The article is devoted to the study of the flow rate depending on the pressure in the gas supply system of the plasma head. The problem was solved by conducting a computer experiment with subsequent verification of the results by a full-scale experiment. The laboratory plasma installation MAK-10 assembled on the basis of the IMET UB RAS, used in the processes of coating, powder production and surface modification of parts, was simulated. The computer experiment was carried out using the SolidWorks Flow Simulation software package. As a result of the work performed, the distribution of the flow rate along its axis was demonstrated during the operation of the plasma installation with a pressure in the gas supply system of 0.1; 0.2 and 0.3 MPa. Recommendations for conducting coating, powder production and surface modification processes have been developed, which have practical benefits for consumers of process equipment.

Keywords: mathematical model, flow, velocity, pressure, plasma method, powder production, coating, surface modification

The construction and substantiation of a finite element model of the capillary tube running-in process, which was obtained by drawing on a fixed mandrel, are considered. The rolling rolls are cylindrical and absolutely rigid. The condition for performing the work is a comparison of the resulting gap between the pipe and the mandrel and the facet formed during deformation. The solid-state model of the process is described by an adaptive grid. Under these conditions, an informative model was obtained, which was used in parametric analysis.

Keywords: drawing with a mandrel, capillary tube, extraction, rolling, model construction, compression selection, pipe size tolerance

The article solves the problem of determining the influence of the use of gas swirlers with various options for combining the direction of the channels on the velocity and temperature of the plasma flow. A comparative analysis of the use of gas swirlers with channels that are directed in one direction and in the opposite direction is carried out. The problem was solved by conducting a computer experiment by the finite element method using the SolidWorks software package. The results of the calculation experiment were verified by conducting a full-scale experiment using an experimental plasma installation, which is used to obtain powder, apply coatings and modify product surfaces, taking into account its design features. Recommendations for the conduct of these processes are proposed. The results are of practical use for developers and consumers of process equipment. In the case of using gas swirlers in which the channels are directed in one direction, the temperature and velocity of the plasma flow are higher than in the case in which the channels are directed in opposite directions. For the coating process, it is recommended to use the option of orienting the channels of gas swirlers in one direction, since the highest values of the velocity and temperature of the plasma flow are achieved, which favorably affect the properties of the applied coatings. For the production process of powders, it is recommended to use the option of orienting the channels of gas swirlers directed in opposite directions, since a lower plasma flow velocity is important for this process, which has a positive effect on reducing the dimensions of the installation and spheroidization of powder particles. For the surface modification process, the results of the study can be used to determine the rational position of the treated surface.

Keywords: mathematical model, plasma flow, temperature, speed, gas swirler, plasma method, powder production, coating, surface modification

TThe modeling of the process of distribution of profile oil pipes in a well by means of a cone punch is considered and the determination of the force necessary for its pushing is carried out on this basis. The normal force for one protrusion of the pipe profile was found. The change in the deformation resistance and profile geometry during distribution is taken into account. The optimal taper angle is determined and the geometric parameters of the punch are selected, including the largest and smallest diameters and its length. A numerical example of calculation based on the obtained formulas is given, which shows the technical feasibility of the process.

Keywords: distribution, oil profile pipes, protrusion force, equilibrium equation, deformation resistance, tool geometry, numerical example

A mathematical model of the surface of deformation zones as a set of flat cross-section described on the basis of spline functions for profiling pipes in rollers with subsequent calibration is proposed.

Keywords: Mathematical model, deformation zone surface, flat cross-section, spline functions, рipe profiling

The issues of improving the quality of products produced by predicting the resulting geometric characteristics of the shape of the pipes to be profiled and their accuracy are considered. An objective mathematical model was created that adequately describes the real process. The computational experiment was performed using software packages that allow implementing the ANSIS and DEFORM finite element method. The dependencies of the studied shape parameters on the outer diameter of the workpiece are established. The presented dependencies and the proposed guidelines for the conduct of the process are of practical use and are useful to developers and consumers of process equipment for predicting the results of profiling

Keywords: Pipe profiling, deformation, stress, mathematical model, finite element method, accuracy, quality

The process of profiling tubes with rollers was considered. The method of solving the problem was considered. The stress-strain state of the metal in this process was determined, the equations of relative deformations was given, the shear strain intensity in cylindrical coordinates are given for the case of a plane homogeneous deformed state. The stress state index was defined

Keywords: Pipe profiling, deformation, stress, flat pattern, mathematical model, stress concentration, stress-strained state, stress state index

In article statistical data on failures on a linear part of the main gas pipelines are presented, the reasons of their emergence are defined. Standard scenarios of development of emergencies are provided, and also the basic principles of determination of frequency of emergence of failures are shined.

Keywords: accident, analysis, diameter, linear part of the main gas pipelines, depressurization, scenario, pipeline.