Poksevatkin M.I., German S.V., Basova E.M.

Improving the efficiency of processes for producing thin-walled hollow parts on the basis of contact friction forces

The article shows two aspects directly concerning to the process of forming a thin-walled hollow parts stamping by extrusion: correlation of the relative penetration depth of plastic deformation with the process parameters and their quantitative assessment; the relationship of kinematic and force factors in the process of forming a thin-walled hollow parts (including components) produced by the joint plastic deformation of the workpieces. The analytical dependencies of technological parameters of processing and implementing effective ways of forming by extrusion of thin-walled hollow parts using the active action of the contact forces of friction are provided. Activation of the contact slides processed metal also creates conditions for the formation of permanent connection of workpieces by means of their joint plastic deformation when receiving hollow composite parts. In addition, it is revealed that the greatest effect shows the method of indirect extrusion with rotating ejector on the end of which a radially extending depression. In this case, along with the activation of the contact slides on the bottom of the matrix, the metal of the deformation is forcibly pushed into the wall of the product, to minimize the thickness of the sidewall and bottom of the product.
Keywords: stamping the extruded; thin-walled hollow parts; activation; contact friction; composite hollow parts.

Lebedinsky I.N.

Analysis of broach in the manufacture of tubes according to the scheme «firmware– broach» on hydraulic presses with the support of the friction forces on the mandrel before the entrance to the deformation zone

The article shows the features of the broach through the annular grooves of the pipe, pre-compressed on a long holder, with the formation of the plastic wave front of the entrance to the deformation zone from the forces of friction on the holder. It is revealed that this causes the increase in the actual degree of deformation of the walls of the pipe, relative to the ratio of the cross section area of the hollow workpiece before and after deformation, and reduction of the permissible degree of deformation when the holder more than half of the original length of the pipe. The article describes the parameters of the plastic wave and the stroke of the mandrel corresponding to their maximum values, and the permissible degree of deformation based on the availability of plastic waves with a corresponding increase in the actual compression relative to the ratio of cross-sectional areas before and after deformation. Examples of the calculation of the admissibility of adopted compressions based on the data parameters are presented.
Keywords: deformation zone; broaching of pipes on a long holder through the annular groove; plastic wave; the friction on the holder; the friction forces thrust in front of the entrance to the deformation zone; the degree of deformation.

Gliner R.E., Katuyhin E.B.

Evaluation of formability of steel during cold forging

The prediction of formability of steels in cold volume stamping is considered in the article. At the same time taking into account the expediency of specific working deformed determined in a laboratory compression test. It is set specific correlation with yield strength is detected in the compression test, the same for different strength steels.
Keywords: steel; cold stamping; compression test; deformation; compressive deformation.

Baburin M.A., Baskakov, V.D., Zarubina O.V.

Drawing of metalfluoraplastic sleeves from disk workpieces of variable thickness

The article presents the results of research quality of metalfluoraplastic sleeves, made on the basis of a new low-operation technological process. This process is based on using a single drawing of a cylindrical cup from a disk workpiece of variable thickness. The article describes a stepwise description of the operations of the new method, as well as the practical experiment of receiving metalfluoraplastic bushing. The results of the study are found that the combination of a single drawing of glass from the disk of the workpiece of variable thickness, followed by hood provides a constant wall thickness and high quality anti-friction layer. In addition, the wear of the sliding layer meets the requirements for products of this type, and provides frictional properties at the level, at least not inferior staffing technologies.
Keywords: metalfluoraplastic bushing; variations in the thickness of the workpiece; extraction; limit the degree of extraction; anti-friction layer.

Loginov Yu.N.

Die rotation as a means of empowering the extrusion process

The aim of this article is identification of additional opportunities for using the rotation mode of the matrix during compaction. A new extrusion method based on the die rotation having the hole shifted from the center for metal outflow. It is found that using axisymmetric process ensures reduction of the forces of deformation. It is also shown the Schemes of extrusion that allow to solve the following problem: getting profiles of variable cross-section along the length of which varies or gradually or in a stepwise manner. Additional effect is identified: the possibility of separating article from the butt-end without using special devices. Results of experiments, confirming the possibility of the method are given.

Keywords: extrusion; die rotation; the extrusion rate; deformation.

Topolyansky P.A., Ermakov S.A., Topolyansky A.P.

Strengthening treatment of part-separation tooling with thin-film coatings

Theoretical aspects of achieving the maximum adhesive strength of the hardening coatings for shearing die matrix and punches, as well as for other units working in the same conditions (for instance, guillotine cutters), are given. Theory on minimization of the adhesive component of friction between the blank out part and the hardening coating of the shearing die is studied. The phenomenon of the greasing adhesion to the hardening material (the oil-retaining ability of the greasing) is described. Regarding the hardening Si-O-B-C-N system coating (deposited with the use of the finishing plasma hardening technology) the following is given: quantitative assessment of the adhesive strength by scratch-test in accordance with ISO 20502:2005, qualitative assessment of the adhesive strength in accordance with VDI 3198 (1991), research carried out by the methods of the scanning electron microscope investigation and Auger spectroscopy, tribological tests in accordance with ISO 20808:2004, research on the greasing adhesion work in accordance with DIN EN 828:2013-04 and DIN 55660-2:2011-12. Results of the punch shear dies and guillotine cutters with the Si-O-B-C-N system coating full-scale testing are showed.
Keywords: wear-resistance; punch shear dies; hardening; coating; shear dies durability.

Kremleva L.V., Malygin V.I.

Laser hardening of die tools

The article shows the results of experimental studies of the process of laser hardening of alloyed tool steels used for the manufacture of die tools. It is revealed that preliminary volumetric heat of steel samples has a significant influence on the quality of the surface layer in the laser hardening: the magnitude of residual stresses, the depth of hardening and the hardness of the surface. The growth temperature of pre-hardening tool steels has a positive effect on the indicators of the quality of the hardened layer, but leads to lowering of machinability that has a negative influence on subsequent machining operations and the clamping surfaces of the dies prior to surgery laser hardening.
Keywords: stamping tool; laser hardening; tempering; residual austenite; the depth of the hardened layer; microhardness.

Hardin, M.V., Burtsev, S.G.

Analysis of the possibility of occurrence of defects during hot stamping of large parts

The article considers the process of manufacturing large components by the method of die forging with the use ofcomputer programs based on the finite element method, such as QFORM, Deform, etc. It is analyzed the distribution of deformations, residual stresses and the formation of possible defects, the conclusions about the possibility of defects in certain areas of the product and recommendations for further mechanical processing. As a result, taking into account the symmetry of the fields of residual stresses on the plane of the connector, it is recommended to carry out machining by alternating passes over upper and lower surfaces of the workpiece. In areas with elevated residual stresses it is recommended to reduce the depth of stock removal in one pass to reduce the likelihood of warpage.
Keywords: forging; modeling; finite element method; deforming stress; stress-strain state.