Boldyrev D.A. Modification of high-strength cast iron: technology improvement, mechanism, key parameters
The technologies widely used in world practice to produce high-strength cast iron are given, their ranking in terms of technical and economic efficiency is carried out with the recognition of the preferred method of "tundish cover". The influence of magnesium and other accompanying elements that enhance spheroidization is shown in terms of the effectiveness of the formation of stable crystallization centers of graphite as products of reactions with impurities. The mechanism of formation and growth of spherical graphite inclusions in magnesium-treated cast iron melt is described, including from the point of view of crystallography. Regression mathematical relationships of some technological parameters and the most complete list of key technological parameters and their determining factors are given.
Keywords:Magnesium, ferrosilicomagnesium, rare earth metals, calcium, extra-furnace treatment of cast iron melt, modification, graphite crystallization centers.

Panov A.G. On the theory and practice of modification of cast iron in modern conditions
The paper presents the results of work on optimization of manufacturing processes of hermetic castings of the "Cylinder head" type from ductile iron in unpretentious production conditions using the theory and practice of the author. The relevance of the work is due to the increasing demand for castings and high defectiveness of castings in modern conditions of low competence of personnel, chaos among modifiers and suppliers of modifiers, priority in decision-making on technological issues by supply services. The goal is achieved by optimizing the chemical composition, operations of preparation and modification of the melt, including processing the melt with refining and modifying material L-CAST® 10K13, optimization of the amount and technique of application of standard modifiers, as well as the use of a little-known heavy modifier on an iron-nickel basis, optimization of temperatures and mold pouring technique.
Keywords:Ductile iron, science, practice, modification, modern conditions.

Mikhailov И.А., Boldyrev D.A. Optimization of silicon in ferritic high-strength cast iron for production of rotary fist castings without annealing
An analysis of the structure of annealed castings of rotary cams revealed the predominance of granular Pt2 perlite over lamellar Pt1 and the high plasticity of ferritic high-strength cast iron. During impact bending tests at -40°C, the fracture of all samples is predominantly brittle, with numerous facets of chips. The chemical composition, the proportion of ferrite and the mechanical properties of ferritic high-strength cast iron with a furnace silicon content of 2,4…2,5% and 2,2…2,3% correspond to the regulatory documentation. The recommended range of silicon content is 2,2…2,3%, based on the maximum increase in silicon concentration in the bucket sample to 1% after spheroidizing modification of FSMg cast iron (3,2…3,3% in the casting). Cast rotary knuckles made of high-efficiency materials with a silicon content of about 3,3% correspond to the design documentation on bench durability and static strength.
Keywords:Ferritic high-strength cast iron, silicon microalloying, annealing, rotary knuckle.

Belyaev S.V., Kosovich A.A., Partyko E.G., Tanachev L.E., Dombrovskiy N.S. Grain refinement of 5XXX series aluminum alloys with salt compositions
The article presents the results of a study of the process of modifying (grain refinement) 5XXX series aluminum alloys using salt compositions based on fluorides: potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4). The methodology includes statistical analysis of the experimental results using Minitab Statistical Software, casting of samples according to the American Aluminum Association TP-1 method, and metallographic analysis of the macrostructure. The experimental part of the work included 72 sequential melts conducted on a K-240 high-frequency induction furnace using various compositions of modifying salt compositions. The study investigated the influence of the ratio of various components included in the salt composition and the impact of technological parameters of the process on the effectiveness of modification (grain refinement). The work experimentally determined the optimal modification parameters when using these compositions, which include the percentage composition and technological modes of melt processing. The ratio of components at which the maximum grain refinement effect is achieved was established.
Keywords:Aluminum, aluminum alloys, grain refinement, fluorides, statistical analysis, grain size, structure.

Grigorev E.V, Kapelyushin Y.E., Stepanov D.V., Halikulov A. Production of cast grinding balls from briquetted dust from electric arc steelmaking after Waelz process
The aim of the study was to investigate the possibility of producing cast iron grinding balls from briquetted electric arc furnace (EAF) dust after Waelz process. EAF dust is a multicomponent waste containing iron, zinc, manganese oxides and various harmful impurities, which makes it both environmentally problematic during storage and potentially valuable for recycling. The study involved briquetting the dust using a binder and a reducing agent, after which the briquettes were metallized with zinc evaporation. After metallization of the briquettes, induction smelting was used as a method for their subsequent processing. During a series of smelting operations the effect of the reducing agent composition and temperature conditions on the metal yield, chemical composition and casting properties of cast iron were studied. Smelting with and without the addition of a reducing agent was compared and an additional smelting operation was carried out to average the chemical composition.
Keywords:EAF dust, induction furnace smelting, cast iron, grinding balls, mould, hardness.

Malinov L.S., Malinov V.L. Atypical isothermal hardening is an alternative to the applied heat treatment technologies for a number of foundry steels
The expediency of eco-friendly isothermal hardening of the studied casting steels has been shown to obtain their mechanical properties, which cannot be achieved by the applied normalization with high tempering and improvement. This is due to the obtaining of a multiphase micro-heterogeneous structure with metastable austenite, undergoing dynamic deformation martensitic transformation-DDMT (self- hardening effect under loading-SHL) when loaded. Unlike the standard technology, the process involves austenitization in the intercritical temperature range (ITR), followed by cooling and aging at a constant temperature without the use of non-environmentally friendly substances using the water-furnace-air scheme. Reducing the austenitization temperature and eliminating high-temperature tempering ensures energy savings.
Keywords:Casting steels, isothermal hardening, mechanical properties, multiphase structure with metastable austenite.

Kropachev D.Yu., Kozlov A.G., Lobov D.G., Shkaev A.G. Development and implementation of a method and means of measuring the temperature of a metal melt
The article describes a new approach to measuring the temperature of melts using an infrared measuring thermocouple (IMT). A review of methods and tools for measuring the temperature of melts is provided. The performance characteristics of the materials used in contact thermometry are presented. Calculations and experimental results are provided to justify the spectral characteristics of the materials used in the emissive cover of the blackbody model. The results of field tests of the proposed IMT for measuring the temperature of melts in induction furnaces are presented.
Keywords:Black body, melt temperature, emissivity coefficient, quartz cover.

Gruzman V.M. Hot crack in shaped steel castings
In the event of a defective hot crack in a shaped steel casting, a search for a violation of the accepted technology is immediately carried out, starting with the metal. However, the main role in this event is played not by the metal, but by the form and not by a violation of the technology, but by fluctuations in the disturbing effects of the external environment. As a result of the phase transition, the melt in the volume of the mold cavity is sufficient only for the first solidified parts of the casting. In the mold for shaped casting, frequent small protrusions retain heat for a long time and form small porosity in the body of the casting: potential stress concentrators. With undesirable temperature field of the incipient casting and effects of the external environment after removal from the mold, the hot crack is realized to visual dimensions
Keywords:Steel casting, casting defect, metal bath, foundry mould, surface inkorrect shape, thermal centre, freezing, hot crack, out break.

Trapeznikov N.V., Rozhkov M.Yu., Shumkov A.A., Salimov V.A. Verification of the results of numerical modeling of casting production for responsible appointment in PoligonSoft
The article discusses the results of verification of numerical modeling of the processes of manufacturing a cast piece of a critical purpose "press" made of alloy 513L, performed in the SPM LP "PoligonSoft". To verify the results of numerical modeling of the formation of defects of shrinkage nature in the casting made by the LVM technology in the support filler, the modeling of the processes of manufacturing the casting "press" is performed. The results of numerical modeling of the processes of pouring, solidification and formation of shrinkage defects with convergence with the experimental data obtained as a result of control of macro-grinding are obtained. The ability of PoligonSoft to simulate the formation of microporosity in critical castings has been confirmed.
Keywords:Investment casting, micro porosity, defects, PolygonSoft, numerical simulation, solidification.

Boldyrev D.A. Modification of high-strength cast iron: technology improvement, mechanism, key parameters

Panov A.G. On the theory and practice of modification of cast iron in modern conditions

Mikhailov И.А., Boldyrev D.A. Optimization of silicon in ferritic high-strength cast iron for production of rotary fist castings without annealing

Belyaev S.V., Kosovich A.A., Partyko E.G., Tanachev L.E., Dombrovskiy N.S. Grain refinement of 5XXX series aluminum alloys with salt compositions

Grigorev E.V, Kapelyushin Y.E., Stepanov D.V., Halikulov A. Production of cast grinding balls from briquetted dust from electric arc steelmaking after Waelz process

Malinov L.S., Malinov V.L. Atypical isothermal hardening is an alternative to the applied heat treatment technologies for a number of foundry steels

Kropachev D.Yu., Kozlov A.G., Lobov D.G., Shkaev A.G. Development and implementation of a method and means of measuring the temperature of a metal melt

Gruzman V.M. Hot crack in shaped steel castings

Trapeznikov N.V., Rozhkov M.Yu., Shumkov A.A., Salimov V.A. Verification of the results of numerical modeling of casting production for responsible appointment in PoligonSoft