Poksevatkin M. I., Ivanaysky A. A., Ivanayskaya E. A., German S. V., Basova E. M.

Modeling of the process of reverse extrusion of thin-walled hollow products with activation of contact slip of metal

A mathematical model of the process of reverse extrusion of thin-walled hollow products with the activation of contact slides on the bottom of the matrix (the end of the ejector) is developed. A three-module optimization algorithm has been designed, which makes it possible to control the power and kinematic parameters of the process in order to increase its efficiency.
Keywords: mathematical model; reverse extrusion; thin-walled products; activation of metal contact slides; algorithm; efficiency.

Ovechkin L. M., Sosenushkin E. N., Sosenushkin A. E., Krivenko G. G.

Evaluation of technological efficiency of the process of equal channel angular extrusion

The lows of equal channel angular extrusion process estimation on the basis of surplus view and geometrical piece distortion in the process of deformation.
Keywords: equal channel angular extrusion; surplus; deformation; piece; estimation.

Vaytsekhovich S. M., Panov D. V., Krivenko G. G., Bereznikov Yu. I.

New technologies of tube riffles forming and development of recommendations for improving heat exchangers

The question of increase of the coefficient of the fins of smooth tubes for boilers of utilization and other high temperature heat exchangers, the efficiency of the surface of the fin pipe heat exchangers, e.g. for combined-cycle plants and the replacement of smooth tubes on the tube zhelobkova spiral-shaped (SPT) – passive intensity-pictorama heat transfer.
Keywords: technology; the cross-fins; spiral-shaped tube (SPT); heat exchanger; hydraulic resistance; flow of a viscous fluid; brazed finned tube.

Kozhevnikova G. V., Rudovich A. O., Shchukin V. Ya.

Increasing of fatigue strength of shafts through the cross-wedge rolling process

As a result of large accumulated strains and compression stresses in the contact area of the deformation zone cross-wedge rolling forms in facial layers of shafts a metal structure that prevents nucleation and growth of fatigue cracks. Residual compression stresses that are present in the facial layers of shafts after rolling also facilitate the effect of increased fatigue strength of shafts.
Keywords: plastic deforming; cross-wedge rolling; fatigue strength of shafts.

Kolmogorov G. L., Melnikova T. E.

Hydrodynamic effect of technological lubricant during upset forging

The results of mathematical modeling of compression conditions of the technological lubrication between the tool and the workpiece for upset forging are presented. formulas for calculating the thickness of the lubricating layer are obtained, which include the main technological parameters of upsetting. using the experimental method of moire bands the effectiveness of the proposed calculation formulas is shown. the results of the work explain the more effective lubrication for upset forging on the hammers compared to this process on the press due to a significant difference in the working speeds of the forging and pressing equipment.
Keywords: upset forging; lubricant; hydrodynamic effect; frictional conditions; deformation; forming processes; moire stripe method.

Tyurin V. A.

Phenomenology of macroshears during deformation with crossed working surfaces dies

Some findings of new phenomenon investigation what taking place during deformation of cylindrical blanks with crossed working surfaces dies are presented at the paper. Three forging processes using macroshears – by “rings”, by “passes” and by “screw” were realized in production. Unexpected results on a different deformation action of a die working surface front on material extrusion directions are obtained – for example in forth, but two directions. It is a phenomenon of sign changing shifts, what happens in five plans and in four parts of material extrusion. Quantitative estimations of macroshears effect are proposed.
Keywords: macroshears; dies; crossed working surfaces; deformations; alternating shear.