Metalloobrabotka № 2 (122)/2021

Metal cutting

Mokritskii B. Ya., Shelkovnikov V. Yu. Blade machining of workpieces of the details, that have strengthening by high-hardness surfacing

The details, which material is a sandwich with controlled physical and mechanical characteristics, are becoming more demanded due to exceptional performance properties, that cannot be obtained using traditional methods. One of the methods of obtaining such sandwich materials is a surfacing of a high-hardness material on an ordinary structural steel. The surfaced layer must be processed to ensure the required dimensions of the details and the quality of the machined surface. Modern metal-cutting equipment and tools allow such processing. It can be done in the machine workshop of a machine building enterprise, or it can be pre-processed in a procuring workshop and then transferred to the machine workshop for final processing. The first option is simple, but not effective due to the fact, that modern production culture requires a separate execution of rough work. This will reduce tool consumption and the wear of machine tools. The second option is more rational, but it also requires a special preparation of production. At least in the choice of metal cutting tools. The results of the choice of a metal-cutting tool for processing workpieces of the details, which working (surface) layer is surfaced with a material, the hardness of which is at the level of 65 HRC.

Keywords: processing of high-hardness materials in procuring workshops, high-hardness surfacing, metal-cutting tool.

Kizhnyaev Yu. I., Tarasov S. I. Investigation of elastic deformations of the rod during ring drilling of deep holes in shaft parts

A method for calculating elastic deformations of a rod (kernel) formed during ring drilling of deep holes in long shafts is considered. The boundary values of the drilling depth at which the rod acts on the tool stem are determined. The rod pressure forces on the stem are calculated, causing it to bend and vibrate, which negatively affects the basing and stability of the ring drill. The developed method is used to assess the deformations of the rod when it is cantilevered in the stem and when the end is supported by a special support. The designs of supports for the rod when drilling with external (ELB) and internal (BTA) chip removal are given. These examples confirm the advantages of using supports to support the rod and determine the scope of their use in a wide range of values of the diameter, drilling depth and cutting width of the drill.

Keywords: deep ring drilling, deflections of the cantilever and feathered rod, method of calcula-tion, boundary lengths and loads.

Petrov V. M., Alexandrov A. S., Petrov V. M. Investigation of the machinability of heat-resistant steel by the method of contour milling on a portal-type CNC machine

Modern mechanical engineering does not stand still and requires the improvement of various technological solutions. To obtain a high-quality part during its manufacture, it is necessary to ensure the accuracy of the dimensions, shape and location of the part surfaces. This requires considering a set of factors influencing the solution of this problem. The paper proposes to apply a systematic approach to the selection of tool materials, the design of the cutting tool, the type of equipment, the appointment of cutting modes for processing steels with special physical and mechanical characteristics. Knowing the features of the material being processed, you can choose the most profitable processing strategy, following the algorithm specified in the work.

Keywords: wear, quality, carbide tool, processing modes, tool life.

Electrophysical and electrochemical processing methods

Zorenko D. A., Barchukov D. A., Afanasieva L. E. Simulation of temperature fields at laser cutting of rolled steel

The main results of CAE-modeling of temperature fields during laser cutting of steel sheet are presented. An experimental verification of the simulation results on samples of structural steel has been carried out. It is shown that the research results can be used to assess the feasibility and scope of locksmith operations to remove metal from the laser-affected zone.

Keywords: gas laser cutting, temperature field, finite element method, rolled steel, calculation model.

New materials and technology

Prokopov A. N. New technological solutions for ensuring the quality of the parts surface

This article describes methods for mechanical deburring, polishing, and removal of marks from a cutting tool. The use of a number of different tools and examples of workpieces are examined. As a result of testing, an increase in productivity, an improvement in the roughness class, removal of burrs, and restoration of the honing mesh were revealed. The stability and predictability of the result is also observed.

Keywords: deburring, automation of plumbing, roughness class, polishing, hole machining.

Sannikov A. V., Stoyanov T. Yu. On the use of lining in the manufacture and repair of various types of equipment

1. V. Sannikov, T. Yu. Stoyanov

Saint Peterburg State Marine Technical University, Saint Peterburg, Russia

Lining — fixing a thin-walled sleeve (liner) in a thick-walled pipe (carrier pipe) or a shell of another shape, which protects the product from corrosion and other types of wear. Lining is used both for refurbishment and for the manufacture of bimetallic pipes. The article discusses the options for using lining, and also describes the main methods of fixing the liner in the carrier pipe.

Keywords: lining, liner, tubing, stripper distiller, bimetallic pipes, pipe clamping, hydraulic expansion, tape-screw cone rolling.

Vasilkov D. V., Alexandrov A. S., Golikova V. V., Cherdakova V. S. Investigation of the sensitivity of a dynamic model of a technological system to changes in parameters during mechanical processing

A method for studying the sensitivity of a dynamic model of a technological system to changes in parameters during mechanical processing is proposed, which is based on the displacement of the stability boundary. The sensitivity function is constructed in the form of a polynomial regression equation depending on the variable parameter. It represents a change in the response function as a result of the displacement of the stability boundary in relation to the characteristic points associated with absolute stability. The criterion evaluation is a functional in the form of a uniform metric of the integral characteristics of the sensitivity function.

Keywords: sensitivity function, dynamic model, technological system, stability boundary, mechanical processing, polynomial regression, uniform metric.

The organization and production control

Sokolov Yu. A., Gusev S. A. Simulation of production systems

This article discusses the formalization of the manufacturing system design process using the Unified Modeling Language (UML). Examples of construction of production system models for implementation of selective laser alloying technology are given.

Keywords: production systems, object-oriented approach, simulation language, selective laser alloying, hardware design, class model, model types.