DE2116038A1 - Process for electroslag melting of ingots and devices for carrying it out - Google Patents

Description

METHOD OF ELECTRIC SLAG MELTING BLOCKS AND DEVICES FOR ITS IMPLEMENTATION

The invention relates to the field

specialized electrometallurgy and, more precisely, a process for electroslag melting of blocks and devices for its implementation. This process can be used in the production of steels and alloys.

It is a process for electroslag melting Blocks known by means of direct and alternating current using non-consumable graphite or silicon electrodes.

However, graphite and silicon electrodes are not practical Cannot be consumed, as such electrodes are used during the Elektroschlacice process under the influence of high temperatures and the

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The chemical action of the slag gradually dissolves, whereby they dissolve the slag melt through foreign inclusions, i.e. through Solution products of the electrodes, contaminate.

The consequence of this is that when metals are remelted, the latter with carbon, silicon and other harmful substances Admixtures such as sulfur, phosphorus, etc. are enriched, which reduces the quality of the ingot metal.

Experimental results have shown that when conducting the electroslag process to remelt metals by means of Direct current of negative polarity \ effekt ^ / ^ cooled metal electrodes can be used as non-consumable electrical sources.

Using such electrodes prevents the remelted Metal is enriched with harmful additions. j

Such electrodes are, however, especially when using alternating current and direct current with positive polarity,

an electrochemically destroyed, which also fouling the

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Melt _ due to foreign components as well as premature Wear and tear on the electrode itself.

The same disadvantage is present in casting hollow blanks. In this case the cooled metal electrode, in particular the hole-forming mandrel through which the Hohlings interior is formed, also destroyed electrochemically.

It is the aim of the invention to remedy the above

Eliminate disadvantages.

The invention is based on the object of a method 109847/1 160

to develop for electroslag melting of ingots and to create devices for its implementation which it

Prevent the cooled and non-consumable electrodes from being electrochemically destroyed, and thereby their To extend the service life and also to preserve remelted metal with greater purity.

The problem posed is achieved in that the proposed Method for electroslag melting of ingots using non-consumable cooled metal electrode ^ according to the invention, the part of the non-consumable electrode immersed in the melt of the pressurized electrode Gaeetrömen is washed around.

This prevents * the non-edible

Electrodes are electrochemically destroyed

In the apparatus for performing the method according to the invention, the ^e unv it contains' zehrbare cooled metal electrode which has dipped in, in the melt electrode part, openings are according to the invention on the end face

this electrode part has grooves which carry the current the gas bubbles emerging from the electrode openings

leak, pass over the entire surface of the immersed electrode part, thereby "preventing chemical destruction.

Expediently, the surface of the end-face part immersed in the melt becomes the non-consumable

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Spherical electrode. This will make a lot of things Coiling through gas streams which form a protective cover, of the whole 'i'eiis of the inedible immersed in the melt Electrode ensured.

A variant of the device is proposed for melting hollow blocks, the cooled metal mandrel that forms a hole for shaping the interior det BlÖcice owns, which is used as a non-consumable electrode, whereby according to the invention in this device in the walls of the hole-forming mandrel at the level of the metal and 'Schlackenschiueize channels are designed with openings for the gas supply line.

The channels with openings in the walls of the hole-forming Dorns jcÖnneA be arranged tangentially to its axis.

This favors the lengthening of the path ^1, which the cover, the protective shell-forming gas bubbles along the surface on the immersed into the melt portion of the unverzehrbaren hole forming mandrel.

The proposed method and associated device, which correspond to the present invention successfully solve the task at hand.

The following are provided for a better understanding of the essence der .Erfindung Examples of devices for performing the method according to the invention with reference to illustrative Drawings described in detail; it shows tfig. 1 the general view of the device for electrical

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Slag melting of blocks,

Fig. 2 is a view from below of the non-edible cooled Metal electrode,

Fig. 3 is a section along line III-PII of Fig. 2,

4 shows the overall view of the device for Elektroschlakke melting of hollow blocks and

FIG. 5 shows a section along line V-V of FIG. 4.

It is the implementation of the method according to the invention considered on the basis of concrete examples of the devices for electroslag melting of ingots. As can be seen from Fig. 1, the device contains

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Mold cooled for electroslag melting of ingots 1 and also refrigerated base plate 2, "refrigerated non-consumable Metal electrode 3 and consumable electrodes 4. The part

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of the non-consumable electrode 3> which is immersed in slag bath 5, has openings 6 and grooves 7 (Fig.3 £, 3). the The device is switched from the supply source 8, which is connected between the non-consumable electrode 3 and the substitute plate 2 is fed.

The device works as follows.

Before the start of the electroslag process, the non-consumable Electrode 3 is placed in mold 1 and cooling liquid 9 and gas 10 (or a gas mixture) are fed into electrode 3. Molten slag is poured into the mold 1

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pouring, which forms the slag bath 5. Gas 10 emerges from the openings 6 in the non-consumable electrode 3 and reaches the zone of the non-consumable electrode 3 in the form of individual gas bubbles 11, which is directly adjacent to the non-consumable electrode 3, with a gas envelope being formed which covers the non-consumable electrode 3 protects against electrochemical destruction. Here, the gas bubbles 11 are evenly distributed with the help of the grooves 7 over the surface of the part of the electrode 3 which is immersed in the slag bath 5. Then, voltage is applied to the non-consumable electrode 3 and to the base plate 2, which voltage is obtained from the AC power supply source 8. Then the accessible electrodes 4 are introduced into the slag bath. As soon as the lower end faces of the consumable electrodes 4 touch the slag bath 5, the same begins to melt. Liquid metal, which is formed when the consumable electrodes ¹ / ent melts, flows into the mold 1 and forms the block 12. The consumable electrodes 4 can be designed as rods of various shapes made of steels and alloys. They can also consist of rods obtained by pressing or sintering powders and other lumpy materials.

The surface of the forehead part of the indestructible electrode 3, which is immersed in the slag bath 5, has a spherical or any other curvilinear shape, whereby it is achieved that the gas bubbles 11 are all in the melt

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Rinse the immersed part of the non-consumable electrode 3 quickly.

Another variant of the device, the one used for electric steel melting is determined by hollow blocks, also contains

one

cooled mold 13 (Fig. 4) and cooled base plate 14 with Opening / "consumable electrode 15 and cooled hole-forming Mandrel 16, which is used to shape the interior of the block 17 and which is used as a non-consumable electrode.

In the walls of the hole-forming cathedral 16 are in the amount of Metal bath 18 and the slag bath 19 channels 20 with. Openings 21 are provided through which gas is supplied from the gas distributor 22 will.

You canals 20 pit the openings 21 are in the walls of the hole-forming dome 16 (Fig. 5) tangential to its axis arranged

In addition, the supply source 23 can be seen in FIG. 4, between the consumable electrode 15 and the hole-forming mandrel (

16 is switched. Such a device works analogously to the device described above. The only difference consists in that during the whole melting of the hollow block

17 of the hole-forming mandrel 16 relative to the mold 13 and the Pedestal 14 with a melted block on top of it | 17 executes a movement, the speed of which is approximately equal to the speed at which the slag bath 19 rises.

In the described implementation examples of the invention Process are the gas streams which

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Rinse around the electrode part immersed in the melt, under pressure not less than hydrostatic pressure is, which is generated by the melt column, whose height e equal to the length of the part immersed in the melt the non-consumable electrode. Inert gas streams can be used Gases, e.g. helium, argon and also other gases, reagents and gas-powder mixtures can be used.

However, if there are convection currents in the melt, the part of the non-consumable electrode that is immersed in the melt is washed around by gas flows, the pressure of which is the hydrostatic one Pressure can fall below which is generated by the melt column.

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Claims (5)

P 56 7W2 April 1, 1971 - 9 - EZ / Br PATENT CLAIMS 1. A method for electroslag melting of blocks using non-consumable cooled metal electrode »} characterized in that the part of the non-consumable electrodes immersed in the melt is washed around by the gas flow, the pressure of which is not lower than the hydrostatic pressure which is caused by the melting column - ' * is generated, the height of which is equal to the length of the electrode part immersed in the melt 2. Apparatus for performing the method according to claim 1, which contains ^e non-consumable cooled metal electrode which has openings in the electrode plate immersed in the melt, characterized in that on the end face of the immersed in the melt part of the irreversible electrode (3) grooves (7) are carried out, which the flow of gas bubbles (11), which from the Openings (6) of the electrode (3) emerge, pass over the entire surface of the part of the electrode (3) immersed in the melt. 3. Apparatus according to claim 2, characterized in that the surface of the immersed in the melt, frontal part of the electrode (3) is spherical. 4. Apparatus for performing the method according to claim 1, the cooled hole-forming mandrel for forming «/« it 109847/1160 in Interior has the blocks, which is considered to be inedible Electrode is used, thereby. marked, that in the walls of the hole-forming dome (16) at the level of the molten metal (18) and the molten slag (19) Channels (£ 0) are designed with openings (21) for the gas supply line. 5. Apparatus according to claim 4, characterized i c hnet that the channels (20) with openings (21) in the walls of the hole-forming mandrel (16) tangentially to its axis are arranged. 109847/1160 Blank page