RU2397842C1 - Procedure and device for fabrication of metal band by continuous casting - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: slab (3) is subject to milling on milling machine (4) and to one rolling operation in installation (2) of continuous steel casting after coming out of crystalliser and after turning from vertical into horizontal position. Rolling and milling directly follow slab casting. Rolling is divided into two separate operations of rolling on first rolling mill (5) and second rolling mill (6). Between both rolling operations there is performed milling at milling machine (4). Thus, there is facilitated upgraded quality of pipes.

EFFECT: new procedure and device for fabrication of metal band by continuous casting.

14 cl, 4 dwg

Description

The invention relates to a method of manufacturing a metal strip by continuous casting, and initially a slab is cast in the casting installation, in particular a thin slab that is rotated from a vertical position to a horizontal position, and in the direction of transporting the slab behind the casting plant, the slab is subjected to milling operations on a milling machine and, according to at least one rolling operation in at least one rolling mill. In addition, the invention relates to a device for manufacturing a metal strip by continuous casting.

During continuous casting of slabs in a continuous casting installation, surface defects can occur, for example, traces from the mold swinging, defects in the heat-insulating layer or surface cracks running along and across. They are found in conventional foundry plants and foundry plants for the manufacture of thin slabs. Therefore, depending on the use of the finished tape, conventional slabs are partially subjected to firing. Some slabs are fully fired at the request of the client. At the same time, the demands on the surface quality of devices for manufacturing thin slabs are constantly growing.

For surface treatment, fire stripping, grinding or milling are used.

Fire stripping has the disadvantage that, due to the high oxygen content, the molten material cannot be re-deposited without preparation. When grinding, metal chips with dust from the grinding disc occur, so the waste should be removed.

Therefore, they propose to process surfaces by milling. In this case, the hot milling chips are collected and packaged and, without preparation, re-melted without difficulty and reintroduced into the manufacturing process. Based on this, the proposed method and the related device are oriented mainly to milling.

A known method and device of the aforementioned type with a milling operation or a milling machine located or located behind the installation for continuous casting. In this case, it is recommended to refer to CH 584085 and DE 19950886 A1.

A similar solution is also disclosed in DE 7111221 U1. This publication shows the processing of aluminum strips using melting heating, in which the unit is connected to a foundry.

Also, a line-integrated surface treatment of a thin slab on the upper and lower sides, or only one-sided (fire processing, milling, etc.) immediately in front of the rolling mill has already been proposed, for which it is recommended to turn to EP 1093866 A2.

Another embodiment of a surface milling machine is shown in DE 19717200 A1. This publication describes, inter alia, the possibility of changing the milling contour of a milling device located behind a continuous casting plant or in front of a rolling mill.

Another arrangement of a line-integrated milling machine in a conventional rolling mill for a hot-rolled steel strip for processing a strip blank and its implementation is proposed in EP 0790093 B1, EP 1213076 B1 and EP 1213077 B1. Similar or other solutions are known from EP 0646431 A1, from US 3702329, from EP 1097764 A2 and from DE 1508952 A1.

When treating the surface of thin slabs in the so-called casting and rolling module (CSP) on the processing line (“intermediate”), approximately 0.1-2, should be removed from the warm surface of the slabs, on one or two sides, depending on the detected surface defects 5 mm of material. In order not to significantly reduce the yield of the material, the largest possible thickness of a thin slab (N = 60-120 mm) is recommended.

An integrated in-line milling machine is used, as a rule, not for all products of the rental program, but only for those with higher surface treatment requirements. This is preferable in relation to the material being removed and the reduction in wear of the milling machines, and therefore rational.

There is a desire to apply the already known technology more efficiently and at the same time it is more economically feasible. However, at the same time, it should preferably be possible to quickly and high-quality production of not only extremely thin slabs.

In particular, but not exclusively for this, the manufacturing method proposed in the invention is aimed at manufacturing high-quality pipes. This requires a slab surface with absolutely no cracks. In addition, for metallurgical reasons, the first rolling mill requires a roughing stand group.

Therefore, the objective of the present invention is such an improvement in the method and device of the aforementioned type, in which, with high economy, it is possible to provide a more advanced manufacturing process or processing process. In this case, optimization should take place, in particular, taking into account the necessary heat supply, in particular, into the billet or during the manufacturing process, with the simultaneous presence of a crack-free surface and the desired metallurgical and mechanical properties.

The solution to this problem of the invention according to the method part is characterized in that the rolling operation and the milling operation directly follow the casting of the slab in the foundry installation, the rolling operation being divided into at least two separate rolling operations, at least in the first rolling mill and the second rolling mill and, moreover, between both rolling operations carry out a milling operation on a milling machine.

Preferably, if the slab is heated in front of the first rolling mill and / or behind the first rolling mill and milling machine, for example in a roller hearth furnace.

In addition, the slab can be cleaned in front of the first rolling mill in a cleaning device and / or in a descaling device.

A device for manufacturing a metal strip during continuous casting with a casting plant in which a slab is cast, in particular a thin slab, wherein a milling machine and at least one rolling mill are arranged in the direction of transporting the slab behind the casting machine, according to the invention, that in the transport direction, directly behind the casting plant, the first rolling mill and the second rolling mill are located, the milling machine being located between the rolling mills.

If we are talking about a double-strand CSP installation, then the milling machine and the first rolling mill are located behind the furnace conveyor, so that they can process workpieces from both streams.

Preferably, a furnace is provided between the first rolling mill and the second rolling mill. In addition, a cleaning device and / or a descaling device may be located in front of the first rolling mill. A different furnace may be located in front of the first rolling mill. Each rolling mill may accordingly have at least one rolling mill; however, in particular, it should be remembered that the first rolling mill has one or two rolling stands, made as a duo stand or as a quarto stand. It may also be provided that the device comprises means for adjusting the installation of the milling cutter of the milling machine depending on the installation position, condition, thickness and / or amount of rotation of the rolling mill or pulling device in front of the milling machine.

According to one embodiment of the invention, slab milling on a milling machine occurs so that the upper side of the slabs and the lower side of the slabs are processed in one place in the transport direction. However, it may alternatively be envisaged that the milling of the slab takes place on a milling machine such that the upper side of the slabs and the lower side of the slabs are machined in the direction of transport in two consecutive places.

The passage made at the first rolling mill can be a leveling passage, especially when it comes to a single-strand rolling mill. Thus, it is preferable that the milling is carried out already with a certain profiling of the slab and at the same time more efficiently (the relative values for the determined rolling forces are selected depending on the width of the slab). Dents from the support rollers, traces of the mold swinging and similar surface damage are already partially smoothed out during the rolling process in the first rolling mill, so to get a clean slab surface after milling, you need to remove a small amount of material during milling.

By means of the invention also possible lateral bends of the slab are eliminated.

Relatively insignificant chip removal during milling pursues the goal, so that it turns out not a “ski”, but a straight slab.

The proposed solution can also be preferably used to sharpen the head of the slab before milling, to facilitate filling the workpiece into the milling machine.

The number of revolutions of the roll in the rolling stand may be different on the upper side and on the lower side of the slab.

In general, the resulting quality is improved manufacturing of slabs, in particular thin slabs.

The drawings show examples of the invention. Figure 1-4 schematically shows a side view of a device for manufacturing a metal strip during continuous casting, in which, in particular, rolling mills and a milling machine are connected to the foundry installation.

Figure 1 shows a device for the manufacture of metal tape 1 during continuous casting. The metal strip 1 or the corresponding slab 3 is obtained in a known manner by continuous casting in a casting plant 2. By slab 3 is meant preferably a thin slab. The cast billet is rotated or bent in a known manner in a roller guide, from the vertical direction V to the horizontal - H. After turning the horizontal H direction, it is possible to clean the slab using cleaning agents 10 and then measure the cross section or examine the surfaces with means 11 . They allow you to register the surface properties of the slab, as well as its geometry. In the conveying direction F, one furnace 9 is initially connected, and then a conveyor 12 is connected.

After measuring 13 cross section, immediately after the heated conveyor 12, at a high temperature of the slab and thereby at a reduced load, the surface is processed on the milling machine 4. On the milling machine 4, the slab 3 is treated with a milling cutter on its upper side and lower side.

In this case, the milling of the upper side and the lower side of the slab 3 is carried out in two successive places when viewed in the transport direction F, and two cylindrical cutters 14 are used. In this case, the slab 3 is respectively supported by the support roller 15.

Most preferably, if it is possible to set the transport speed through the milling machine 4, regardless of the casting speed (in the casting plant 2) and independently of the second rolling mill 6 (finishing rolling). The milling machine 4 in front of the rolling mill 5 sets the speed of transportation of the slab 3. The first rolling mill 5 is coordinated with it.

After the milling process, 8 scale is removed from the slabs, used if necessary. Then, in the transport direction F, a rolling mill 5 is connected, which in this case consists of two rolling stands. By means of both stands, a strong reduction can be carried out.

The temperature loss during the milling and rolling process in the first rolling mill can for the most part be compensated again by the subsequent second furnace 7, so that subsequent deformation can occur in a preferred manner in the second rolling mill 6 at sufficiently high temperatures in the rolling mill 6. The second furnace 7 can be also made as an unheated casing of the roller table, reducing the temperature loss of the processed slab 3. Behind the furnace 7 is a device 16 for descaling and the already mentioned rolling camp 6.

The rolling mill 6 may consist of at least one stand (also a reverse stand). However, as a rule, the rolling mill 6 contains from four to seven rolling stands. Further processing behind the rolling mill 6 by cooling and winding metal strip 1 or stacking thicker metal sheets of plates in this publication is not described in detail.

Another embodiment of the invention is shown in FIG. The casting of the slab 3 in the casting plant 2 and the heating of the slab in the furnace 9 and the conveyor 12 occurs similarly to figure 1. Behind the conveyor 12, a cleaning device or a descaling device 8 is positioned, in which the prepared slab 3 is cleaned or descaled. Then, the slab enters the first rolling mill 5. The first rolling mill 5 is preferably equipped with a rolling stand, which can be implemented as a two-roll rolling stand or four-roll rolling stand. In the first rolling mill 5, a leveling passage is carried out, which can eliminate geometric irregularities on the surface of the slabs. In addition, already in the first rolling mill 5 can be performed targeted reduction in thickness. Then the slab 3 enters the milling machine 4.

In this case, the first rolling mill 5 in front of the milling machine 4 can also be performed as a pulling device to ensure reliable transportation of the slab 3 through the milling machine 4. After the milling machine 4, further processing occurs similarly to Fig. 1: in the second furnace 7, the descaling device 16 and rolling mill 6 - to the finished product 1.

Another alternative embodiment of the device is shown in FIG. The layout and tasks are the same as in the installation of figure 2. Only in this case, only the first rolling process 5 and surface treatment by milling on a milling machine 4 are carried out behind the furnace, consisting of the first furnace element 9, the conveyor 12 and the second furnace element 7. In this embodiment, refusal to reheat the slab 3 before the second rolling mill 6 is refused.

In the embodiment of the installation according to figure 4, the installation consists of two rolling mills. After casting in the casting device 2 and heating in the first furnace 9 and on the conveyor 12, the first rolling process 5 is carried out. After reheating the rolled slab 3 in the second furnace 7, a surface treatment is carried out immediately before the finishing rolling mill.

In particular, FIG. 4 shows another embodiment of a device for manufacturing a metal strip 1 during continuous casting. The metal strip 1 or the corresponding slab 3 is again cast in a known manner by continuous casting in the casting unit 2. After turning the slab 3 into a horizontal location H, the slab can be cleaned with cleaning agents 10 and then measure the cross section or examine the surfaces with the measuring means 11. In this case, again, the properties of the surface of the slab, as well as its geometric performance, can be controlled.

In the conveying direction F, one furnace 9 is initially connected, and then a conveyor 12. A cleaning device or descaling device 8 is positioned behind the conveyor 12, in which the prepared slab 3 is cleaned or descaled. Then it enters the first rolling mill 5. The first rolling mill 5 is preferably equipped with a rolling stand, which can be implemented as a two-roll rolling stand or four-roll rolling stand. In the first rolling mill 5, a leveling passage is carried out, which can eliminate geometric irregularities on the surface of the slabs. In addition, already in the first rolling mill 5 can be targeted reduction in thickness. After the first rolling mill 5, the slab 3 enters the holding furnace 7, and from there into the milling machine 4. Between the holding furnace 7 and the milling machine 4, measuring means 13 for measuring the cross section are arranged.

On the milling machine 4, the slab 3 is treated with a milling cutter on its upper side and on its lower side. In this case, the milling of the upper side and the lower side of the slab 3 is carried out in two successive places when viewed in the transport direction F, and two cylindrical cutters 14 are used. In this case, the slab 3 is respectively supported by the support roller 15.

Behind the milling machine 4, a second rolling mill 6 is disposed, which may have several rolling stands. On the second rolling mill 6, the slab 3 is finalized to the desired metal strip 1.

It is essential that the rolling and milling operations are carried out directly following, in particular in a continuous manner, the casting of the slab 3 in the casting machine 2, the rolling operation being divided into at least two separate rolling operations, at least in the first rolling mill 5 and a second rolling mill 6; between both rolling operations carry out the operation of milling the slab 3 on the milling machine 4.

In particular, the deformation of the slab 3 is carried out before milling. The first rolling mill 5 can be located in this case in front of or behind the second furnace 7. Also, surface treatment can occur in front of or behind the furnace 7.

A generalized solution can be formulated as follows.

The surface treatment by cutting is carried out immediately before the first stage of deformation or alternatively between two stages of deformation (groups of rolling stands). According to the image in FIG. 1, the milling machine and the rolling mill 5 are located directly in front of the second furnace 7 before they are finally deformed with good input quality of surfaces to the desired final thickness in the finishing rolling mill 6. The location of the rolling stand 5 can also be behind the supporting furnace 7 It is also possible to surface treatment by cutting directly between the rolling mill 5 and the holding furnace 7, so that heating can be carried out after preliminary deformation and surface treatment STI.

In the presented forms of execution on the upper side and lower side, you can respectively see one milling roll. It is assumed that if there is a need for large material removal by a milling cutter on each side or with very hard materials, sequentially place two unified milling heads on the upper side and lower side.

As an alternative to using cylindrical mills, it is also possible to use other mills at the designated places, such as face mills, or even grinding tools, or other tools that remove material from the surface of the tool (such as fire stripping). Alternative to the use of cylindrical mills or face mills, the use of surface-removing tools is also possible.

As cutting tools for milling cutters, in particular, the following can be provided: HSS (high speed tool steel); carbides without coating or preferably coated; ceramics; polycrystalline tool materials. As a rule, standard non-rotatable cutting inserts can be used.

A milling machine may consist of two or more standardized milling heads on one side of the slab, which can be arranged in series.

The milling machine can adjust the slab transportation speed in front of the first rolling stand regardless of the casting plant and the second rolling mill.

The furnace behind the milling machine mainly serves to correct the temperature loss in the area of the milling machine and the first rolling mill.

Preferably, the slab head is sharpened in a targeted manner in the first rolling mill. For optimal matching of the milling machine with the entry conditions (in particular, with the thickness of the slab and the wedge-shaped slab), along with measuring the geometry of the slabs, you can use the installation position of the rolling stand or pulling device in front of the milling machine. That is, to adjust the cutters, in particular the installation position of the cylindrical cutters, the thickness position and the rotation amount of the rolling stand or the pulling device are attracted. For example, if an oblique location is detected, a decision can be made: adapt to it and process the slab with a milling cutter uniformly in width or cut a wedge-shaped profile of the slab with a milling cutter.

Notation list

1 - metal tape

2 - foundry

3 - slab

4 - milling machine

5 - first rolling mill

6 - second rolling mill

7 - second oven / roller table casing

8 - cleaning device and / or descaling device

9 - the first furnace

10 - cleaning agent

11 - measuring tool

12 - conveyor

13 - measuring tool

14 - mill

15 - support roller

16 - descaling

F - direction of transportation

V - vertical

N - horizontal

Claims (14)

1. A method of manufacturing a metal strip (1) during continuous casting, including casting a slab (3), in particular a thin slab, in a casting installation (2), turning it from a vertical position (V) to a horizontal position (H), milling the slab into milling machine (4), which is carried out in the direction (F) of transporting the slab (3) behind the casting plant (2), rolling the slab in a rolling mill (5), characterized in that it further carry out the rolling of the slab on the second rolling mill (6) directly for casting a slab, and milling f slab is carried out between rolling operations on the first and second rolling mills (5, 6). 2. The method according to claim 1, characterized in that the slab (3) is heated in the furnace (7) between the first rolling mill (5) and the second rolling mill (6). 3. The method according to claim 1 or 2, characterized in that the slab is cleaned in the device (8) for cleaning and / or descaling in front of the first rolling mill (5). 4. The method according to claim 1 or 2, characterized in that the temperature of the slab (3) in front of the first rolling mill (5) is kept constant in the furnace (9). 5. A device for manufacturing a metal strip (1) during continuous casting, comprising a casting installation (2) for casting a slab (3), in particular a thin slab, a milling machine (4) located in the direction (F) of transporting the slab (3) behind foundry plant (2), rolling mill (5), characterized in that it is equipped with a second rolling mill (6) located in the direction (F) of transportation directly behind the casting plant (2), and the milling machine (4) is located between the rolling mills (5, 6). 6. The device according to claim 5, characterized in that it is equipped with a furnace (7), which is located between the first rolling mill (5) and the second rolling mill (6). 7. The device according to claim 6, characterized in that the furnace (7) is made in the form of a heat-insulating casing of the rolling table. 8. The device according to claim 5, characterized in that it is equipped with a device (8) for cleaning or descaling, located in front of the first rolling mill (5). 9. The device according to claim 5, characterized in that it is equipped with a furnace (9) located in front of the first rolling mill (5). 10. The device according to claim 5, characterized in that each rolling mill (5, 6) contains at least one stand. 11. The device according to claim 5, characterized in that the first rolling mill (5) contains one or two stands, made as two-roll stands or four-roll stands. 12. The device according to claim 5, characterized in that the milling machine (4) contains a cylindrical mill. 13. The device according to p. 12, characterized in that the milling machine (4) contains one or more cylindrical mills on each side of the slab. 14. The device according to claim 5, characterized in that the milling machine (4) contains an end mill.

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