EP3223978B1 - Device for the strip casting of metal products - Google Patents

Description

The invention relates to a device for strip casting of metallic products with at least one strip running device, on the circulating strip of which molten metal can be applied, and with two side limiting devices, in which the strip running device and the two side limiting devices form a solidification space for the molten metal solidifying therein, and in which the two side delimitation devices each comprise a multiplicity of mutually interacting wall elements, each with a wall side facing the solidification space, a wall part made of copper or an alloy thereof comprising a surface interacting with the molten metal being arranged on this wall side facing the solidification space.

Generic strip casting devices are widely known from the prior art. However, known strip casting devices often have the disadvantage that their parts are subject to high wear, so that entire component groups have to be replaced frequently. This results in high operating costs, among other things.

For example, from the EP 2 689 870 A2 a device for strip casting with a rotating mold is known, in which the mold comprises at least one rotating mold with a plate chain, which consists of individual plates connected to one another in an articulated manner. These plates are made up of copper mold shells that determine sections and steel carriers, whereby good heat conduction for more intensive cooling of a cast strip is achieved through the copper material.

In the DE 198 52 275 C2 a system for strip casting is disclosed, which includes a horizontally circulating conveyor belt and mold parts for Forming of band narrow sides of endless casting molds, in which the mold parts rotate with the conveyor belt. These mold parts are made up of individual segments that interlock to seal against a solidifying melt.

Furthermore, in the WO 97/06906 A1 a continuous casting machine is shown, which is characterized by a motor-driven, horizontally running and cooled endless belt made of a heat-conducting material such as copper. The endless belt has lateral dam elements, which move with the endless belt, but can also stand still. By means of the lateral dam elements, a liquid metal poured onto the endless belt can be guided laterally, in particular until it solidifies. The dam elements can be moved transversely so that different belt widths can be set.

In the JP 57118843A describes a rotary casting mold with a rotary casting ring and with a continuous metal belt, which comprises cold-formed copper side plates and bottom plates that are welded together by an electron beam process to minimize distortion during welding.

From the DE 24 11 448 A1 a belt casting machine is known in which a casting belt is delimited by two metal casting belts lying opposite one another. These casting belts have a heat-insulating layer on their sides facing the casting, with at least one abrasion-resistant metallic cover layer being arranged on this heat-insulating layer, which has a higher melting point than the metal to be cast on.

Furthermore, in the EP 1 340 564 B1 describes a hardenable copper alloy which enables improved material properties for casting molds and in particular for side dams for strip casting plants. In this respect, this copper alloy is excellently suited as a material for the production of all mold blocks for the provision of the side dams of strip casting plants, which are subject to a typical changing temperature stress during the casting process.

Next is from the GB 2 099 339 A a side boundary of a strip casting line comprising an upper and lower circulating belt is known, with the side boundary consisting of a large number of dam blocks lined up next to one another, which are arranged on both sides of the strip casting line in such a way that adjacent dam blocks abut with their respective side walls facing each other in order to separate the opposite Circumferential bands to obtain laterally completely closed side borders. The dam blocks rotate with the belts, causing the side walls of two directly adjacent dam blocks to dynamically abut, especially in curve areas. As a result, these interacting side walls are subject to increased wear, particularly at the edges. In order to counteract this increased wear, the edges have a wear-resistant coating which is inseparably connected to the respective dam block, with the coatings having dimensions of 5 mm x 5 mm.

Furthermore, the WO 2010/108278 A1 Lateral dam blocks for laterally delimiting a strip casting section of a strip casting device, the side of the lateral dam blocks facing a molten metal having a corrugated or notched surface in order to reduce the contact area with respect to the molten metal, so that less heat is extracted from this molten metal.

In the U.S. 4,545,423A describes a strip casting apparatus having a strip casting line bounded laterally by side barriers consisting of individual, abutting dam blocks arranged laterally along the strip casting line. The sides of the dam blocks which face a molten metal conveyed along the strip casting line exist full surface made of heat-resistant sintered material to protect the dam blocks from heat.

the JP S62 176647 A discloses in general a mold in which the inside which comes into contact with a melt is made entirely of a thermally insulating material to generally protect the mold from heat.

The invention is based on the object of further developing generic strip casting devices in order to be able to operate such strip casting devices more economically.

The object of the invention is achieved by a device for strip casting of metallic products with at least one strip running device, on the circulating strip of which molten metal can be applied, and with two side limiting devices, in which the strip running device and the two side limiting devices form a solidification space for the molten metal solidifying therein, and in which the two side delimitation devices each comprise a large number of mutually interacting wall elements, each with a wall side facing the solidification space, a wall part made of copper or an alloy thereof comprising a surface interacting with the molten metal being arranged on this wall side facing the solidification space, and wherein this surface interacting with the molten metal is at least partially modified in such a way that the at least partially modified surface has a surface with the Me wall part interacting with the metal melt comprises a fixed but exchangeable surface element, and the surface interacting with the metal melt has at least two different surface areas which have different properties.

Advantageously, the at least partially modified surface comprises a fixed wall part that interacts with the molten metal arranged but replaceable surface element. As a result, the wall element can also be equipped with exchangeable elements in the relevant areas, which carry the present modified surface.

Elements or surface elements in this regard can be attached to the wall element as plates or the like at attachment points provided for this purpose, these surface elements forming the surface of the wall part modified in the sense of the invention.

For example, the surface elements are screwed to the wall element for this purpose. In this respect, the present invention is also characterized by replaceable wear areas.

If this surface interacting with the molten metal has at least two different surface areas, with these two different surface areas having different properties, the at least partially modified surface of the wall part interacting with the molten metal has different physical or haptic properties.

For example, surface areas of the affected wall part that are subject to less mechanical stress only have a surface made of copper or an alloy thereof, while surface areas of the affected wall part that are subject to greater mechanical stress are optimized in terms of their hardness.

This wall part interacting with the molten metal can be formed in one piece with the wall element delimiting the solidification space, for example by the wall element and the wall part being produced from a common block element made of copper or an alloy thereof.

Alternatively, a wall part can also be fastened to the wall element, which is designed as a further component. This wall part is here then from the Worn wall element, wherein the wall part is also made of copper or an alloy thereof.

In any case, the features explained in connection with the modified surface or with the wall part apply to both versions.

The present device is preferably a strip casting device, by means of which continuous casting of metals is possible. For example, this strip casting device is part of a Hazelett strip casting plant.

In the context of the present invention, the term “metallic products” includes all products that can be produced by casting, in particular by means of strip casting processes. For example, such metallic products include any type of slabs, ie thin, medium or thick slabs or the like. Specifically, the molten metal can be liquid steel.

In the present case, the term “wall element” describes a dam element, by means of which the solidification space is delimited laterally on the encircling belt, with this wall element preferably moving with the belt. For example, the wall element can be moved at the same speed or at a relative speed in relation to the circulating belt. Preferably, a plurality of wall elements are hinged together to form a side boundary device.

Due to the fact that the wall part or parts that come into contact with the solidifying molten metal has a surface that is modified at least in some areas, a wide variety of effects can be achieved in interaction with the molten metal. A significant advantage that can be achieved in this way is more economical operation of the present strip casting device.

The expression “at least partially modified surface” describes, in the context of the invention, a solidification space or the molten metal facing surface, which comprises at least one surface area, which is designed in such a way that it has different properties than a remaining surface area of the wall part or this at least partially modified surface.

It goes without saying that such a modified surface facing the molten metal can be implemented in many ways.

In any case, the solidification space is delimited by this at least partially modified surface. Thus, this at least partially modified surface is placed on the wall part or on the respective wall element in such a way that it comes into contact with the molten metal, ie interacts with it.

In this respect, a correspondingly designed refinement of this wall side or surface facing the molten metal is advantageous compared to other wall sides or surfaces of the wall element, since this allows the wall element, which is highly stressed by the molten metal, to be reinforced in a targeted manner.

A preferred embodiment variant therefore also provides that this surface interacting with the molten metal has a surface that is at least partially modified compared to at least one other wall side of the wall element. As a result, the wall element with an at least partially modified surface can interact particularly advantageously with the molten metal, as a result of which the present wall element in particular differs from previously known dam elements.

For example, it is particularly advantageous if this surface interacting with the molten metal has a surface that reduces mechanical and thermal wear at least in some areas. The previous surfaces of wall parts of the wall element that came into contact with the solidifying molten metal consist of copper or an alloy thereof, so that the heat energy inherent in the molten metal can advantageously be dissipated via this wall part or the wall element. However, as a result, the surface or this wall part is relatively susceptible to wear, so that the wall element that characterizes the wall part has to be frequently replaced again and again.

If the wall part that laterally delimits the solidification space or that comes into active contact with the solidifying molten metal is characterized by the present modified surface, the service life of the wall element can be significantly increased.

Cumulatively or alternatively, it is advantageous if this surface interacting with the molten metal has a surface structure that is changed at least in some areas. Such a changed surface structure can be formulated, for example, by a differently designed roughness or the like of the modified surface. Depending on how the roughness is selected, the wall part or parts can interact more intensively with the molten metal, as a result of which, for example, heat transfer from the molten metal to the wall element can be improved.

It goes without saying that, on the one hand, the entire surface of the wall part that comes into active contact with the rigid molten metal can be modified accordingly. This means that the relevant surface of the wall part facing the molten metal can be modified entirely within the meaning of the invention.

On the other hand, however, this surface can also be correspondingly modified only in regions in order to be able to implement different properties in combination, for example, or to be able to use special surface properties in a more locally targeted manner.

It goes without saying that the surface modified at least in regions within the meaning of the invention can be produced on the wall element in a wide variety of ways.

So that the wall part can be equipped at different locations with a surface that faces the molten metal and is modified at least in some areas, without being completely provided with the modified surface at the same time, it is advantageous if this wall part, which interacts with the molten metal, has a plurality of surface regions arranged at a distance from one another with a modified surface.

It is particularly expedient if this wall part interacting with the molten metal has one or more replaceable edge and/or corner elements which have a modified surface compared to other surface areas of the wall part. In particular at the edges and corners, the or the wall part is subjected to particularly high mechanical loads, so that a harder surface is particularly desirable there in order to be able to significantly reduce the susceptibility to wear.

In this way, particularly vulnerable areas of a movable side delimitation device can be reinforced in a structurally simple manner, for example with optimized, i.e. harder, materials, which are preferably designed to be quick-changeable.

Cumulatively or alternatively, it can be expedient if the surface modified at least in some areas includes an insoluble coating. In this way, the present invention differs significantly from wall elements that are only temporarily acted upon by cooling, contact and/or lubricating agents, since the present invention is a permanent coating, by means of which the wall part or parts present is finished at least in certain areas. Conventional cooling, contacting, and/or lubricating means have to be resprayed onto the wall element approximately after each revolution in order to be effectively arranged on the wall element.

It is irrelevant here what type and by what method the insoluble coating is or is applied.

In order to be able to use the present wall elements in at least two installation positions on the side delimitation devices, it is advantageous if a further wall side of the wall element comprises a wall part which interacts with the molten metal and has the at least partially modified surface.

By means of the present invention, an increase in the service life of, in particular, movable wall elements and thus also a reduction in wear and tear on a moving side boundary on a strip casting device can be achieved by means of particularly simple structural measures.

In addition, the casting quality of cast metal products can be significantly improved with very little design effort.

Further features, effects and advantages of the present invention are explained on the basis of the attached drawing and the following description, in which a device for strip casting of metallic products from a molten metal with an at least partially modified surface on a wall part interacting with the molten metal is shown and described by way of example.

Figur 1

schematisch eine Aufsicht einer Vorrichtung zum Bandgießen von metallischen Produkten aus einer Metallschmelze mit einem umlaufenden Band und mit umlaufenden Wandelementen, welche an einem mit der Metallschmelze wechselwirkenden Wandteil eine dieser Metallschmelze zugewandten, zumindest bereichsweise modifizierte Oberfläche umfassen;

Figur 2

schematisch ein erstes Wandelement mit einem mit der Metallschmelze wechselwirkenden Wandteil umfassend eine zumindest in den Eckbereichen des Wandelements modifizierte Oberfläche, welche mit der Metallschmelze wechselwirkt; und

Figur 3

schematisch ein alternatives weiteres Wandelement mit einem mit der Metallschmelze wechselwirkenden Wandteil umfassend eine zur Gänze modifizierte Oberfläche, welche mit der Metallschmelze wechselwirkt.

Show in the drawing:

figure 1

a schematic top view of a device for strip casting of metallic products from a metal melt with a circulating belt and with circulating wall elements which, on a wall part interacting with the metal melt, comprise a surface which faces said metal melt and is modified at least in regions;

figure 2

schematically shows a first wall element with a wall part interacting with the molten metal, comprising a surface which is modified at least in the corner regions of the wall element and interacts with the molten metal; and

figure 3

schematically shows an alternative further wall element with a wall part interacting with the molten metal, comprising a completely modified surface, which interacts with the molten metal.

The one in the figure 1 The strip casting device 1 shown schematically for strip casting of metallic products 2, such as a cast strip 3 in this exemplary embodiment, is part of a strip casting system 4, which is not shown here and which, for example, also includes a rolling device (not shown) etc. connected downstream of the strip casting device 1.

The strip casting device 1 essentially has a strip running device 5 with a circulating strip 6 which runs endlessly around two deflection rollers 8 and 9 each driven by a motor 7 in such a way that its upper strand 10 runs in the conveying direction 11 .

Furthermore, the strip casting device 1 has two side limiting devices 12 and 13 which are placed to the side of the circulating strip 6 .

A substantially horizontally extending solidification section 15 is formed by means of the strip transport device 5 and the two side delimitation devices 12 and 13, along which a molten metal 17 fed to the solidification section 15 by a feed system 16 cools and thereby solidifies to form the metallic product 2.

So that the molten metal 17 poured onto the circulating belt 6 is guided laterally on both sides, so that this molten metal 17 on the belt 6 cannot flow away to the sides 18 and 19 before the molten metal 17 has solidified accordingly, the two side limiting devices 12 and 13 each via a variety of articulated interacting wall elements 20 (numbered only as an example), which in this Each embodiment consists of an alloyed copper block 21 (numbered only as an example).

The present wall elements 20 are wall elements 20 that move with the circulating belt 6 or dam elements that move along with them (not numbered separately), which are moved parallel to the circulating belt 6 at least along the solidification path 15 .

In this respect, a movable dam is configured on both sides of the encircling belt 6 by means of the large number of wall elements 20 interacting with one another in an articulated manner.

By means of the circulating belt 6 and the plurality of wall elements 20 interacting in an articulated manner, a solidification space 22 is formed along the substantially horizontal solidification section 15 , into which the molten metal 17 is poured in order to solidify to form the metallic product 2 .

Here, the individual wall elements 20 interact with the encircling belt 6 in such a way that the molten metal 17 cannot escape to the sides 18 or 19, or only to a negligible extent.

More precisely, the solidification space 22 is bounded by the wall elements 20 by a strip top side 23 facing the metal melt 17 and by many wall sides 24 facing the metal melt 17 (numbered only as an example).

As a rule, only one part of the wall comes over the top (see in particular figure 2 ) of the wall side 24 or of the wall element 20 is in direct contact with the molten metal 17, the wall part in this exemplary embodiment being formed in one piece with the alloyed copper block 21 forming the actual wall element 20. As a result, the thermal energy inherent in the molten metal 17 can be dissipated particularly effectively via the two side delimitation devices 12 and 13 .

Above the wall part 25 of the wall element 20 is a border 26 (see in particular figure 2 ) a holding device 27 for holding the individual wall elements 20 is provided, which is not part of the wall part 25 coming into active contact with the molten metal 17 .

Rather, the actual wall part 25 of the wall element 20 begins below this border 26, so that the wall part 25 is predominantly characterized by a smooth copper surface 28 (cf. also figure 2 ).

The present strip casting device 1 is now characterized according to the invention in that this wall part interacting with the molten metal 17 has an at least partially modified surface 30 (numbered only as an example), which faces the solidification space 22, i.e. interacts with the molten metal 17.

Namely, the surface 30 that faces the solidification space 22 and is modified at least in regions is designed significantly differently than the other wall sides (not numbered) of the respective wall element 20 or its other surfaces, with the surface 30 modified at least in regions being designed to reduce thermal and mechanical wear in this exemplary embodiment .

As shown in the figure 2 As can be seen clearly, the wall side 24 facing the solidification space 22 has at least two different surface areas 31 and 32, these two different surface areas 31 and 32 having different properties.

The first surface area 31 is the smooth copper surface 28, ie a relatively smooth surface structure 33, which is implemented directly by the alloyed copper block 21 of the wall element 20 in this exemplary embodiment.

The other surface area 32 (numbered only as an example) is a harder surface structure 34 (numbered only as an example) compared to the softer, smooth copper surface 28, which is provided or attached by four spaced, replaceable surface elements 35, 36, 37 and 38 the wall part 25 interacting with the molten metal 17 . The surface elements 35, 36, 37 and 38 face the solidification space 22 and the molten metal 17, respectively.

These surface elements 35, 36, 37 and 38 are arranged interchangeably on the wall part 25 interacting with the molten metal 17, with the surface 30 modified thereby at least in certain areas being arranged on the wall part 25 within the meaning of the invention.

The four spaced, replaceable surface elements 35, 36, 37 and 38 are placed in the four corners 39 (numbered only as an example) of the wall part 25, so that these four corners 39, which are particularly heavily loaded by the molten metal 17, can be loaded very well and are protected .

Thus, these four interchangeable surface elements 35, 36, 37 and 38, spaced apart from one another, immediately embody first interchangeable edge or corner elements 40 (also only numbered as examples) facing the solidification space 22, which have modified surfaces 30 compared to the surface area 31 of the wall part 25 .

The edge or corner elements 40 are designed in such a way that the short sides 41 of the further surface areas 32 formed by the four interchangeable surface elements 35, 36, 37 and 38 that are spaced apart from one another are on the long edges 42 of the wall part 25 and the long sides 43 are formed on the short edges 44 of the wall part 25.

The long edges 42 and thus also the short sides 41 are arranged running essentially horizontally, while the short edges 44 and thus also the long sides 43 are aligned running essentially vertically.

In any case, the four interchangeable surface elements 35, 36, 37 and 38, which are spaced apart from one another, extend in the vertical direction with their respective longitudinal extent, so that the long edges 42 of the wall part 25 are largely reinforced.

According to the representation according to the figure 3 the alternative wall side 24A facing the solidification space 22 is cumulatively or alternatively completely provided with an insoluble permanent coating 51, the complete wall side 24A for example having an increased roughness compared to the smooth copper surface 28.

For this purpose, the alternative wall side 24A is covered over a large area with the correspondingly designed insoluble permanent coating 51 so that the wall part 25 interacting with the molten metal 17 has a further modified surface structure 52 .

Thus, the wall part 25 interacting with the molten metal 17 has an alternative wall side 24A with a surface 28 characterized in particular by the smooth copper surface (cf. figure 2 ) different surface area 53.

At this point it should be explicitly pointed out that the features of the solutions described above or in the claims and/or figures can also be combined if necessary in order to be able to cumulatively implement or achieve the features, effects and advantages explained.

It goes without saying that the exemplary embodiment explained above is merely a first embodiment of the invention. In this respect, the design of the invention is not limited to this exemplary embodiment. All features disclosed in the application documents are claimed as being essential to the invention, insofar as they are novel over the prior art, individually or in combination, within the scope of the present claims.

Reference character list:

1

strip caster

2

metallic products

3

casting tape

4

strip caster

5

conveyor device

6

circulating band

7

engine

8th

front pulley

9

rear pulley

10

upper run

11

conveying direction

12

first side delimitation device

13

second lateral delimitation device

15

horizontal solidification line

16

feeding system

17

molten metal

18

left side

19

right side

20

wall elements

21

copper block

22

freezing space

23

band top

24

wall side

24A

alternative wall side

25

wall part

26

surround

27

holding device

28

smooth copper surface

30

partially modified surface

31

first surface structure

32

further surface structure

33

smooth surface structure

34

harder surface structure

35

first interchangeable surface element

36

second interchangeable surface element

37

third interchangeable surface element

38

fourth interchangeable surface element

39

corners

40

interchangeable edge and corner elements

41

short sides

42

long edges

43

long sides

44

short edges

51

insoluble permanent coating

52

further surface structure

53

different surface area

Claims (8)

1. Device (1) for belt casting of metallic products (2, 3) with at least one belt guide device (5), to the circulating belt (6) of which a metal melt (17) can be applied, and with two lateral boundary devices (12, 13), with which the belt guide device (5) and the two lateral boundary devices (12, 13) form a solidification space (22) for the metal melt (17) solidifying therein, and in which the two lateral boundary devices (12, 13) each comprise a plurality of mutually co-operating wall elements (20) each with a respective wall side (24, 24A) facing the solidification space (22), wherein a wall part (25) of copper or an alloy thereof and having a surface (30) interacting with the metal melt (17) is arranged at this wall side (24, 24A) facing the solidification space (22), wherein the surface (30) interacting with the metal melt (17) has at least two surface regions (31, 32, 43) which differ from one another and have different characteristics, characterised in that the surface (30) co-operating with the metal melt (17) is at least regionally modified in such a way that the at least regionally modified surface (30) comprises a surface element (33, 34, 35, 36) which is fixedly arranged at the wall part (25) interacting with the metal melt (17), but which is exchangeable.
2. Device (1) according to claim 1, characterised in that this surface (30) interacting with the metal melt (17) has a surface (30) which is modified at least regionally by comparison with at least one further wall side of the wall element (20).
3. Device (1) according to claim 1 or 2, characterised in that this surface (30) interacting with the metal melt (17) has a surface (30) which is mechanically and thermally wearreducing at least regionally.
4. Device (1) according to any one of claims 1 to 3, characterised in that this surface (30) interacting with the metal melt (17) has an at least regionally modified surface structure (33, 41, 42).
5. Device (1) according to any one of claims 1 to 4, characterised in that this wall part (25) interacting with the metal melt (17) has a plurality of mutually spaced-apart surface regions (32) with a modified surface (30).
6. Device (1) according to any one of claims 1 to 5, characterised in that this wall part (25) interacting with the metal melt (17) has one or more exchangeable edge and/or corner elements (38) which have a surface (30) modified by comparison with other surface regions (31) of the wall part (25).
7. Device (1) according to any one of claims 1 to 6, characterised in that the at least regionally modified surface (30) has a non-detachable coating (51).
8. Device (1) according to any one of claims 1 to 7, characterised in that a further wall side (24) of the wall element (20) comprises a wall part (25) which interacts with the metal melt (17) and which has the at least regionally modified surface (30).

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