Davydov S.V. Diagram of the state of alloys of the Fe-100%C system
It is shown that the entire structural organization of the phases (alloys) in the "Fe-100%C" diagram from the concentration of 6.67%C (cementite Ɵ-Fe3C) to 9.7%C (carbide ε-Fe2C) is a single isomorphic quasi-carbide solid solution, which includes introduction phases of stoichiometric compositions of cementite Ɵ-Fe3C, Hegg carbide χ-Fe5C2, Ekstrom-Adcock carbide æ-Fe7C3 and ε-carbide Fe2C. A variant of the "Fe-100%C" diagram with the phase transformations of cementite Ɵ-Fe3C, ε-carbide Fe2C, Hegg carbide χ-Fe5C2 and Ekstrom-Adcock carbide æ-Fe7C3 by the nonvariant three-phase peritectic equilibrium reaction is proposed. The low-temperature peritectoidal carbide transformation, in which solid solutions of ferrite and cementite form a solid solution of a wide area of homogeneity based on bertollide ε-carbide Fe2C, is introduced. The phase equilibrium lines in the region of "liquid-vapor" phases are constructed. The presence of a triple point of phase equilibrium "vapor (Fe)+liquid (Fe+C)+solid phase (graphite)" in the system "Fe-100%C" is established.
Keywords:The diagram «Fe-100% C», nonvariant peritectic equilibrium, cementite, carbide, isomorphic quasi-carbide solid solution, of phase equilibrium.
Sidorov E.V. The full equilibrium phase diagram of the iron-carbon system based on the theoretical and experimental investigations
A further detailed Fe-C state diagram based on the theoretical and experimental studies of the author is proposed. It is noted that the formation of all phase components in the Fe-C alloys is predetermined by non-equilibrium processes of crystallization and cooling in the solid state.
Keywords:Phase diagram, microstructure, equilibrium, temperature.
Boldyrev D.A., Prasolov S.G., Popova L.I. High-strength hybrid iron with nodular and vermicular graphite as an alternative to ductile iron
The characteristic positive features of ductile iron with floccular graphite, which previously ensured its widespread industrial use, can be reproduced without its inherent disadvantages in high-strength cast iron with spherical and vermicular graphite at a ratio of spherical/vermicular graphite in it (40…80/20…60). The prospects of using such hybrid cast iron as a rational technical and economic alternative to ductile iron with floccular graphite are shown, and potentially achievable by varying the ratio of spherical/vermicular graphite grades are proposed.
Keywords:Ductile iron with flake graphite, hybrid high-strength cast iron with spherical and vermicular graphite; ratio of spherical/vermicular graphite.
Panov A.G. About the choice of carburizing agent in the production of synthetic cast iron melts
The paper considers the problem of uncertainty in the quality of carburizing agents for cast iron melts, which is caused by a variety of both chemical composition and structure of materials of natural and artificial origin used as carburizing agents, is reflected in poor reproducibility of assimilation of carbon and ash impurities by the cast iron melt and as a result poor reproducibility of structure and consumer properties of cast iron products, especially made of synthetic cast irons.
Keywords:Cast iron melt, carburizing agent, microstructure, microcomposition.
Makarenko K.V., Sazonov V.O. Improving the efficiency of modification of low-sulfur gray cast iron
The results of the study of various modifiers on the structure of gray low-sulfur cast iron are presented. It is shown that the efficiency of modifying cast iron is determined by the content of active elements in the modifier. The theoretical foundations of the selection of active elements for modifiers of low-sulfur cast iron from the standpoint of the principle of structural and dimensional correspondence of Dankov-Konobeevski are presented.
Keywords:Cast iron, sulfur, graphite, modification, nucleation.
Murataev F.I., Vasilyeva I.V. Study of the structure of wheels cast from ChN15D7 iron
The nature of damages in cast wheels made of ChN15D7 iron for high-performance centrifugal submersible pumps was studied in the initial state and during operation. Chill hard spots were revealed in the structure of the castings near the cracks.
Keywords:Cast pump impellers, high-alloy cast iron, cracks, structure.
Tkachenko S.S., Sokolov A.V., Druzhevsky M.A., Mikhailov O.V. Investigation of the processing characteristics of liquid glass cold hardening mixtures with liquid hardeners and the development of easily shacked-out mixtures. Part 1
The results of a study of the properties of liquid-glass cold-hardening systems with UKhP-KhA "S" liquid hardeners are presented. An influence of quartz sands from several deposits on the quality of liquid-glass cold hardening mixtures intended for molds and cores is considered. Cold hardening mixtures based on liquid glass with 3K3O4016 quartz sand of the Novinsky deposit (Novinka village, Leningrad region) were considered.
Keywords:Cold hardening mixtures, liquid glass, liquid hardeners, liquid glass mixtures (liquid glass mixtures, sand-salt mixtures, CO2-process), molding sands.
Table of content
Davydov S.V. Diagram of the state of alloys of the Fe-100%C system
Sidorov E.V. The full equilibrium phase diagram of the iron-carbon system based on the theoretical and experimental investigations
Boldyrev D.A., Prasolov S.G., Popova L.I. High-strength hybrid iron with nodular and vermicular graphite as an alternative to ductile iron
Panov A.G. About the choice of carburizing agent in the production of synthetic cast iron melts
Makarenko K.V., Sazonov V.O. Improving the efficiency of modification of low-sulfur gray cast iron
Murataev F.I., Vasilyeva I.V. Study of the structure of wheels cast from ChN15D7 iron
Tkachenko S.S., Sokolov A.V., Druzhevsky M.A., Mikhailov O.V. Investigation of the processing characteristics of liquid glass cold hardening mixtures with liquid hardeners and the development of easily shacked-out mixtures. Part 1
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