The influence of one-sided accelerated cooling of A32 plate shipbuilding steel with thickness of 10·10–3 m on structure and mechanical properties was investigated. As a result of such cooling, continuous spectrum of microstructures from ferrite-bainite on the rapidly cooled surface to ferrite-perlite on the opposite surface is formed along the billet thickness. Therefore, over the billet thickness strength properties are reduced from rapidly cooled surface to the opposite one. Thus, the gradient of strength characteristics (hardness, yield strength and rupture strength) along the billet thickness is directed to rapidly cooled surface. For comparative analysis, other batches of billets were subjected to normalization and hardening with high tempering. The analysis of mechanical properties has shown that strength and plastic properties of the samples at unilateral accelerated cooling are at level of heat-strengthened state. Testing on impact strength of the samples with variable distribution of mechanical properties over their thickness has shown that the impact depends on correlation of gradient directions of strength properties and load application. In impact bending test at the temperature of –40 °C, if the direction of load application is opposite to gradient of strength properties, the impact work was more than 300 J (the sample did not collapse). At coincidence of directions of the gradient deformation resistance and load, energy of the blow was 262 J. Thus, if the direction of deformation resistance gradient coincides with the direction of external applied load, then it leads to an increase in plasticity of steel. It is shown that, knowing distribution of strength characteristics over the sample thickness, it is possible to calculate integral values of yield strength and rupture strength of the sample. Value of relative through-thickness elongation increases from the rapidly cooled surface to the opposite one. Integral elongation of the billet is less than the smallest relative through-thickness elongation. With changing thickness strength of the billet during bending, displacement of the neutral deformation line relative to the geometrically average line in the direction of the strength properties gradient is inevitable. The position of neutral line of deformation during bending is proposed to be determined by the value of experimental integral yield strength (rupture strength).

High technical and economic efficiency of the use of bimetals in chemical, oil, transport and energy engineering and other industries is described. The urgency of creating high-performance continuous processes for the production of bimetallic strips is substantiated. The authors have established the main technological tasks for development of the processes of obtaining bimetal of wide class. The paper describes resource-saving production technology of three-layer bimetals alloyed steel – constructional steel – alloyed steel at the unit of combined process of continuous casting and deformation. Possibilities of the proposed technology are outlined from the standpoint of improving the quality of bimetallic strips. The initial data are given to determine the temperature change over time of the main steel strip as it passes through the molten metal of the alloyed steel. The equations are given for non-stationary heat conduction, initial and boundary conditions for determining the temperature fields of main strip and cladding layer when obtaining a three-layer bimetallic strip on the unit of a combined process of continuous casting and deformation. The values of density, thermal conductivity and heat capacity for steel St3 were determined in a given temperature range. A procedure is described for calculating temperatures in the ANSYS package by solving a non-stationary heat conduction problem in a flat formulation by the finite element method. The authors have described the geometric model for calculating the temperature of strip and molten metal of the cladding layer. Values of the coefficient of heat transfer between the main strip and molten metal of the cladding layers of bimetallic strip are given adopted for calculation. Characteristic points are indicated in the model for calculating the temperatures of main strip and molten metal of the cladding layer. The graphs show temporal changes in these temperatures at production of a three-layer bimetallic strip on the unit of combined process of continuous casting and deformation. Calculated data on the time variation of temperature of main strip and molten metal of the cladding layer at characteristic points are given for different values of the contact heat transfer coefficient.

The methods of microgeometry formation for the surface of temper mills rolls are presented providing the required roughness of the cold rolled strip. It was established that with the electroerosion processing a more uniform structure is formed on the roll surface with a smoothly changing microrelief, compared with the mechanical action of the abrasive. The most effective abrasive for the microrelief formation on the rolls surface is cast and split steel shot. The process of interaction predominantly occurs with round-shaped shot, since the sharp edges of the split shot also become blunt during it. In the present work, the microdepression of the roll is approximated by a spherical shape. A model of roll roughness transfer to the strip was developed taking into account the type of roll processing and tempering conditions, which makes it possible to evaluate the degree of filling of a single microdepression relief at known pressures at contact of the strip with the roller, friction coefficient, roll roughness parameters and tempering modes. A quantitative estimation of reproduction of the roll roughness on the trained strip was obtained, characterized by the roughness ratio, which is the ratio of the depth of the metal flow into the strip microdepression to the depth of the roll spherical microdepression. Determination of the dimensionless pressure required for flowing a deformable metal into it was performed using the superposition method for meridian sections in two mutually perpendicular planes. The reproduction dependencies of the micro-geometry of a temper mill roll on a rolled strip on the shot size, tension, and the height parameter of roughness are presented during the tempering of stripes with various thickness, which can be used to simulate the transfer of the roll micro-relief to the rolled strip.

Studies of welding and surfacing fluxes containing ladle slag of electric-steel production of rail steel of JSC “EVRAZ ZSMK” were carried out. Welding under the flux was performed on the samples of sheet steel 09G2S by Sv-08GА wire using the weldingtractor ASAW1250 at exhaust modes. Chemical compositions of welding fluxes and slag crusts were determined. Also chemical composition of the studied welded samples was determined according to GOST 10543 – 98 by x-ray fluorescence method on XRF-1800 spectrometer and by atomic emission method on DFS-71 spectrometer. Metallographic studies were carried out with the use of an optical microscope OLYMPUS GX-51. The content of total oxygen and surface oxygen was studied using the LECO TC–600 analyzer. The possibility of using technogenic waste products of metallurgical production is shown for the production of welding fluxes. The following components were used for production of welding flux: ladle slag of electric steelmaking of rail steel from “EVRAZ ZSMK” JSC; BSK barium-strontium modifier produced under the terms of 1717-001-75073896 – 2005 by “NPK Metallotekhnoprom”; slag of silicomanganese production from “West Siberian steel plant”; electrostatic dust of aluminum production from “RUSAL” (carbonfluor-containing supplement). The studies have shown the suitability of the use of ladle electric steel slag for welding and surfacing of alloyed metal. The introduction of various flux additives reduces the concentration of total oxygen in the weld metal, which in turn increases the toughness. From the point of oxygen concentration in weld metal and impact toughness, it is better to use silica-manganese slag and carbon-fluoride additive as flux additives.

Analysis of structure phase states and properties of the layers formed on HARDOX 450 low alloy steel by welded-on wires with boron content of 4.5 and 6.5 % wt. was made by the methods of modern physical material science. In the initial state HARDOX 450 steel has the structure of tempered martensite, in the volume and along the boundaries of crystals of it the cementite particles are located. The particles located in the volume have acicular shape and those along boundaries are mainly round. The presence of extinction bend contours has been revealed, indicative of the curvature torsion of crystal lattice of the material’s portion. They originate and finish on the interfaces of martensite crystals. Scalar density of chaotically located dislocations and forming the netlike substructure is 6.2·1010 cm–2. The layer welded on HARDOX 450 steel has microhardness increasing by more than two-fold that of the base. Analysis of state diagrams of Fe – C, Fe – B, B – C systems and polythermal cross–sections in Fe – C – B system has shown that the rapid cooling of Fe23C6 – Fe23B6 alloys from liquid state would facilitate the formation of multiphase structural states. It is stated by the methods of transmission electron diffraction microscopy that the reasons for the high microhardness level of the surface layers are the following: formation of iron borides and crystals of ultafine-dispersion (up to 100 nm) packet martensite with high level (~1011 cm–2 ) of scalar density of dislocations; presence of nanodimentional particles of iron and boron carbides in the volume and on the boundaries of martensite crystals; high level of curvature torsion of crystal lattice of iron borides and α-phase grains, caused by the internal stress fields along interphase (interface of iron boride crystals and α-phase grains) and intraphase boundaries (interface of iron borides and martensite crystals packet). Increase in boron concentration from 4.5 to 6.5 % is accompanied by the sufficient increase (by 1.2 – 1.5 times) in hardness of welded layer. It is caused by the increase of dimensions and relative content of iron boride regions by 1.5 – 2.0 times.

The interrelation between the mechanisms of surface layer deterioration of powder composites and the elemental compositions of their primary structures under extreme conditions of friction was studied. Extreme conditions were set by sliding under high pressure (higher 100 MPa) in boundary lubrication or by dry sliding under high density electric current (higher 100 A/cm2). It caused plastic deformation of the surface layers and their deterioration due to lowcycle fatigue. High wear resistance of materials in such conditions should be achieved due to satisfactory stress relaxation in the surface layers. It was suggested that stresses should be relaxed due to local plastic deformation in vicinity of the emerging stress concentrators. The ease of plastic deformation (and ease of relaxation) should be ensured by reducing the doping of the composites structural components, i.e. due to the lack of solid solutions. It was shown that the composites having the Cu – steel (alloy) – TiC compositions obtained by the method of self-propagating high-temperature synthesis with simultaneous pressing of the burning charge had strong adhesion in the sliding contact and showed low wear resistance under high pressures boundary friction. The absence of solid solutions in the primary structure of the Cu – Fe – TiC composite corresponded to high wear resistance due to the absence of adhesion in the contact and easy stress relaxation. Composites of Cu – steel-graphite compounds, made by sintering in vacuum, showed strong adhesion in a dry sliding electrical contact and low wear resistance due to the high content of alloying elements. It was noted that the absence of solutions in the composite composition of Cu – Fe – graphite caused the absence of adhesion in contact and the corresponding high wear resistance. In addition, stresses in the surface layer were also relaxed by the formation of FeO oxide in the contact space during sliding with the current collector. Composites containing solid solutions were not capable of forming FeO oxide on the sliding surface. It was an additional reason for the low wear resistance realization. It was noted that solid solutions caused a decrease in the thermal conductivity of the surface layer. Therefore, it led to an increase in temperature gradients on the sliding surface and to a сorresponding acceleration of the friction zone deterioration.

The work presents a new technique for determining the temperature dependence of the alloy specific volumes in Fe – C equilibrium system based on known from the literature calculated and empirical dependence for account of the phases’ specific volumes. These data were based on the independent reports of S.F. Yuryev and were obtained for temperatures below 1200 °C. When using these forms at temperatures above 1200 °C, the specific volume of austenite exceeds specific volume of ferrite. However, it is known that austenite has the smallest specific volume among all phases of the Fe – C system. In this regard, in the field of high temperatures, it is proposed to use other dependences that do not contradict the physics of polymorphic and phase transformations in this system. Thus the authors have obtained the general expressions for calculating the alloys’ specific volumes separately for three intervals of carbon concentrations in which the change in shares of the temperature phases are calculated according to Fe – C equilibrium diagram using the lever relation. As an example, results of the calculated determination of specific volumes of alloys with carbon vontent of 0.05, 0.13 and 0.33 % in the temperature range of 20 – 1600 °C are considered. The presented results are compared with the results obtained with the help of the phase diagram calculation package JMatPro®, on the basis of which the adequacy of the proposed calculation method was established. The developed technique can be used to calculate not only specific volumes of alloys, but also their density and coefficient of linear expansion depending on temperature and carbon concentration. It is the basis for the correct use of methods for determining the size of continuous cast billets due to shrinkage in order to correctly configure the equipment of continuous casting machines.

The paper describes the pump gear-multiplier drive of sheet shears with a two-cylinder power unit. The description of the developed drive scheme with the use of dual dispensers (reducer and multiplier) of periodic action is given. The gear is engaged at idle, the multiplier – at work. Their charging comes up at the reverse course of the power unit. Each dispenser has an input cylinder connected to the pump and two dosing (output) cylinders connected separately with the power cylinders of the power unit. In this case, the cylinder bodies form a fixed block, and the plungers (pistons) – a movable block. It solves the main task: synchronization of movement of the pistons (plungers) of the power cylinders during all operation periods. Due to different ratio of the area of pistons (plungers) of inlet (Fв ) and dosing cylinders (2Fд ), a direct stroke mode with two stages of pump speed and pressure is provided. For the reducer, ratio (Fв /(2Fд )) determines reduction coefficient (Kp < 1), for the multiplier – the coefficient of multiplication (Kм > 1). As a result, the idling speed of the pistons of the power cylinders and pressure developed by the pumps increase, and  during the working stroke – these values decrease. Working pressure of the pumps is equalized at a direct flow at a reduced level, which determines reduction of their installation power (up to 30 %). The analysis of graphs of power loading and speed was made. The condition of constant load at each of three main periods of the drive operation was accepted as: idle, working and reverse. Determinant parameters of the considered drive are the coefficients Kр (reduction), Kм (animation) and Kс – the gain of the power unit. The paper presents a comparative analysis of the considered and simple pump drive in order to establish the received combination and range of these values.

Studying the interaction between oxygen and magnesium and aluminum dissolved in liquid iron is an important task in order to choose optimal parameters for refining and casting of steels. Relevance of this research is caused by determining the possibility and conditions for formation of unfavorable refractory particles of magnesium oxide
and magnesian spinel in a metal melt. In the course of this research, thermodynamic modeling of phase equilibria implemented in liquid metal of such systems as Fe – Mg – O, Fe – Al – O and Fe – Mg – Al – O within the temperature range of 1550 – 1650 °С was carried out. Calculation was made using the technique of constructing the solubility surfaces for the metal components which connects quantitative changes in composition of a liquid metal with qualitative changes in composition of products obtained as a result of interaction of a metallic melt’s components. The modeling method was based not only on usin­g equilibrium constants of reactions occurring between components of the systems under research in the selected temperature range, but also on taking into account the values of interaction parameters of the first order (according to Wagner) of elements in liquid iron. In order to simulate activities of the oxide melt conjugated with the metallic one, approximation of the theory of subregular ionic solutions was used. To model activities of oxides solid solution, approximation of the theory of regular ionic solutions was used. And the theory of ideal ionic solutions was used for the solid solution of spinels. In the course of the work, isotherms of oxygen’s solubility in liquid metal of systems Fe – Mg – O, Fe – Al – O and Fe – Mg – Al – O have been constructed, and regions of thermodynamic stability of oxide phases conjugated with the metallic melt have been determined. In particular, compositions area of a liquid metal which is going to be in equilibrium with the solid solution of spinels | FeAl 2 O 4 , MgAl 2 O 4 | solid solution has been determined for Fe – Mg – Al – O system. Results obtained in the course of thermodynamic modeling have been compared to experimental data.

Electromechanical processes occurring when the load is lifted by an overhead crane are considered. The main idea of the work is to identify emergency mode (crane overload) by a method based on control of stator current of lift motor. To obtain stator current diagrams of electric motor, mathematical model of overhead crane (three-mass circuit) has been developed, which includes equations describing elastic properties of crane beams and its rope. A system of (α, β) coordinates, fixed relative to electric motor stator, is adopted to describe the drive asynchronous motor. Lifting cycle is considered as sequence of three steps: choice of the rope “slack”; rope tension; separation of cargo lifting. For each stage, a system of differential equations has been compiled describing motion of masses of overhead crane elements and electrical parameters of electric motor. Initial and boundary conditions for each of the stages were determined. Preliminary transformations of the system of equations to their solution by numerical methods and subsequent modeling of stages of lifting loads were carried out for different weights. Sequential solution of three boundary value problems allows obtaining values of stator currents at time of load separation. Diagrams of stator phase currents of an electric motor were obtained for loads of different mass. Simulation results indicate the presence of fixable difference in magnitudes of stator currents after the load is separated from the support surface. On basis of the developed model and the study results, a functional diagram of crane overload protection device is proposed and its principle of operation is described. It consists in controlling lifted load mass and stator current when lifting
the load. Conclusion is made about feasibility and effectiveness of monitoring electrical values of lifting motor for development of overhead crane protection against overloads. Effectiveness of the proposed system was evaluated.

Accurate accounting and rating of duration of production cycles is necessary for rational planning and forecasting of production time. Production duration of products batches is the basis for operational schedules design. Without duration of cycles, it is impossible to establish calendar dates for start-up of semi-finished products to a particular stage of processing, as well as to determine timing of production and timing of the products batch for individual production sites. The considered task of multivariate estimation of standard duration of manufacturing of a specific batch of steel wire is to determine optimal duration of operations required for this batch production for each situation. To solve it, it is necessary: to build models of production processes performed in each branch of steelwire complex; to determine composition, duration and conditions for performing technological, natural, labor, control and transport operations; to specify the type and amount of equipment used in each department; to
list types of material flow units (riots, skeins, coils); to establish nature and type of movement of semi-finished products (products) in operations of each process; to specify ways of moving products from each previous peration for each subsequent (piece, batch, batch), as well as the number of packages and lots being moved; to take into account the type of applied production lines (continuous, semi-continuous, discrete). All of the above is reflected in presented multi-loop algorithm, approbation of which is performed by simulation method using field data of operating enterprise.