RU2570268C1 - Method of plastic structuring of metal - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: multiple deformation of blank is performed by means of its pressing-through by punch through coaxially located first and second channels of die. The first and the second channels have similar cross-sections in form of rectangular, ration width:height is in range from 2:1 to 3:2. The cross-section of the second channel is at angle 90° relatively to the cross-section of the first channel. Between the channels the transient zone is located, in which deformation is performed with change of profile of the blank cross-section. Upon the blank reception after pressing-through the second channel with cross-section that is smaller then cross-section of said channel, during repeated deformation the blank is reduced in the first channel to initial dimensions.

EFFECT: increased strength characteristics of treated material.

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Description

The invention relates to the procurement of machine-building enterprises and can be used to obtain ultrafine-grained (UFG) materials, billets with a crushed homogeneous equal density structure for the further manufacture of highly loaded parts in mechanical engineering, aircraft manufacturing, medical equipment and petrochemicals.

A device is known for hardening metal by pressure, containing a node for deformation, having two communicated channels, in one of which the workpiece is placed, and a node for loading, with which the workpiece is pushed into the second channel. The axis of the channels are located at an angle to each other and have the same diameters equal to the diameter of the workpiece (AS USSR No. 541877, C21D 7/00, B21J 5/00, 1977).

A known method of metal forming by deposition of a workpiece in a deforming tool by pushing a subsequent workpiece through a deforming tool, while upsetting the rear end of the previous and front end of the subsequent workpieces (AS USSR No. 595046, B21J 5/00, 1978).

The disadvantage of analogues is the heterogeneity of the fine-grained structure over the entire volume of the workpiece.

A device for processing metals by pressure angular pressing (RF patent No. 2333062, V23C 25/02, 09/10/2008), containing a matrix with three intersecting channels located therein - receiving, intermediate and output, and it is made with an additional channel following the output channel, fourth channel in the form of a calibration belt, the axis of symmetry of which is parallel to the axis of the receiving channel, the output channel is made uniformly tapering from the beginning of the channel to the calibration belt, while the cross-sectional area of the calibration belt with leaves no more than 0.95 of the cross-sectional area of the receiving channel, the symmetry axis of the receiving and output channels are at an angle of 10-50 °, and the symmetry axis of the receiving and intermediate channels are at an angle of 100-140 °, the intermediate channel has a length of at least H × sin (2θ), where H is the distance between the inner walls of the receiving channel, θ is the angle between the symmetry axes of the receiving and intermediate channels.

The disadvantage of the analogue is the complexity of the device.

The closest in technical essence and the achieved result to the claimed one is a method for producing workpieces with a fine-grained structure (RF patent No. 2191652, B21J 5/00, 10.27.2002), including plastic deformation of a workpiece from metals and alloys under specified thermomechanical conditions by pressing in a pressing container through a profiling tool installed in its pressing channel, which directs the flow of metal and creates a combined scheme of intense plastic deformation of torsion - upset - shear without breaking continuity bristle preform is carried out while repeatedly pressing and maintaining pressing direction or changing it on the contrary.

The disadvantage of the closest analogue is the heterogeneity of the fine-grained structure over the entire volume of the workpiece.

The objective of the invention is to increase the strength characteristics of the material, in particular the tensile strength and yield strength.

EFFECT: obtaining a homogeneous fine-grained structure over the entire volume of the workpiece without stagnant zones when exposed to intense plastic deformations.

The problem is solved, and the technical result is achieved by the fact that in the method of plastic structure formation of metal billets, including repeated deformation of the billet by pressing it with a punch through coaxially arranged first and second channels of the matrix, made with cross sections having the same profile and dimensions, and placed between the channels transition zone in which the workpiece is deformed with a change in the profile of its cross section; they are revealed through the first and second channels having cross sections in the form of a rectangle, the ratio of the width to the height of which is in the range from 2: 1 to 3: 2, the cross section of the second channel being located at an angle of 90 ° relative to the cross section of the first channel, while receiving the workpiece after being pressed through the second channel of the matrix with a cross-section that is less than the cross-section of the said channel, upon repeated deformation, the workpiece is upset in the first channel to the initial dimensions.

The friction force of the workpiece in the transition zone and in the second channel provides support for the deformation of the workpiece in the transition zone.

An increase in the friction force in the second channel will allow for a more complete filling of the transition zone by metal. This is achieved by narrowing the second channel to the exit to 10% in height and width.

In the process of deformation, the metal structure is crushed by intensive plastic deformation while maintaining the cross-sectional profile of the workpiece.

The invention is illustrated by the following drawings:

in FIG. 1 shows a General view of the device in its original position;

in FIG. 2 shows the relative position of the channels in the transition zone;

in FIG. 3 shows a diagram of forcing a workpiece into a second channel;

in FIG. 4 shows the initial stage of deformation of the second workpiece;

in FIG. 5 shows a transition zone made by repeating a turn of the section by another 90 °;

in FIG. 6 shows a longitudinal section of the transition zone of the matrix with two profile rotations along its axis by an angle of 90º;

in FIG. 7 shows a cross-sectional shape of a channel.

A device for implementing the method includes a matrix 1, a punch 2 and a workpiece 3 (Fig. 1). The angle α in the transition zone can be from 20 to 90º. Matrix 1 is made with two coaxial channels of rectangular cross section. Channels have the same profile and dimensions. The profile of the second channel is rotated relative to the first by an angle of 90 ° along its axis (Fig. 2). Between the channels there is a transition zone that provides a smooth transition of one rectangular section of the first channel into a rectangular section of the second channel.

The device operates as follows.

The workpiece 3 fits into the first channel of the matrix 1 and then the punch 2 is pressed into the second channel (Fig. 3).

The second workpiece during its deformation pushes the first until it is removed from the matrix 1 (Fig. 4). To facilitate separation, the workpieces are separated by a gasket. Thus, the preform remaining in the matrix is pressed into the second channel by the subsequent preform. After extraction, the workpiece can be subjected to repeated deformation. Moreover, if after pressing the workpiece into the second channel, the cross section of the workpiece is less than the channel section, i.e. Since it does not completely fill the channel, then upon repeated deformation in the first channel, sediment occurs to its initial size. Next, the deformation cycle is repeated as many times as necessary.

To increase the degree of deformation in one pass, the transition zone can be performed by repeating the rotation of the section by another 90 degrees (Fig. 5). A cross section of the transition zone of the matrix with two profile rotations along its axis by an angle of 90 degrees is shown in FIG. 6. Deformation in such a matrix is carried out as in the previous matrix. The ratio of the width B and the height P of the cross-section of the B / H channels can range from 2: 1 to 3: 2 (Fig. 7). To prevent the appearance of longitudinal folds, the cross-section angles can be made with a chamfer or radius.

An example of a specific implementation of the method

As an example, computer simulation was performed in the DEFORM 3D environment. A billet made of steel 10 (analogous to AISI-1010 steel) 30 × 20 × 90 mm in size was deformed by forcing the billet with a punch from the first channel of the matrix into the second through the transition zone. Then, after removing the preform from the second channel, it was placed again in the first channel and the deformation was repeated. The angle of inclination of the wall of the transition zone to the axis of the channels was 10 °.

During the simulation, the following assumptions were made: a deformation temperature of 20 ° C, deformation heating was not taken into account, a friction coefficient of 0.12, the workpiece material is isotropic, softened before deformation. The tool is taken absolutely tough. The material of the initial billet is accepted as plastic.

The billet filled the second channel when leaving the transition zone completely along the height of the channel and only partially by 80-90% in width. When moving into the first channel for re-deformation, the preform first precipitated and only then did it begin to push another preform through the transition zone. The distribution of the strain intensity over the cross section turned out to be uneven, less in the center along the axis of about 0.6, more to the periphery up to 0.8. After repeated deformation, the strain intensity was 1.1 and 1.5, respectively. A study of the deformation process, carried out using computer simulation, showed that the flow of material in the deformation channels occurs fairly uniformly. There is no folding, the metal almost completely (100% in height and 80-90% in profile width) fills the second channel of the matrix. Upon repeated deformation of the preform, it first settles in the first channel of the matrix and only then is the metal pushed through the transition zone into the second channel of the matrix.

When implementing the method used techniques that expand its technological capabilities:

- repeated deformation of the workpiece while maintaining the direction of deformation or changing it to the opposite;

- the second channel can be made tapering to the exit to increase the friction forces and create backwater forces;

- the rotation of the cross-sectional profile in the transition zone can be carried out once or, if necessary, twice or more times.

The proposed device is advisable to use in the procurement of machine-building enterprises to obtain blanks with a crushed homogeneous equal density structure for the further manufacture of highly loaded parts in mechanical engineering, aircraft manufacturing, medical equipment, petrochemicals.

So, the claimed invention allows to increase the strength characteristics of the material, in particular the tensile strength and yield strength, and to obtain a homogeneous fine-grained structure throughout the volume of the workpiece without stagnant zones when exposed to intense plastic deformations.

Claims (1)

The method of plastic structuring of metal preforms, including repeated deformation of the preform by pressing it with a punch through coaxially arranged first and second channels of the matrix, made with cross sections having the same profile and dimensions, and a transition zone located between the channels in which the workpiece is deformed by changing its profile cross-section, characterized in that the pressing of the workpiece is carried out through the first and second channels having cross-sections a rectangle shape, the ratio of the width to the height of which is in the range from 2: 1 to 3: 2, and the cross section of the second channel is located at an angle of 90 ° relative to the cross section of the first channel, while upon receipt of the workpiece after forcing through the second channel of the matrix with a cross section that is less than the cross section of the said channel, upon repeated deformation, the workpiece is upset in the first channel to the initial dimensions.

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