RU2532625C1 - Hot forging of semis from cylindrical billets - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to blank production and can be used in press shop in production of semis. Blank is arranged in capsule with cylindrical wall and flat bottoms. Capsule is fitted in container pass through hole, container being mounted at press bed to displace axially thereat. Through hole length part features diameter corresponding to capsule wall OD. Bore features diameter corresponding to capsule wall ID on side facing the pressure male diameter. Axial force P_ax is applied by pressure male die with diameter corresponding to ID of capsule wall ID via one of capsule bottoms. Blank thrusts via second bottom on support male die. Force P_c is applied to container in direction opposite that of force P_ax application. Force P_pres is applied ion direction of force P_ax application at termination of forging stage. Note here that P_ax<P_c<P_pres.

EFFECT: higher quality of semis.

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Description

The invention relates to procurement and can be used in forging shops of metallurgical and engineering plants.

There is a method of hot pressing a semi-finished product from a workpiece, the latter being mounted in a capsule. This method is often used to increase the density of pre-pressed (or sintered) billets from powders of metal alloys, discrete metal materials, pressure treatment of metal castings to remove internal discontinuities formed during their solidification, etc. (see A. Prokhorov. Isostatic presses for cold and hot pressing of products. Page 5, publ. 02/11/2013 - Internet address:

http // www / ruscastmgs.ru / work / 168/5617/5664/6636).

This method provides high quality semi-finished products and allows you to bring their properties closer to semi-finished products obtained using deformation technologies.

The disadvantage of this method is the difficulty of ensuring the uniformity of the properties of the resulting semi-finished products throughout their volume.

There is a method of hot pressing a semi-finished product from a cylindrical billet, the latter being mounted in a metal capsule with a cylindrical wall and flat bottoms, comprising placing the capsule in the through hole of the container stream, and this opening is made with a diameter that corresponds to the outer diameter of the cylindrical wall of the capsule moreover, an axial force is applied to the workpiece by a pressure punch with diameters corresponding to the inner diameter of the cylinder the walls of the capsule, through one of the said bottoms with its support through the second of the said bottoms on a support punch fixed to the press frame (see US Pat. No. 7037466, class 419/48, publ. 2006 - prototype).

The disadvantage of this method is the irrational deformation scheme that does not provide "study" of the Central zone of the semi-finished product.

The proposed method of hot pressing a semi-finished product from a cylindrical billet mounted in a metal capsule with a cylindrical wall and flat bottoms, includes placing the capsule in the through hole of the container stream. On a part of the length, this hole is made with diameters D _b corresponding to the outer diameter of the cylindrical wall of the capsule. An axial force P _os is applied to the workpiece by a pressure punch with diameters D _m corresponding to the inner diameter of the cylindrical wall of the capsule, through one of the said bottoms with its support through the second of the said bottoms, onto a supporting punch fixed to the press frame.

On the container side, facing the pressure punch, on the rest of the said hole of the stream is made with diameters D _m corresponding to the inner diameter of the cylindrical wall of the capsule. The container itself is mounted on a press frame with the possibility of axial movement. To the container is attached _{to a} force F in a direction opposite to said axial force F _a, and the final step of hot pressing the container and attached punch force _P-touch in the same direction as the force F _a, wherein said addiction related efforts:

P _OS <P _to <P _press

The proposed method differs from the prototype method in that, from the container side facing the pressure punch, the rest of the length of said stream opening is made with diameters D _m corresponding to the inner diameter of the cylindrical wall of the capsule. The container itself is mounted on a press frame with the possibility of axial movement. To the container is attached _{to a} force F in a direction opposite to said axial force F _a, and the final step of hot pressing the container and attached punch force _P-touch in the same direction as the force F _a, wherein said addiction related efforts:

P _OS <P _to <P _press

The technical result of the use of the invention is that by optimizing the “study” of the central zone of the semi-finished product and streamlining the deformation scheme, a high-quality semi-finished product is obtained.

The invention is illustrated by drawings, where Fig. 1 shows a capsule with a workpiece before hot pressing;

Fig. 2 schematically shows the experimental stamp in the initial position (before hot pressing);

Fig. 3 - the same, at the time of sampling the gap A;

Fig. 4 - the same in the final position (completion of hot pressing).

The present invention is illustrated by examples of the method of hot pressing of semi-finished products on experimental dies.

Example 1. A pre-prepared blank 1 (Fig. 1) made of MA-14 magnesium alloy granules pressed to a density of 0.62 from the density of a solid material is placed in a degassed and sealed metal capsule in the form of a cylindrical wall 2 and welded bottoms 3 and 4. The dimensions of the workpiece - ⌀ = 150 mm; H = 190 mm. The experimental stamp (Fig. 2) includes a heated container 5 mounted on the bed 6 of the press with the possibility of axial movement. A stream is made in the container in the form of a through circular hole, a length part 7 of which has diametrical dimensions D6 corresponding to the outer diameter of the cylindrical wall 2 of the capsule. Part 8 of this hole is made with diameters D _m corresponding to the inner diameter of the wall 2 of the capsule. The capsule with the workpiece is heated and mounted in part 7 of the opening of the stream of the container on the support punch 9, mounted on the bed 6 of the press. In part 8 of the creek opening, a pressure punch 10 is placed. Between the side 11 of the bottom 3 facing the punch 10 and part 8 of the creek opening, a gap Δ is provided.

The gap Δ in the experiment is selected in the range (6 ÷ 8) mm. An axial force P _os (Fig. 3) is applied to the workpiece 1 through the bottom 3 by a pressure punch 10 and is supported through the bottom 4 by a support punch 9. The elastic element 12 exerts a force P _to the container 5 in the direction opposite to the direction of the force P _os . Wherein

P _to = (1.05-1.25) P _OS

Workpiece settling occurs. In this case, the cylindrical wall 2 is extruded in the direction opposite to the direction of the force P _OS , and after the clearance A is removed, the upward extrusion of the wall 2 is terminated. The workpiece is pressed under full compression.

At the final stage of the process (Fig. 4), with the stop of the lowering punch 10 in the container 5, the force P _os begins to increase, exceeding the force P _to and reaching the values of the force P _pressed . With such an effort, the support punch 9 is pressed into the wall 2 of the capsule lowering together with the container 5, and the part 13 of the wall 2 adjacent to this punch is pressed into the hole part 7 of the container stream. In this case, P _press = (1.1-1.35) P _to

When the lowering container 5 rests against the stroke limiter (not shown) on the press frame 6, the pressing process ends.

Then the capsule is removed from the container (not shown). By mechanical processing, for example, the capsule is separated from the finished semi-finished product.

The finished semi-finished product has a density (0.98-0.99) of the density of the solid material.

Example 2. A pre-prepared blank 1 (Fig. 1) in the form of a casting of aluminum alloy 1201 is placed in a steel capsule, analogously to example 1. The dimensions of the blank ⌀ = 145 mm; H = 175 mm.

Hot pressing is carried out as in example 1.

The finished semi-finished product has no internal discontinuities, such as porosity, internal shrinkage, and interdendritic cracks that formed during the solidification of the casting. Increases ductility and cyclic strength.

Thus, the proposed method allows the economical production of high-quality semi-finished products. Of particular importance is the method in the production of structural elements of modern aircraft.

Claims (1)

A method of producing a semi-finished product by hot pressing of a cylindrical billet placed in a metal capsule with a cylindrical wall and flat bottoms, comprising placing the capsule with the billet in the through hole of the container stream, which is made part of the length with a diameter corresponding to the outer diameter of the cylindrical wall of the capsule, and applying axial to the billet efforts P _{os a} pressure punch with a diameter corresponding to the inner diameter of the cylindrical wall of the capsule through one of the bottoms of the capsule with preparations through the second bottom of the capsule on the support punch mounted on the press frame, characterized in that they use a container mounted on the press frame with the possibility of axial movement, the through hole of the stream from the side facing the pressure punch, on the remaining part of the length is made with a diameter, corresponding to the inner diameter of the cylindrical wall of the capsule, wherein the force is applied to a container P in _a direction opposite to the direction of action of said axial force F _a, and the Finish ayuschey stage hot pressing the container and _punch-touch force F is applied in the direction of action force F _a, wherein said force associated dependence P _oc <P _{to <P-touch.}

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