RU2660497C2 - Method of plastic structure formation of metals in intensive plastic deformation and a device for its implementation - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of pressure metal treatment and can be used to produce an ultra-fine grain metal structure in ring billets. Ring billet is placed on a die and the inner and peripheral parts are alternately deformed by repeating the reverse and direct extrusion operations. Two movable hollow punches are used. First punch is installed inside the second one. Reverse extrusion operations of the ring billet are performed by applying extrusion force to the first punch and back force to the second punch. Direct extrusion operations are carried out by applying extrusion force to the second punch and back force to the first punch.

EFFECT: as a result, the ultra-fine grain structure in massive forgings is obtained.

2 cl, 5 dwg, 3 tbl

Description

The invention relates to the field of metal forming, and can be used to obtain ultrafine-grained (UFG) metal structures in ring blanks, including large ones.

A known method and device for the structuring of metals by deformation of a metal billet by upsetting with torsion [1]. The method is as follows: the workpiece is installed on a stationary lower press plate, then it is exposed to the upper press plate moving on the workpiece, which (the plate) simultaneously translates, producing draft of the workpiece and rotational movement - torsion of the workpiece.

The disadvantage of [1] is the restriction on the size of the workpiece, the workpiece should not exceed the size: diameter 10 mm, thickness 1.2 mm

A known method and device for structure formation of metals by rolling them between two or more smooth rolls of large diameter [2]. The method is as follows: the workpiece is fed into the space between two smooth rotating rolls, it is captured by them and subjected to rolling between them, i.e. reducing one size by increasing the other two. If required, the workpiece is subjected to re-rolling between the rolls installed with a smaller gap, to further reduce the size of the workpiece.

The disadvantage of [2] is the inability to obtain ring blanks with large dimensions and a fine-grained structure.

A known method and device for the structure formation of metals with equal channel angular pressing [3], the device contains a node for deformation, having two communicating channels, one of which is placed the workpiece, and a node for loading, with which the workpiece is pushed into the second channel, this channel node for deformation are located at an angle to one another and have the same diameters equal to the diameter of the workpiece.

The disadvantage of [3] is the limitation on energy-power parameters, in particular on the strength characteristics of the pressing matrix, which in turn affects the maximum dimensions of the workpiece. It is also a certain technical difficulty to create a high hydrostatic compression pressure in this circuit to increase the ductility of the metal.

A known method and device for the structuring of metals during deformation according to the hourglass [4], in which a cylindrical metal billet in a cold state is subjected to direct extrusion and sediment in several cycles. The method involves repeated deformation of the preform with preservation of its original shape and size after each deformation cycle, while the deformation of the preform in each cycle is carried out by extrusion followed by simultaneous settlement of the extruded part of the preform, and in each subsequent deformation cycle, the extrusion direction is reversed relative to the direction extrusions in the previous cycle.

The disadvantages [4] are the restrictions on the dimensions of the workpiece and on power parameters, as well as on the strength parameters of the matrix for pressing.

The closest to the essence of the claimed invention, the prototype is a method of structure formation [5], which consists in the fact that for plastic structure formation a heated billet is placed in the annular channel of the matrix, and then deformed by forcing through intersecting annular channels through an annular punch. During deformation, transverse extrusion is carried out.

The disadvantage of the prototype [5] is the impossibility of manufacturing large-sized blanks and blanks in the form of rings.

The technical result of this invention is to obtain UFG structures in massive forgings from metals and alloys having a ring shape.

The goals are achieved by the fact that the workpiece is sequentially deformed by direct and reverse extrusion, until the desired material structure is achieved. The deformation is performed according to one of the following algorithm or a combination of algorithms (Fig. 1):

1. The initial state (A) - reverse extrusion (U ₁ ) of the shaped ring - the formation of the original shape (O _to ) by direct extrusion from the U of the shaped ring (A + U ₁ → Ok);

2. The initial state (A) - reverse extrusion (T ₁ ) of the shaped ring - the formation of the original form (O _to ) by direct extrusion from (T ₁ ) the shaped ring (A + T ₁ → O _to );

3. The initial state (A) - reverse extrusion (U ₁ ) of the figurative ring - the formation of the original form (O) by direct extrusion from (U ₁ ) the figurative ring - reverse extrusion (T ₂ ) of the figurative ring - the formation of the original form (O _to ) direct extruding from (T ₂ ) a shaped ring (A + U ₁ + O + T ₂ → O _k );

4. The initial state (A) - reverse extrusion (T ₁ ) of the figurative ring - the formation of the original form (O) by direct extrusion from (T ₁ ) the figurative ring - reverse extrusion (U ₂ ) of the figurative ring - the formation of the initial form (O _to ) direct extruding from (U ₂ ) a shaped ring (A + T ₁ + O + U ₂ → O _k );

5. The initial state (A) - reverse extrusion (U ₁ ) of the figurative ring - the formation of the original form (O) by direct extrusion of the (U ₁ ) figurative ring-groove (K) - reverse extrusion (U ₂ ) of the figurative ring - the formation of the original form (O _k ) by direct extrusion of a (U ₂ ) shaped ring. (A + U ₁ + O + K + U ₂ → O _k );

6. The initial state (A) - reverse extrusion (T ₁ ) of the shaped ring - the formation of the original shape (O) by direct extrusion of the (T ₁ ) shaped ring-groove (K) - the reverse extrusion (T ₂ ) of the shaped ring - the formation of the original shape (O _k ) by direct extrusion of a (T ₂ ) shaped ring (A + T ₁ + O + K + T ₂ → O _k );

7. The initial state (A) - reverse extrusion (U ₁ ) of the figurative ring - the formation of the original form (O) by direct extrusion of the (U ₁ ) figurative ring-groove (K) - reverse extrusion (T ₂ ) of the figurative ring - the formation of the original form (O _k ) by direct extrusion of a ring (A + U ₁ + O + K + T ₂ → O _k ) from (T ₂ );

8. The initial state (A) - reverse extrusion (T ₁ ) of the shaped ring - the formation of the original form (O) by direct extrusion from (T ₁ ) the shaped ring - canting - reverse extrusion (U ₂ ) of the shaped ring - the formation of the original form (O _to ) by direct extrusion of a (U ₂ ) shaped ring.

To select the most rational deformation schemes and parameters of devices for deformation, modeling was performed. The results of modeling the stress-strain state (VAT) in the QForm software package according to the indicated algorithms are presented in Appendix 1.

The essence of the claimed invention is illustrated: FIG. 1, where A is the initial state; U, T - reverse extrusion; O - direct extrusion; one; P ₁ -P ₂ - extrusion forces at different stages, R _p - backpressure force; v1, v2 - tool speed; FIG. 2, where 1 is the first movable punch, 2 is the second movable punch, 3 is the body, 4 is the workpiece, 5 is the matrix, 6 is the core; D _k is the outer diameter of the housing, D is the outer diameter of the second movable punch, d ₁ is the inner diameter of the first movable punch, d ₂ is the outer diameter of the first movable punch / inner diameter of the second movable punch.

The device operates as follows.

A metal, annular, workpiece is placed on the matrix 5, in the gap between the rod 6 and the housing 3, then movable punches 1 and 2 are installed on the workpiece (Fig. 2). The deformation is carried out by applying a force P ₁ to the edges of the movable punch 1, a back pressure P _p (reverse extrusion) is applied to the movable punch 2, which leads to an increase in hydrostatic pressure and, accordingly, the plasticity of the workpiece. The movement of the punches is carried out until a specified distance is reached (from 10 to 50% of the length of the workpiece), then the pressure P _{2 is} applied to the second movable punch 2, and the force P _{p is} applied to the first movable punch 1 (direct extrusion). Next, the process is repeated as many times as necessary, after which the punches 1 and 2 are removed, the case 3 with the workpiece and the core 6 in it is turned (turn over) 180 °, the body 3, with the workpiece located in it, is placed on the die 5, the punches 1 are installed and 2, the process is repeated.

The first and second movable punches are made with round radii, their value is directly proportional to the diameter of the workpiece.

The matrix, the first and second movable punches are made with a cone-shaped part. The parameters of the cone-shaped part are directly proportional to the ductility of the deformable workpiece (Appendix 2).

The implementation of the proposed method provides ultrasound of the structure of the ring blanks by accumulating the degree of deformation due to the repetitive operation of direct and reverse extrusion. The device provides alternating deformation of the peripheral and inner part of the workpiece, which allows you to adjust the size of the fine-grained zone in diameter (Appendix 2).

Compared with the prototype of the claimed invention allows to deform large annular forgings to obtain a given structure of the material by combining the operations of direct and reverse extrusion. Back pressure allows you to maximize the ductility of the material by creating comprehensive compression and to avoid defects inherent in extrusion.

The proposed device is advisable to use at engineering, aerospace, shipbuilding enterprises to obtain ring blanks with an ultrasound structure for the further manufacture of highly loaded parts such as turbine disks.

The present invention satisfies the criteria of novelty, since when determining the level of technology, no means have been found that have characteristics that are identical (that is, matching the functions performed by them and the form in which these signs are performed) to all the signs listed in the claims, including the purpose of the application.

The inventive method has an inventive step, because it has not been identified technical solutions having features that match the distinguishing features of this invention, and the popularity of the influence of distinctive features on the specified technical result is not established.

The inventive method was tested on full-scale samples of aluminum alloy AD-1, the results had deviations from the simulation results by no more than 15%.

Information sources

1. Subich V.N., Demin V.A., Shestakov NA., Vlasov A.V. Stamping with torsion. - M.: MGIU, 2008 .-- 389 p.

2. Forging and stamping: Handbook. In 4 t. / Ed. tip: E.I. Semenov (previous) and others. - M.: Mechanical Engineering, 1986. - T. 2. Hot stamping / Ed. E.I. Semenova, 1986. 592 p., Ill., P. 387.

3. A.S. 492780 USSR, MKI ³ G01N 3/00. Device for hardening material by pressure / V.M. Segal, V.Ya. Schukin (USSR). - 1924516 / 25-28: Declared June 11, 73. Publ. 02/23/76. Bull. 43.

4. A.S. 1741960 USSR, MKI ⁴ B23J 5/00. The method of plastic structure formation and device for its implementation / Amirov M.G., Greshnov V.M., Golubev O.V., Lavrinenko Yu.A. Application 4763954 / 25-27 from 4.12.89, publ. 02.22.92, bull. 23.

5. RF patent No. RU 2450882 C2, B21J 5/00. The method of hardening the ring billet channel angular pressing and a device for its implementation / Ivanov A.M., Ivanov V.A., M.A. Ivanov. Publ. 05/20/2016. - 6 p.

Claims (2)

 1. The method of plastic structure formation of a large-sized metal annular billet, comprising deforming the annular billet placed on the matrix to the required level of grinding of the microstructure, characterized in that the inner and peripheral parts of the annular billet are alternately deformed by repeating the reverse and direct extrusion operations with two movable hollow punches, the first of which installed inside the second, while the operation of reverse extrusion of the annular workpiece is carried out by applying a force to first extrude the punch and counter-force to the second punch, and the direct extrusion operation carried out by application of force to extrude the punch and the second force counter to the first punch. 2. A device for the plastic structure formation of a large-sized metal annular blank containing a matrix with a rod and a hollow punch, characterized in that it is provided with a housing forming a gap with a matrix and a rod for installing the annular blank, and a second hollow punch, inside which the first hollow punch is installed wherein the first and second hollow punches are configured to move and alternately deform the inner and peripheral parts of the annular blank by repeating the operas of reverse and direct extrusion when applying each of them to one of these hollow punches extruding forces, and to the other - back pressure forces.

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