SU733948A1 - Method of making laminated articles - Google Patents

Description

one

The invention relates to the field of mechanical engineering and can be used in the manufacture of polymetallic products, such as sheets, rods and pipes of dissimilar metals by means of pressure treatment.

A known method for producing multilayer products from dissimilar metals, in which the workpiece is hardened from a more durable metal (alloy), the assembly of a multilayer package from dissimilar metals (alloys); heating the package and its deformation 1.

 The described method meets the high demands placed on the strength of the welded joint. However, the presence of a smooth surface in the contact of dissimilar metals decreases the quality of multilayer products due to the inconsistency of the cross sections of the contacting layers and an increase in allowances for processing, if necessary, from the preparation of multilayer semi-finished products with chip removal.

The purpose of the invention is to eliminate the noted disadvantages of the known method.

2

The goal is achieved by the fact that before assembling the package components made of a more durable metal (alloy) are annealed at temperatures of 0.95-1.2 Tr (-Tp is the recrystallization temperature, ° C) ensuring the size of the recrystallized grain. 5 -40 microns. Heat treatment of a stronger component is performed or before

10 by assembling the bag, or in the process of heating the assembled bag before deformation.

Thermal treatment in the temperature range of 0.95-1.2 Tr leads

15 to the removal of strain hardening and aims at aligning the mechanical properties of the workpiece in different directions. .

In addition, with a regulated size of recrystallized grain (5–40 µm), the grain boundaries and their area reach significant values. The latter, under the conditions of pressure treatment at

Claims (1)

25 elevated temperatures, for example, 0.7–0.9 Tr (that is, when diffusion processes play an important role in the mechanisms of plastic deformation) provide a drastic decrease in the strength characteristics and significantly reduce the possibility of manifestation of anisotropy of mechanical properties; crystals. In the process of pressure treatment at the above temperatures, which promote the alignment of the mechanical properties of the package j of the fine grain, the structure of the billet of a stronger metal is deformed, not only by sliding (as in the case of a bullet material), but also by shifts along the grain boundary and turning past. As a result, structural elements of a billet of a more durable metal, which are responsible due to the anisotropy of mechanical properties in them for shaping the relief, become (for example, during pressing) unable to resist (locally) selectively against radial compressive stresses evenly distributed around the perimeter. do not form protrusions and depressions on the surface. Thus, after deforming a multilayer package, in contact of dissimilar metals, an even surface is obtained and thus a high accuracy of the layers in the M13 OILDING product is achieved. According to the results of the conducted studies, the following conditions are optimal for:; processing of the billet of a more durable metal with ensuring the size of recrystallized grain, 15 25 microns. The lower limit of the temperature range (0.95 Tr) with long isothermal exposures used x in the practice of heat treatment of materials with a low coefficient of thermal conductivity. From burning the blanks at the upper limit of temperature (1.2 Tr) implies a high-speed heating (over 100 ° / sec), as a result of which the onset of recrystallization shifts to high temperatures by 5-15 % "EXAMPLE. It was carried out, the manufacture of bimetallic pipes, low angle roddist steel, grade 3, alloy VM-1 molybdenum. Size of pipes 15, 9x8,5 mm, Raw materials, steel, grade Art. 3 - 40 mm bar, hot-rolled molybdenum alloy VI-1 - mm bar, crimped with a degree of deformation of 5% by pressing at 1000 ° C, Temperature of the recrist-closest alloy, Production of the pipe is carried out as follows. The VM-1 alloy bar was annealed at a temperature of 1500 ° C (1.07 Tr) for a period of 1 h in vacuum with a residual pressure I-IO mm Hg. After firing, the size of the recrystallized mirror is 25 µm. From the obtained semi-finished product, the hollow-cylindrical billet is machined out of the obtained semi-finished product and set into a glass made of steel of st. 3. A sleeve with an outer collar, intended for sealing the surface of the joining of dissimilar metals and made of steel, st. 3. The assembled bag is welded on an electron beam installation in a vacuum not worse than 1 Hg, heated in an induction furnace to a temperature of 1100-1150 ° C (0.78-0.82 Tr) and pressed on a needle with a stretch ratio 8. Control For the state of the contact surface of the steel with molybdenum alloy, a visual inspection of the pipe made of VM-1 alloy is performed after removing the steel cladding layer from its surface by chemical etching, as well as on bimetallic pipe cross sections. The proposed method was also tested by pressing bimetallic pipes steel Х18Н10Т - ВН-1 alloy, steel Х18Н10Т - niobium alloy, steel of steel grade. 3 - tungsten alloy. The dimensions of pipes varied from 16.0x11.0 to 36.0x32.0 mm. The results of the experiments were similar to those obtained in the manufacture of bimetallic pipes Art. 3 - alloy VM-1. The proposed method for producing GOST-LAYERED articles from dissimilar metals (alloys) in comparison with existing methods provides the following advantages. The accuracy of the cross sections of the layers of dissimilar metals in the product increases, thereby improving the quality of the latter, the possibility of manufacturing poly-metal products with particularly thin layers and a constant volume content of the components in each section of the product, as well as an increase in the yield of multilayer products tiyem chips due to the reduction of allowances for processing. Claims The method of manufacturing laminated products from dissimilar metals, including assembling the components into a package, heating and plastic deforming the assembled package, characterized in that, in order to improve the quality of the products, 57339486 assembling into a package, components, information sources, of durability, taken into consideration during the examination annealed at a temperature of atura equal to 1. USSR author's certificate 0.95-1.2 temperature recrystallization according to application number 2640448 / 25-27, zinc 21 C 23/24, 09.03.77.