The paper presents the results of mathematical modeling and  experimental researches executed during the development of the  techno logy of differential water-air cooling of bearing rings made  of 52100 (EN1.3505) steel produced by JSC “Vologda Bearing  Plant”. Overlapping the mathematical model of temperature variation curves across the bearing cross-section on the thermokinetic  diagram of the decomposition of supercooled austenite calculated  according to the mathematical model developed by JSC VNIIMT  has shown that a required microstructure of the heat-treated metal is  achieved in a wide range of differentiated water-air cooling modes.  Experimental studies of heat-strengthening of bearing rings by water-air jets were carried out on a specially assembled experimental  industrial device with a cooling system equipped with mixers and  collectors with flat-jet nozzles of the original design that ensure the  stability of the torch and the uniformity of spraying the water-air  mixture over a wide range of flow rates and water and air pressure.  The thermal hardening of the rings carried out at various cooling  regimes, followed by the determination of the mechanical properties and structural characteristics of the steel, has confirmed that the  water-air cooling technology achieves the required structural and  mechanical characteristics of the bearing rings and is a competitive,  environmentally friendly alternative to the technology of volume  quenching in oil tank.

The main loads acting on the backup-walls of the assembled  mold of the combined continuous casting and deformation unit in production of steel sheets for welded pipes are described. The technique  for determining the total stresses in backup-walls of the installation of  the compression forces and the temperature load is given. The temperature boundary conditions for determining the temperature fields in  the backup-walls of the assembled mold of the unit for steel sheets for  welded pipes production are depicted. The dependence for determining the heat flux density of the deformation center hot metal influencing working surface of the backup-wall during workpiece drafting is  considered, as well as the technique for determining values   of effective  heat transfer coefficients for backup-walls cooling by water. The procedure for determining temperature fields and thermoelastic stresses  on backup-walls of the installation is described using the ANSYS  package. The article considers the initial data for determining temperature fields and thermoelastic stresses in backup-walls of the assembled  casting mold of the installation. The results of temperature fields and  thermoelastic stresses calculation are achieved in five sections of the  backup-wall and are provided for the typical lines. The nature of temperature distribution along the backup-wall thickness during cooling  by water at idle and at contact with the workpiece during its compression is shown. For the calculated temperature fields, axial and equivalent stresses, that arise in the backup-walls without channels when the  workpiece is drafted and cooled with water at idle, are determined. The  values   and regularities of distribution of axial and equivalent stresses  along the thickness of the contact layer and along the height and thickness of the backup-walls during drafting of the workpiece and at idle  are presented. The values   and regularities of the distribution of total  axial stresses along the thickness of the contact layer, the height and  thickness of the backup-walls from the drafting forces and the temperature load are given.

 The further development of the Russian coal industry, especially in the regions of Siberia and the Far East, in line with the  Energy Strategy, predetermines the need to address the problem of  utilization of ash and slag wastes in newly implemented projects.  The total amount of ash and slag in the ash dumps in Russia is more  than 1.5  billion tons, and the area occupied by fly ash and slag wastes  (FASW) is more than 220 km2. At the same time, the degree of FASW  use does not exceed 10  %. It is shown that the main solutions for the  recycling of the industrial solid waste generated by thermal power  plants are their use in the production of building materials, road construction, or the complex processing of FASW with the extraction  of metals and the production of building mate rials either. Some fly  ash can be used in agriculture. The physicochemical properties of  fly ash and slag wastes and, accordingly, the directions of their use,  as well as the choice of technology, are determined by the mineral  part of the fossil coals and the way they are burned. To use fly ash in  the construction industry, it is necessary to transfer the ash removal  system to the dry method, accompanied, on the one hand, by a large  volume of capital investments in equipment and facilities for storage,  classification, crushing and grinding, the transfer of new physical and  chemical properties to fly ash and slag waste, and on the other side,  an increase in organizational and transport barriers. Examples of proposed technologies for utilization of ash and slag wastes in the form of metal recovery and production of building materials are given. To  obtain iron-containing concentrates, one-stage magnetic separation  is used, but the quality of the concentrate does not meet modern requirements. The most technologically effective for the extraction of  metals from ash and slag wastes are technologies based on flotation  methods. At the same time, it follows from the provided data that  their application can be limited to economic, organizational factors  and the emergence of new environmental risks. The conclusion is  made on the possibility of using the above technologies for existing  coal-fired power plants only with state support.

The creation of new structural materials for cladding tubes  of fast neutron reactors is an urgent task of modern nuclear power  engineering. A three-layer radiation-resistant and corrosion-resistant material based on vanadium alloy and stainless steel, intended  for work under extreme conditions (high temperatures, radiation  and aggressive environment) of operation of fast neutron reactor  cladding tubes has been developed in recent years. The most important aspect determining the operability of this material during  operation is the quality of the joining of different materials layers  among themselves, determined by the modes of thermomechanical treatment. The effect of the annealing on the chemical composition, structure, and fracture resistance of the “steel/vanadium  alloy” interface in the steel/vanadium alloy/steel three-layer tube,  obtained by hot co-extrusion of three-layer tube billet at 1100  °C  was studied. The 20Kh13 (AISI 420 type) steel for the outer layers and V – 4Ti – 4Cr vanadium alloy for the core were used as the  components of the tube. The structure and chemical composition  in the layer joining zone were studied using the optical microscopy and electron microscopy with X-ray microspectral analysis.  The fracture resistance of the “steel/vanadium alloy” interface was  evaluated by a compression test of a three-layer ring sample with  notch using an acoustic emission (AE) measurement. It is shown  that after co-extrusion a “transition” area of diffusion interaction  having a variable chemical composition with a width of 10–15 μm  is formed between vanadium alloy and steel, which represents the  continuous series of solid solutions, without precipitation of brittle  phases, providing a strong bonding between vanadium alloy and  steel in the three-layer material. No voids, delaminations or defects 
were detected at the “steel/vanadium alloy” interface. However, a  crack is formed in the steel layer during the compression tests of  the notched semi-ring three-layer samples after hot co-extrusion.  Annealing favorably influences the formation of the “transition”  area due to the increase in the width of the diffusion interaction  area. No cracks or delaminations at the boundary between steel and  vanadium layers were observed in the three-layer tube samples after annealing, and the three-layer material behaves like a monolith  material during testing.

Using  transmission  electron  microscopy  methods  at  various  distances from the rolling surface along the central axis, changes in  structure, phase composition, and defective substructure of the head  of differentially hardened rails were studied after passed tonnage of  691.8  million tons of gross weight. It is confirmed that prolonged  operation of rails is accompanied by two simultaneous processes of  transformation of structure and phase composition of plate-pearlite  colonies: cutting of cementite plates and dissolution of cementite  plates. The first process is carried out by mechanism of cutting carbide  particles and removing their fragments, accompanied only by change  in their linear dimensions and morphology. The second process of  dest ruction of the cementite plates of perlite colonies is carried out by  leaving carbon atoms from crystalline lattice of cementite on dislocation, as a result of which phase transformation of rails metal is possible. This is due to a noticeable relaxation of mean energy of carbon  atom  s binding to dislocations (0.6  eV) and to iron atoms in cementite  lattice (0.4  eV). The stages of transformation of cementite plates are 
considered: enveloping the plates with sliding dislocations and then  splitting them into weakly oriented fragments; penetration of sliding  dislocations from ferrite lattice into lattice of cementite; dissolution of  cementite and formation of nanoscale particles. The presence of nanosized cementite particles in ferrite matrix is noted due to their removal  during dislocation slide. Using expressions of modern physical materials science and X-ray diffraction analysis, influence of content of  carbon atoms on structural elements of rail steel was estimated. It is  shown that prolonged operation of rails is accompanied by a significant  redistribution of carbon atoms in surface layer. In the initial state, the  main quantity of carbon atoms is concentrated in cementite particles,  and after a long operation of rails, along with cementite particles, carbon is located in defects of crystal structure of steel (dislocation, grain  boundaries and subgrains), and in the surface layer of steel atoms carbon is also found in crystal lattice based on α-iron.

At the present time, rare-earth elements in metallurgy are used in  the form of mischmetal – a rare-earth elements natural mixture (with  atomic numbers from 57 to 71). It contains about 50  wt.  % of cerium.  The remaining elements are mainly lanthanum and niobium. The specific composition is determined by the ore deposit. Inconstant composition of the modifier containing rare-earth metals (REM) can significantly reduce its efficiency. Experimentally, for every branded steels  composition the ratio of various REMs can’t be selected because of the  high costs of obtaining technically pure rare-earth metals. The task of  determining the each rare earth element optimum concentrations and  complex ligature composition can be solved by thermodynamic modeling. In the framework of thermodynamic modeling, the interaction  between magnesium, aluminum and lanthanum with oxygen in liquid  iron is presented. And the thermodynamic model of steel deoxidation  by these active metals composition is considered. On the basis of available literature data on the phase diagrams of the systems MgO – Al2O3 ,  MgO – La2O3 and La2O3 – Al2O3 , the coordinates of the invariant equilibria points in the system MgO – La2O3 – Al2O3 were determined. The  phase diagram of the system MgO – La2O3 – Al2O3 was constructed. It  made possible to establish all phase equilibria realized in the process  of deoxidation of steel with magnesium, lanthanum and aluminum and  to describe these phase equilibria by chemical reactions equations. The  activity of the components in liquid oxide melts was determined using  the theory of subregular ionic solutions, which takes into account the  dependence of the coordination number of cations on the composition  of the oxide melt. The activity of components in metal melts conjugated with oxide systems were determined by Wagner’s theory using the  parameters of the first order interaction. Equilibrium constants values  for the steel deoxidation reactions are installed indirectly by thermodynamic calculations. On the basis of the obtained data the components  solubility surface in the metal melts of Fe – Mg – Al – La – O system  was constructed, which allowed to determine the liquid metal composition regions associated with the corresponding oxide phase.

The magnitude decrease of the dynamic loads that arise during  the operation of machines in general and metallurgical ones in particular, is one of the main tasks of general problem of increasing their  reliability and durability. The analysis of work of lever mechanisms  of jaw crusher with internal degrees of freedom conditioned by presence of clearances in hinges, was made. It has shown that presence of  unstable forces of locomotive masses inertia during work of oscillating  crank drive results in breakage of pin surfaces in joint of piston-rod  with a crank, and in subsequent change of working surfaces of this  kinematics pair, followed by hitting of the masses of movable links  and in generation of considerable dynamic load, providing the reason  of breakages of details of executive mechanism and the source of resilient vibration (vibrations) and harmful acoustic vibration generation.  With the purpose of removal of influence of clearances in hinges on the  origin of additional dynamic forces it is necessary to reveal regularities of impulse loads appearance. Regularities of such loads appearance in crank-type mechanisms with clearances in joints of kinematics  pairs, caused by contact fault as a result of change in working surfaces contact, can be determined by kinetic static analysis. Analysis  of work of crank-type hinge with clearance of oscillating crank drive  of jaw crusher was conducted. Based on the analysis results it was  determined, that contact fault in joint of crank-piston-rod kinema tics  pair elements is conditioned by change of sign of reaction force. Clearance overtravel in a crank-type hinge takes place when both links are  on one line. Determination of mechanism links positions, at which  there is interconnection of crank-type hinge contact surfaces, allows  to use mechanisms rationally for selection of clearances with resilient  elements that during all work cycle of oscillating crank drive choose  clearance in crank-type joint and prevent additional dynamic load occurrence. That promotes reliability of jaw crusher operation in whole.

The main scientific and practical results of the improvement of  vibrating feeders-screens for mining and metallurgical industry are  presented on the basis of dynamic calculation of the vibrating feederscreen with two differently directed self-balancing vibrators. Methods  of theoretical generalizations are described using mathematical statistics, physical and mathematical modeling, computation and feasibility studies, laboratory and full-scale experimental studies, industrial  tests in the conditions of operating enterprises using standard and new  methods. Mathematical modeling and calculation of the parameters of  a vibrating feeder of the PVG type are proposed. It is recommended  when choosing dynamic parameters of the feeder, to use the vibration  transmission coefficient, which is taken within the limits (1.5  –  3.5)g,   and in heavy loading modes, is up to 5g. It is shown that during preparation of breeze coke in the crushing body, from 10 to 50  % of fine  material is received from its bunker with a particle size of 0  –  3  mm,  which is additionally re-milled, reducing the quality of coke. A vibrating feeder-screen with a spatial oscillation of the working element will  increase the efficiency of screening of the material by 15  –  20  % and  will improve the self-cleaning of the screen. The driving forces of the  exciters are directed at different angles of 15 and 45° to the screening surfaceand are attached from each other at a distance equal to half  width of the box, i.e. 600  mm. It is established that in the resonance  mode at a constant amplitude with increasing frequency the coefficient  of the vibro-displacement regime increases according to a quadratic  dependence, at a working frequency of 100 rad/s it also increases from  the loading edge of the feeder to the unloading and from one side to  another, the value of which varies within 2.62  –  2.84.

 Planning of pilot testing is among important problems of creation of Enterprise resource planning. Pilot (experimental) projects are  intended for testing of the main functions of the created system by  limited number of “advanced” users. A key task when planning pilot testing is determination of its volume. If the volume of the pilot  project is small, then essentially important functions of system can be  not checked, and the probability of detection of essential mistakes at  full introduction will be high. If the volume is big, then amount of  works on implementation of the pilot project considerably increases, and there will be no necessary speed and flexibility of testing of the  main functions, because of which pilot testing is organized, and its  efficiency will be close to efficiency of full introduction. The article describes mathematical problem definition of pilot testing scoping which  relies on results of the solution of formation problems of a portfolio  of IT services and creation scheduling of Enterprise resource planning  of the large metallurgical company. The solutions for the considered  task are sets of the services and communications which are subject to  check between them satisfying to the set restriction for volume of the  resources allocated for testing realization, and delivering an optimum  to the set criterion. The procedure of the task solution is based on network programming method which relies on structural and similar network representation of criterion and restrictions. The procedure and an  example of the solution of the studied task in which separate estimated  tasks are solved by method of dichotomizing programming are shown.  The received approximate solutions of an objective can be improved by means of the solution of a dual problem of network programming.  For the purpose of finding of initial task global optimum, the method of  branches and borders can be used in which the criterions of function of  the found approximate solutions are applied as border values. The considered task can be generalized for preferences of the consumers of IT  service concerning need of check of services various communications.  These preferences can be considered by introduction of “scales” of the  corresponding communications. The general scheme of the solution of  a task at the same time doesn’t change.

A design method of multifunctional digital prototypes of drawing mills performance as an active man-machine system is developed.  The structure of models is determined, including machine drawing time and time of manual operations, equipment coefficients and labor  operations, theoretical, feasible and normative cycles and performance  of man-machine systems. Fragments of tabular implementation of the  proposed integrated normative model of the man-machine system are  given.

Thermodynamic analysis of the effect of aluminum on the solubility of oxygen in Ni – Cr melts has been carried out. Aluminum at  very low levels practically does not affect the concentration of oxygen  in the melt, which is determined by the chromium content. When the  aluminum content is above ~0.01  % for all alloys, it already determines the solubility of oxygen in the melt. The minimum values of  the oxygen concentration are achieved with an aluminum content of  ~0.2  %. With the increase of chromium content in the melt, the minimum oxygen concentration increases. For Ni – 10 % Cr, Ni – 20 %  Cr and Ni – 30 % Cr alloys, it is 2·10–3, 7·10–3 and 10–2, respectively.

A computer simulation of the internal pressure expanding was  performed for pipes with uneven wall thickness made of steel, aluminum and titanium alloys. For this simulation software tool ESI Virtual-Performance 2016.0 was used that implements the finite element  method. The convergence and accuracy of the solution was estimated  by comparison with known solutions. A full factorial computational  experiment was performed by varying factors: the initial wall thickness variation of pipes, D/S and parameter of alloys hardening. The  regression equations were obtained by the internal pressure at the time  of destruction and final wall thickness variation from these factors. It  was found that the variation in wall thickness in the distribution pipe  rupture occurs in the thin wall. A wall with minimum thickness continues thinning with an almost constant maximum wall thickness, which  leads to an increase in the transverse variation in wall thickness. It was  concluded that the increase of the initial variation in wall thickness  pipe speeds up the process of rupture in the area of thin wall. It is recommended in conduits conducting high-pressure fluid to apply pipes  with minimal variation in wall thickness.