RU2404016C2 - Device for production of metal strip by continuous casting - Google Patents

Abstract

FIELD: process engineering. ^ SUBSTANCE: invention relates to metallurgy. Proposed device comprises casting machine 2 to cast flat billet. Milling machine 4 is mounted behind casting machine 2 in direction F of flat billet transfer. Milling machine 4 is arranged to be moved in direction Q, across said direction F, to be removed from machining line and be replaced by another machining element. ^ EFFECT: optimum machining to suit diverse operating requirements. ^ 13 cl, 8 dwg

Description

The invention relates to a device for manufacturing a metal strip by continuous casting, with a casting machine in which flat billets, preferably thin flat billets, are cast, and at least one milling machine is located in the area of transporting flat billets behind the casting machine, in which at least milling can be performed at least one surface of the cast billet, preferably two opposing surfaces. In addition, the invention relates to a method for manufacturing a metal strip.

During continuous casting of flat billets in a continuous casting plant, surface defects can occur, for example, marks arising from vibration, defects in the casting powder or transverse cracks. They arise when using conventional foundry machines and machines for casting thin slab billets. Depending on the purpose of using the finished strip, ordinary flat billets (slabs) for this reason are partially fired cleaned. Some flat workpieces are fully fired cleaned at the request of the client. At the same time, the requirements for surface quality provided by plants for the manufacture of flat blanks are constantly increasing.

Suitable for surface treatment are firing, grinding or milling.

Fire treatment has the disadvantage that, due to the high oxygen content, the molten material cannot re-weld without preparatory operations. When grinding, metal chips are mixed with dust from the grinding disc, so that abrasion must be eliminated. Both methods are difficult to match with a given transportation speed.

For this reason, a method for surface treatment by milling is proposed. In this case, the hot chips generated during milling are collected and can be packaged and, without preparation, be melted again without any problems and thus added to the process. In addition, the number of revolutions of the cutter can easily be matched to the speed of transportation (casting speed, input speed into the finish rolling mill). A device of the type mentioned above according to the invention is therefore based on milling.

A device of the type indicated above with a milling machine, which is located behind the continuous casting unit, is known. For this purpose, you can make reference to documents CH 584085 and DE 19950886 A1.

The essence of a similar device is also disclosed in the application DE 7111221 U1. This document shows the processing of aluminum strips using the heat generated during casting, in which case the machine is connected to a foundry.

The removal of material from the surface of a flat billet, provided for in the production line (firing, milling, etc.), shortly before the rolling mill on the upper or lower side, or only on one side, as indicated by EP 1093866 A2, has also already been proposed.

A further embodiment of a surface milling machine is disclosed in DE 19717200 A1. It describes, among other things, the variability of the milling contour of the milling device, which is located behind the continuous casting line or in front of the rolling mill.

Another arrangement of an in-line milling machine in a conventional hot strip machine with pre-strip processing is proposed in documents EP 0790093 B1, EP 1213076 B1 and EP 1213077 B1.

When treating the surface of thin slab billets in the so-called CSP installation (compact strip production unit) in the processing line, depending on the detected surface defects on one or both sides, about 0.1-2.5 mm from the hot surface of the thin slab should be removed. In order to avoid a significant decrease in productivity, the maximum thickness of a thin slab is recommended (N = 60-120 mm).

The built-in milling machine is used, as a rule, not for all products of the rolling program, but only for those for which high demands are made on the surface. This is predominantly in terms of productivity, but also reduces the wear of the milling machine and is, therefore, advisable.

An in-line milling machine requires space for integration. The temperature loss of thin slabs in the area of the machine also has a disturbing effect. This is true for use after a casting machine, because the casting speed (mass flow) is usually low. However, also before the production line, the temperature loss creates disadvantages, since especially with thinner strips tend to a high temperature of the final rolling at an acceptable speed of exit of the strip from the production line.

For this reason, the object of the present invention is to improve an apparatus and method for manufacturing a metal strip by continuous casting using a milling machine, which makes it possible to optimally process a flat workpiece also under various technological requirements. In particular, the temperature loss should be maintained at a negligible value when processing and processing flat blanks.

The solution to this problem by means of the invention is characterized in that at least one milling cutter of the milling machine, preferably the entire milling machine as a whole, is arranged to move in the direction transverse to the direction of transportation of the flat workpieces.

The thermal conditions of the installation should be optimized, as will be shown below.

In this case, the direction transverse to the transportation direction is preferably oriented horizontally.

At least one coating element with thermally insulating properties may be provided, which is arranged to move transversely to the transport direction. The thermally insulating material is preferably heat-resistant. The goal can be achieved, for example, already using a thick sheet or plate of refractory non-metallic material.

In this case, further, a design may be provided in which at least one cover element is made heated. In this case, the cover element thus performs the function of a furnace.

In the transport direction, a furnace may be located in front of the milling machine. For processing the upper side and the lower side of the flat workpiece, one cutter can be used respectively. In this case, it is preferably provided that both cutters are located in the transport direction at a distance from each other. Further, the option is well proven when each cutter interacts with a support roller located on the other side of the flat workpiece.

A furnace may be located between both milling machines processing the upper side and the lower side of the flat blank.

In the transport direction, a descaling unit may be provided behind the milling machine. It may be provided that a furnace is provided between the milling machine and the descaling unit.

An alternative embodiment of the invention provides that at the same height when viewed in the direction of transportation next to the milling machine there is a descaling unit, and the milling machine and the descaling unit can selectively be inserted into the processing line or withdrawn from it in the direction transverse direction of transportation.

In the transport direction, at least one rolling line is located behind the milling machine.

The milling machine can be divided into two partial machines, which, for example, are milled onto different sides of a flat workpiece, spaced apart from one another.

The advantage also lies in the fact that by integrating a milling machine or part thereof into a descaling unit, a compact structure can be created.

A method for operating a device for manufacturing a metal strip by the continuous casting method is characterized in that, using the simulation model implemented in the machine control system, depending on certain or predetermined surface properties of the flat billet, a decision is made whether the milling machine is used before rolling the flat billet or no. The simulation model is preferably a process model or a so-called three-level system, which as such is known in the art.

Thereby, an automatic optimum manufacturing method may be provided. If there are products with critical surface requirements just before rolling, a milling operation is performed, while for normal products, rolling is performed without surface treatment by milling.

Using the proposed solution, it is possible that heat losses during processing or processing of flat billets are maintained at a low level and that an acceptable temperature at the inlet of the production line is achieved. This leads to a qualitatively improved production of flat blanks, in particular, thin slabs.

The milling machine extended from the processing line can, in principle, be replaced by another functional element, with preference being given to a descaling device. However, for example, it is also possible that instead of a milling machine, part of the furnace is introduced into the processing line. As explained above, it is also possible that instead of a milling machine or milling cutter, an exclusive one insulating element is introduced to prevent strip cooling.

Using the proposed method, it is possible, in addition to that, preferably, an operation method that is optimally coordinated with a specific use case is automatically carried out.

At the same time, an acceptable temperature at the inlet of the finish rolling line is maintained.

The drawings show examples of the invention:

figa schematically shows a side view of a device for manufacturing a metal strip by continuous casting, in which it is possible to use a milling machine,

fig.1b shows a top view of the device of figa,

figa shows an alternative to figa device for manufacturing a metal strip in side view,

fig.2b shows a top view of the device of figa,

figure 3 schematically shows a milling machine similar to that shown in figure 1 in an enlarged view and with marked insulating elements,

figure 4 shows the following alternative figa device in a side view, and the milling nodes are spatially remote from each other and allow milling of different sides of the flat workpiece,

figure 5 shows an alternative device for figure 4 in side view,

6 shows the following alternative to figa device in a side view with a furnace between the milling machine and the rolling mill.

On figa and 1b shows a device for the manufacture of a metal strip 1 by continuous casting. The metal strip 1 or the corresponding flat billet 3 is made in a casting machine 2 in a known manner by continuous casting. In the case of a flat blank 3, this is preferably a thin slab. Directly behind the casting machine 2, the flat billet 3 is cleaned in the cleaning unit 15. Finally, the surface is checked using the surface measuring device 16. Then the flat billet 3 enters the furnace 8, so that it can be maintained at the desired temperature for the process. Conveyor 17 is adjacent to the furnace.

As can be seen from fig.1b, there is a simultaneous casting in two streams, that is, two parallel streams of the installation.

Behind the furnace 8 and the conveyor 17, the flat workpiece 3 enters the milling machine 4. In it, at some distance from each other in the transport direction F, two mills 5 and 6 are located, with which you can mill the lower or upper surface of the flat workpiece 3. Corresponding opposite surfaces flat blanks 3, that is, the upper side or the lower side, are supported by support rollers 9.

Behind the milling machine 4, there is an apparatus 11 for descaling, which can be used to remove scale from the surface of the strip. After installation 11 for descaling, the metal strip 1 enters, finally, in a rolling mill, from which rolling stands 13 and 14 are shown.

Under the milling machine 4 there is a receiving tank 18, which catches the material removed during milling.

It is important that at least one of the milling cutters 5 or 6 of the milling machine 4, preferably, however, the entire milling machine 4 is generally arranged to move in the direction Q transverse to the direction F of transporting the flat blanks 3.

As best seen from fig.1b, the milling machine 4 can be positioned in the first position (shown by a solid line), in which it is inserted into the processing line and can milling flat blanks 3. It can be located, however, also in the second position (shown dashed line) in which it is not used.

In order to prevent heat loss in this case, it is provided that at the same time as the milling machine 4 is pulled out of the processing line, a cover element 7 (see Fig. 1b) is inserted into the processing line, which is thermally insulated, and thereby prevents too much significant cooling of the flat workpiece. The cover element 7 can also be made as part of the furnace, that is, it can be heated.

In order to switch from the milling mode to the non-milling mode and vice versa, the device consisting of the milling machine 4 and the cover element 7 can simultaneously move in the Q direction transverse to the transport direction F.

On figa and 2b as a sketch depicts an alternative solution. It is contemplated herein that an alternative choice can be made between the milling mode and the descaling mode. To this end, at least one descaling unit 11 ′ is provided, which does not work if the milling machine 4 is inserted in the machining position. Meanwhile, the descaling unit 11 ′ is introduced into the processing line if the milling machine 4 is in the idle position as a result of movement in the Q direction.

The descaling unit 11 can thus be completely withdrawn from or introduced into the processing line to replace the milling machine 4, and vice versa. In this preferred embodiment, it is provided that the descaling unit 11 and the milling machine 4 are arranged one above the other, and if necessary, the desired unit can be lifted or moved to the rolling line (processing line).

Figure 3 again in detail, however, only schematically shows how the system can be built. Two beds 19 are shown, in which, as needed, cutters 5 and 6 are located, as well as a corresponding support roller 9, for milling flat blanks 3 coming in the transport direction F on the upper and lower sides. While the cover elements 7 'with good thermal insulation properties can be permanently located next to the beds 19, it is envisaged that the elements 9 and 6 (support roller and cutter) shown above of the flat blank 3, on the one hand, and the cover elements 7, s on the other hand, can be selectively and alternatively located. Thus, if the upper support roller 9 and the cutter 6 are in operation, the cover elements 7 are not in the depicted position. Accordingly, if the elements 7 are positioned, as shown, the upper support roller 9 and the cutter 6 are in the outer position.

The same is true for the underside of a flat workpiece. Here, the support roller 9 and the milling cutter 5 can be replaced by a cover element 7 and rollers 22 of the rolling table.

The following alternative to FIG. 1 or FIG. 2 embodiment of the invention in accordance with FIG. 4 indicates that the milling machine 4 is divided into two partial machines 4 ′ and 4 ″. In the transport direction F, the first milling machine 4 'in this case mills the upper side of the flat workpiece 3; the milling machine 4 ″ mills the lower part of the flat workpiece 3. Between the two milling machines 4 ′, 4 ″ there is a furnace 10.

In front of the first milling machine 4 ', a profile measuring device 20 is further provided.

The embodiment in accordance with FIG. 5 provides that a nozzle beam 21 for descaling is integrated in the second milling machine 4 ″ in order to be able to save scale in combination with milling.

A further alternative embodiment of the invention in accordance with FIG. 6 provides that a furnace 12 is located between the milling machine 4 and the descaling unit 11, whereby it is possible to achieve that, after milling, the flat workpiece 3 is maintained at the temperature desired for the process or is heated to this temperature.

The proposed integrated in-line milling device 4, 4 ', 4' 'can, therefore, be consistent with the case of use and has the task of ensuring the temperature characteristic, as optimally as possible at high temperatures, for the subsequent rolling process or to ensure its maintenance with insignificant temperature losses. A milling machine 4, 4 ', 4' 'for this purpose, depending on the use case, can only be inserted into the rolling or transportation line if necessary, resulting in minimal temperature loss. Figures 1 and 2 show, in this case, the preferred arrangement of the milling machine, furnace and descaling device in front of the finish rolling line and the matching possibilities available. In figure 1, as explained, when using a double-strand CSP installation, the lower part of the furnace or the capsule of the rolling table are transversely movable, so that the furnace segment or the integrated milling machine can stand in the rolling line. Alternatively, it also seems possible to laterally displace the descaling device (hydroscale) or also extend the entire descaling device, and thereby replace it with a milling machine. In addition, it is also possible to tilt up the upper nozzle beam of the descaling apparatus, as shown in FIG. 2b. The location of the milling machine in the line at an insignificant distance from the finish rolling line has the advantage that you can refuse to re-descale, or reduce the pressure of the water, or turn off the entire spray beam as a whole, as the surface is cleaned by the milling machine. In addition, due to this, heat loss is minimized. It is also possible to place inert gas housings between the milling machine and the rolling machine.

Instead of transversely moving the entire milling machine, segment of the furnace or descaling device, it is also possible to alternatively perform the area of the milling machine with a passive coating of the roller table (insulation) and thereby reduce temperature losses in the area of the milling machine, as shown in FIG. To do this, with an inactive milling machine, exclusively milling rolls and possible support rollers are pulled out of the line and can by means of folding or biasing in this area carry out encapsulation of the rolling table.

In order to minimize temperature losses in front of the production line, it is preferable to locally separate the surface treatment into upper and lower sides, see Figs. 4 and 5. This begs the option in which the upper side of the flat billet is processed under the conveyor 17 and the lower side of the flat billet is processed behind the furnace 10, so that the milling area is maintained as far as possible at a minimum distance from the rolling mill.

Alternatively, the milling unit may be integrated on the underside into the scale washing device, as shown in sketch form in FIG. 5. The milling machine behind the furnace on the lower side eliminates not only defects formed during casting, but also possible damage to the surface of the flat workpiece by the furnace rollers.

The possibilities mentioned above can be used on their own or also combined.

Surface treatment on both sides or only on the upper side in front of the furnace (directly behind the casting machine) would also be possible, however, when using a two-strand installation it is doubly time-consuming.

The favorable location of the milling machine 4 in terms of temperature characteristics also lies in the location of the entire milling machine 4 (milling from above and below) behind the conveyor 17 (in the center in the furnace region), as shown in Fig.6. Thus, in a preferred manner, the temperature losses in the rear of the furnace in the area of the milling machine 4 can be compensated again. Instead of the usually gas-heated furnace, induction heating behind the milling machine can also be implemented.

Reference List

1 metal strip

2 Foundry

3 Flat workpiece (slab)

4 Milling machine

4 'milling machine

4 '' milling machine

5 Mill

6 Mill

7 Cover element

7 'Cover element

8 Oven

9 Support roller

10 Oven

11 Descaling plant

11 'Scale removal unit (nozzle beam for descaling)

12 Oven

13 rolling stand

14 rolling stand

15 Cleaning installation

16 Surface measuring device

17 Conveyor

18 receiving tank

19 bed

20 Profile Measurement

21 Nozzle beam for descaling

22 Roller roller

F Direction of transportation

Q Cross direction

Claims (13)

1. A device for manufacturing a metal strip (1) by continuous casting, comprising a casting machine (2) in which a flat billet (3) is cast, located in the direction (F) of transporting the flat billet (3) behind the casting machine (2) at least one milling machine (4) for milling at least one surface of the flat workpiece (3), characterized in that the milling machine (4) is arranged to move in the direction (Q), transverse to the direction (F) of transporting the flat workpieces (3). 2. The device according to claim 1, characterized in that the direction (Q) is oriented horizontally and transversely to the direction (F) of transportation. 3. The device according to claim 1 or claim 2, characterized in that at least one coating element (7) with thermally insulating properties is provided, which is arranged to move in the direction (Q), transverse to the direction (F) of transportation. 4. The device according to claim 3, characterized in that at least one cover element (7) is made heated. 5. The device according to claim 1, characterized in that in the direction (F) of transportation in front of the milling machine (4) is a furnace (8). 6. The device according to claim 1, characterized in that for processing the upper side and lower side of the flat workpiece (3), one cutter is provided (5, 6). 7. The device according to claim 6, characterized in that both cutters (5, 6) are located at a distance from each other in the direction (F) of transportation. 8. The device according to claim 7, characterized in that each cutter (5, 6) interacts with a support roller (9) located on the other side of the flat workpiece (3). 9. The device according to claim 7 or 8, characterized in that a furnace (10) is located between both machining the upper side or the lower side of the flat billet (3) milling cutters (5, 6). 10. The device according to claim 1, characterized in that in the direction (F) of transportation behind the milling machine (4) is the installation (11) for descaling. 11. The device according to claim 10, characterized in that between the milling machine (4) and the installation (11) for descaling is a furnace (12). 12. The device according to claim 1, characterized in that when viewed in the direction (F) of transportation at the same height, next to the milling machine (4) is located the installation (11) for descaling, and the milling machine (4) and the installation (11) for descaling, they are made with the possibility of selective movement into the processing line or movement from it in the direction (Q), transverse to the transportation direction (F) by means of movement. 13. The device according to claim 1, characterized in that in the direction (F) of transportation behind the milling machine (4) is a rolling mill (13, 14).

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