One of the most energy-intensive industries is ferrous metallurgy. The metallurgical sector in industrially developed countries is reducing its specific energy consumption per one ton of products by approximately 1.0 – 1.5 % per annum. In Russia, obsolete technology is the main reason for the high-energy intensity of industrial product. Energy saving in industrial production is associated with production technology and the scope of fuel and energy resources consumption. Therefore, ways to improve energy efficiency focus on reducing energy consumption of any kind during a specific process in a specific process or thermal unit. Ensuring the economical operation of furnace units requires detailed preliminary and verification analyses, upgrading and introduction of state-of-the-art equipment. The study presents a flow diagram and features of thermal operation of a new drum-type chamber furnace for heating metal products for quenching. The technical parameters of the furnace, the results of the thermo-technical analysis, the heat balance and the specific fuel consumption as applicable to the created design are also presented. The flow diagram of the furnace has significant advantages in terms of the energy efficiency of fuel as compared to the roller and conveyor methods of metal transportation. Placing blanks on the drum significantly reduces the complexity of their transportation. Thanks to its small length the proposed design is compact and easy to place in a workshop. The use of a recuperative fuel burning device allows the efficient use of the heat of waste gases in the heating process. The proposed design and method of products transportation in the furnace working space can be used for the heat treatment of bars, pipes, strips, as well as rolled steel of various shapes.

A thermokinetic diagram of decomposition of supercooled austenite of R350LHT steel was constructed based on the results of its dilatometric, metallographic and hardness analysis during continuous cooling and in isothermal conditions. It was found that cooling at a rate of 0.1 and 1 °C/s causes the austenite decomposition in R350LHT steel by the pearlite mechanism. After cooling at a lower rate, the pearlite structure is coarser and has lower hardness (289 HV). This is due to the higher temperature range of transformation, in which diffusion processes associated with the transformation of austenite into pearlite occur more actively. In the range of rates from 5 to 10 °C/s, the austenite decomposition occurs according to the pearlite and martensitic mechanism, which leads to the formation of a pearlite-martensite structure. When the austenite of the steel under study is cooled at a rate of 30 and 100 °C/s, the austenite transforms according to the martensitic mechanism, and a martensitic structure with high hardness is formed. With an increase in the cooling rate of R350LHT steel, an increase in hardness is observed from 289 (at 0.1 °C/s) to 864 – 0 896 HV (at 100 and 30 °C/s, respectively). The conducted studies allow the boundaries of the search for optimal parameters of welding and heat treatment modes of the investigated rail steel to be narrowed. To obtain the required structures and physical and mechanical properties (austenite of R350LHT steel undergoes decomposition by the pearlite mechanism), cooling should be carried out at a rate of no more than 1 °С/s.

The article considers the issues of sulfur removal in the ladle-furnace unit. The sulfur distribution coefficient depends on sulfide capacity of the slag, sulfur activity coefficient, oxidizing potential of the medium and equilibrium constant. The sulfide capacity C_S of slags is one of the most important characteristics of refining capacity of the slags used in extra-furnace steel processing. One of the factors affecting the sulfide capacity is temperature. The formula was proposed showing the dependence of sulfide capacity on the optical basicity and temperature, in the temperature range of 1650 – 1400 °C and when the optical basicity Λ is not more than 0.75; the error of the presented formula does not exceed 6 %. The formula for calculating the optical basicity is proposed, which takes into account the influence of basic, acidic oxides and amphoteric oxide Al₂O₃. It is shown that slags, completely consisting of a homogeneous phase, have an increased optical basicity of aluminum oxide. Heterogeneous slags have a reduced optical basicity of Al₂O₃ in comparison with homogeneous slags. Perhaps, this fact can be explained by the fact that in homogeneous slags there is a deficiency of the basic oxide CaO and in the conditions under consideration Al₂O₃ compound begins to exhibit more basic properties than acidic ones, thus, in homogeneous slags, the optical basicity of aluminum oxide is increased and approaches optical basicity of CaO oxide. Calculations carried out on the basis of real heats have shown that with an increase in the content of Al₂O₃ oxide in the slag, its optical basicity decreases. Known value of the optical basicity makes it possible to determine sulfide capacity of the slag, sulfur distribution coefficient between metal and slag, and, accordingly, final sulfur content in the metal. The research results have shown that it is advisable to apply the ionic theory of slags for the sulfide capacity determination.

The article presents the study of the nature of dust and smoke generation during gas-oxygen blasting of a converter bath. The main reasons causing metal waste have been determined. Influence of the process main parameters on metal loss has been studied during dust removal and evaporation of iron in the reaction zone. The authors have estimated the process of metal pulverization due to CO bubbles floating, determined by the rate of their rise to the bath surface. Specifics of temperature regime of the reaction zone and heat balance have been determined when adding fuel to the oxygen flow. Adding fuel to oxygen makes it possible to increase heat input into the bath, while reducing the rate of decarburization. This enables reduction of dust discharge during rupture and crush of metal films by gas bubbles. The effect of combustion products oxygen use on metal impurities oxidation is considered. By the example of blasting carbon and alloyed steel for mill rolls, it has been shown that the degrees of CO₂ and H₂O decomposition in the bath are the main qualities of gas-oxygen blasting. These indicators determine the oxidizing and heating properties of the blast. Assessment of change in total, consumed heat and its losses with exhaust gases, depending on degree of the oxygen flow dilution with natural gas (methane), has been carried out. Under these conditions, use of submersible combustion torches with change in their oxidizing ability makes it possible to solve various technological tasks, including provision of an effective way to reduce dust emission in converter process.

The possibility of improving the characteristics of a dry sliding electrical contact with a current density higher than 100 A/cm² by using a molybdenum counterbody is considered. It is shown that tungsten or metallic materials containing bearing steel (1.5 % Cr) in sliding against molybdenum at a speed of 5 m/s under electric current, forms a contact with low electrical conductivity and high wear intensity. This observation served as the basis of this work. Using optical and electron microscopy of sliding surfaces it was found that strong adhesion in the interface was the main reason for rapid surface layers deterioration and high wear intensity. A well-known statement was taken into account that adhesion is due to the low oxide content between the contact surfaces. Visual study of molybdenum sliding surface made it possible to establish formation of a thin transfer layer and absence of traces of oxide formation. The same was observed on sliding surface of tungsten that was caused by high temperature of tungsten and molybdenum oxides formation. A layer of iron oxides was observed on sliding surface of steel containing materials. In addition, traces of a thin tribolayer were find out. An increase in concentration of steel in the primary structure led to a slight increase in iron oxides on the sliding surface, but did not lead to a significant increase in electrical conductivity and wear resistance of the contact. Unsatisfactory characteristics of the contact allowed us to conclude that it is impossible to significantly improve sliding parameters with current collection against molybdenum and inappropriateness of its use as a counterbody for these conditions.

The article considers a review of domestic and foreign works on the use of intense pulsed electron beams for surface treatment of metals, alloys, cermet and ceramic materials. The advantages of using electron pulsed beams over laser beams, plasma flows, and ion beams are noted. The promising directions of using electron-beam processing were analyzed and are as following: 1 – smoothing the surface, getting rid of surface microcracks, while simultaneously changing the structural-phase state of the surface layer, to create high-performance technologies for the finishing processing of critical metal products of complex shape made of titanium alloy Ti-6Al-4V and titanium; steels of various classes; hard alloy WC – 10 wt. % Сo; aluminum; 2 – removal of microbursts formed during the manufacture of precision molds (SKD11 steel) and biomedical products (Ti-6Al-4V alloy); 3 – finishing the surface of molds and dies; 4 – improvement of the functional properties of metallic biomaterials: stainless steel, titanium and its alloys, alloys based on titanium nickelide with shape memory effect, and magnesium alloys; 5 – processing of medical devices and implants; 6 – formation of the surface alloys for powerful electrodynamic systems; 7 – improvement of the characteristics of aircraft engine and compressor blades; 8 – formation of thermal barrier coatings applied to the surface of the combustion chambers. It is shown that with the correct choice of process parameters, such as accelerating voltage, energy density of electron beam, number of pulses, and pulse duration, it is possible to control carefully and/or manipulate the characteristics of structural-phase state and surface properties. In order to improve the properties of the material and the durability of the products made of it, an important factor is the structure modification to form a submicro-nanosized grain (or subgrain structure).

Metallographic and X-ray studies of continuously cast billets of E90KhAF rail steel have been carried out. We have established the regularities of non-metallic inclusions distribution over the crystallization zones before and after billets deformation. It was revealed that in crustal zone the main non-metallic inclusions are point oxides, aluminum nitrides, iron silicates (FeO·SiO₂) and alumosilicates (Al₂O₃·SiO₂). They were identified in the zone of columnar crystals. In central zone of the billet, manganese sulfides (MnS), manganese silicates (MnO·SiO₂), alumosilicates (Al₂O₃·SiO₂), iron silicates (FeO·SiO₂), and point oxides were found. It has been determined that concentration and size of nonmetallic inclusions tend to increase from the surface to central zone of continuously cast billets, which is consistent with generally accepted ideas about mechanisms of billet formation during crystallization. The mechanism of deformation of two-phase silicate non-metallic inclusions and their influence on quality of rail products was disclosed. It is shown that inhomogeneous deformability of complex silicate inclusions aggravates their harmful effect on rail products quality. In this case, additional stresses appear in addition to inclusion-matrix deformation and contact stresses existing at interphase boundaries. This pattern also holds for non-deformed silicate inclusions. Such a distribution of inclusions in the billets volume somewhat reduces their negative effect on rails quality, since near-contact layers of the billet undergo more intense deformation during rolling, and as the axial zone of a billet is approached, deformation rate decreases.

The properties, applications and methods for producing titanium and vanadium diborides are considered. These diborides are oxygen-free refractory metal-like compounds. As a result, they are characterized by high values of thermal and electrical conductivity. Their hardness is relatively high. Titanium and vanadium diborides exhibit significant chemical resistance in aggressive environments. For these reasons, they have found application in modern technics. So, they are used as surfacing materials when applying wear-resistant coatings on steel products. It is also possible to use vanadium diboride as a catalyst in organic synthesis and the anode in renewable electrochemical current sources. Perspective are ceramics B₄C – TiB₂ and B₄C – VB₂ , which make it possible to obtain products based on boron carbide with high-quality performance characteristics, in particular, with increased crack resistance. Such composite ceramics are obtained by means of hot pressing, spark plasma sintering and pressureless sintering. The properties of refractory compounds depend on the content of impurities and dispersion. Therefore, to solve a specific problem associated with the use of refractory compounds, it is important to choose the method of their preparation correctly, to determine the admissible content of impurities in the starting components. This leads to the presence of different methods for the synthesis of borides. The main methods for their preparation are: synthesis from simple substances (metals and boron); borothermal reduction of oxides; carbothermal reduction (reduction of mixtures of metal oxides and boron with carbon; metallothermal reduction of mixtures of metal oxides and boron; carbide-boron reduction. Plasma-chemical synthesis (deposition from the vapor-gas phase) is also used to obtain diboride nanopowders. Each of these methods is characterized in the article.

The problem statement and boundary conditions for calculation of axial thermoelastic stresses in backups with collars of the unit of combined continuous casting and deformation are provided for production of three steel billets. The scheme of calculations for determination of thermoelastic stresses in backups with collars in known temperature field was stated using ANSYS software. The results of calculation of thermoelastic stresses in shaped dies were performed in four sections of a backup with collars. In each section, calculation results are given for four typical lines and seven points. Values of axial thermoelastic stresses for seven typical points of each section are given for the contact surface of a backup with collars and the contact layer at a depth of 5 mm from the contact surface. The stress state of a shaped backup in the middle of depression between the middle collars was determined and the regularities of distribution of axial and equivalent stresses over the thickness, length and width of a backup were established during slab compression and at idle. The results of calculation of thermoelastic stresses in the top of the middle collar of a shaped backup on the contact surface and in the contact layer during slab compression and at idle are presented. Graphs of thermoelastic stresses distribution along the line passing through the top of a collar are given, which show the zones of compressive and tensile thermoelastic stresses during slab compression and at idle. The character of the stress state in the base of extreme collar was determined for production of three steel billets in the unit of combined process of continuous casting and deformation.