RU2539892C1 - Wire casting and plant to this end - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: plant comprises vacuum furnace 1 with crucible 2 and pipeline 5 composed of two parts, and mould 8 composed of circular frame. Circular pipes 9 with nozzles 10 are arranged at the frame posts. One part of pipeline is composed of a bend and comprises gaging sleeve 7 at its outlet. After metal smelting and melt degassing, this melt is tapped from the furnace via pipeline 5 and gaging sleeve 7. Note here that pipe bend part is revolved by mechanism 6 to shape fused metal at gaging sleeve outlet to spiral. Crystallising wire is cooled in chiller by nozzles and fed to collector 11 arranged inside the mould to make a bunch.

EFFECT: higher quality and mechanical properties.

2 cl, 2 dwg, 1 tbl

Description

The group of inventions relates to the field of metallurgy and can be used for the production of thin metal wire from aluminum-based alloys.

A known method of continuous casting of a thin metal wire, according to which the molten metal is placed in the tank, which serves an inert gas. To form wire from the reservoir, a calibrated liquid metal stream is released onto a moving substrate, continuously cooling the stream with a stream of liquid supplied to the substrate, while the turbulence of the supplied liquid is dissipated, which is accelerated before the metal stream enters it.

The installation for continuous casting of wire contains a movable substrate, a tank installed above it with an outlet pouring nozzle and a pipe for supplying coolant to the substrate, the installation being equipped with a grid installed perpendicular to the direction of movement of the coolant in the area between the outlet end of the pipeline and the outlet nozzle (see USSR patent No. 1819186, CL B22D 11/06, 1993).

As a result of the analysis of this solution, it should be noted that in the case of impact contact of a jet of molten metal with water, regardless of whether its flow is laminar or turbulent, the metal jet changes its cross section and sections with a reduced size (for example, diameter, if the wire has the shape cross-section in the form of a circle. All this sharply reduces the main characteristics of the obtained wire. In addition, using the metal cooling method used, it is impossible to obtain a sufficiently high crystallization rate and fine grain fifth structure. It is known that at high metal cooling rate (March ¹⁰ ÷ ¹⁰ April) K / s, the microstructure of semi-finished products have a fine grain structure, characterized by high physical-mechanical properties (strength, ductility). In the known solution the metal jet cooling is conducted at the initial time on the one hand, and not on all sides.When a liquid stream of metal enters the water between the water and the liquid metal, a steam jacket forms, resulting in a sharp deterioration in heat transfer.

A known method of casting wire, including melting metal, introducing alloying components into the melt, degassing the melt and releasing it through a heated pipe through a calibrating sleeve, followed by crystallization of the liquid metal jet in a cooling medium and removing it by means of a moving substrate to the collector, moreover, melting and degassing are carried out vacuum furnace at low vacuum, and crystallization is carried out in the mold with a cooling medium supplied in the form of atomized particles at an acute angle in the direction of motion of the crystal sprayed particles, the diameter of the sprayed particles of the cooling medium is not more than 0.01-0.1 times the diameter of the liquid stream of the crystallized melt, and the sprayed particles of the cooling medium are fed to the liquid stream of metal at an angle of 2-7 ° in the direction of movement of the liquid stream of the melt, and melting and degassing of the melt are carried out at a pressure of 10 ^-2 ÷ 10 ^-3 mm RT.article

The wire casting installation comprises a vacuum furnace with a crucible for melting and degassing the melt, a heated pipeline with a calibrating sleeve at its end, and also a substrate for supplying the obtained wire to the collector. The installation also contains a vacuum unit associated with the cavity of the furnace, a unit for supplying inert gas to the cavity of the furnace, and also a mold. The mold is installed under the calibrating sleeve of the pipeline and is made in the form of a hollow body with a nozzle for supplying a cooling medium and an axial hole for the passage of a stream of crystallized metal, the lower wall of the body is conical and the top pointing upwards, and at the bottom there are nozzles made at an angle in the vertical axis case, to the lower part of which a funnel having a conical shape is docked, while the mold nozzles are located at an angle of 2-7 ° to the vertical axis of the case, and the crow angle is Ki is 4-14 °.

(see RF patent No. 2467827, class B22D 11/00, 2012) - the closest analogue for the method and installation.

As a result of the analysis of this solution, it should be noted that during its implementation, the crystallization of a metal jet is carried out in the vertical section of the melt stream. In this case, it is very difficult to obtain a high-quality wire, since under the influence of the weight of the metal stream the initial diameter of the stream and thereby the wire is thinned, and due to pressure fluctuations in the furnace, the metal flow rate also changes, which also affects the change in the diameter of the resulting wire.

When drawing the resulting wire for this reason, frequent breaks occur, which significantly reduces the productivity of the process.

The contact area of the vertical section of the metal jet with the cooling medium is insignificant (small) and, due to its small extent, in order to obtain intensive cooling, it is necessary to increase the flow rate of the cooling medium due to its flow rate (pressure), which leads to the merging of the cooling medium jets, worsening of the cooling conditions, and thereby reduction of physical and mechanical properties of the wire.

The technical result of this group of inventions is the development of a method and installation, providing high-quality wire with enhanced physical and mechanical properties.

The specified technical result is ensured by the fact that in the method of casting wire, which includes melting metal in a crucible placed in a vacuum furnace, degassing the melt and releasing it through a pipe through a calibrating sleeve, followed by crystallization of the liquid metal jet in a cooling medium and laying the resulting wire in a collector, new is that at the exit from the calibrating sleeve and the stream of crystallizable metal entering the mold, they give a spiral shape, and the cooling medium is fed to the formed spiral sprayed metal stream by means of crystallizer nozzles, covering externally a spiral-shaped stream. In the installation for casting a wire containing a vacuum furnace with a crucible for melting and degassing the melt, a pipeline with a calibrating sleeve at its end, a mold, which is installed under the calibrating sleeve of the pipeline and a collection of the resulting wire, it is new that the pipeline is made of two parts, one of which, in which the calibrating sleeve is installed, has a knee-shaped shape and is equipped with a mechanism for its rotation, and the mold is made in the form of an annular frame with vertical struts, on which one is fixed above one another The pipes made in the form of rings are pipelines of the cooling medium, on which nozzles are placed for supplying the cooling medium to the crystallizable wire, and the collector is installed inside the mold.

The essence of the claimed group of inventions is illustrated by graphic materials on which:

- figure 1 - installation for casting wire, General view;

- figure 2 is a rotary mechanism of the knee-shaped part of the pipeline;

- a table of comparative data on the properties of the wire obtained using the developed solution and the closest analogue.

Installation for casting wire includes a vacuum furnace 1, in which a crucible is installed 2. A vacuum unit 3 and an inert gas supply unit 4 are connected to the furnace cavity. A piping 5 is introduced into the crucible 2, which is made up of two parts, one of the parts being knee-shaped and able to rotate relative to the other by means of a rotation mechanism 6. A calibrating sleeve 7 is installed at the outlet of this pipe part. The installation is equipped with a crystallizer 8 made in the form of an annular frame , with vertical posts, on which hollow annular pipelines 9 are installed in height, equipped with nozzles 10. Inside the mold, a wire collector 11 is placed in its lower part.

To seal the junction of the parts of the pipeline 5, a seal is used, made in the form of a sleeve 13 mounted on the pipe and fixed on it with screws 12, in which the sealing element 14 is placed. In principle, the seal can be made in another way known to specialists.

The rotation mechanism 6 includes a hollow housing 15 mounted on a rack (positions not indicated) mounted in bearings 16. The rotating part of the pipe is passed through the housing cavity and fastened to it. The housing through a belt drive 17 is connected to the engine 18. The rotating elbow of the pipe is indicated by 19.

The design of the crucible 2, the vacuum unit 3, the inert gas supply unit 4 is known, it does not represent the subject of patent protection and therefore is not disclosed in the application materials.

The claimed method on the above installation is as follows.

Download the mixture into the crucible 2 of the furnace 1, connect the vacuum unit 3, and melt the metal. Pipelines 9 are connected to a coolant supply source. The melt is degassed at a temperature of 700-850 ° C under a vacuum of 10 ^-3 mm Hg. After holding the melt inert gas is injected into the furnace to a pressure equal to atmospheric. Install the pipe 5 in the crucible at a distance from the bottom of the crucible 10-15 mm Turn on the mechanism 6 of rotation of the part 19 of the pipeline 5 and the supply of the cooling medium through the pipelines 9 through the nozzles 10. The inert gas pressure in the furnace is raised to the required pressure for the metal to flow through the calibrating sleeve 7.

The molten metal at the outlet of the calibrating sleeve, taking into account the rotation of part 19 of the pipeline 5, is twisted and has a spiral shape. The molten metal enters the mold 8, where it is cooled by the sprayed medium supplied by the nozzles 10. It is advisable that the nozzles on the pipelines are staggered relative to each other so that the torches of the medium to be cooled do not overlap each other.

After crystallization, the wire enters the collector 11, forming a bay.

Due to the fact that the metal stream is twisted along a circular path by means of a drive, and the cooling medium is sprayed from the outside of the turns of crystallized metal, the contact area of the metal stream with the cooling medium is increased, since the molten metal stream is cooled along a horizontal plane and simultaneously all turns, and not in a separate vertical section, which leads to an increase in the crystallization rate and an increase in the physicomechanical properties of the resulting wire.

The resulting wire after crystallization has a shiny smooth surface, a change in diameter within 0.02 mm, has high ductility, which allows it to be processed by drawing in a wide range of sizes and without breaks.

Physico-mechanical properties of the obtained wire according to the invention and according to the solution given in the closest analogue are shown in the table. As can be seen, the wire made by the proposed technology, compared with the wire made by the closest analogue, is better in terms of ductility, strength, electrical resistivity and deviation of diameters.

No. p / p Comparative technology The surface roughness of the wire, Rz (μm) σ _in , after annealing σ _in after drawing

при 250°C $${\sigma }_{\mathrm{at}}^{250}$$

at 250 ° C Relative extension Resistivity Wire diameter deviation MPa MPa MPa δ,% ρ, Ohm · mm ² / m mm one 2 3 four 5 6 7 8 9 one By the closest analogue 40 166 216 120 eighteen 5 0,031 0.5 2 According to the proposed 35 170 220 125 twenty 6 0,030 0.1

Claims (2)

1. A method of casting a wire, including melting metal in a crucible placed in a vacuum furnace, degassing the melt and releasing it through a pipe through a calibrating sleeve, followed by crystallization of a liquid metal jet in a cooling medium, laying the resulting wire in a collector, characterized in that it exits the gauge sleeve stream of crystallized metal is given a spiral shape and is fed into the mold with nozzles, while the cooling medium is fed to the spiral metal stream in atomized form by means of nozzles, covering externally a spiral-shaped crystallizing wire. 2. Installation for casting wire, containing a vacuum furnace with a crucible for melting and degassing the melt, a pipeline with a calibrating sleeve at its end, a mold with nozzles, which is installed under the calibrating sleeve of the pipeline, and a collection of the resulting wire, characterized in that the pipeline is made of two parts, one of which, with a calibrating sleeve, has a knee-shaped shape and is equipped with a mechanism for its rotation, while the mold is made in the form of an annular frame with vertical struts, on which one is fixed above one another ring pipelines with nozzles for supplying a cooling medium to the crystallizing wire are len, and the collector is installed inside the mold.

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