Download or read book Direct Observations of Sigma Phase Formation in Duplex Stainless Steels Using In Situ Synchrotron X Ray Diffraction written by and published by . This book was released on 2006 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation and growth of sigma phase in 2205 duplex stainless steel was observed and measured in real time using synchrotron radiation during 10 hr isothermal heat treatments at temperatures between 700 C and 850 C. Sigma formed in near-equilibrium quantities during the isothermal holds, starting from a microstructure which contained a balanced mixture of metastable ferrite and austenite. In situ synchrotron diffraction continuously monitored the transformation, and these results were compared to those predicted by thermodynamic calculations. Differences between the calculated and measured amounts of sigma, ferrite and austenite suggest that the thermodynamic calculations underpredict the sigma dissolution temperature by approximately 50 C. The data were further analyzed using a modified Johnson-Mehl-Avrami (JMA) approach to determine kinetic parameters for sigma formation over this temperature range. The initial JMA exponent, n, at low fractions of sigma was found to be approximately 7.0, however, towards the end of the transformation, n decreased to values of approximately 0.75. The change in the JMA exponent was attributed to a change in the transformation mechanism from discontinuous precipitation with increasing nucleation rate, to growth of the existing sigma phase after nucleation site saturation occurred. Because of this change in mechanism, it was not possible to determine reliable values for the activation energy and pre-exponential terms for the JMA equation. While cooling back to room temperature, the partial transformation of austenite resulted in a substantial increase in the ferrite content, but sigma retained its high temperature value to room temperature.
Download or read book Direct Observations of Sigma Phase Growth and Dissolution in 2205 Duplex Stainless Steel written by T. Palmer and published by . This book was released on 2005 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation and growth of sigma ({sigma}) phase in a 2205 duplex stainless steel is monitored during an 850 C isothermal heat treatment using an in situ synchrotron x-ray diffraction technique. At this temperature, {sigma} phase is first observed within approximately 40 seconds of the start of the isothermal heat treatment and grows rapidly over the course of the 3600 second heat treatment to a volume fraction of approximately 13%. A simultaneous increase in the austenite ({gamma}) volume fraction and a decrease in the ferrite ({delta}) volume fraction are observed. The {sigma} phase formed at this temperature is rapidly dissolved within approximately 200 seconds when the temperature is increased to 1000 C. Accompanying this rapid dissolution of the {sigma} phase, the {delta} and {gamma} volume fractions both approach the balanced (50/50) level observed in the as-received material.
Download or read book In Situ Observations of Sigma Phase Dissolution in 2205 Duplex Stainless Steel Using Synchrotron X Ray Diffraction written by and published by . This book was released on 2006 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synchrotron radiation was used to directly observe the transformation of ferrite, austenite and sigma phases during heating and cooling of 2205 duplex stainless steel. Sigma formed during the initial stages of heating, dissolved as the temperature was increased, and reformed on cooling. The dissolution temperature of sigma was measured to be 985 C ± 2.8 C at a heating rate of 0.25 C/s, and the kinetics of sigma formation at 850 C was determined to be slower after dissolving at 1000 C than before.
Download or read book Phase Transformations in Steels written by Elena Pereloma and published by Elsevier. This book was released on 2012-05-11 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: The processing-microstructure-property relationships in steels continue to present challenges to researchers because of the complexity of phase transformation reactions and the wide spectrum of microstructures and properties achievable. This major two-volume work summarises the current state of research on phase transformations in steels and its implications for the emergence of new steels with enhanced engineering properties.Volume 2 reviews current research on diffusionless transformations and phase transformations in high strength steels, as well as advances in modelling and analytical techniques which underpin this research. Chapters in part one discuss the crystallography and kinetics of martensite transformations, the morphology, substructure and tempering of martensite as well as shape memory in ferrous alloys. Part two summarises research on phase transformations in high strength low alloy (HSLA) steels, transformation induced plasticity (TRIP)-assisted multiphase steels, quenched and partitioned steels, advanced nanostructured bainitic steels, high manganese twinning induced plasticity (TWIP) and maraging steels. The final two parts of the book review advances in modelling and the use of advanced analytical techniques to improve our understanding of phase transformations in steels.With its distinguished editors and distinguished international team of contributors, the two volumes of Phase transformations in steels is a standard reference for all those researching the properties of steel and developing new steels in such areas as automotive engineering, oil and gas and energy production. - Alongside its companion volume, this major two-volume work summarises the current state of research on phase transformations in steels - Reviews research on diffusionless transformations and phase transformations in high strength steels - Examines advances in modelling and the use of advanced analytical techniques to improve understanding of phase transformations in steels
Download or read book Proceedings of the 9th International Symposium on Superalloy 718 Derivatives Energy Aerospace and Industrial Applications written by Eric Ott and published by Springer. This book was released on 2018-05-12 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt: This technical meeting will focus on Alloy 718 and Superalloys in this class relative to alloy and process development, production, product applications, trends and the development of advanced modeling tools. The symposium provides an opportunity for authors to present technical advancements relative to a broad spectrum of areas while assessing their impact on related fields associated with this critical alloy group. There are continuing innovations relative to these alloys as well as novel processing techniques which continue to extend applications in very challenging environments ranging from corrosion resistance in the deep sea to high-stressed space applications.
Download or read book In situ Studies with Photons Neutrons and Electrons Scattering II written by Thomas Kannengiesser and published by Springer. This book was released on 2014-06-14 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an insight into current research topics, focusing special attention exactly on welding issues. The presented research work demonstrates that application of synchrotron and neutron radiation in combination with other techniques enables the basic understanding of material-related processes to be extended appreciably. It also shows ways of how to improve new materials and their use in industry. Following on from the 1st workshop in 2009 at BAM Berlin, a 2nd workshop dealing with this subject matter was held in 28-30 November, 2012 in Osaka/Japan with international participation of scientists from sixteen countries. The book includes selected contributions from the various subject blocks, precisely covering issues of practical and immediately implementable benefit to industrial enterprises. Therefore, peer-reviewed papers dealing with the following topics are contained as well: - Phase transformation during welding, metallurgy and material development - Evolution and significance of residual stresses - Investigations into laser and electron beam welding
Download or read book Alloys and Intermetallic Compounds written by Cristina Artini and published by CRC Press. This book was released on 2017-07-12 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the role of modeling in the design of alloys and intermetallic compounds. It includes an introduction to the most important and most used modeling techniques, such as CALPHAD and ab-initio methods, as well as a section devoted to the latest developments in applications of alloys. The book emphasizes the correlation between modeling and technological developments while discussing topics such as wettability of Ultra High Temperature Ceramics by metals, active brazing of diamonds to metals in cutting tools, surface issues in medicine, novel Fe-based superconductors, metallic glasses, high entropy alloys, and thermoelectric materials.
Download or read book Materials Design and Applications II written by Lucas F. M. da Silva and published by Springer. This book was released on 2018-12-31 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights fundamental research on the design and application of engineering materials, and predominantly mechanical engineering applications. This area includes a wide range of technologies and materials, including metals, polymers, composites, and ceramics. Advanced applications include manufacturing cutting-edge materials, testing methods, and multi-scale experimental and computational aspects. The book introduces readers to a wealth of engineering applications in transport, civil, packaging and power generation.
Download or read book Reflections on the Present State of British India written by and published by . This book was released on 1829 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of the Pitting Corrosion Under Insulation of Duplex Stainless Steels written by Khalil Masoud Alahmadi and published by . This book was released on 2008 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transactions of JWRI written by 大阪大学. 溶接工学研究所 and published by . This book was released on 2007 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In situ Synchrotron X ray Diffraction Observations of Phase Transformation and Micromechanics in SAE 52100 Steel written by Daniel Foster and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase Transformations in Cast Duplex Stainless Steels written by Yoon-Jun Kim and published by . This book was released on 2004 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as sigma and chi can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-MO-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase ([sigma] + [chi]) formation were analyzed using the Johnson-Mehl-Avrami (JMA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities, a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, [sigma] was stabilized with increasing CR addition and [chi] by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by local composition fluctuations in the cast alloy. This may cause discrepancy between thermodynamic prediction and experimental observation.
Download or read book Phase Transformations in Cast Duplex Stainless Steels written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as [sigma] and [chi] can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase ([sigma] + [chi]) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, [sigma] was stabilized with increasing Cr addition and [chi] by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by local composition fluctuations in the cast alloy. This may cause discrepancy between thermodynamic prediction and experimental observation.
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 Metallurgical Modelling of Welding written by Øystein Grong and published by CRC Press. This book was released on 1997 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallurgical Modelling of Welding gives graduate students, engineers and researchers an in-depth insight into the field of welding metallurgy, providing a broad overview of its fundamental principles. In recent years, significant progress has been made in the understanding of the chemical and physical processes which take place during weldning. This book brings together all the basic components to reach the goal of faster process development, optimisation of processes and properties, and the possibility of developing new and weldable alloys.The second edition includes a new chapter of exercis.
Download or read book Kinetics of Sigma Formation and Dissolution in Duplex Stainless Steel written by Elisabeth M. L. E. M. Jackson and published by . This book was released on 1997 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
