on the kinetics and extent of embrittlement of the high-carbon CF-8 and CF-8M steels, particularly after aging at temperatures greater than or equal to400°C. The influence of N content and distribution of ferrite on loss of toughness are discussed. The data also indicate that existing correlations do not accurately represent the embrittlement behavior over the temperature range 280 to 450°C, i.e., extrapolation of high-temperature data to reactor temperatures may not be valid for some compositions of cast stainless steel.
Download or read book Low Temperature Aging Kinetics in Cast Duplex Stainless Steels written by JJ. González and published by . This book was released on 1997 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-temperature aging (280 to 300°C) of duplex (austenite-ferrite) stainless steels and their resulting long-term loss of toughness is a well-known problem in the energy-producing as well as in other industrial sectors.In order to analyze the problem, the phenomenon was assumed to be thermally activated, accelerated aging at higher temperatures (350 to 400°C) was planned, and the activation energy was estimated.Assuming that the cause of brittleness is the ferrite's spinodal decomposition into the ? and ?' phases, the present work analyzes the aging kinetics at three temperatures (280, 350, and 400°C) by means of microhardness measurements of the ferritic phase taken in three different duplex stainless steels named after their ferrite content, 12F, 18F and 22F.In view of the microhardness results, an exponential law is proposed to represent the temporal evolution for each of the steels, with three parameters, of which one varies with aging temperature.It should be noted that there is no unique value for the activation energy in all the 280 to 400°C range.This should be divided into smaller subranges for more precision, and here it is shown that in all cases the extrapolation to the service temperature (280°C) of the results obtained in the 350 to 400°C range produces non-conservative results.These results are discussed considering the effect of the G-phase precipitation on the spinodal decomposition kinetics.For assessment applications a mathematical law is proposed that represents the aging kinetics of these steels and that provides reliable results for their service temperature (280°C).
Download or read book Proceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems Water Reactors written by John H. Jackson and published by Springer. This book was released on 2018-12-20 with total page 2460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set represents a collection of papers presented at the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors. The purpose of this conference series is to foster an exchange of ideas about problems and their remedies in water-cooled nuclear power plants of today and the future. Contributions cover problems facing nickel-based alloys, stainless steels, pressure vessel and piping steels, zirconium alloys, and other alloys in water environments of relevance. Components covered include pressure boundary components, reactor vessels and internals, steam generators, fuel cladding, irradiated components, fuel storage containers, and balance of plant components and systems.
Download or read book Mechanical and Creep Behavior of Advanced Materials written by Indrajit Charit and published by Springer. This book was released on 2017-02-04 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection commemorates the occasion of the honorary symposium that celebrated the 75th birthday and lifelong contributions of Professor K.L. Murty. The topics cover the present status and recent advances in research areas in which he made seminal contributions. The volume includes articles on a variety of topics such as high-temperature deformation behaviors of materials (elevated temperature creep, tensile, fatigue, superplasticity) and their micromechanistic interpretation, understanding mechanical behavior of HCP metals/alloys using crystallographic texture, radiation effects on deformation and creep of materials, mechanical behavior of nanostructured materials, fracture and fracture mechanisms, development and application of small-volume mechanical testing techniques, and general structure-property correlations.
Download or read book Long term Embrittlement of Cast Duplex Stainless Steels in LWR Systems written by O. K. Chopra and published by . This book was released on 1986 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Kinetics and Mechanism of Thermal Aging Embrittlement of Duplex Stainless Steels written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstructural characteristics of long-term-aged cast duplex stainless steel specimens from eight laboratory heats and an actual component from a commercial boiling water reactor have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle neutron scattering (SANS), and atom probe field ion microscopy (APFIM) techniques. Three precipitate phases, i.e., Cr-rich .cap alpha.' and the Ni- and Si-rich G phase, and .gamma.2 austenite, have been identified in the ferrite matrix of the aged specimens. For CF-8 grade materials, M23C6 carbides were identified on the austenite-ferrite boundaries as well as in the ferrite matrix for aging at greater than or equal to 450°C. It has been shown that Si, C, and Mo contents are important factors that influence the kinetics of the G-phase precipitation. However, TEM and APFIM analyses indicate that the embrittlement for less than or equal to400°C aging is primarily associated with Fe and Cr segregation in ferrite by spinodal decomposition. For extended aging, e.g., 6 to 8 years at 350 to 400°C, large platelike .cap alpha.' formed by nucleation and growth from the structure produced by the spinodal decomposition. The Cr content appears to play an important role either to promote the platelike .cap alpha.' (high Cr content) or to suppress the .cap alpha.' in favor of .gamma.2 precipitation (low Cr). Approximate TTT diagrams for the spinodal, .cap alpha.', G, .gamma.2, and the in-ferrite M23C6 have been constructed for 250 to 450°C aging. Microstructural modifications associated with a 550°C reannealing and a subsequent toughness restoration are also discussed. It is shown that the toughness restoration is associated primarily with the dissolution of the Cr-rich region in ferrite.
Download or read book Aging Degradation of Cast Stainless Steel written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich .cap alpha.' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by .cap alpha.' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 450°C. Data from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450°C are presented and correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed.
Download or read book Steel Heat Treatment written by George E. Totten and published by CRC Press. This book was released on 2006-09-28 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of two self-contained volumes belonging to the newly revised Steel Heat Treatment Handbook, Second Edition, this book examines the behavior and processes involved in modern steel heat treatment applications. Steel Heat Treatment: Metallurgy and Technologies presents the principles that form the basis of heat treatment processes while incorporating detailed descriptions of advances emerging since the 1997 publication of the first edition. Revised, updated, and expanded, this book ensures up-to-date and thorough discussions of how specific heat treatment processes and different alloy elements affect the structure and the classification and mechanisms of steel transformation, distortion of properties of steel alloys. The book includes entirely new chapters on heat-treated components, and the treatment of tool steels, stainless steels, and powder metallurgy steel components. Steel Heat Treatment: Metallurgy and Technologies provides a focused resource for everyday use by advanced students and practitioners in metallurgy, process design, heat treatment, and mechanical and materials engineering.
Download or read book Effect of Thermal Aging on Mechanical Properties of Cast Stainless Steels 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 Compilation of Contract Research for the Materials Engineering Branch Division of Engineering Technology written by and published by . This book was released on 1983 with total page 322 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 Characterization of Advanced Materials written by W. Altergott and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the U S Nuclear Regulatory Commission Twelfth Water Reactor Safety Research Information Meeting Held at National Bureau of Standards Gaithersburg Maryland October 22 26 1983 i e 1984 written by and published by . This book was released on 1985 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Multicomponent Alloys written by Zengbao Jiao and published by Springer Nature. This book was released on 2022-09-19 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book integrates aspects of computational materials science, physical metallurgy, alloy design, structure-properties relationships, and applications of advanced multicomponent alloys. It can serve as a textbook for courses on advanced structural and functional materials for undergraduate and graduate students. Notably, the book compiles cutting-edge research on the progress of materials science of multicomponent alloys from fundamentals to engineering applications. It can be of considerable interest for researchers and scientists in the field of materials science and engineering, mechanical engineering, and metallurgy engineering. In addition, this book not only summarizes the compositions, properties, and applications of various types of multicomponent alloys but also presents a complete idea on the efficient design of materials and processes to satisfy targeted performance in materials and structures. Thus, it can also be used as a reference book for engineers and researchers in industries.
