ZA200605451B - Device for producing a metallic product by rolling - Google Patents

Description

TRANSLATION (HM-737PCT-or-iginal):

PCT/EP2005/013,546

INSTALLATION FOR PRODUCING ROLLED METAL PRODUCT

The invention concerms an installation for prodwmcing rolled metal product, which has: a first zone, in which slambs are produced by primary formimg; a second zone downstream of the first zone in the direction of flow of the material, in which at least a first rolling installation is installed for r-olling the slabs; a third zone downs tream of the second zone in the direction of flow of the material, in which at least a second rolling installation is installed for rolling the slabs or the intermediate product produced from them; and a fourth zone downstream of the third zone in the direction of flows of the material, in which at lea st one installation for furt—her processing of the rolled material is installed.

Rolling installations of this type are sufficieratly well known in the prior art. For example, flat stock made of steel and/or nonferrous materials in sheet and/or strip fomm can be produced in these install ations. In a continuous cassting installation, a metal strand can be cast, which is p=assed through a roughing mill (first roll. ing installation) and then i through a finishing mill (second rolling installation), in which the product is rolled from the slal> and is finished with respect : to its geometry. This is followed by further processing of the i rolled product, especially cooling, coiling, and possibly hot straightening.

In the roughing mill, the slal> can first be heated in a furnace to rolling temperature and can then be rolled out to the desired sheet dimensions in a singF e-stand or multiple-stand rolling mill by means of a rolling sequence, which can also include a 90° rotation of the rolling stock. Special turning equipment for the material to be rolled is described, for example, in DE-OS 14 52 161 and DE—O0S 16 52 560.

Steckel mill rolling has provesn to be an especially advantageous rolling process in the finishing mill. The Steckel mill has a first hot box, which is located in an upstream position with respect to the directzion of flow of the material, and a second hot box located in a Jownstream position. In regard to this technology, the reader is referred to WO 96/40456, WO 96/41024, and WO 00/033042, which describe the

Steckel rolling process. In this porocess, for example, long continuously cast slabs are rolled out to long end lengths without turnincy in a Steckel mill by coeiling the rolling stock ) between the firmishing passes in heated Steckel hot boxes. After the last pass, the long end lengths are- optionally coiled into : coils or cut irato individual sheets by a shear. The individual ) sheets can be cooled and straightened a_s part of this process.

The Stecke=l rolling process has va._rious advantages in the processing of am roughed slab into metal strip. One advantage that deserves sspecial mention is that t he process of rolling out the slab to a r-elatively thin strand ca n be carried out in a relatively smal_.1l space.

However, t he process also has the disadvantage that it takes a relativ-ely long time to carry o—ut the numerous passes im the Steckel mil 1. The Steckel mill par t of the finishing installation is. thus often the rate-det.ermining part of the installation, o-n which the throughput amd thus the economy of the plant depen _ds.

Therefore, the objective of the invention is further development of an installation of the a=forementioned type that makes it possib le to achieve greater plant economy, especially when the Stecke 1 rolling process is used.

The soluti on to this problem in accordance with the invention is ch aracterized by a conveyamice system with which the metal stock can be removed between the second zone and the third } zone of the installation, conveyed, and then returned to the treatment process between the third zone and the fourth zone of : the installation. ] The idea of the invention is thus to utilize only the first - rolling installation (i.e., the roughing mill) for the purpose of using the production plant while dispensing with rolling in the second rolling installation (i.-e., the finishing mill), and then (in order to be able to use thee further processing installation for the rolling stock -—that has been rolled only in the first rolling installation) to «convey the roughed material around and parallel to the second reolling mill and back to the treatment process upstream of the further processing installation.

The second rolling installatiom is preferably a Steckel mill, which has at least one rollineg stand with a first hot box upstream and a second hot box downstream of the stand in the direction of flow of the metal rolling stock. In other words, the Steckel rolling process is carrzded out in this installation.

The further processing installation is preferably a cooling installation for the rolled product .

The conveyance system for bypasssing the second rolling instal lation, i.e., especially the Steckel mill, can have a } roller table that is arranged parallel to the second rolling instal lation. In addition, the conveyance system can have at ‘ least one and preferably two devices with which metal rolling stock can be conveyed transversely to the direction of flow of the ma_terial. In this way, the material roughed in the first rollimg installation can be conveyed directly from the first rollimg installation to the further processing installation in the manner of a bypass.

I_t is advantageous for the fir st zone of the installation to hawe a continuous casting instal lation. A slab storage area can bee located in the first zone or the second zone of the instal lation. At least one heating furnace (preferably two furnaces) for the material to be rolled is preferably arranged betwee=n the slab storage area and t he first rolling installation for tlie purpose of heating the material to the optimum rolling temper—ature. In addition, a descal ing system can be installed betweean the one or more heating furnaces and the first rolling insta3 lation.

Einally, it is advantageous to install a shear downstream of the second hot box of the Stecke=l mill in the direction of flow oof the metal rolling stock.

The economy of the production process can be significantly ) increased with the above-described design of an installation for the rolling of metal stock, since during the Steckel rolling (in ‘ the second rolling installation), the first rolling installation } can be used for different rolling stock, which can then be treated directly in the further processing installation.

A specific embodiment of the invention is illustrated in the drawings. -- Figure 1 shows a schematic drawing of an installation for producing a rolled metal produ.ct. -- Figure 2 shows the path-ti me diagram for metal rolling stock processed with the installat ion.

Figure 1 shows a production installation for producing and processing metal rolling stock 1. The installation has essentially four zones 2, 3, 5, amd 7, which follow one another in the direction of flow F of the metal rolling stock. The primary forming of the stock 1, i. e., the casting, takes place in the first zone 2, which comprisses a continuous casting installation 17, in which strand material is produced by well- known means from molten metal (stesel, light metal) and then further processed as slab. In thi s regard, it can be useful to provide a slab storage area 18 forr holding cast slabs downstream of the continuouus casting installation 17. i As they ares needed, the slabs kept ira stock in the slab storage area 18 are conveyed cold or hot or in a combined form : to at least one heating furnace 19, in whi.ch they are heated to the temperature required for the subsequerat rolling operation.

After the slab Hhas been discharged from the heating furnace 19, it is descaled —in a descaling system 20 (furnace scale sprayer) and fed into the= roughing mill.

The roughimng mill extends over the seacond zone 3 of the installation ancd comprises the first rolling installation 4, which is shown —in only a schematic way in Figure 1. The roughing mill ceconsists of a horizontal roM ling stand and possibly a vert-ical stand and one or two turning devices before or after the stand for turning the slab.

Therefore, metal rolling stock can already be rolled in the first rolling imstallation 4 in such a wasy that it is sufficiently shaped for certain applicaticons, so that it is not necessary to cazxrry out an additional roll=ing operation.

In other weords, the slab can be rolle=d out to well-defined intermediate diwmensions with well-defined temperatures in the first rolling imstallation 4 and then fed to the finishing mill.

Alternatively, "however, it is also possible to roll out the slab to well. -defined final dimensions with well — defined temperatures ) in the first rolling installation 4 and then to convey it furthers, as will be described in greater detail below. : If the material that has been roughed in the first rolling i install. ation 4 is to be further rolled, it is conveyed to the third =one 5, which contains a second rolli ng installation 6.

This rolling installation is a Steckel roll ing mill, i.e., it has a rrolling stand 10 with a first hot bo 11 arranged upstream and a second hot box 12 arranged downstreamn in the direction of flow F_

Tle Steckel rolling installation can also be followed by a shear 21, which can be used both for croppfing the ends of the rolling stock for the Steckel process and as dividing shears after the last finishing pass. Figure 1 skows a rolling stand schematically. It can also be provided for the finishing mill to have a horizontal stand and a vertical stand. The metal stock 1 is then rolled at well-defined tempoeratures in the finishdng mill to the desired final dimens=ions, and it is coiled in the hot boxes 11, 12 between the passes . However, it is also possible for the finishing mill to be used without the Steckel process3, as in the case of conventional tweo-stand sheet mills for thes finish-rolling of metal sheet.

B

In each c ase, i.e., in the case of rollimg only in the i first rolling installation 4 and in the case -of additional rolling in thes second rolling installation 6, the rolling is : followed by adlditional treatment of the rolle d product in a further processsing installation 8, which is 1 ocated in the fourth zone 7 of the installation.

The furtlmer processing installation 8 has a cooling installation 1.3, in which well-known means ar-e used to bring the rolled and sti. ll hot material to a desired temperature according to technological requirements. In the illust rated embodiment, a coiler 22 for coiling the finished strip and a hot straightening machine 23 are additionally provided, so that- after the finished product has beeen cooled in the cooling line, it can either be cooled or further conveyed to the stretcher 1 eveler.

To make &.t possible, when required, to f£eed metal product that has been rolled in the first rolling insstallation 4 directly to tlie further processing 8 by bypassing the second rolling instal lation 6, in which other materi_al can be simultaneously’ processed by the Steckel roll#f ng process, the conveyance sysstem 9 is provided, which constitutes a bypass of the second rollling installation 6 or the third zone 5. Means 15, which are shown only schematically, are wised to remove the

} rolled product leaving the second zone 3 out of the actual ’ processing lines and convey it transversely to the di rection of flow F. The rolled product is then conveyed in dire ction of : flow F on the moller table 14, which runs parallel t o the } finishing mill with the second rolling installation 6. At the end of the roller table 14, means 16 are arranged, w-ith which the rolled procduct 1 is again conveyed transversely to the direction of flow F and back into the actual processing line, so that the mater:jal bypasses the third zone 5 and dire=ctly enters the further precocessing installation 8, in which it is cooled in the cooling in stallation 13 and possibly subjected t-o other treatment oper.ations (coiling, straightening).

This desi gn makes it possible for the installation and especially the first rolling installation 4 in the second zone 2 and the furthe r processing installation 8 in the fowarth zone 7 to be used for- the processing and treatment of metall rolling stock, while t he relatively time-consuming Steckel ®molling process is bei ng carried out in the second rolling -installation 6 in the third zone. It is thus possible, while the third zone and especial ly the Steckel mill (finishing mill) =is being used for a relatively long period of time, to carry out a rolling operation in tthe first rolling installation 4 (roughing mill)

witch or without cooling pauses —for thermomechanical rolling sand : then to feed the products directly to the further processing installation, e.g., the water-ccooling system and/or the hot : strraightening machine, by bypasssing the finishing mill.

Without the proposal of the invention, the first rollin g insstallation 4 and the further Processing installation 8 wou 1d be largely passive during the Stteckel rolling, which would h_ave an adverse effect on the econom=y of the plant.

A path-time diagram for an actual application is sketch ed in Figure 2. The diagram indicates how the metal stock to bee processed moves through the rolZling mill over time. The flow for each product is reproduced, with each leading end and trailing end shown.

A slab with the dimensions 150 mm x 2,500 mm x 16 m is heated in a first furnace RHF1 (corresponding to the first he=ating furnace 19 in Figure 1) and -- after descaling in tlme dewice PD -- reduced to the nea r-net strip thickness of 45 mm in a moughing mill RM (corresponding to the first rolling insstallation 4 in Figure 1). T’he roughed slab is then rolle=d out to the finished strip thickmess of 5 mm in the finishing mill FM (corresponding to the s econd rolling installation 6 in

Figure 1) by the Steckel proces s. The finishing mill is followed by the shear SH, the cooling line ACC and the coiler ) DC.

While the finishimg mill FM is occupied with the strip ‘ rolling, two slabs with the dimensions 250 mm x 2,100 mm =< 2,100 mm, which are heated im a furnace RHF2 (again correspondirmg to furnace 19 in Figure 1), can be rolled in the roughing mill RM into plates with dimens=sions of 10 mm x 3,650 mm x 30 m in ,» for example, 15 passes and by means of turning, and they can #then be conveyed past the fini shing mill FM and to the cooling lime ACC (corresponding to the <ooling installation 13 in Figure 1) or to the stretcher leveler Dy the parallel roller table 9. A strip- rolling operation can then be carried out again in the ro—ughing mill and finishing mil 1.

In this example, the simultaneous rolling of a total of three products increas es the production capacity by about 37%. i2

List of Reference Numbers 1 metal rolling stock 2 first zone (casting) 3 second zone

4 first rollineg installation third zone 6 second rollimg installation 7 fourth zone 8 further proc-essing installation 9 conveyance system rolling stand (Steckel mill) 11 first furnac e (Steckel hot box) 12 second furna ce (Steckel hot box) 13 cooling inst allation 14 roller table means for tr-ansverse conveyance i6 means for tr-ansverse conveyance 17 continuous c=asting installation 18 slab storages area 19 heating furmace descaling system : 21 shears . 22 coiler 23 hot straightening machine

F direction of flow of the mater ial

Claims (10)

1. Installation for producing rolled metal product (1), which has: -- a fA rst zone (2), in which slabs are proeduced by primary forming; -- a sexcond zone (3) downstream of the firsst zone (2) in the direction of flow (F) of the material, in whaich at least a first rollirmg installation (4) is installed for rolling the slabs; -- a tkird zone (5) downstream of the secornd zone (3) in the directicon of flow (F) of the material, in which at least a second rollzing installation (6) is installed for— rolling the slabs or thee intermediate product produced from them; and -- a feourth zone (7) downstream of the thir-d zone (5) in the directieon of flow (F) of the material, in whknich at least one installatiom (8) for further processing of the molled material is installe 4, characteriz ed by a conveyance system (9) with wkaich the metal stock (1) c an be removed between the second zone= (3) and the third zone (5), conveyed, and then returned to tthe treatment

- Process between the third zone (5) anA the fourth zone (7).

:

2. Installation in accordance wi th Claim 1, characterized by the fact that second rolling instal lation (6) is a Steckel ‘ mill, which has at least one rolling stand (10) with a first hot ] box (11) upstream and a second hot box (12) downstream of the stand in the direction of flow (F) of the metal rolling stock

(1).

3. Installation in accordance wi. th Claim 1 or Claim 2, characterized by the fact that the further processing imstallation (8) comprises a cooling installation (13) for the rolled product (1).

4. Installation in accordance wi_th any of Claims 1 to 3, characterized by the fact that the coraveyance system (9) has a roller table (14) that is arranged parallel to the second rolling installation (6).

5. Installation in accordance wi th any of Claims 1 to 4, characterized by the fact that the coraveyance system (9) has at 1 east one and preferably two devices €15, 16) with which metal rolling stock (1) can be conveyed trarasversely to the direction of flow (F) of the material.

6. Installation in accordance wEth any of Claims 1 to 5, c haracterized by the fact that the first zone (2) has a cont #nuous casting installation (17).

- 7. Installation in accordance wit=h any of Claims 1 to 6, characterized by the fact that a slab Storage area (18) is : locatzed in the first zone (2) or in the second zone (3) of the installation.

8. Installation in accordance with Claim 7, characterized by tlne fact that at least one heating furnace (19) is arranged betwe=en the slab storage area (18) and the first rolling installation (4).

9. Installation in accordance wit=h Claim 8, characterize by tke fact that a descaling system (20) is installed between the one or more heating furnaces (19) and the first rolling installation (4).

10. Installation in accordance with any of Claims 2 to 9 , charazacterized by the fact that a shear (21) is installed downsstream of the second hot box (12) Zin the direction of flow (F) of the metal rolling stock (1). Figume 2. KEY: Zeit in s = time in s