SU1346377A1 - Method of producing bimetallic tubes - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in the manufacture of bimetallic pipes on batch machines. The aim of the invention is to improve the quality of bimetallic pipes by improving adhesion between the layers. The workpiece is served in the deformation zone. In the reduction zone, the billet is burned in diameter, in the crimping zone, both in diameter and in wall thickness over a length of 0.15-0.3 of the compression zone. Such a scheme of the process ensures maximum compression in the wall thickness and minimum compression in diameter, which allows to keep the layers in tight contact and eliminates delamination. 1 il., 1 tab. 10 (L 4 and with

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of bimetallic pipes in batch mills.

The purpose of the invention is to improve the quality of bimetallic pipes by improving adhesion between the layers.

The drawing shows a process diagram.

The method is carried out as follows.

The workpiece 1 is fed to a deformation zone of length 1, consisting of successively located zones of reduction 1;, eA and reduction Ifffjif In the zone of reduction, diameter reduction is carried out. In the process of further deformation in. Crimping zone 1oBzi. On the base 2, the workpiece is crimped both in diameter and in wall thickness. The prerequisite for welding the layers is to create a maximum reduction in wall thickness and a minimum in diameter. In the proposed method, 2/3 of the total reduction in wall thickness is determined on the first part of the crimping zone with a length of 0, losjii.

3-. | -

where t, and tj. - wall thickness of the workpiece and the finished pipe; t. - wall thickness in the area of the crimp zone length

ooz

- 0.15 -4- 0.3 1

OSjis, as a result, at the beginning of the blooming zone, high specific pressures between the layers develop, heat deformation is intensely released, which promotes the setting of the layers. In the second part of the compression zone, the deformation occurs in a falling mode and the creation of conditions with low degrees of deformation allows the layers to remain in tight contact at elevated temperatures, ensures uniform deformation, which eliminates the appearance of delamination and increases the accuracy of the pipes.

The amount of crimping along the wall thickness at the initial part of the crimping zone, which is 0.15-0.3 of its total length, established experimentally and constituting 2/3 of the total crimping, is determined by the conditions for obtaining strong welding between the layers. A smaller amount of reduction in the specified area does not provide

removing irregularities on the contact surfaces and, consequently, welding of layers, and at larger, steel is destroyed (sho and oxidation of the surfaces to be welded. When deformation (wall cutting) is carried out on the length of the compression zone, from in general, the metal flows little in the longitudinal direction, resulting in significant ovalization, which contributes to the destruction of the weld between the layers. um in a large volume of space and longer time, resulting in the metal per unit volume per unit time is recovered and less heat Melting at the boundary layers is insufficient to form a weld.

An example is made. The bimetallic billet is made from the basis of Article 10, MZR grade copper clad inside. and hot water.

To displace air from the annular space and eliminate oxidation of the surfaces to be welded, when heating, the coaxially assembled pipes are subjected to joint distribution until the layers are completely in contact.

Then, the bilayer preform is heated by an inductor (which is located in front of the deformation zone) to 500 ° C and rolled along the route of 65 liters 9 mm - X 4.5 mm with a reduction of 20% and a reduction in wall thickness of 50%, a deformation through the inner diameter of 9%. The compression along the wall of 50% is smoothly distributed over the entire length of the crimping zone, equal to 490 mm (deformation of 5% by 49 mm) ..

In the manufacture of pipes of the same batch by the proposed method, everything is used as for the known, but the deformation through the wall thickness after reduction is carried out with a reduction of 2/3 by 0.1; 0.15; 0.22; 0.3; 0.4 vol. 490 mm of the crimping zone, counting from its beginning, i.e. by 49 mm; 73.5 mm; 107.8 mm; 147 mm; 196 mm.

Further wall crimping is carried out smoothly on the remaining part of the crimping zone. The proposed method obtained bimetallic pipes STU + MZR; CrlO + bxiSHIOT CAB1 + ADO. By a known method, these pipes can not be obtained.

The results of the comparative tests are shown in the table.

The proposed method, in comparison with the known method, provides bimetallic pipes with high quality, and provides layer welding that is robust along the entire length and perimeter. In addition, the product range is expanded in terms of the materials to be combined as a result of an additional release of .10 + copper.

Art.10 + + OH18N10T

SAV1 + ADO

Famous

St.1R + copper

Art.10 + + OH18N10T

CABI + ADO

0.1 0.15

0.22 0.3 0.4 0.1

0.22

0.4 0.1

0.22 0.4 5% by 49 mm

Also

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Claims (1)

heat generated by large reductions in a short area. Invention Formula A method of manufacturing bimetallic pipes, including coaxial assembly of layers with prepared surfaces, deformation to tight contact of the layers, heating the billet and rolling it with successive reduction and reduction in wall thickness, so as to improve the quality of bimetallic pipes by improving adhesion between the layers, rolling with compression along the wall thickness begins with a compression equal to 2/3 of the total amount of compression on the length (0.15 - 03) laffxt, D 06vc the length of the compression zone. Destruction of the base layer, no welding Durable welding along the entire length and perimeter, lack of delamination l is the same There are local bundles Cracking of pipe ends, oxidation of welded surfaces, no welding Lack of bundles Welding in some places Metal leakage in releases, formation of whiskers and sunsets, lack of welding Durable welding along the length and perimeter Local bundles Weak welding along the length of the pipe No welding Local delamination Editor N. Tupitsa Compiled by I.Nikolaeva Tehred A. Kravchuk Order 7001 TapajK 922 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, st. Project, 4 Proofreader L. Pilipenko Subscription