EP3027330B1 - Continuous casting and rolling installation for producing metal strips - Google Patents

Description

Specifically, the invention relates to small caster rolling mills, so-called micro-mill plants for the production of flat steel with an annual production between 350,000 and 700,000 t carbon steel. Die Erfindung wird nachfolgend anhand der Zeichnung näher erläutert. The plant concept according to the invention is characterized by low investment and production costs, a fast project realization with good and short-term profitability of the invested capital and a compact plant layout. The plant according to the invention is particularly suitable for steel producers in regions where so far no flat steel production took place and where a specialization to regional requirements should take place.

Cast rolling are basically known in the art, such. B. from the EP 2 441 540 A1 , of the DE 196 39 302 A1 , of the WO 2007/039483 , of the DE 41 35 214 A1 and the EP 0 535 368 A1 ,

The German patent application DE 41 35 214 A1 discloses a cast roll mill having a vertical exit mold for producing a cast strand and a strand guide for diverting the cast strand from the vertical to the horizontal. The strand guide comprises a vertical part following the mold in the casting direction and a deflecting part adjoining the vertical part. The vertical part in turn comprises a first parallel section following the mold, a reduction section following the parallel section in the casting direction, and a second parallel section following the reduction section in the casting direction, in which the through solidification of the cast strand takes place. Subordinated to the strand guide is a dicing device for dividing the casting strand into metal strips of predetermined length, a tunnel kiln, a Steckel mill for further reduction in thickness of the metal strips, a cooling section and a reel device for winding the rolled metal strip to a collar. The strand guide consists of a plurality of successively connected individual pairs of rollers, these pairs of rollers or the individual roles of the pairs of rollers are each made individually.
The EP 0 535 368 A1 discloses a casting and rolling plant for producing metal strips, comprising: a mold with a vertical output for producing a casting strand and at least one strand guide for deflecting the casting strand from the vertical to the horizontal, wherein the strand guide has a mold downstream of the mold in the casting direction and a deflection part. The vertical part has a first parallel section following the mold, a reduction section following the parallel section in the casting direction, and a second parallel section following the reduction section in the casting direction, in which solidification of the cast strand takes place (FIG. 4). A dividing device for dividing the casting strand into metal strips of predetermined length, a tunnel kiln, a Steckel mill, a cooling section and a reel device for winding the rolled metal strip into a collar are connected downstream of the strand guide.

The preamble of claim 1 is based on EP 0 535 368 A1 , The invention has the object of developing a known cast roll mill for the production of metal bands to the effect that they can be made more compact in particular in their height and that they also produce cheaper and easier to use.
This object is solved by the subject matter of patent claim 1. Accordingly, the cast roll mill according to the invention is characterized in that the supported length of the casting mill, which extends from the mold level in the mold to the last roll of the vertical part of the strand guide, 2 to 5 m and that the vertical part of the strand guide of a maximum of two, preferably only a single segment is formed with a fixed side and a lot side.

The supported length is measured in the casting direction from the casting mirror in the mold to the end of the second parallel part, but not to the end of the vertical part, that is, not to the bending driver.
Due to the claimed short supported length, the cast rolling mill also builds in height only briefly compared with other known in the art casting rolling plants. The formation of the vertical part of the strand guide in segmental design with preferably only a single segment with a continuous one-piece fixed side and a multi-part lot side has the advantage that the number of actuators, ie the number of necessary for the roles Anstell is smaller than in a design of the strand guide with a variety of individually controllable roles. The multi-part designed Losseite is therefore required to make the first parallel section, the subsequent reduction section and the second parallel section with their respective roles individually.

The diameter of all strand guide rollers is less than 140 mm. This roller size is sufficient, in particular if it is reduced within the reduction section not only with one, but with a plurality of roller pairs. The overall height H2 of the casting rolling mill is less than 7.5 m.
According to a first embodiment, the first parallel section has a supported length less than 500 mm and comprises one to three pairs of rollers, which are arranged one behind the other in the casting direction or it is designed in the form of a grid for initially bending-free guidance of the cast strand.
The reduction section advantageously comprises three to eight roller pairs, which are arranged one after the other in the casting direction over a length of less than 1.5 m and form a liquid core reduction LCR reduction section.
The second parallel section preferably has a length of less than 1.5 m.

The two last-mentioned features, that is, the number of pairs of rollers in the reduction section and the length of the second parallel section advantageously serve to limit the height of the casting mill.

The cast last in the last pair of rollers of the second parallel part of the strand guide is advantageously adjustable to a size of the roll gap of 20 to 40 mm.

The narrow sides of the mold lead to a casting thickness ex Kokilles from 40 to 60 mm.

Figur 1

die erfindungsgemäße Gießwalzanlage; und

Figur 2

eine Detailansicht der Strangführung der erfindungsgemäßen Gießwalzanlage

zeigt.The description is attached to 2 figures, wherein

FIG. 1

the cast roll mill according to the invention; and

FIG. 2

a detailed view of the strand guide of the cast roll mill according to the invention

shows.

The invention will be described in detail below with reference to the said figures in the form of embodiments. In all figures, the same technical elements are designated by the same reference numerals.

FIG. 1 shows the casting and rolling system according to the invention in an overall view. Accordingly, the casting rolling mill 100 as seen in the casting direction R comprises the following components: a casting platform 105, a mold 110, a strand guide 120, a dicing device 130, a tunnel kiln 140, a Steckel mill 160, a cooling section 170 and a coiler 180. In addition, between the Tunnel furnace and the Steckel rolling mill optionally still an inductive heating 150 may be arranged. The individual components are described in more detail below.

Casting platform 105 includes a turret or pan for handling pans. A distributor is used for sequence casting, wherein the cast rolling mill and in particular the strand guide are designed for single-strand operation. The casting operation enables concealed casting with ceramic components between pan and distributor (shadow tube) or between distributor and mold (dip tube). The distributor is typically covered with cover powder while the mold is covered with casting powder.

The mold 110 is typically a compact strip production CSP mold. It can consist of four individual side walls, typically two broad sides and two narrow sides, or be formed as a frame mold. In training with narrow sides a narrow-side adjustment is advantageously provided for adjusting the Gießformates before and during the casting operation; Preferably, the setting is done online. The mold is equipped with an integrated level measurement, which works, for example, radiometrically or based on an eddy current measurement.

The mold can be designed as a funnel mold with a crown of 20 to 60 mm on the upper Kokillenkopf. The output can be formed in parallel or also have a Restbombierung of less than 10 mm. The mold plate, d. H. the side walls of the mold are made of copper or a copper alloy with or without full or partial wear-reducing coating. The mold is preferably equipped with an oscillation drive for up to 660 oscillation strokes per minute and for amplitudes of up to +/- 5 mm. The mold is typically water cooled with water levels of 1,000 to 4,000 liters per minute per meter of casting width. The length or height of the hopper mold is 0.9 to 1.3 m. The outlet thickness is 40 to 60 mm. The casting speed is between 2.5 and 7.5 m / min.

The strand guide 120 following the mold 110 in the casting direction comprises a vertical part 125 and a deflection part 128 adjoining it in the casting direction R. Both parts will be described below with reference to FIG FIG. 2 described in more detail.

The vertical part 125 comprises a first parallel section 125-1 following the mold, a reduction section 125-2 following the parallel section in the casting direction, and a reduction section 125-2 following in the casting direction Casting subsequent second parallel section 125-3, in which the solidification of the cast strand.

The first parallel part 125-1 comprises a maximum of three roller pairs, which are arranged below the mold and with respect to the casting direction in alignment with the exit of the mold. Alternatively, it may be formed as a guide grid. Regardless of its training, its length in the casting direction is a maximum of 500 mm.

sind einstellbar.The reduction section 125-2 comprises three to eight roller pairs and extends over a length of less than 1.5 m, preferably less than 1 m. Within the reduction section, the cast strand is reduced in thickness between 33% and 66% according to the Liquid Core Reduction LCR process. By way of example, there is a reduction in thickness starting from 40 to 60 mm to 20 to 40 mm. Accordingly, a short strand guide, in particular a short reduction part, with a simultaneously large reduction or thickness decrease in the conically set reduction section 125-2 is typical for the plant concept according to the invention; $\mathrm{reduction\; rates}>13\frac{\mathit{mm}}{m}$

are adjustable.

The reduction section 125-2 is followed in the casting direction by the said second parallel section 125-3 with a length of less than 1.5 m, preferably less than 1.0 m. The second parallel section comprises four to ten pairs of rollers. In practice, the second parallel section may also be slightly tapered to accommodate the thermal taper, i. H. shrinkage of the material due to cooling.

The vertical strand guide region 125 is preferably formed of only one segment with a fixed side and a loose side. The fixed side, left of the cast strand 210 in FIG. 2 , the segment is formed in one piece, while the lot side, right of the casting strand 210 in FIG. 2 , is divided into three parts by way of example. This means there are individually engageable segment frame provided for the first parallel part 125-1, for the reduction section 125-2 and for the second parallel section 125-3. The employment of the pairs of rollers or the frame of the segments is carried out, as usual, via position-controlled hydraulic cylinder with force monitoring. Within the segment area can be dispensed with a roller drive. The strand guide rollers are at least simply divided rollers with diameters of less than 180 mm, preferably in axle roller design with internal cooling. The secondary cooling in the region of the vertical part via single-fluid or two-fluid nozzles with specific Wasserbeaufschlagungsdichten of 0.5 to 4 l / kg of cooling medium, z. B. liters of water per kilogram of steel. Secondary cooling is controlled via spray plans or preferably via a process model.

As in FIG. 2 illustrated, the strand drive comprises at the end of the vertical part 125 a bending driver 190, which is in the form of one or at most two roller pairs, in which both rollers are driven. The distance between the end of the second parallel part 125-3, seen in the casting direction, and the bending driver 190, in particular the axes of rotation of the pair of rollers, is less than 1 m. In addition, the strand drive includes a directional driver 195 with up to 4 driven rollers in the directional range, ie at the end of the deflection 128. The bending and straightening are individually controllable pairs of rollers, preferably with position and force monitoring. Bending and guide rollers in the deflecting 128 provide sufficient guidance of the metal strip between the bending driver 190 and the straightening driver 195 at the end of the deflection.

The total height H2 of the plant, which is measured from the casting level to the strand after its deflection into the horizontal, is between 5 and 7.5 m.

As I said, after the deflection part 128 is followed by a dicing device 130 and a tunnel kiln, for the decoupling of the hitherto taken place Casting process from the subsequent rolling process. Optionally, behind the tunnel kiln 140, said inductive heating 150 is arranged to heat the slab or the metal strip and / or to equalize the temperature of the metal strip over its length.

In the Steckel mill 160 with two coiler ovens 162, 164, the metal strip is rolled in, for example, three, five or seven passes to a predetermined final thickness. Behind the Steckel mill follow the said cooling section 170 and the reel 180th

LIST OF REFERENCE NUMBERS

100

continuous casting and rolling

105

casting platform

110

mold

120

strand guide

123

roller pair

125

vertical part

125-1

first parallel section

125-2

reduction section

125-3

second parallel section

128

deflecting

130

Zerteileinrichtung

140

tunnel kiln

150

inductive heating

160

Steckel mill

162

Winding furnace (Steckel)

164

Winding furnace (Steckel)

170

cooling section

180

coiler

190

bending driver

195

straightening

210

cast strand

220

metal bands

250

Federation

R

casting

H1

supported length / height

H2

height

D

diameter

Claims (6)

1. Casting-and-rolling plant (100) for producing metal strips (220), comprising:

   a mould (110) with a vertical outlet for producing a cast strip (210),

   at least one strip guide (12) for deflecting the cast strip from the vertical to the horizontal,

   wherein the strip guide (120) has a vertical part (125), which follows the mould in casting direction (R), and a deflecting part (128), wherein the vertical part has a first parallel section (125-1) following the mould, a reduction section (125-2) following the parallel section in casting direction and a second parallel section (125-3), which follows the reduction section in casting direction and in which hardening-through of the cast strip takes place;

   a dividing-up device (130) for dividing up the cast strip (210) into metal strips (220) of predetermined length;

   a tunnel furnace (140);

   a Steckel rolling mill (160);

   a cooling path (170); and

   a coiler (180) for coiling the rolled metal strip (220) to form a coil (250);

   characterised in that

   the supported length (H1) of the casting-and-rolling plant (100), which extends from the casting surface in the mould to the last roller of the second parallel part (135-3) of the strip guide (120), is 2 to 5 metres;

   the vertical part (125) of the strip guide is formed from at most two segments with a fixed side and a movable side;

   the diameter (D) of all strip guide rollers (122) in the strip guide is less than 140 millimetres; and

   the overall constructional height (H2) of the casting-and-rolling plant (100) is less than 7.5 metres.
2. Casting-and-rolling plant (100) according to claim 1, characterised in that the first parallel section (125-1) is smaller than 500 millimetres and comprises one to three roller pairs, which are arranged in succession in casting direction, or a grating for initial bending-free guidance of the cast strip (210).
3. Casting-and-rolling plant (100) according to one of the preceding claims, characterised in that the reduction section (125-2) comprises three to eight roller pairs, which are arranged in succession in casting direction over a length of less than 1.5 metres and form a liquid core reduction (LCR) path.
4. Casting-and-rolling plant (100) according to any one of the preceding claims, characterised in that the second parallel section (125-3) has a length of less than 1.5 metres.
5. Casting-and-rolling plant (100) according to any one of the preceding claims, characterised in that the gap of at least the roller pair (123), which is last in casting direction, of the second parallel part (125-3) of the strip guide is settable to a casting thickness for the cast strip of 20 to 40 millimetres.
6. Casting-and-rolling plant (100) according to any one of the preceding claims, characterised in that the narrow sides of the mould (110) form a casting thickness of the cast strip of 40 to 60 millimetres.

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