Foundry
The article presents the results of a study of the movement of dispersed materials in tilting rotary furnaces. The proposed scheme describes a complex helical reciprocating movement of materials in rotary tilting furnaces that are designed for recycling of dispersible metal-containing wastes.
It is shown that melting and molding of hypoeutectic silumin are difficult physical and chemical nanostructural processes. In them the major role is played by the centers of crystallization of primary dendrites of aluminum, aluminum nanocrystals, the dissolved and adsorbed hydrogen. The role of the modifying crystals of an intermetallid of TiAl3 is reduced to absorption of the dissolved hydrogen and an intensification of process of a koalestsention of nanocrystals of aluminum in the centers of crystallization of primary dendrites of aluminum.
The influence of a thixotropic heat treatment on the structure formation of the eutectic aluminum-silicon alloy subject to the temperature and time of exposure near the eutectic equilibriumis giver in the article. The theoretical study of the process based on the data obtained and the thermal analysis of microstructures is made and described.
Information on researches and design development in the field of air-sand blowing process and creation of core-blowing installations which were carried out in 1950–1960 is provided in the article. The reference is made to the scientific centers and concrete design engineers who performed the specified activities.
The essence of air-sand blowing process and the principles of its realization in core-making machines by design development and manufacture executed by the experts of NIILITAVTOPROMA (JSC BELNIILIT) is briefly stated.
The main ratios of the areas between elements of system the sand-blowing installation systems, the basic rules and recommendations for design and manufacture of core-making machines and equipment for them are made. The retrospective of development and improvement of design solutions of air-sand blowing process is laid out. The essence and the modern design solution of caseless option of air-sand blowing process is stated. Illustrations of standard core-making machines for production of cores in the heated equipment and with amines blow are given. Systems the air-blowing devices, hold-down unit for blast and discharge and a special design of caseless option of sand-blowing process are described.
The principle of rational combination of air-blowing process and process of a purging in modern blowing technologies is designated. The current trend of transition to computer design of system the air-blowing devices and its elements is shown (reference sections for boost, ventilation, etc.).
Methods of increasing the shock resistance of cast-iron grinding bodies are researched. The models of heat transfer in the process of casting and shock-abrasive wear are presented. Tooling to produce experimental samples of milling bodies chilling(gravity die casting) is manufactured, samples of cylpebs are produced.
The review describes the design of metal castings produced by use of 3D-technologies. Some new ways of 3D-processing of materials connected with additive processes are described, which represents the next step in environmental resource-saving production. Examples of patterns and casting of complex design with an optimal combination of materials, durability and attractive appearance are shown. Described 3D high-tech processes are expanding the existing range of metal products and the ways of its production.
The interconditionality of characteristics of major structure-sensitive properties of the liquid metals and the some parameters of electronic and atomic structure such as the first coordination number, electron charge and Boltzmann constant are displayed.
The task of replacing the LVM dissolves polystyrene molding on models is at the present time, technologically, economically and environmentally promising from the point of view of industrial applications for gas turbine plants in Ukraine. The authors proposed and tested manufacturing process of casting ceramic molds way to remove the polystyrene model of the dissolution of her organic solvents. Kinetic parameters of the process of dissolving and removing patterns of degradation products the polystyrene in the group of solvents depending on the type and amount of polystyrene were identified. The absence of surface defects of castings, reduction of roughness, increased their accuracy class in comparison to accepted technological regulations of the process of production, which reduced the cost of machined parts and increased utilization of expensive heat-resistant alloys were produced.
The possibility of increasing the hardness (strength) nonburning-on coatings based on distensilimonita and lingosulfanata as binding by the addition of sodium aluminate and polyethylene glycol (PEG-200) was usearched. It was found that addition of these substances enhances strength for the first one temperature ranges 130–1200 ºC, and for the second one – only after drying.
It is shown that for distensilimonita zircon (ZrSiO4) these substances provide high strength and as separate binders. But for paints based on Al2O3 their use is not efficient.
Comparative researches showed that sodium aluminate can be successfully used as a modifying addition into the foundry paints on the basis disthen-sillimanite and lignosulfonate, as well as the binder for the chill mould paints based on graphite.
Metallurgy
Criteria of efficiency the slitting process. For example double-line rolling of rebar No. 20 identified such criteria separation efficiency in non-dividing device as the size of the crossbar.
Investigations have shown a positive impact of increasing the mass of the liquid residue (swamps) in an electric arc furnace EAF-160, from 10 to 20–30 tonnes on increasing of usable output and reducing the specific energy consumption per ton of liquid metal.
Possibility of solid-phase restoration of ferriferous scale by various reducing agents is studied in the article. Tests on solidphase restoration of scale by a firm reducers in the developed laboratory rotary installation are carried out. As a result of tests the iron-rich product with the general content of iron of 87% is received, degree of metallization 96,2%.
The analysis of modern status and tendencies of development of ferrous metallurgy in the countries of the EAEU is described in the article. On the basis of the conducted analysis are revealed the identified systemic problems of metallurgy and the conclusions on possible ways of their solution using the potential of integration are given.
A number of actions were carried out during the operation the steel-pouring ladles with working lining of periclasecarbonaceous products, directed on increase of lifetime of industrially used products and on selection of alternative suppliers of these refractory materials.
Science of materials
The features of the process of longitudinal rolling bands of variable thickness with increasing compression are considered. The graphs of changes of instant advance when rolling with increasing compression are given. Compression modes bands of variable thickness that achieve the desired dimensional accuracy are defined. Schemes of experimental device for rolling bands of variable thickness along the length are presents.
Imitation modeling of direct hot extrusion of bushes made from high-strength cast iron is performed using finite-element method. The evolution of stress and strain fields during processing and the probability of crack formation are evaluated. The specific feature of the work is that during hot forming a special technique was used which permitted obtaining a gradient distribution of graphite inclusions over the cross-section of bushes. The results of modeling are used in certain technologies which are implemented in industrial practice.
The paper describes the effect of ultrasound activation of dolomite, which is used for producing refractory material by the SHS method, on the final product. X-ray investigation has demonstrated that ultrasound activation of the initial charge brings about changes in the phase composition of the synthesized product.
The results of development of the compositions of protectors for the corrosion protection low-carbon alloys used in the automotive industry, using as the raw material of the secondary aluminum raw materials. The results of research on the effectiveness of the tread designed to protect the alloy composition.
The present study focuses on increasing resistance of highly-loaded instrument (in particular, punches) for stud driving head diameter of 8 mm and 10 mm countersunk hex through the optimization of heat hardening process using a forged-rolled steel billet DI23 in its production.
The peculiarity of the technology of obtaining high-strength cast iron is application in out-furnace treatment various inoculants containing magnesium. In practice of foundry production spheroidizing master alloys based on ferrosilicon (Fe-Si-Mg type) and «heavy» alloying alloys on copper and nickel base are widespread. The urgent issue is to improve their efficiency by increasing the degree of magnesium assimilation, reduction of specific consumption of additives, and minimizing dust and gas emissions during the process of spheroidizing treatment of liquid iron. One method of solving this problem is the use of inoculants in a compact form in which the process of dissolution proceeds more efficiently. For example, rapidly quenched granules or «chip»-inoculants are interesting to apply.
The aim of present work was to study the peculiarities of production and application of «Chips»-inoculants on copper and magnesium base with additions of yttrium oxide. The principle of mechatronics was used, including the briquetting inoculants’ components after their mixing with the subsequent high-speed mechanical impact and obtaining plates with a thickness of 1–2 mm.
Spheroidizing treatment of molten metal has been produced by ladle method using «Chips»-inoculants in the amount of 0.8%. Secondary graphitization inoculation was not performed. Studies have shown that when the spheroidizing treatment of ductile iron was performed with inoculants developed, the process of interaction of magnesium with the liquid melt runs steadily without significant pyroeffect and emissions of metal outside of the ladle.
This generates a structure of spheroidal graphite of regular shape (SGf5). The presence in the inoculant of yttrium oxide has a positive impact on the spheroidal graphite counts and the tendency of high-strength cast iron to form «white» cast iron structure. Mechanical properties of the obtained alloy correspond to high-strength cast iron HSCI60.
Young scientists
Methodology of the calculation of the vertical gating systems for DISA automatic lines with use of the standardized elements is given in the article. The example of calculation of the gating system for a concrete article and results of modeling of the developed gating system with use of packages of the applied programs ProCast, Poligon are presented. The example of a choice of the standard feeder on the cooling module is given.
As a result of the carried out work abundant type of steel was chosen for casting production of asterisk of the excavator «Kamatsu». This type of steel is widely used as the wearproof steel working in the conditions of abrasive and shock – abrasive wear. Mathematical modeling of process of filling and hardening of casting was done and it confirmed a choice of the technology to produce casting without faulty parts.
ISSN 2414-0406 (Online)