SU995962A1 - Blank for pressing bimetallic articles - Google Patents

Description

(54) PREPARATION FOR THE PRESSING OF BIMETALLIC

one

The invention relates to the processing of metals by pressure, and more specifically to the technology of pressing polymetallic products (bars, pipes, profiles).

A bimetallic billet is known, consisting of a core and a shell, the gap between which at the rear end of the blank is sealed with a ring of material (polyester), whose yield strength is less than the yield strength of the shell material (copper). The ends of the shell and core at the rear end of the workpiece are in the same plane 1.

However, when pressing this type of blank, the quality of the welding of the parts of the blank is not sufficiently high, the end edge remains at a sufficiently high level.

Closest to the present invention is a billet for compacting bimetallic products, comprising shells with a conical lead-in area and a core concentrically installed in it with a conical lead-in area, jointly forming a gap along the height of the workpiece with a width in the zone between the conical thrust piece.

kami shell and core. The use of this preform allows the bimetallic products to be extruded with a high-pressure liquid 2.

The disadvantage of this stub is

5 that its use does not allow the uneven outflow of the shell material from the matrix point in the initial unsteady process, which is typical of bimetal pressing processes, to be avoided. Interior

The 1Q layer of the workpiece (core) in the initial stage of pressing is ahead of the casing, which leads to a significant unevenness of the cladding and determines a significant end cut at the front end of the finished product.

15 The purpose of the invention is to improve the quality of products by improving the uniformity of cladding.

This goal is achieved by the fact that - In the billet for pressing bimetallic, Q kih products; containing a shell with a conical lead-in area and a core concentrically mounted therein with a conical lead-in area, jointly forming a clearance along the height of the blank with a width decreasing towards the lead-in width in the zone between

the conical inlet areas of the shell and core, the gap in the area between the conical inlet areas of the shell and core are filled with bulk metal material having a bulk volume of 0, 4-0.6 volumes of this gap, and a hardness exceeding the hardness of the shell and core materials.

The drawing shows the blank, general view.

The preform comprises a shell 1, a core 2, a gap 3 between the shell and the core in the main portion of the preform, particles of metallic material 4 filling the gap 5 between the shell and the core at the front conical end of the preform. ki entering the die into the die.

The shell and the core are fixed relative to each other due to their contact at the end of the front end of the workpiece. The gap 3 between the shell and the core on the main part of the workpiece is constant, and at the front conical end of the workpiece the gap has the form of an annular gap narrowing from the main part of the workpiece to its end face, which is 0.4-0.6 of its volume filled with particles Higher than the hardness of the sheath and core materials.

Pressing bimetallic products using the proposed preform is carried out as follows.

A cylindrical flat or hollow core 2 is introduced into the cylindrical shell 1. After that, the front end of the preform is subjected to rolling, for example, on a roll forging machine. As a result of running in the front end at the front end of the preform, the shell and core come into contact and are fixed in a strictly defined position relative to each other. Next, the workpiece is installed in a vertical position and the particles of a substance sew up into the gap between the shell and the core.

The ratio of the bulk volume of the filler to the volume of the gap at the front end, And

sucker (O)

whose hardness is higher than the hardness of the shell and core materials. The bulk volume of particles is 0.4-0.6 the volume of the gap at the front conical prepared end (parameters were determined experimentally). Next, the workpiece is subjected to heating, placed in a container of a vertical press, setting the front of the prepared end in the matrix, and subjected to pressing. At the initial stage of pressing the particles of the substance 4 are pressed into the surface

the shells and the core are pressed together. This prevents the shell from sliding against the core and ensures reliable adhesion of the shell and the core, which leads to

At the initial stage of pressing, the shell and core are extruded almost simultaneously. This helps to increase the uniformity of the cladding and reduce the end trim. After the product has been fully extruded, the front section is cut, where filler particles are present in the interlayer zone. The product is going to finish.

Example. The pressing of the proposed billet is carried out under a 30 MN press for the production of carbon steel-stainless steel-type steel pipes. In order to fill the gap between the casing and the core of the filler, sawdust steel U8, is used. the hardness of which (HB) exceeds the hardness of carbon (HB 120) and stainless (HB 145-150) steel. In one series of experimentally used as filler sawdust bronze (HB 70-75). In the experiment, the relationship between the bulk volume of sawdust and the volume of the gap between the casing and the core at the conical end of the workpiece is varied.

The results of the experiment are given in the table.

Filler

End trim

1100 ± 50

Y8 950 ± 50

Y8 Y8

950 ± 25 95П ± 25

Y8 Y8

900 ± 25 900 ± 25

Y8 Y8 Y8 Y8 Y8

900 ± 25

925 ± 25

975 + 25

1000 + 25

1050 ± 50 onza

1050 ± 50

Experiment parameters: Shell size, mm130x36

Core size mm50x8

The gap between the shell and the core on the main part of the workpiece, mm4

The volume of the annular conical gap at the front inlet end of the workpiece after running in, mm 200 ± 10 Size of the finished pipe, mm 60x6

As follows from the data in the table, the optimum is the ratio of the bulk volume of the filler to the volume of the slit within A 0.4-0.6. At the ratio, 4, the core and the shell do not securely adhere to the initial stage of pressing. At, 6, the end trim increases due to the fact that the filler particles are present in the interlayer zone of the product at a considerable length of the front end. It also follows that the hardness of the filler should exceed the hardness of the materials of the shell and core, which ensures their reliable adhesion in the initial stage of pressing.

As follows from the data in the table, the use of the proposed preform allows a 15-20% reduction in the size of the end cut on the pipes due to a decrease in the longitudinal thickness variation of the layers.

Economic efficiency from the implementation of the invention in a press plant

Type 30 MN is about 200 rubles. per ton of finished products.

Thus, the invention allows significant metal savings, which gives an economic effect in the national economy of the country.

Claims (2)

1. The patent of Sweden No. 393757, cl. B 21 C 23/22, 1977. 2. US patent number 3807032, cl. B 21 C 23/22, 1974 (prototype I S H |. Wl l lltl