Download or read book Kinetics of Isothermal Martensitic Transformation written by Naresh N. Thadhani and published by . This book was released on 1986 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement and Interpretation of Isothermal Martensitic Kinetics written by V. Raghavan and published by . This book was released on 1970 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: A brief survey of experimental work on isothermal martensitic transformations is given. Recent results on quantitative metallography are presented. Models for the isothermal kinetics and the method of evaluating the autocatalytic factor as well as the activation free energy for nucleation are discussed. The linear dependence of the activation energy on the chemical free-energy change is found to extrapolate satisfactorily to the low M sub s temperatures exhibited by Fe-Ni alloys. The values obtained by substituting the above empirically-determined parameters into the Kaufman-Cohen nucleation equation indicate that the embryos in Fe-Ni alloys are more potent than those in Fe-Ni-Mn alloys, whereas the interfacial energies are quite similar. (Author).

Download or read book On the Kinetics of the Isothermal Martensite Transformation Close to Absolute Zero written by B. Ya Lyubov and published by . This book was released on 1955 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Supporting Evidence for Double C Curve Kinetics in the Isothermal delta alpha Phase Transformation in a Pu Ga Alloy written by and published by . This book was released on 2006 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Isothermal Martensitic Transformations in Near Equi atomic Au Cd Alloys written by James Alan Mullendore and published by . This book was released on 1963 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stress Assisted Isothermal Martensitic Transformation and Transformation Plasticity written by G. B. Olson and published by . This book was released on 1979 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-temperature plastic flow in TRIP steels has been found to be controlled by stress-assisted isothermal martensitic transformation. Under these conditions, theory of the transformation kinetics can be used to predict the temperature dependence of the flow stress, the shape of the stress-strain curve, and the dependence of flow properties on stress state. (Author).

Download or read book Proceedings of the International Conference on Martensitic Transformations Chicago written by Aaron P. Stebner and published by Springer. This book was released on 2018-04-11 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection is organized around the central theme of “Martensite by Design.” Contributions include design, microstructure, properties, advanced processing and manufacturing, performance, phase transformations, and characterization.

Download or read book Martensitic Transformation written by Zenji Nishiyama and published by Elsevier. This book was released on 2012-12-02 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Martensitic Transformation examines martensitic transformation based on the known crystallographical data. Topics covered range from the crystallography of martensite to the transformation temperature and rate of martensite formation. The conditions for martensite formation and stabilization of austenite are also discussed, along with the crystallographic theory of martensitic transformations. Comprised of six chapters, this book begins with an introduction to martensite and martensitic transformation, with emphasis on the basic properties of martensite in steels such as carbon steels. The next two chapters deal with the crystallography of martensite and discuss the martensitic transformation behavior of the second-order transition; lattice imperfections in martensite; and close-packed layer structures of martensites produced from ? phase in noble-metal-base alloys. Thermodynamical problems and kinetics are also analysed, together with conditions for the nucleation of martensite and problems concerning stabilization of austenite. The last chapter discusses the theory of the mechanism underlying martensitic transformation. This monograph will be of interest to metallurgists and materials scientists.

Download or read book Phase Transformations in Materials written by G. Kostorz and published by Wiley-VCH. This book was released on 2001-10-25 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt: For all kinds of materials, phase transformations show common phenomena and mechanisms, and often turn a material, for example metals, multiphase alloys, ceramics or composites, into its technological useful form. The physics and thermodynamics of a transformation from the solid to liquid state or from one crystal form to another are therefore essential for creating high-performance materials. This handbook covers phase transformations, a general phenomenon central to understanding the behavior of materials and for creating high-performance materials. It will be an essential reference for all materials scientists, physicists and engineers involved in the research and development of new high performance materials. It is the revised and enhanced edition of the renowned book edited by the late P. Haasen in 1990 (Vol. 5, Materials Science and Technology).

Download or read book Isothermal Martensite Formation at Sub Zero Temperatures written by Allan Stojko and published by . This book was released on 2011 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sub-zero treatment of steels with an Mf below 0°C relies (partly) on a continuation of the martensite formation. The present work reports on the observation of isothermal martensite formation in the sub-zero temperature regime for two steels: AISI 1070 and AISI 52100. Samples were austenitized, quenched in oil, and thereafter investigated with vibrating sample magnetometry, which allows a quantitative assessment of the fraction of retained austenite as a function of the sub-zero temperature and time. Iso-thermal martensite formation was observed on interrupting the continuous cooling (5 K/min) at temperatures in the range of 80-233 K. The kinetics of isothermal martensite formation depends strongly on the temperature and can be described by Johnson-Mehl-Avrami-Kolmogorov kinetics. Isothermal experiments with dilatometry indicated the occurrence of a volume increase on isothermal holding, consistent with a continuation of the martensitic transformation. On prolonged isothermal holding, a volume reduction was observed for AISI 52100, but not for AISI 1070.

Download or read book Mechanisms of Transformation Toughening written by and published by . This book was released on 1992 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modelling the thermodynamics and kinetics of isothermal martensitic transformation under stress, transformation toughening in austenitic steels, and dispersed phase transformation plasticity in low alloy steels are discussed briefly in this progress report for Doe Grant DE-FG02-88ER45365.

Download or read book Martensitic Transformation in High Magnetic Fields written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The kinetics of the isothermal martensitic transformation in Fe--29.6 Ni and Fe--22.5 Ni--4 Mn alloys were investigated as a function of constant magnetic fields, ranging up to 140 KOe (11 x 106 ampere/m). The principal role of the applied magnetic field is to increase the free-energy difference between the product and parent phases in these iron-based alloys, and so the transformational driving force for a given composition can be varied even at a fixed temperature. In the Fe--Ni alloy, the isothermal transformation rate is increased by raising the magnetic field as well as by lowering the temperature, leading in either case to the entre of burst characteristics. The Fe--Ni--Mn alloy does not transform perceptibly without an applied field, but exhibits isothermal C-curve kinetics in fields above 60 KOe (4.8 x 106 ampere/m). The average volume per martensitic plate ad the average plate orientation are found to be insensitive to the strength and direction of the magnetic field, undoubtedly indicating the dominance of autocatalytic nucleation during the course of the isothermal transformation. However, there is some tendency for the morphology to become less lath-like and more plate-like with increasing field strength at a given transformation temperature, and likewise with increasing temperature at a given driving force. Evidently, the prevailing view that martensite becomes more plate-like with decreasing transformation temperature is a consequence of the attendant increase in driving force rather than a pure thermal effect. Nucleation rate measurements have also been carried out as a function of temperature and magnetic-field strength. In testing nucleation models against these results, it is necessary to take into account the effects of magnetic field, as well as of temperature, on the elastic constants.

Download or read book Theory of Transformations in Steels written by Harshad K. D. H. Bhadeshia and published by CRC Press. This book was released on 2021-03-25 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the leading authority in the field of solid-state phase transformations, Theory of Transformations in Steels is the first book to provide readers with a complete discussion of the theory of transformations in steel. Offers comprehensive treatment of solid-state transformations, covering the vast number in steels Serves as a single source for almost any aspect of the subject Features discussion of physical properties, thermodynamics, diffusion, and kinetics Covers ferrites, martensite, cementite, carbides, nitrides, substitutionally-alloyed precipitates, and pearlite Contains a thoroughly researched and comprehensive list of references as further and recommended reading With its broad and deep coverage of the subject, this work aims at inspiring research within the field of materials science and metallurgy.

Download or read book Phase Transformations written by Srikumar Banerjee and published by Elsevier. This book was released on 2010-05-31 with total page 837 pages. Available in PDF, EPUB and Kindle. Book excerpt: The terms phase transitions and phase transformations are often used in an interchangeable manner in the metallurgical literature. In Phase Transformations, transformations driven by pressure changes, radiation and deformation and those occurring in nanoscale multilayers are brought to the fore. Order-disorder transformations, many of which constitute very good examples of continuous transformations, are dealt with in a comprehensive manner. Almost all types of phase transformations and reactions that are commonly encountered in inorganic materials are covered and the underlying thermodynamic, kinetic and crystallographic aspects elucidated. Shows readers the advancements in the field - due to enhanced computing power and superior experimental capability Drawing upon the background and the research experience of the authors, bringing together a wealth of experience Written essentially from a physical metallurgists view point

Download or read book Science and Technology of Zirconia V written by M., Bannister and published by CRC Press. This book was released on 2023-05-09 with total page 881 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on the Fifth International Conference that was held on 16-21 August, 1992 in Melbourne, Australia, in conjunction with AUSTCERAM 92. It demonstrates that the field of Zirconia ceramics remains one of scientific challenge and technical attraction.

Download or read book Nucleation of the Isothermal Martensitic Transformation in Iron nickel manganese Alloys written by Satya Ranjan Pati and published by . This book was released on 1967 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: By means of quantitative metallography and electrical resistance measurements, the incubation period (time to form a detectable amount of martensite) and the initial nucleation rate have been determined as a function of subzero reaction temperature and austenitic grain size in three iron-nickel manganese alloys containing 23-25 percent nickel, 2-3 percent manganese and 0.02-0.04 percent carbon. The isothermal martensitic transformation in these alloys has been found to occur over a wide temperature range of at least -1960 to -200 C, and the martensitic structure over the entire range is body centered cubic. The incubation period and nucleation rate as a function of reaction temperature at various austenitic grain sizes show typical C-curve kinetics. The true initial nucleation rate (not the apparent initial nucleation rate during the incubation period) is independent of grain size, and so the effect of grain size on the incubation period arises merely because of the size of the first-formed plates. Accordingly, it may be concluded that grain boundaries do not predominate as preferred nucleation sites for the martensitic transformation in the alloys studied. Calculations of the relevant thermodynamic functions indicate that 1 atomic percent manganese is thermodynamically equivalent to 1.6 atomic percent nickel in the driving force for the martensitic transformation. However, alloys of equivalent thermodynamic driving force exhibit striking differences in kinetic behavior due to slight differences in their manganese and carbon contents, suggesting that these elements reduce the potency of the embryos. The observed activation energies of the isothermal martensitic transformation are in very good agreement with the calculated activation energies based on a nucleation model. Moreover, in these alloys, the potency of the active embryos remains almost constant during the course of the isothermal transformation, notwithstanding the progressive generation of new embryos due to autocatalytic factors. The best fit between theory and experiment is obtained on the assumption that the number of pre-existing embryos in the parent austenite is 107 per cm3 . The probability of detecting such embryos by transmission electron microscopy is less than 1 in 105. The increase in the rate of isothermal martensitic transformation as a function of time has been shown to be due to the formation of new plates by auto catalysis, while the subsequent retardation is attributable to the partitioning of the austenite by the martensitic plates. The model used provides quantitative agreement with the course of the isothermal transformation up to 12 percent martensite.

Download or read book A TEXTBOOK OF METALLURGICAL KINETICS written by AHINDRA GHOSH and published by PHI Learning Pvt. Ltd.. This book was released on 2014-01-01 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical kinetics constitutes one of the basic subjects for Metallurgical Engineering. This well-written book presents the subject of kinetics of metallurgical processes in a compressive fashion. Organized into 14 chapters, the book begins with an introduction of the broad basic concepts. It then discusses the kinetics of homogeneous and heterogeneous chemical reactions with some real-life examples from the metallurgical field. The book adequately covers the concepts of diffusion, convective mass transfer and mixing in fluids, as well as mass transfer in fluids adjacent to a solid surface. Several important processes in metallurgical and materials engineering involve reactions of porous solids with gases. The book discusses this with the help of two important reactions, namely, reduction of iron ores and gasification of carbon. It also deals with mass transfer among two fields and presents the kinetics of electrochemical reactions and phase transformation in a simple manner. The book also contains plenty of numerical worked-out examples and problems, some of which involve computer programs. The Appendix gives some important data useful for solving problems in kinetics. The book is designed for one-semester course for undergraduate students of metallurgical discipline.