Plenary session
The analysis of thermal processes of formation of castings from wearproof chromic cast irons for replaceable details of centrifugal mills and crushers is carried out. Influence of protective and dividing coverings on intensity of heating of the chill mold is investigated.
It is shown that the introduction of high-temperature heating installation charge fusion provides increased security, stability of operation arc, reduced noise to 75–85 dB, the elimination of fugitive emissions in the work zone
Based on the simulation results distributions of the statistical characteristics of the molten metal for Widening and Narrowing gating systems with high static pressure was calculated. A comparative analysis of Widening and Narrowing gating systems with high static pressure was held. Found that only at the time of 12 sec, number of cells with high speeds for Narrowing gating system is excessed.
Research has been conducted to determine the feasibility and availability of pistons manufacturing for forced diesel engine from special piston-alloy with Tix-structure by Tix-formation methods.
The economic and technical problems on creation of metallurgical mini-plants for production of high-quality bar of construction purpose with productivity of 100–200 thousand tons per year are considered in the article. Prospective features of such production are indicated. Examples of the projects developed in VNIIMEIMASH and also implemented objects on the example of «LPK-200» situated in Yartsevo city are given.
The article describes the use of a number of promising casting technologies applied to produce the castings of steel and cast iron with special properties. Such as, technology of centrifugal casting of large-size workpieces made of steel, forecasting method composition of slag in the smelting of high-manganese steels, method of complex modifying chromium cast irons, analysis of properties of perspective high-alloy aluminium cast iron.
Some features of the use of mixtures of metal phosphate binder and management principles of their properties for production of castings of ferrous and non-ferrous metals and alloys were shown.
Experimental melting of the grade 20A steel during which desulfurization degree from 88 to 94% is reached, is carried out at ESPTs-2 of JSC «BMZ». The content of sulfur in teeming assay [S]82 = 0,0015% and correlation [Ca]/[S] =1,46 are reached at melting with application of «pure burden» and double induction of refining ladle slag.
Foundry
The investigation of the modifying effects of surface-active metals carbonates on the structure and mechanical properties of eutectic silumin was held. The research results were checked by thermodynamic calculations.
Compositions of master-alloys on the basis of systems Al-Zr, Al-Cu-Zr, Al-Cu-Ni-Zr for modification of aluminium based alloys have been developed. The samples of these materials in microcrystal state in the form of powders and extruded rods have been obtained and investigated. The possibility of obtaining in their structure of metastable intermetallid Al3Zr, which is an active modifier of aluminium alloys have been shown. On the example of the modification of high-strength aluminium alloy B95 the effectiveness of the use of the developed master alloys have been demonstrated.
The features of coal chemical recovery cassiterite concentrate in molten salt system Na2Co3–NaNO3 (1:0,3) were studied. It is shown that cassiterite (SnO2) in the salt melt (900–950 °C) proceeds in the form metastannate (Na2SnO3) and reduced to the metal, mainly gas CO, with high speed and completeness (97%).
The aim of this work analysis of the influence of chromium on the process of carbide formation, changes in chemical composition of the metal substrate in the areas adjacent to the carbides and at the hardness of iron while economy nickel and manganesealloying.
The aim of this work analysis of the influence of chromium on the process of carbide formation, changes in chemical composition of the metal substrate in the areas adjacent to the carbides and at the hardness of iron while economy nickel and manganesealloying.
An experimental and calculated thermal analysis of the bronze billets continuous casting plant is developed. Allowable thermal conditions for rolling-out are calculated.
The article describes the features of the technology of casting using consumable models derived from photopolymer composition IPLIT-3. Shows feature of applied tiered gating system intended for the removal of the products of thermal destruction model material.
The results of the analysis of the influence of changes in the structure of the metal substrate and form of graphite inclusions in cast iron on the magnetic coercive sensitive parameter and the speed of sound are given. The efficiency of shared use of the results of magnetic and ultrasonic measurements to control the shape of inclusions in ductile iron and pearlite content in its metal matrix is shown.
The results of complex evaluation of working conditions in workshops of special casting, and based on research of industrial environmental factors jobs are given. The hygienic overview of working conditions classification in working stations of special castings shops is given.
The results of experimental studies of the AK7ч alumunium alloy solidification in the electromagnetic field produced by a pulse generator of the FID-technology are presented. The scheme of the experimental set, the photos of microstructures of the alloy, the results of physical and mechanical tests termometring of the alloy crystallization and X-ray analysis are adduced.
For the first time the theoretical mechanism of calculation of tension in crystallizing castings taking into account its cooling speed is presented. The mathematical model is developed and the chart of tension while crystallizing of the steel 30HNMFL is built.
The report reveals the most difficult questions of a quality management system of casting processes creation.
The article describes system for computer-aided design technologies gravity casting of mold castings on the basis of synthesis system, based as the basic method accepted a rolling calculation of solidification of castings.
The influence of the parameters of controlled rolling on the structural phase transitions in low-alloy and carbon steels was analyzed.
The way of cooling of castings from silumin AK15M3 is developed at the vertical centrifugal casting, enabling to receive bimetallic blanks with high-disperse eutectic and hypereutectic microstructures and minimal allowance for machining.
Influence of ways of the mold cooling on structure of castings with diameter of 135 mm from AK15M3 silumin at vertical centrifugal casting is investigated. It is established that for production of castings with diameter 135 mm from AK15M3 silumin with high mechanical and tribotechnical properties it is necessary to apply a shaped mould with water-spray cooling at expense of cooler of 0,42 m3/h.
Influence of the gravity coefficient value on structure and extent of allowance zone on machining of castings with diameter of 135 mm from AK18 alloy is investigated. It is established that optimum value of gravity coefficient makes 120–140.
The technologies and the small-sized machines of centrifugal casting developed by JSC «BELNIILIT» are given.
In the course of the work the basic details of foundry equipment were developed. On the basis of mathematical modeling of casting processes the filling and solidification «Suspension of PMD» were analyzed, the most portable places of pore formation were identified. Basic details of foundry equipment and process parameters were adjusted.
Efficiency of using particulate materials as deoxidazing mixtures for steel diffusive deoxidation in acid and basic furnaces is shown.
The technological features of the production of castings of aluminum alloys by chill casting are showed. The most important features of chill casting are considered.
Cellular automata simulation of the distribution of shrinkage defects in the casting of «The bearing housing» with a head during the metal flow to various parts of the casting was held. It is established that the casting is completely filled with metal, without forming runout, for the considered options for the metal flow. It is established that during the metal flow to the massive part, a bubbles up to 739 cm3 were formed, which is 69% less than in the same form without a head (2,355 cm3).
The application of differential interference contrast to visualize the surface of metals and alloys was considered. The examples of diffraction staining of sample surface areas, varying in height were given.
A process of heat transfer in continuous casting mould is considered. The substantiated equations predict shell growth, temperature distributions, solidification rates and can be used for continuous casters control systems.
It is shown that the use of complex modifier is not accompanied by gas evolution and the pyroelectric effect, which increases the sustainability of the process. When using modifier simplifies complex technology of the modified roller melt and reduced the duration of melting due to lower discharge temperature of the melt from the melting unit.
The opportunity of use ultrafine and nanosized particles obtained from production waste, for the manufacture of cast iron modifiers was shown.
Metallurgy
The manufacturing technology for wire rod with an optimized chemical composition was developed. It allows to produce reinforced steel class V550A in accordance with the requirements of ONORM B 4707:2010 taking into account changes its quality characteristics after mechanical changes and certify these products on the standard.
The research carried out in laboratory of metal science on detection of hydrogen presence in reinforcement depending on period of aging and reinforcement profile and also its influence on plastic properties of reinforcing bar is described in this article. The method of glycerine tests was applied for identification of hydrogen presence in finished reinforcing bar, the essence of which is in the fact that at gas emission from metal the bubbles stay too long on the surface of cross samples under glycerin layer. The revealed regularities enable to recommend actions for providing stable mechanical properties of the heat-strengthened reinforcement by creation of conditions for lowering of steel saturation with hydrogen, preventing thereby occurrence of hydrogen embrittlement of reinforcement on JSC «BMZ» – management company of holding «BMK».
With the development of a new process for the production of seamless hot-rolled pipes, specialists of the enterprise encountered difficulties in determining the causes of unsatisfactory quality of pipes, determining their nature and causes. In this regard, this article contains created and developed «Classification of defects of hot rolled seamless pipes made of OJSC «BSW – management company of «BMC» holding».
Vulcan TM is a small innovative company, specializing in the manufacture of steel and alloys casting systems and refractory accessories.
Available for foundry and metallurgical industries, special technological equipment, designed and manufactured by LLC NPP “Vulkan-TM.”Influence of the defects of brass covering on quality of the thin brass-covered wire produced in conditions of steel-wire shops of Belorussian metallurgical plant is shown.
Influence of the defects of brass covering on quality of the thin brass-covered wire produced in conditions of steel-wire shops of Belorussian metallurgical plant is shown.
VNIIMETMASh has been dealing for a long time with the problems of electromagnetic agitation at continuous pouring of profi ed and round billets. The principle of the maximum possible close approach of the EPM stator to liquid phase of ingot is put into basis of the concept of VNIIMETMASh. Being the design engineer of the MNLZ equipment including crystallizers, VNIIMETMASh has developed a typical number of the EMP devices built in the case of crystallizer without essential change of its construction.
The results of the smelting of converter steel grades 09G2C, C45, 10HSND, S355J2, A322 and others with various options for deoxidation of steel with full and / or partial replacement of secondary aluminum ferroaluminum were shown. Technological and economic efficiency of steel deoxidation with ferroaluminum were confirmed. Found that the replacement of secondary aluminum AB87 to Ferroaluminum FA30 to recovery of aluminum was secured to 17.0–19.9% compared to 11.8–13.1% for deoxidation of the steel by conventional techniques.
The mathematical model of Fe – C-melt decarbonization, with the assistance of the theory of critical concentrations was developed in this work. The model takes into account the kinetics of the process of removing carbon from the melt in the foreign – and intradiffusion limiting process of decarburization. The algorithm of the model is implemented in an automated process control system of converter smelting. Pilot plant testing of a mathematical model of decarburization process control BOF melt showed a significant improvement of technical and economic parameters of steelmaking.
A comparative assessment of energy intensity of converter steel production in different types of smelting with slag processing in the ladle was made. Analysis of the data shows that the use of liquid steel slag in steel production for its refining saves about 2.2 GJ or 75 kg of coal equivalent for each ton of metal.
ISSN 2414-0406 (Online)