KR20080106891A - Method and casting/rolling plant for the production of hot-rolled metallic strips, especially steel strips, having great surface quality - Google Patents

Abstract

Disclosed are a method and a casting/rolling plant for producing hot-rolled metallic, particularly steel, strips (7) having great surface quality from slabs or flat thin bars (2, 2a) that are cast in a continuous casting process, descaling being performed based on a rotary descaling process. In order to take into account parameters which are not considered in prior art in addition to rotary descaling, the hydraulically oscillated permanent mold (9) travels along several different oscillation curves (16, 17, 18) while the oscillation marks are deep-cleaned by adjusting the oscillation pattern that is determined to be optimal for each casting material. ® KIPO & WIPO 2009

Description

METHOD AND CASTING / ROLLING PLANT FOR THE PRODUCTION OF HOT-ROLLED METALLIC STRIPS, ESPECIALLY STEEL STRIPS, HAVING GREAT SURFACE QUALITY}

The present invention relates to a method for producing hot rolled metal strips, especially steel strips, and cast rolling plants with high surface quality from slab strands or thin strands cast by a continuous casting method. According to the invention, the strip is descaled to the strand surface, heated to a rolling temperature, and rolled to a degree having a slight strip thickness in a hot rolling strip rolling sequence consisting of a plurality of stands. In addition, the cast strand is discharged from the strand guide before entering into the heat compensation furnace and / or after exiting from the heat compensation furnace and entering the hot rolling strip rolling column, on one or both sides of the strand, respectively, under high feed pressure. The scale and / or cast powder is removed by a number of rotary nozzles that periodically spray pressure fluid towards the same surface location, and the traces of vibration are deeply cleaned.

Such methods are similarly known from DE 43 28 303 C2. However, the case of cited documents does not start from the continuously cast slab cross section or the thin slab cross section, and the rotary descaling process applies only to the rolled material in essence, and therefore does not take into account the particular manufacturing method by continuous casting. In addition, the removal depth is not sufficient, and in addition to the invisible scale, vibration traces generated according to manufacturing conditions are detected. In addition, with very high quantities, the rolled material is cooled so strongly that it is undesirable.

EP 0 586 823 B1 discloses a descaling device for casting and rolling trains. In this regard, a rotatable arm with a nozzle is used and a retention, protection and recovery plate for the removed scale and a large amount of spray water are needed.

EP 0 625 383 B1 discloses a first descaling device, which can be composed of a scale scrubber having a conventional structure, and a second descaling device with rotary nozzles.

EP 0 611 610 B1 discloses a rotary descaling process using low consumption jetting water. This rotary descaling process results in a relatively low temperature drop of the rolled product.

The object of the present invention is not only to apply a rotary descaling process, but also to include a parameter provided by continuous casting but not considered heretofore.

The object is that, in combination with the type originally indicated, according to the invention, the hydraulic vibratory permanent mold is moved according to a number of different vibration curves, and the deep cleaning of the vibration traces is determined to be optimized for each casting material. This is achieved by performing by adjusting the pattern. Preferably, in addition to the inherent descaling, according to the present application the vibration traces can be cleaned very extensively, thereby facilitating the finishing rolling which is set to the final rolling thickness of the ultra thin film equal to or thinner than 1.2 mm. In other words, it is possible to finish-roll, for example, in an austenite region having a crystal structure for the above dimensions.

According to an embodiment, the supply of pressure fluid by the rotary nozzles is made by a pressure medium which is clearly reduced even more so than what has been applied in so-called scale scrubbers so far at the same parameters of the casting or rolling process. By doing so, the amount of pressure medium such as, for example, water can be reduced even under conditions where the descaling effect is the same or improved.

According to a further feature, the pressure fluid supply of the rotary nozzles is made in a controlled manner taking into account the temperature level of the cast or rolled strand, so that the temperature loss of the cast strand is kept low. Doing so also reduces the temperature loss of the slabs and thin strands, thereby achieving essentially further improved conditions for hot rolling and energy saving of the final roll thickness of the ultrathin film.

The corresponding cast rolling plant, in particular the compact cast rolling plant (CSP), consists of a continuous casting device for liquid metals, in particular for liquid steel materials, the permanent mold of which is connected with a hydraulic vibration drive and also this permanent The mold is followed by a continuous arrangement of at least one strand guide in the direction of strand discharge, temperature compensation, optionally a row feeder, a hot rolled strip finishing mill consisting of a plurality of stands and a winding machine. The cast rolling plant according to the invention comprises a device with rotary nozzles between the strand guide and the temperature compensation furnace, or between the calibration driver and the shearer, and / or between the temperature compensation furnace and the connecting rolling strip finishing rolling train. And, from these nozzles, the pressure medium with the high supply pressure is periodically improved in such a way that they are each sprayed towards the same surface position. By doing so, the effect of the above-described method can be achieved.

As is known in another association, a number of nozzles provided for the pressure medium are arranged in the rotor. However, it is desirable to provide such nozzles for other media than normal temperature water.

According to yet another embodiment, a plurality of rotors with nozzles arranged for the pressure medium on the rotor circumferential surface are arranged in a row transverse to the direction of travel of the cast or rolled strand. By doing so, the spray bars that have been used so far in the scale scrubber can be replaced individually or completely.

Finally, in a hot rolling strip rolling train with seven or more finishing roll stands, a rotor descaling process is always applied before entering the first finishing roll stand.

In the drawings an embodiment of a feature according to the invention is shown, which is described in more detail below.

1 is a perspective view showing a side view of a compact cast rolling plant.

FIG. 2 is a perspective view showing a permanent mold disposed in a compact protective housing with a hydraulic vibration drive. FIG.

3 is a number of graphs illustrating various vibrational motions in a permanent mold.

Figure 4 is a schematic diagram showing one individual rotor with nozzles arranged on the rotor circumferential surface.

<Description of main parts of drawing>

1 CSP Plant (Compact Steel Plant) 2 Slab Section Steel

2a foil strand shaped steel 2b casting strand

2c strand surface 3 strand guide

4 temperature compensation furnace

Horizontal feeder of 5 furnace type 6 Hot rolling strip Rolling mill

6a finishing roll stand 7 steel material strip

8 Winding machine 9 Hydraulic vibratory permanent mold

9a vibration drive 10 vibration curve

11 Strand discharge direction 12 Calibration driver

13 Shearers 14 Devices with rotary nozzles

15 Rotary Nozzles 16 Vibration Curves

16a vibration curve pattern 17 vibration curve

17a pattern of vibration curve 18 vibration curve

18a pattern of vibration curve 19 pressure fluid

20 rotor 20a rotor circumferential surface

21 rotor heat

The cast rolling plant 1 shown in FIG. 1, in particular a CSP plant (compact steel plant), consists of a continuous casting device 2. In this continuous casting device the liquid metal, in particular the liquid steel material, is precast by means of a permanent mold 9. The permanent mold 9 has a hydraulic vibration drive device 9a (Fig. 2). Following the permanent mold 9, it consists of a strand guide 3, a temperature compensation path 4 in the strand discharge direction 11, a row feeder 5 in the form of a furnace, and a plurality of stands in the point provided. The hot rolling strip finishing rolling train 6 to be followed by a winding machine 8 for winding the strip 7 is subsequently arranged.

Between the strand guide 3 and the temperature compensation furnace 4, or between the calibration driver 12 and the shearer 13, and / or between the temperature compensation furnace 4 and the hot rolling strip finishing rolling train 6. In the arrangement is arranged a device with rotary nozzles 15 (FIG. 4). From the nozzles a pressure medium (usually a fluid such as water, for example) with a high supply pressure is periodically sprayed towards the same surface position at all times.

3, the hydraulic vibratory permanent mold 9 is moved according to a number of different vibration curves 16, 17 and 18, thereby generating various vibration patterns 16a, 17a and 18a for each of the selected casting materials. Done. Vibration curves 16, 17, 18 can be obtained by various mold strokes, various casting speeds, mold speeds provided with various accelerations in downstrokes (so-called negative strips), various curve shapes (e.g. sinusoidal vibrations), and the like. have. The pressure fluid 19 supply of the rotary nozzles 15 consists of a pressure means (pressure medium) which is clearly further reduced than if it had been applied so far in a so-called scale scrubber, even when the conditions of the processes encountered, ie the parameters were the same. In addition, the pressure medium supply of the rotary nozzle 15 is controlled taking into account the temperature level to be maintained in the cast or rolled strand 2b so that the temperature loss of the cast strand 2b is kept as low as possible.

A plurality of nozzles 15 provided for the pressure medium are coupled to the rotor 20 (FIG. 4), and the plurality of rotors 20 are nozzles fixed to the rotor circumferential surface 20a for supplying the pressure medium. And (15). The plurality of rotors are then arranged in the nozzle row 21 provided transversely with respect to the traveling direction of the cast or rolled strand 2b. In addition, a plurality of nozzle rows 21 is provided, which provides a desirable advantage, i.e. smaller nozzle beams can be used than in only one nozzle row 21.

The rotor descaling process may be applied before the hot rolled strip enters the first finishing roll stand 6a in the hot rolling strip rolling sequence 6 having seven or more finishing roll stands.

Claims (7)

As a method for producing hot rolled metal strips, in particular steel strips 7, having a high surface quality from slab strands or flat foil strands 2, 2a cast by a continuous casting method, The strip 7 is descaled to its strand surface 2c, heated to a rolling temperature, and trimmed to a degree having a slight strip thickness in a hot rolled strip finish rolling train 6 consisting of a plurality of stands. Also, after the casting strip 2a is discharged from the strand guide 3, before entering into the heat compensation furnace 4, and / or from the heat compensation furnace 4, the hot rolled strip rolling train 6 After being introduced into, scale and / or cast on one or both sides of the strand surface 2c by means of a number of rotary nozzles 15 which periodically spray a pressure fluid 19 having a high supply pressure towards the same surface position, respectively. In a method for producing hot rolled metal strips, in particular steel strips 7, of said high surface quality, in which powder is removed and deeply cleaned of vibrations, The hydraulic vibratory permanent mold 9 is moved according to a number of different vibration curves 16, 17, 18, and the deep cleaning of the vibration traces is determined to be optimized for the respective casting material. , A method for producing hot rolled metal strips, in particular steel strips (7), having a high surface quality, characterized in that it is carried out by adjustment of 18a). The pressure fluid (19) of the rotary nozzles (15) according to claim 1, wherein the supply of the pressure fluid (19) by the rotating nozzles (15) is made by a pressure medium which is clearly further reduced than if the parameters of the casting or rolling process were applied so far in a scale scrubber. A method for producing hot rolled metal strips, in particular steel strips (7), characterized by high surface quality. 3. The temperature of the cast strand 2b according to claim 1, wherein the pressure medium supply of the rotary noses 15 is controlled in a controlled manner taking into account the temperature level of the cast or rolled strand 2b. A method for producing hot rolled metal strips, in particular steel strips (7), with high surface quality, characterized in that the losses are kept low. As a casting rolling plant 1, in particular a compact casting rolling plant (CSP), consisting of a continuous casting device 2 for liquid metal, in particular liquid steel material, The permanent mold 9 of the continuous casting device is connected with a hydraulic vibration drive device 9a, followed by the permanent mold 9 in the strand discharge direction 11 with at least one strand guide 3, with temperature compensation ( 4) said liquid metal, in particular liquid steel material, in which a row feeder 5 of the furnace type and, optionally, a hot rolled strip finishing roll consisting of a plurality of stands and a winding machine 8 are arranged in series In a casting rolling plant (1), in particular a compact casting rolling plant (CSP), consisting of a continuous casting apparatus (2) for Between the strand guide 3 and the temperature compensation path 4 or between the calibration driver 12 and the shearer 13 and / or the temperature compensation path 4 and the hot rolled strip finishing Between (6) a liquid metal, in particular liquid steel, characterized in that the device 14 is provided with rotary nozzles 15 which periodically spray a pressure medium with a high supply pressure towards the same surface position. Casting rolling plant 1, in particular compact casting rolling plant (CSP), consisting of a continuous casting device (2) for a material. The casting and rolling plant of claim 4, wherein the nozzles for pressure medium are arranged on the surface of the rotor 20, characterized by a continuous casting device 2 for liquid metal, in particular liquid steel material. (1), in particular, a compact cast rolling plant (CSP). 6. The cast or rolled strand according to claim 4 or 5, wherein a plurality of rotors (20) with nozzles (15) arranged in the rotor circumferential surface (20a) for providing a pressure medium are arranged in line (21). A casting rolling plant 1, in particular a compact casting rolling plant (CSP), consisting of a continuous casting device 2 for liquid metal, in particular liquid steel material, characterized in that it is arranged transverse to the travel direction of (2b). . 7. The rotary descaling process according to any one of claims 4 to 6, wherein the rotary descaling process comprises a first finishing roll stand (6a) in a hot rolled strip rolling train (6) having seven or more finishing roll stands (6a). Casting rolling plant (1), in particular compact casting rolling plant (CSP), consisting of a continuous casting device (2) for a liquid metal, in particular a liquid steel material, characterized in that it is applied before it enters.

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