Download or read book Crystallization and Related Phenomena in Continuous Casting Mold Powders written by Sankararaman Sankaranarayanan and published by . This book was released on 1992 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 2nd International Symposium on High Temperature Metallurgical Processing written by Jiann-Yang Hwang and published by John Wiley & Sons. This book was released on 2011-04-12 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Temperature Metallurgical Processing contains the proceedings of the Second International Symposium on Thermal Processing of Minerals, Metals and Materials. This symposium explores physical and chemical transformations in materials that have been designed to facilitate the recovery of valuable metals or produce other useful materials. Representatives from both industry and academia focused on the latest innovative high temperature technologies. Because high temperature processes require high energy input, the presenters addressed the need for sustainable technologies that could provide low energy consumption and low pollution emissions. The symposium also examined the thermodynamics and kinetics of chemical reactions, phase transformations at elevated temperatures, and characterization of materials used or produced in high temperature processing.
Download or read book Mold Flux Crystallization and Mold Thermal Behavior written by Elizabeth Irene Peterson and published by . This book was released on 2017 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Mold flux plays a small but critical role in the continuous casting of steel. The carbon-coated powder is added at the top of the water-cooled copper mold, over time it melts and infiltrates the gap between the copper mold and the solidifying steel strand. Mold powders serve five primary functions: (1) chemical insulation, (2) thermal insulation, (3) lubrication between the steel strand and mold, (4) absorption of inclusions, and (5) promotion of even heat flux. All five functions are critical to slab casting, but surface defect prevention is primarily controlled through even heat flux. Glassy fluxes have high heat transfer and result in a thicker steel shell. Steels with large volumetric shrinkage on cooling must have a crystalline flux to reduce the radiative heat transfer and avoid the formation of cracks in the shell. Crystallinity plays a critical role in steel shell formation, therefore it is important to study the thermal conditions that promote each phase and its morphology. Laboratory tests were performed to generate continuous cooling transformation (CCT) and time-temperature-transformation (TTT) diagrams. Continuous cooling transformation tests were performed in an instrumented eight cell step chill mold. Results showed that cuspidine was the only phase formed in conventional fluxes and all observed structures were dendritic. An isothermal tin bath quench method was also developed to isothermally age glassy samples. Isothermal tests yielded different microstructures and different phases than those observed by continuous cooling. Comparison of aged tests with industrial flux films indicates similar faceted structures along the mold wall, suggesting that mold flux first solidifies as a glass along the mold wall, but the elevated temperature devitrifies the glassy structure forming crystals that cannot form by continuous cooling"--Abstract, page iv.
Download or read book Steelmaking Conference Proceedings written by and published by . This book was released on 1981 with total page 998 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1996 with total page 1622 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Alumina Pick up on Mould Flux Behaviour in Continuous Casting written by Gert Adrian Bezuidenhout and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this study was to determine the influence of alumina increase on the functioning of casting powder during continuous casting. Two aspects of the powder's performance were experimentally measured, namely the influence of alumina on the viscosity and the crystallisation behaviour. These two aspects were then related to the in-mould functioning of the casting powder with the aid of literature references. Casting slag must provide lubrication between the mould surface and the thin steel shell. Alumina increase will cause viscosity increase in casting slags and will hinder lubrication when the inflow of casting slag into the mould/strand gap deteriorates. Heat transfer across the gap is determined by the amount of solid casting slag and the form (glass or crystalline) thereof. Heat transfer across a crystalline material may be up to seven times lower than that across a glass phase. The increased alumina will serve to increase the ratio of glassy phase to crystalline phase in the gap, so increasing the heat transfer. To determine the true extent of alumina increase with modern clean steel practice, samples were taken from the moulds of both the VI and V2 continuous casters at ISCOR Vanderbijlpark. The influence of this alumina increase on the viscosity and the crystallisation behaviour of the casting slag were experimentally measured. Viscosity measurements were done with a rotating bob viscometer (in a vertical tube furnace) on two commercial casting powders (with increasing AI2O3 content). Viscosity prediction models were evaluated with the data from the measured viscosity values. Crystallisation measurements were done by quench experiments with the aid of the hot thermocouple technique. Crystallisation behaviour after a specified heat cycle was presented as the percentage opaque material (crystalline) to vitreous material (glassy) measured with an optical microscope. For the seven sequence casts during which samples were collected from the mould, it was found that the alumina content of the casting slag reached a steady-state value within the first ladle (first 40 minutes) with an increase of 3 to 4 mass %. The influence of a 4 mass % alumina increase on the measured viscosity is small enough that proper lubrication function of the slag will not be negatively affected. Viscosity prediction models vary in their accuracy and are limited with respect to the composition range of the casting powder and the temperature range for which they are valid. The increased alumina content was found to have a strong influence on the percentage crystalline material present. After the sample was heated to 1300ʻC, kept there for 10s, and then quenched, the crystalline material will decrease from 60 % to 30 % for 5 mass % alumina added. This decreased crystalline material present may notably increase heat transfer. Full crystallisation does not occur at a single temperature, and crystallisation occurs over a temperature interval (of up to 200ʻC). This means that crystallisation temperature values quoted by casting powder manufacturers depend on the heat cycle and the technique used during crystallisation measurements. Several crystalline phases are usually present in solidified casting slag and these crystalline phases are strongly influenced by the alumina content: the stable crystalline phases may change as alumina content increases. For the current alumina increase in casting powders the effect on viscosity is small, while crystallisation behaviour may be influenced to a greater extent.
Download or read book Physical thermal Relationships of Synthetic Mold Powders for Continuous Casting of Steel written by Sankararaman Sankaranarayanan and published by . This book was released on 1988 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mold Powders for Continuous Casting and Bottom Pour Teeming written by and published by Iron & Steel Society. This book was released on 1987 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Molten Slags Fluxes and Salts written by Ramana Reddy and published by Springer. This book was released on 2017-01-10 with total page 1373 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection focuses on ferrous and non-ferrous metallurgy where ionic melts, slags, fluxes, or salts play important roles in industrial growth and economy worldwide. Technical topics included are: thermodynamic properties and phase diagrams and kinetics of slags, fluxes, and salts; physical properties of slags, fluxes, and salts; structural studies of slags; interfacial and process phenomena involving foaming, bubble formation, and drainage; slag recycling, refractory erosion/corrosion, and freeze linings; and recycling and utilization of metallurgical slags and models and their applications in process improvement and optimization. These topics are of interest to not only traditional ferrous and non-ferrous metal industrial processes but also new and upcoming technologies.
Download or read book Crystallisation Control for Fluorine free Metallurgical Slags written by Jeferson Leandro Klug and published by LAP Lambert Academic Publishing. This book was released on 2014-10-17 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The continuous casting process is applied to the majority of steel grades by most steel manufacturers. Good understanding and control of phenomena in the mould during production of steel are essential to the success of the process. The slags used in the mould are very important when considering casting results, e.g., the quality of the steel slabs and "sticking severity." The mould slags ultimately have an influence on the capacity of the caster, i.e., how fast it is possible to cast with a good quality and without breakouts caused by sticking. During continuous casting process, the presence of crystals in mould slags has a decisive effect on both the lubrication and the heat transfer rate between the mould and the steel strand. Once the mould powder is melted on the top of the liquid steel and the mould slag infiltrates between the mould and the strand surface, the liquid slag is exposed to different cooling paths that can promote or prevent crystallisation. In fact it is common to see glassy parts of the slag in areas of high cooling rates with crystalline fractions at lower cooling rates. In the present work crystallisation behaviour for fluorine-free slags is discussed.
Download or read book The Theory and Practice of Mold Fluxes Used in Continuous Casting written by and published by . This book was released on 1980 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Initial Solidification Phenomena in the Continuous Casting Slab Mould microform written by Eiichi Takeuchi and published by National Library of Canada. This book was released on 1984 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Carbonaceous Materials with Respect to Mold Powder Design for Continuous Casting of Steel written by Pooja Bhardwaj and published by . This book was released on 2007 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Melting behavior of mold powders during continuous casting plays an important role in the casting performance, production rate and steel quality. Carbon is an important constituent of the mold powders and in this study the effect of different carbonaceous materials on the melting characteristics of mold powders was evaluated. Different types of carbon were characterized quantitatively based on their internal structure. Reactivity experiments were conducted to establish a relationship between the structure of carbons, their reactivity and the melting rate of the mold powders. This study revealed that different types of carbon are comprised of different fractions of amorphous and crystalline structures, which in terms of reactivity have different activation energies. This in turn has an influence on the melting behaviour of the mold powder.
Download or read book Science and Technology of Casting Processes written by Malur Srinivasan and published by BoD – Books on Demand. This book was released on 2012-09-26 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with various science and technology factors that need careful consideration in producing a casting. It consists of 11 chapters contributed by experts in their respective fields. The topics include simulation of continuous casting process, control of solidification of continuous castings, influence of mold flux in continuous casting, segregation in strip casting of steel, developments in shell and solid investment mold processes, innovative pressure control during filling of sand molds, fracture toughness specifically of castings, permanent molding of cast iron, wear resistant castings and improvement of accuracy in estimating graphite nodularity in ductile iron castings.
Download or read book Development of a New Mould Powder for Continuous Casting written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mold Powders for Continuous Casting and Bottom Pour Teeming written by and published by . This book was released on 1987 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
