EP1981660B1 - Method for the production of hot-rolled metallic strips, especially steel strips, having great surface quality - Google Patents

Description

The invention relates to a method for producing hot-rolled metal, in particular high-quality steel material strip from slab or flat thin strands cast in a continuous casting process by means of a hydraulically oscillating continuous casting mold, which descaled at its strand surface, heated to rolling temperature and heated in a multi-stand hot-rolled strip. Walzstraße is finished with low strip thicknesses, the casting strand after emerging from a strand guide, before entering a heat balance furnace and / or after exiting a heat balance furnace and entering the hot strip mill at one or both strand surfaces by a plurality of rotating nozzles from which printing fluid recurring sprayed on a respective same surface area with high applied pressure, freed of scale and / or casting powder and the oscillation marks are deeply cleaned, as by the WO-A 00/10741 A known.

Such a method is similar to the DE 43 28 303 C2 known. However, it is not assumed that there is a continuously cast slab or thin slab cross section and the rotor descaling is essentially applied to rolling stock and thus does not take into account the special manufacturing process by continuous casting. In addition, the depth of ablation is not sufficient to detect not only invisible tinder but also any oscillation mark caused by its manufacture. In addition, caused by a very high amount of water an undesirably high cooling of the rolling stock.

From the EP 0 586 823 B1 a descaling device for casting and rolling mills is known. It uses a rotatable arm with nozzle and Retention, protection and Rückgewnnnungsplatten proposed for the removed scale and the large amount of spray water.

From the EP 0 625 383 B1 a first descaling device is known, which may consist of a scale washer of conventional design and a second descaling device with rotating nozzles.

From the EP 0 611 610 B1 is a Rotorentzunderung known with low water consumption, which should cause a lower temperature drop of the rolling stock.

The invention has for its object, in addition to the application of the rotating Entzunderns previously included not included parameters that are given by the continuous casting.

This object is achieved in a method of the type mentioned in the present invention that the hydraulically oscillated continuous casting mold is driven in several different oscillation curves, the oscillation curves are obtained by different Kokillenhübe, different sliding speeds, different leading Kokillengeschwindigkeiten on the downward stroke and different waveforms, and that the deep cleaning of the oscillation marks is performed by adjusting the determined for each casting material oscillation curve. The advantages are that in addition to the actual Entzundem Now the oscillation marks can be cleaned very extensively and thus a finish rolling on ultrathin Endwalzdicken equal to / less 1.2 mm is favored. This means that, for example, for these dimensions, finish rolling in the austenite region of the crystal structure is possible.

In Ausgestakung provided that the pressurization of the rotating nozzle with hydraulic fluid by significantly less pressure medium than hitherto In so-called. Tinder scrubbers has been spent, with the same parameters of the casting or rolling process. This can be saved with the same or better Entzunderungswirkung of printing medium, such as, for example, water.

A further embodiment advantageously provides that the temperature losses of the cast strand are kept low via a pressurization of the rotating nozzles regulated with regard to the temperature level of the casting or rolling train. As a result, there is a reduction in the temperature losses of the slabs and thin strands, resulting in much better conditions for hot rolling the ultrathin Endwalzdicken and energy Erspamis are connected.

In the drawings, embodiments of the features of the invention are shown, which will be explained in more detail below.

Fig. 1

eine Gieß-Walz-Kompakt-Anlage in perspektivischer Seitenansicht,

Fig. 2

eine in einem kompakten Schutzgehäuse befindliche Stranggießkokille mit hydraulischem Oszillationsantrieb,

Fig. 3

mehrere Diagramme von unterschiedlichen Oszillationsbewegungen der Stranggießkokille und

Fig. 4

einen einzelnen Rotor mit am Rotorumfang angeordneten Düsen.

Show it:

Fig. 1

a casting-rolling compact plant in perspective side view,

Fig. 2

a continuous casting mold with hydraulic oscillation drive located in a compact protective housing,

Fig. 3

several diagrams of different oscillatory movements of the continuous casting mold and

Fig. 4

a single rotor with arranged on the rotor circumference nozzles.

A cast-rolling plant 1 ( Fig. 1 ), which in particular represents a CSP plant (Compact Steel Plant), consists of a continuous casting apparatus 2, in which liquid metal, in particular liquid steel material, is cast by means of a continuous casting mold 9. The continuous casting mold 9 is provided with a hydraulically oscillating drive 9a (FIG. Fig. 2 ) Mistake. On the Stranggleßkokllle 9 follows in strand withdrawal 11 a strand guide 3, a temperature compensation furnace 4, if provided, a furnace ferry 5 and a multi-stand hot strip finishing train 6 and behind a reel 8 for winding the tape. 7

Between the strand guide 3 and the temperature compensation furnace 4 or between a straightening 12 with scissors 13 and / or between the temperature compensation furnace 4 and the hot strip finishing train 6 Is a device 14 with rotating nozzles 15 (FIGS. Fig. 4 ), from which pressure media (usually liquid, such as, for example, water) with a high application pressure is repeatedly directed to a respective same surface location.

Finally, the application of rotor descaling to a hot strip rolling mill having seven or more finishing stands is provided prior to entry into the first finishing stand.

In the drawings, embodiments of the features of the invention are shown, which will be explained in more detail below.

Fig. 1

eine Gieß-Walz-Kompakt-Anlage in perspektivischer Seitenansicht,

Fig. 2

eine in einem kompakten Schutzgehäuse befindliche Stranggießkokille mit hydraulischem Oszillationsantrieb,

Fig. 3

mehrere Diagramme von unterschiedlichen Oszillationsbewegungen der Stranggießkokille und

Fig. 4

einen einzelnen Rotor mit am Rotorumfang angeordneten Düsen.

Show it:

Fig. 1

a casting-rolling compact plant in perspective side view,

Fig. 2

a continuous casting mold with hydraulic oscillation drive located in a compact protective housing,

Fig. 3

several diagrams of different oscillatory movements of the continuous casting mold and

Fig. 4

a single rotor with arranged on the rotor circumference nozzles.

A cast-rolling plant 1 ( Fig. 1 ), which is in particular a CSP plant (Compact Steel Plant), consists of a continuous casting apparatus 2, in which liquid metal, in particular liquid steel material, is cast by means of a continuous casting mold 9. The continuous casting mold 9 is provided with a hydraulically oscillating drive 9a (FIG. Fig. 2 ) Mistake. On the continuous casting mold 9 follows in strand withdrawal direction 11, a strand guide 3, a temperature compensation furnace 4, if provided, a furnace ferry 5 and a multi-stand hot strip finishing train 6 and behind a reel 8 for winding the tape. 7

Between the strand guide 3 and the temperature compensation furnace 4 or between a straightening 12 with scissors 13 and / or between the temperature compensation furnace 4 and the hot strip finishing train 6 is a device 14 with rotating nozzles 15 (FIGS. Fig. 4 ), from which print media (usually liquid, such as, for example, water) with a high application pressure is directed repeatedly to a respective same surface location.

According to Fig. 3 the hydraulically oscillating continuous casting mold 9 is moved in a plurality of different oscillation curves 16, 17, 18, so that a respectively different oscillation profile 16a, 17a, 18a is produced for the respectively selected casting material. The oscillation curves 16, 17, 18 can, by different Kokillenhübe, different casting speed, different leading Kokillengeschwindigkeiten on the downward stroke (so-called negative strip) different waveforms (eg, sine waves) u. Like. Be obtained. The pressurization of the rotating nozzle 15 with hydraulic fluid 19 can be done with significantly less pressure medium (pressure medium) than has been used in so-called. Zunderwäschem, where equal ratios, ie parameters of the opposing processes are based. At the same time, the temperature losses of the cast strand 2b are kept as low as possible by way of a temperature level of the casting or rolling train (2b) to be observed with regard to the pressurized medium.

A plurality of nozzles 15 for the pressure medium are on a rotor 20 ( Fig. 4 ) and several rotors 20 have attached to the rotor circumference 20a nozzles 15 for pressure medium and are arranged in a row of nozzles 21 transversely to the course of the casting or rolling train 2b. Advantages also result from a plurality of such rows of nozzles 21, smaller nozzle jets than can be used in a single row of nozzles 21.

The rotor descaling may be applied to a hot strip rolling mill 6 having seven or more finish rolling stands 6a before the entry of the rolled strip into the first finishing stand 6a.

LIST OF REFERENCE NUMBERS

1

CSP plant (Compact Steel Plant)

2

slab profile

2a

Thin extruded profile

2 B

cast strand

2c

strand surface

3

strand guide

4

Temperature equalizing furnace

5

oven ferry

6

Hot strip rolling mill

6a

Finishing stand

7

Steel material band

8th

reel

9

hydraulically oscillated continuous casting mold

9a

Oscillation drive

10

oscillation curve

11

Strand withdrawal direction

12

straightening

13

scissors

14

Device with rotating nozzles

15

rotating nozzle

16

oscillation curve

16a

Course of the oscillation curve

17

oscillation curve

17a

Course of the oscillation curve

18

oscillation curve

18a

Course of the oscillation curve

19

Hydraulic fluid

20

rotor

20a

Rotor circumferential

21

Row of rotors

Claims (3)

1. Method of producing hot-rolled metal strip, particularly steel material strip (7), with high surface quality from slab strips or flat thin strips (2, 2a) cast in a continuous casting method with the help of a hydraulically oscillating continuous casting mould (9), which strip is descaled at its strip surface (2c), heated to rolling temperature and rolled to finished state in a multi-stand hot-strip rolling train (6) with small strip thicknesses, wherein the cast strip (2a) after emerging from a strip guide (3), before entry into a heat compensation oven (4) and/or after emerging from a heat compensation oven (4) and running into the hot-strip rolling train (6) is freed of scale and/or casting powder at one or both strip surfaces (2c) by a plurality of rotating nozzles (15), from which liquid (19) under a pressure is repeatedly sprayed with high action pressure onto the same surface location, and the oscillation marks are deep-cleaned, characterised in that the hydraulically oscillating continuous casting mould (9) is moved in a plurality of different oscillation curves (16, 17, 18), wherein the oscillation curves (16, 17, 18) are obtained by different'mould strokes, different casting speeds, different advance mould speeds during the downward stroke and different curve forms, and that the deep-cleaning of the oscillation marks is carried out by setting the oscillation course determined for each casting material.
2. Method according to claim 1, characterised in that the loading of the rotating nozzles (15) with liquid (19) under pressure takes place by a significantly smaller amount of pressure medium than previously employed in so-termed scale washers for the same parameters of the casting or rolling process.
3. Method according to one of claims 1 and 2, characterised in that the temperature losses of the cast strip (2b) are kept low by way of a loading, which is regulated with respect to the temperature level of the cast or rolled strip (2b), of the rotating nozzles (15) with pressure medium.

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