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In the automotive industry there is an increasing demand for the wider application of high strength steels due to their favourable mechanical properties. The steel producers continuously developing new generations of high strength steels to insure higher strength and toughness properties. Since in most cases these steels are joined in welded structures, great attention must be taken to their weldability. The weldability of high strength steels has still challenges which are as follows: cold cracking sensitivity; reduction of strength and toughness of heat affected zone (HAZ); filler metal selection. Because the mechanical properties of ultrahigh strength steels are provided by using various alloying elements, micro alloys, and by different metallurgical methods, the steels may lose their outstanding properties during welding. In real welded joints the critical parts of the HAZ have small extent so their properties can be limitedly analysed by conventional material testing methods. With the help of physical simulators, the different parts of the heat affected zone can be produced in an adequate size for subsequent tests. In our research work the weldability, especially the HAZ properties of an ultrahigh strength structural steel (Rp0.2 = 1300 MPa) were investigated on thermal simulated samples with the help of Gleeble 3500 physical simulator. Three relevant technological variants for gas metal arc welding (GMAW), t8/5 = 5 s, 15 s and 30 s were applied during the HAZ simulations in the selected coarse-grained (CGHAZ), intercritical (ICHAZ) and intercritically reheated coarse-grained (ICCGHAZ) zones. Both the microstructure was studied by optical microscope and the mechanical properties were analysed by Vickers hardness tests and Charpy V-notch impact tests at -40 °C. According to the results the investigated ultrahigh strength steel was softened on account of the welding heat cycles, besides that the strength of the investigated ultrahigh strength steel can be better with the application of shorter t8/5 cooling time.

Special features of the high-damping state formation in bimetallic materials produced by explosion welding have been studied. High-damping Mn-Cu alloy was used for the damping base of the bimetallic composite and high–strength steel (grade: 30HGSA) was used to form the coating layer. The effect of planar tensile stresses (observed in the damping component of the bimetal and caused by valuable difference between coefficients of thermal expansion of components of the bimetal) is discussed. Damping properties of bimetallic materials were found to be comparable with damping characteristics of monolithic high damping alloys. High-strength steel provides high-strength characteristics of the surface layer of the bimetal, where the strength level reaches 1100MPa and the hardness is equal to 50 HRC. Obtained combination of high damping and high strength in developed bimetallic materials provides real chance for practical application of these materials in industry.

This paper deals with three types of triplex steel, where containing 25 to 28 wt.% manganese, 0.8 to 0.89 wt.% Carbon, 9.9 to 11.11 wt.% Aluminum, and with different Nickel content. Two types contain Ni in range of 0.9 to 2 wt.% and third type doesn’t contain Ni. The precipitation of Nano-size kappa carbides is the most proper technique used for this objective. It is expected that inter-metallic strengthening mechanism should act more effective in promoting the strength of Triplex steel with ductility. From this point of view, this research was designed to study the effect of inter-metallic inductive alloying element as Nickel on promoting of the strength and ductility of the high aluminum containing high manganese steel. Optical microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to detect of inter-metallic precipitates through steel investigated ranged in Nickel from 0 to 2 wt.%. Mechanical and strain hardening properties were determined in the steel investigated after different regimes of heat treatment. It was found that Ni3Al inter-metallic compound provides the austenite matrix with good strength and ductility, depending on the ageing time. Further deterioration was obviously observed in the steel investigated as increasing the ageing time, attributing to coarse structure occurrence.

At the production of the steel thick-walled large-diameter pipes according to UOE-technology at the tube electrical welding aggregation 1020 (TEWA 1020), the steel sheet is in series bent on the flanging press, the pre-forming press and the final-forming press. When the steel sheet is deformed on the final-forming press, the excessively curved sections of the sheet are partially unbent in the opposite direction. The calculation of sheet’s curvature at the alternating bending causes the significant difficulties because of Bauschinger’s effect at bending, in which the mechanical characteristics of the steel change significantly. In this paper, the analytical method for calculating the final curvature of steel pipe billet at the alternating bend at UOE-technology is proposed. The results of the paper can be applied in metallurgy.

The article examines a number of regularities in the production of primary cast ingots of AlSi7Mg, AlSi7MgSr, AlSi11Mg, and AlSi11MgSr. Peculiarities of melting and cast of these alloys, as well as the effect silicon and strontium have on the formation of the shrinkage cavities, have been explored. It has been demonstrated that strontium, when used as a modifier, changes not only the morphology of silicon, but also the nature of solidification and shrinkage of the alloy. Defects formed in the ingots manufactured from near – eutectic AlSi11MgSr alloy have been studied in greater detail.

The work is devoted to a study of the probable causes of a decrease in joint strength during explosion welding of metals with sharply differing physical and mechanical properties. The influence of kinematic and energy parameters on the structure and strength of the steel-aluminum composite under various conditions of explosive loading is shown.

This work presents studies on the material composition and physico-mechanical characteristics of an alumina-containing estimate formed during the production of aluminum on electrolyzers with self-baking anodes during technological operations. The material is a mixture of fine powder 2.5 mm in size (62.78% on average mass) with the presence of pieces of material ranging in size from 0.5 to 6 cm (average 20.26% by weight). The samples contain pieces of hardened aluminum with sizes from 5 to 20 mm (16.96%). The largest content in the sample has the fineness classes-0.315 + 0.16 mm in the volume of 29.85% and the largest class +2.5 mm-37.22%. B It was established that aluminum is concentrated in the fractions-0.315 + 0.16 mm (45.7%) and 0.16 + 0 mm (48.8%), silicon in the fraction-0.63 + 0.315 mm (1.91%), iron at-1.25 + 0.63 mm (0.601%) and-0.63 + 0.315 mm (0.62%). The material consists of cryolite (Na3AlF6), chiolite (Al3F14Na5), quartz, feldspar, carbonaceous matter and the technogenic phase of the composition (NaF) 1.5CaF2 AlF3. The material is characterized as non-abrasive (working index Ai - 0.0184) and very soft in relation to impact crushing (working index CWi - 3.64), the working index of ball grinding Bond (BWi - 6.47) characterizes a very low resistance to ball grinding. The implementation of the crushing operation of an alumina-containing estimate will allow the use of dry cascade-gravity and centrifugal classification to separate impurities in the form of SiO2, and Fe2O3 for the use of alumina-containing material in primary aluminum technology. On the basis of laboratory tests, it is established that alumina-containing raw materials can be separated and photometric and gravitational separation methods can be used. A mathematical model of the motion of particles of primary and prepared alumina-containing raw materials in a cascade-gravity classifier was developed. The criteria and factors characterizing the alumina-containing material, as well as influencing and determining the maximum material enrichment, are established.

The article is devoted to the study of destructibility of the annealed anode paste of different composition in the CO2 current. It is shown that the destructibility of CO2 current of petroleum coke is much less than that of pitch coke. The comparison of the qualitative characteristics of the anode paste on the basis of pitch coke and petroleum coke revealed the advantage of petroleum coke, due to its low sodium content. The average destructibility of the anode paste on the basis of different grades of cokes in the CO2 current is determined. The conducted semi-industrial tests were in good agreement with the laboratory studies.

During heat treatment of machine parts and tools, besides the usual task of ensuring a high complex of mechanical and operational properties, there is a problem of distortion of products in the process of heat treatment and the need for editing operations (which are carried out manually and require significant labor costs). The known methods do not solve the problem of removing distortion for thin-walled parts of the ring shape completely. This paper shows the technical possibility of using the energy of a constant magnetic field for the "internal" straightening of products during heat treatment in the temperature range of super-plasticity of transformation. The use of special equipment makes it possible to eliminate virtually the distortion of thin-walled parts of the ring shape and to improve their mechanical properties.

Aluminum is widely used in various industries in the form of alloys due to its unique properties - lightness, high electrical conductivity, and corrosion resistance. However, when casting alloys, various defects arise, the main of which are nonconformities of the ingot chemical composition, mechanical properties, and internal structure. The RUSAL Bratsk PJSC (, Irkutsk Region) aluminum alloy samples have been examined for pores, cracks, and oxide films. The causes of their occurrence have been analyzed and ways to eliminate these defects proposed. It has been found that, with increasing hydrogen content in the melt, micro-porosity leads to friability and macro-porosity of the alloy structure. According to the study results, the likelihood of cracks in the ingots could be reduced by evenly decreased metal temperature and casting velocity. The oxide film defects have been eliminated by feeding metal into the mold in a steady turbulence-free manner, increasing the metal settling time in a mixer, and reducing the alloy preparation time in a furnace.

The paper is devoted to the urgent issue of processing the dust waste of metallurgical-grade silicon production, i.e. wet cleaning sludge, which contains a significant amount of valuable silica. The paper analyzes the formation of finely dispersed techno-genic materials that are generated in significant quantities (up to 120 t/d) at the Kremniy JSC. The composition and properties of the silicon production wet cleaning product have been studied. In analytical studies of the wet cleaning sludge samples, the modern certified analysis techniques have been used: laser diffraction, X-ray diffraction, and X-ray fluorescence. According to the analysis, the L:S ratio of liquid sludge is 2.1:1; after dehydration, the sludge cake has a grain size of 150 μm, with the prevailing (90 %) grain size of 59.65 μm in the test sample. The chemical composition of the sludge is 95.86 % SiO2; therefore, the wet cleaning sludge is a valuable raw material to produce metallurgical-grade silicon. Based on the analysis of the composition and properties of the silicon production wet cleaning sludge sample, we have developed a program for its processing. Sustainable sludge processing techniques are aimed at obtaining a briquetted charge, which can be used as an additive to the main raw material.

The article is devoted to the study of technological modes of hot rolling of tube steel on a thick-sheet mill and mechanical properties of the finished products. Five slabs were rolled under the experimental regime in accordance with the study plan. The temperature conditions of rolling at the final stage of deformation and the modes of accelerated cooling of rolled products were changed. Dependencies between technological parameters and mechanical properties allowed developing recommendations on improvement of technology of rolling and of the subsequent accelerated cooling of metal.

The article presents the test results of complex microcrystalline modifiers containing calcium, barium, strontium, rare earth metals. Complex modifiers were used in the processing of steel for 17G1S-U pipes in order to reduce its contamination with non-metallic inclusions, including corrosive ones. The use of modifiers allowed to reduce metal contamination by non-metallic inclusions of all kinds. The most experimental non-metallic inclusions were obtained during metal processing with INSTEEL®5.1 and INSTEEL®9.4 modifiers. In addition, the use of experienced modifiers ensured the production of complex oxysulfides of calcium, cerium and lanthanum with low oxygen content and thermal expansion coefficients, which increases the corrosion resistance of steel.

For steels of different grades, the effect of the chemical composition, structure, and surface etching on the contact potential difference is studied using the Kelvin probe method. It was shown experimentally that, with a change in the structure and chemical composition, the contact potential difference changes. Etching the surface of the steel with a 4% solution of nitric acid leads to a sharp decrease in the magnitude of the contact potential difference, which allows us to conclude that the value of the electron work function from the sample surface increases. The ability to control the composition and structure of the material by the Kelvin probe method is shown.

The microstructure of the advanced low carbon steel with a superior hardenability was studied. The steel contained the following main alloying elements, wt. %: C – 0.20; Cr – 2.0; Mn – 2.0; Si – 1.04 Ni – 1.0; Mo – 0.3. The dilatometer investigation of the steel under consideration revealed the only phase transformation occurring during continuous cooling (0.1...30 °C/s), which started at the martensite start temperature Ms. It was shown that the isothermal treatment of the studied steel led to the bainite formation above and below Ms. The temperature of the bainite morphology shift was determined.

This research investigates the nickel content added by 1.1wt%, 2.2wt%, 3.7wt% and 4.5wt% on the microstructure and mechanical properties in the nodular cast iron. The results demonstrate that the microstructure of nickel addition consists of nodule graphite, ferrite and pearlite phase while nickel was added to 4.5 wt% the microstructure becomes ferrite transform to fully pearlite phase. In addition the ductile iron has the highest nodularity (0.79%), followed by 1.1%Ni (0.75%), 2.2%Ni (0.71%), 3.7%Ni (0.69%) and 4.5%Ni (0.58%). The hardness and tensile strength increase when increasing the nickel content. Elongation is enhanced with nickel increasing and reaches a maximum of 12% at 1.1 wt% Ni, then decreases with the further increase of nickel.

The study aims at reviewing manufacturing schedules for hot-rolled and intercritically-annealed and thermomechanically processed medium-Mn sheet steels. Major differences between these two types of processing are indicated. They include initial microstructure (low-C martensite for hot-rolled products and deformed austenite for thermomechanically processed products), partitioning of alloying elements (depending on intercritical annealing or batch annealing conditions) and microstructure prior to cooling (ultrafine-grained lath mixture of ferrite and austenite for hot-rolled, intercritically annealed products and deformed austenite for directly cooled products). The comparison of typical microstructures (LM, SEM) and phase transformation behavior are presented. A role of Mn as an austenite stabilizer in a range used for medium-Mn steels is explained. Some results are provided for economic steels containing 3% and 5% Mn.

Austenitic stainless steels are widely used in industry. Increased requirements for the quality of products from these steel grades, the difficulties associated with the implementation of technological processes, as well as the high cost of steel, determine the necessity to assess probable causes of defects. This article presents an analysis of the influence of main process parameters on the quality of products from the grade 08X18H10T steel. Based on the results of statistical analysis and thermodynamic modeling, it was concluded that the increased content of titanium and nitrogen affects the quality of products, which is caused by the formation of titanium carbonitrides in the process of steel solidification.

The purpose of this study was to analyse the failure of the super heater pipe of the Heat Recovery Steam Boiler Generator (HRSG), which had broken. Investigations are carried out in several stages. First of all, the microstructure of the pipe was observed using an Optic Olympus GX71 Microscope and a Scanning Electron Microscope (SEM) was used to observe the fracture surface to find the initial crack. Thereafter, chemical composition testing, to determine the type of material used in the super heater pipe. The presence of deformation by creep was due to overheating seen on the super heater pipes. Moreover, It was due to operating at elevated temperatures and pressures with long operating times. This condition caused the thickness of the pipe to thin so that it would break due to crack propagation which penetrated the wall of the pipe until breaking as the material was no longer able to withstand the steam pressure inside the pipe. Obviously that this condition indicates that the crack propagation occurred until final failure.

The paper is devoted to the practical implementation of the new torsion testing method for studying rheological properties of materials in a hot state. This method involves the testing of cylindrical samples in the grips of a test setup, the angular velocity of which changes exponentially. The testing mode allows you to restore the hardening curves of a material according to the test results. This article aims to formulate the requirements for possible ways to implement the proposed testing method, and presents two different ways to obtain the specified exponential testing mode. The experience of their use on the test setup in the Ural Federal University indicates the feasibility of the new testing method, as well as the possibility of a smooth transition to the specified testing mode.

Studies have shown that using nonferrous metallurgy waste in the ceramic mixture for the making of roof tiles improves the final product quality; one can use the clayey portion of the zircon-ilmenite ore gravity tailings as the clay, pyrite cinders as leaners and sintering intensifier, and wollastonite as an agent to reduce shrinkage and prevent deformation-related buckling. The common method of linear regression was used to study the dependency of the basic physico-mechanical properties of tiles on how much clay from the zircon-ilmenite ore gravity tailings, pyrite cinders, and wollastonite is used in manufacture. The resultant mathematical model takes into account the combined effects these components have on the physico-mechanical properties of tiles; it matches well the experimental data.

The melt thermo-temporal processing technology of using the results of analysis, which allowed to recommend it in the production of large-tonnage ingots and amorphous materials on iron, nickel and aluminum bases, was carried out. Thermo-temporal treatment of the melt leads to a favorable structure formation, decrease in its chemical and physical heterogeneity, reduction in size and number of shrinkage defects. These usually are accompanied by an increase in technological and service characteristics of alloys. The usable products suitable alloy increases, the metal consumption of products decreases.

Microstructure of ingot and industrial blanks made of copper M2 was examined for quality control. Microstructure was examined by means of traditional metallographic analysis methods. Exogenous nonmetal inclusions and pores in microstructure were found. The transition from exogenous inclusions and pores, which were not removed in initial processing stage, to the crack, which leads to billet destruction on one of last processing stages, is shown. Without quality control of copper blanks by a metallographic method, it is impossible to provide guarantee of reliable operation of machines and responsible purpose constructions. A comparative study of the temperature dependences of the viscosity of the melts of charge materials and finished ingots for copper M2 was carried out. The study of the viscosity of copper melts M2 was carried out with the aim of quality control in the chain of "charge-melt-ingot" at the foundry stage.

The carbon surface saturation process of the steel plates during the catalytic gas carburization was under consideration. The rate of the carburization was determined, as well as the hardness of the diffusion layer, after quenching. A mathematical model based on experimental and numerical modeling data had been obtained. The carbon concentration profile of the surface layer was estimated depending on the carburization process parameters. A simplified simulation technique of the steel carburization was proposed.

Silicon production by silica-containing raw material reduction by carbon in ore-smelting furnaces (OSF) is a complex pyro-metallurgic process. Silicon is produced in a system consisting of charge, furnace electrodes, air, melt, slag, and gases at temperatures above 2000°C, which generates silicon monoxide and carbide unavoidably. The finished product contains impurities (Fe, Ca, Al, Ti, etc.) in small amounts; however, it is still unknown for sure how impurities, contained in raw materials, behave and interact with each other and with silicon. To analyze the distribution of charge components during smelting, the research team used thermodynamic (mathematical) modeling in Selector software. The constructed four-tank silicon production model describes adequately the process. The assumed tank temperatures correspond to the OSF reaction zones (400°C, 1530°C, 2200°C, and 2000°C). Modeling involves 15 charge-carried elements: quartzite from the Cheremshanskoye deposit, charcoal and black coal, petroleum coke, wood chips, and OSF coal electrodes. According to the model, silicon recovery (with a 97.15 wt% silicon content in the melt) is 75%, which is consistent with literature and production data (AO Kremniy, Shelekhov, Irkutsk Oblast).

The influence of the mold filling rate on the content of oxide films in aluminum alloy castings is considered. The existing methods for estimating the probability of formation and entrainment of oxide films in the bulk of the liquid, which are associated with surface disturbances during the melt flow through the channels of the mold, are analyzed. A criterion for estimating oxide impurities in the melt using numerical process modeling is proposed. A comparative analysis of the results of numerical simulation with the data of practical experiments obtained by M. V. Sharov and N. M. Galdin was performed. This comparative analysis and experience in the development of technological processes for shaped castings showed the possibility of using the criterion in numerical modeling.

The properties of steel 42HMFA, which has been tempered in various environments at thermal improvement, are investigated. Advantages of application to training of water solutions of polymers are shown. Training in synthetic environments provides higher rates of mechanical properties of steel products. As a result of training in water solutions of polymer, the maximum level of hardenability on the section of product and fatigue strength of detail is reached.

A study of the high-strength HY-TUF steel applied for the manufacturing of heavy loaded parts was carried out. The mechanical properties of the austempered HY-TUF steel were compared to the characteristics obtained after the conventional oil quenching and tempering. The upper bainite with low impact strength was formed during the austempering at 400 °C and higher. Conventional oil quenching and tempering at temperature 400...500 °С also led to the embrittlement of the steel under consideration. The best combination of toughness and strength of the HY-TUF steel was achieved after the austempering at the temperature of lower bainite formation.

The structure of martensite obtained by quenching steel under the action of a constant magnetic field was studied. The kinetic changes of the martensitic transformation, caused by the action of a magnetic field, are expressed in the structure by an increase in the dispersity of the transformation products. Samples of steels C45, 100CrMn6 and 30HGSA were investigated. Dispersity was evaluated statistically in images obtained on light and electron microscopes. The specific surface area was measured and the parameters of the surface relief caused by martensitic transformation were studied. Experimental data show that after quenching in a magnetic field, a decrease in the volumetric strain of the transformation, an increase in the dispersity of packets of martensitic crystals and components of the packets are observed. It is concluded that an increase in dispersion and a fragmentation of the structure of martensite are mainly the result of multiplicative nucleation.

The study considers the formation of the structure, texture, and hardness of hot extruded tube of titanium alloy PT-1M. It is shown that hot extrusion at 840 °C, which is higher than the α-phase recrystallization temperature, results to the development of dynamic and primary recrystallization processes and ensures the formation of homogeneous and fine-grained structure through-out the cross section with a two-component tangential texture (0001)TDED+(0001)TDED (TD – tangential direction, ED – extrusion direction) and hardness of 155 HV. It has been established that a higher cooling rate of the surface areas of the tube after extrusion results to a less active development of recrystallization processes, which lead to the formation of a finer granular structure near the outer surface. This weakens recrystallization component of (0001)TDED, compared to other areas of the tube.

This paper presents the results of statistical tests, carried out to identify the mechanical properties of Ø 16-150 mm VT6 titanium alloy bars, as a function of their post-annealing chemical composition and structure. It is shown that the high variation of mechanical properties may be, due to fluctuations in the grade composition and structure type. 50% to 60% of variations in strength properties are due to composition + structure co-effects. To improve the stability of such properties, the paper identifies maximum permissible total fluctuations in the chemical composition in terms of aluminum/molybdenum equivalents of alloying elements and impurities. The research team has fitted the regression dependencies for evaluating the mean values of the mechanical properties of Ø 16-60 mm VT6 bars, as a function of the structure type and aluminum/molybdenum equivalents of the alloying elements and impurities.

The article is devoted to the study of the method of modeling the core shooting process of manufacturing core from cold hardening mixtures (CHM) in the software package Flow-3D, as well as consideration of recommendations on the parameters of the core shooting process, to ensure quality castings of cast iron and steel. This technology of production of cores belongs to technologies which are widely used in foundry production.

The paper considers the problem of recycling the dust waste resulting from metallurgical silicon production; such dust contains considerable amounts of valuable silica. The problem is solved by redirecting this byproduct to the silicon smelting process. We herein propose using the dust left in silicon and aluminum production as a component of pelletized charge, used for silicon smelting in ore-thermal furnaces (OTF). Mathematical (physico-chemical) modeling was applied to study the behavior of pelletized-charge components, in order to predict the chemical composition of smelting-produced silicon. We generated a model that simulated the four temperature zones of a furnace, as well as the crystalline-silicon phase (25°С). The model contained 17 elements entering the furnace, due to being contained in raw materials, electrodes, and the air. Modeling produced molten silicon, 91.73 wt% of which was the target product. Modeling showed that, when using the proposed combined charge, silicon extraction factor would amount to 69.25%, which agrees well with practical data. Results of modeling the chemical composition of crystalline silicon agreed well with the chemical analysis of actually produced silicon.

Modernization of physical and mechanical properties of casting alloys, through the introduction of new processes, which can be used to obtain a precise casting with a smooth surface, which does not require machining, with a constant increase in the productivity of the implemented processes, is changing the technological and economic profile of modern foundry. The most advanced equipment is the induction crucible, melting furnace, which belongs to the main production assets and has a direct impact on productivity and, consequently, on profitability. For this reason, it is the main factor determining the content of the development strategies of the enterprise as a whole. Since 2000, iron scrap has been gone, due to the active sale of it abroad, the cost of pig iron and foundry has increased dramatically, in addition, the cost of their delivery increased. This led to higher prices in the production of castings made of synthetic iron, due to the increase in the cost of batch materials. In addition, there were problems with the use of acidic lining, as the cheapest and having a high resistance, as a part of the metal began to use an increased amount of scrap steel and, for this reason, to raise the melting temperature above 1450 Celsius. For this reason, the efficiency of production must be paid great attention.

The research results on the effect of small additions of yttrium 0-0.3 wt.% on the structure, hardness, microhardness and distribution of elements in various structural components of chromium white cast iron are presented. It has been established that small additions of yttrium contribute to the grain refinement of the carbide phase and the formation of trigonal chromium carbide (Fe,Cr)7C3 in the structure of chromium white cast iron.

Fe-Cu alloys are used as structural materials for manufacture of large machine parts subjected to shock loads. Fe-Cu alloys have a higher corrosion resistance in a humid atmosphere and in salt solutions than cast steel. Fe-Cu alloys have high enough damping characteristics. Upon cooling the Fe-Cu melts is stratified into two phases before crystallization which in field of gravity are separated by density. It is possible to suppress delamination and obtain a material with structure of a “frozen emulsion” by heating melt to the temperature T* determined for each composition by a specific way. In this paper, we studied surface tension of liquid alloys of Fe-1wt.% Cu, Fe-20wt.% Cu, and Fe-30wt.%Cu in order to determine the temperature T*. For the melt of Fe-20wt.% Cu value T*=1670°C is highest. It is confirmed by results of measuring temperature dependence of surface tension. Temperature dependence of the surface tension Fe-Cu melts is characterized by a positive value of the temperature coefficient of surface tension dσ/dT which is abnormal for metal melts. Experimental data on the density, the surface tension of Fe-Cu liquid alloys have of independent metrological importance for practical foundry.

The results of experimental studies of the thin surface layer of samples made of steel 45 after treatment with surface plastic deformation (SPD) multiradius roller (MR-roller) are presented. On the basis of the apparatus of the mechanics of technological inheritance, taking into account the effect of the solidified body, a model of the process according to the scheme of multiple loading-unloading of metal, taking into account the phenomenology of the SPD process and the properties of the material, is created. Distributions of parameters of the stress-strain state in the deformation centre are obtained, the parameters of roughness and microhardness of the surface layer are investigated.

Results of the developed industrial technology of restoration of a surface corrosion-resistant staly are presented by method of laser building up. The comparative analysis of a microstructure of the built-up wearproof layer, an alloyage zone with material of a basis and diffusive zone at the different technological modes of building up is given. Influence of morphology of particles of additive powder on parametrical characteristics of the roller received by laser gas powder building up is investigated. The optimum modes of building up on a substrate from steel 12Cr18Ni10Ti are set. Tests for firmness against intercrystalline corrosion of the built-up powder compositions are executed by the AM method. Metalgraphic assessment of corrosion resistance is presented.

The mechanical properties and microstructure of low-carbon high-silicon alloy steel were examined under various tempering temperatures using the quenching, partitioning and tempering (Q–P–T) process. The performance changed with the variation in tempering temperature. The results show that the microstructure of low carbon high silicon alloy steel treated by Q-P-T process was mainly ferrite, martensite, carbide-free bainite and film-like retained austenite. This alloys exhibited good mechanical properties at tempering temperature of 300 °C. The product of strength and elongation were 33.7 GPa%. Specifically, the Ultimate tensile strength were 1508 MPa, the yield strength were 1048 MPa, and the elongation were 22.4%. At this temperature of 300 °C, the volume fraction of retained austenite reached 10.4%.

With the development of the petroleum industry, more and more high temperature, high pressure and high corrosion wells have appeared. In order to adapt to the harsh environment of oil fields, nickel-based alloy oil country tubular goods have been developed and applied in the world. Nickel-based alloy oil country tubular goods have excellent high-temperature performance and good corrosion resistance, but their manufacturing and processing are difficult and the cost is high, which restricts their large-scale application and development in the petroleum industry. In this paper, the microstructure and properties of the commonly used nickel-based alloys were analyzed, the corrosion mechanism in the acidic environment and the pipe processing technology was discussed.

Carbon steel containing boron-dual phase was produced by casting and were heated to 1200 °C for hot forging to produce plates of 10 and 6 mm thick. The plates produced were heated to the inter-critical annealing temperature for 15 min. and then water quenched followed by tempering process. The microstructure of the produced steel is ferrite with islands of martensite. Welding was done to the heat treated steel plates (6mm) using SMAW process and applying AWS-E11016 electrode and as a result an over-tempered region in the heat affected zone was formed with a significant reduction of the ultimate tensile strength of the welded joint. Reduction of heat input resulted in an increase in the joint strength. Welding of the hot rolled plates with a subsequent heat treatment resulted in formation of homogenous joint with good mechanical and metallurgical properties. Application of Electron Beam Welding to this dual phase steel resulted in a welded joint with good mechanical properties comparable to that of the base metal. The results were discussed based on microstructure analysis and hardness distribution of the welded joints.

The set of studies on modified superficial layer friction pair parts made of X155CrVMo12-1steel was discussed. The said layer is produced according to the duplex process of nitriding and oxidation and is investigated using methods of metallography, X-ray diffraction analysis and micro-hardness measurement based on the oblique and transverse polished sections of the studied surfaces. The results produced proved the duplex process efficiency.

The article provides an overview of existing methods of testing specimen for torsion, in order to determine the rheological properties of materials. In addition, the approaches to the post-processing experimental data, obtained in the form of torque-twist angle curve, are reviewed. It is shown that there is no universal and reliable method to study the rheological properties of materials that are sensitive to the strain rate. This paper proposes the new testing method that takes into account the effects of strain rate hardening initially. This method is that the torsion tests are carried out with the variable grips acceleration. The post-processing of obtained experimental data can be carried out with the use of modified Nadai method. In addition, with the use of mathematical modeling it is shown that the new method is reliable, regardless of material properties. The application for invention of the new testing method No2018132149 was directed in Federal Institute of Industrial Property on September, 7, 2018.

In the article the results of the finite element modeling of cold extrusion of carbon steel, the stress-strain state of massive dies at high cyclic stresses characteristic of the cold extrusion of steel are presented. The possibility of significant amplification of dies in their working area by creating a variable external pressure from the rims of a special design is shown. Dies banding with variable external pressure, proportional to the internal pressure in the die, is aimed at increasing the technical resource of the tool.

Improving the quality of hardware through the improvement of the microstructure is one of the main trends of modern metallurgy. This approach allows us to achieve special properties without the expense of expensive alloying additives. The basic idea is to grind the grain structure of the material to a size less than 1 μm. At the specified grain sizes, the hardening properties begin to manifest with a relatively small loss of plasticity. In this case, one can speak of ultrafine-grained (UFG) materials. This direction is especially important for areas of science and technology, where there are very strict requirements for the size and weight of parts with their high strength. These are aerospace engineering and medicine (implantology and orthopedics). Therefore, it makes sense to conduct research primarily on relevant materials. Titanium is known for its biological inertness, therefore it is the basis for prosthetics. In this work, the experiments on technically pure titanium using a technology close to industrial implementation, were performed. An experiment, in which a lengthy number billet at a temperature of 500 °C rolled from a diameter of 30 mm to a diameter of 15 mm in the mill SVP-08, was conducted. After that, the billet was cooled with water, and samples for studying the microstructure and samples for studying the mechanical properties, were prepared. Analysis of the microstructure showed the presence of an equiaxial ultrafine-grained structure in the peripheral areas of the work-piece and the presence of an elongated fibrous texture in the axial zone. The strength of the work-piece has increased by more than 1.5 times, while the plasticity has decreased not so much.

The article develops one of the main directions of improving the technology of pipe rolling on a reduction-stretching mill, in order to reduce the end crop. The article describes a speed adjustment technique of the reduction mill, when rolling the front end and back end of pipes, the length of which corresponds to the length of the thickness of ends of the finished pipe. A distinctive feature of the technique is the calculation of volume of the thickness end, which must be reduced by an adjusted value, when rolling the end area in the head stands. The sequence of technological calculations and the results of industrial testing of pipe reduction by standard rolling modes, and modes calculated by the proposed technique, are given. An analysis of the results of industrial testing showed the possibility of reducing the mass of the thickness ends by no less than 7%.

The thermodynamic calculation of the phase composition of the PT-1M, PT-7M, Ti-3Al-2.5V alloys versus temperature is performed using the Thermo-Calc software. The comparison of calculation results with the available experimental data is made.

The main characteristics of metal long products quality include mechanical properties, depending on the microstructure state. The key indicator for evaluation the micro-structure of high carbon steel can be considered the 1st grain grade lamellar pearlite Bfp. For the currently used pearlite dispersion method, according to GOST 8233-56, it is characterized by the subjectivity of the view fields choice for the microstructure evaluation, that reduces the quality of the obtained results. The study purpose was to improve the method of high-carbon steel wire rod microstructure estimation, to reduce the error magnitude in determining the 1st grain grade lamellar pearlite. The experiments were carried out on samples of high-carbon steel wire rod with a carbon content of 0,58 – 0,77 %. The pearlite dispersion was evaluated in 27 view fields, located on mutually perpendicular diagonals of the sample cross section. The study results showed the possibility of reducing the error in determining the estimated value of the high-carbon steel wire rod microstructure pearlite dispersion. Microstructure evaluation in the five view fields should be carried out, taking into account the weight coefficients, determined by the ratio of the zones length, occupied by pearlite with a certain percentage of the 1st grade grain pearlite to the wire rod radius. The proposed method of the microstructure evaluation increases assessment accuracy, without complication of its implementation process.

In this work, the technology of Al-Gd alloys production has been developed, in which gadolinium is added as an alloying element during induction melting or in the composition of Gd2O3 disperse particles in the complex use of powder metallurgy and foundry technologies. The design of Vibration-jet agitator (VJA) and technology of its use for introduction of disperse particles into aluminum melts were developed. Aluminum alloys and dispersion-strengthened composites containing gadolinium have been obtained, their structure and neutron absorption properties has been studied.

Basing on the developed methodology for data transfer between the ProCAST and Deform-3D software products, which allows exporting geometry, temperature, residual stresses and microstructure of the casting, it is simulated semi-continuous casting of ingots from aluminum alloy 5182 into a direct chill mold and their following hot rolling in a reversing rolling stand to with aim to study microstructure the evolution.