EP0045400B1 - Installation for direct-strand reduction of steel at high velocities - Google Patents

Abstract

1. Installation for the casting-rolling of steel at high speeds, in which the continuously produced cast length is completly solidified, after passing through a temperature-equalisation path (4 and 4a) is fed to a pre-rolling section (7) and thereupon rolled in several intermediate and final rolling sections (14, 16, 17), before it is subjected in bar or wire form to further treatment operations, characterized by two mutually independent casting apparatuses (1 and 1a) each consisting of a casting machine (2 and 2a) with a secondary cooling path (3 and 3a), following temperature-equalisation path (4 and 4a) and a guillotine (6 and 6a), and by a prerolling section (7) movable transversely of the casting direction (double arrow 13), which can be driven according to choice into the region of the longitudinal axis (12 and 12a) of one of the two casting apparatus (1 and 1a).

Description

The invention relates to a system for the casting-rolling of steel at high speeds, in which the continuously produced casting strand completely solidifies and, after passing through a temperature compensation section, is fed to a roughing section and then rolled in several intermediate and finishing rolling sections before it is rolled into bars. or wire form is subjected to further treatment processes.

From DE-A1-2418 853 a system of the type mentioned at the beginning for the casting-rolling of non-ferrous metals is known, which has a casting machine consisting of a casting drum and a belt and a rolling mill permanently assigned to it. In view of the short solidification length of non-ferrous metals compared to steel, this can be arranged at a short distance behind the casting machine.

The disadvantage of such systems can be seen in the fact that the combination of casting machine and rolling mill can lead to a less good output, because if the casting machine or the rolling mill fails, the other sub-system fails.

The invention has for its object to provide a system for the casting of steel, which allows a high output at low investment costs. The system should also be designed so that the space required at high casting speeds is reduced.

The object is achieved by a system which has the features of claim 1. The idea of the solution on which the invention is based then consists in equipping the casting and rolling system with two mutually independent casting devices, to which a single roughing section movable transversely to the casting direction is optionally assigned. The second casting device is put into operation if the other casting device fails, so that the downstream rolling sections can continue to work with a short interruption. In addition to the cost savings due to the use of only one roughing section, its displaceable arrangement has the advantage that the casting strand can be introduced into the rolling stands of the roughing section without deflection.

Each pouring device can additionally be equipped with a drive unit, which is located behind the temperature compensation section, advantageously in the area between this and the subsequent one. Cutting scissors.

DE-A-15 27 706 has already described a single roll stand which can be moved transversely to the rolling direction; however, this is moved from the work area to a rest position for changing the rollers.

In one embodiment of the subject matter of the invention, a 180 ° deflection unit is arranged in the area between the roughing section and the finishing section concluding the rolling treatment (claim 2). This also opens up the possibility of feeding the casting strand to further treatment processes without changing its direction of movement.

The 180 ° deflection unit is in any case arranged in an area behind the roughing section, i. H. in an area in which the cross section of the pre-rolled casting strand can be deflected without any particular difficulty. The length of the casting and rolling system can be shortened by up to 50% by deflecting the casting strand; This not only leads to a reduction in the hall length, but also to a reduction in the installation costs for the oil, water, air, hydraulic and electrical supply to the casting and rolling system.

If the system has two intermediate rolling sections downstream of the roughing section, the 180 ° deflection unit is at most behind the second intermediate rolling section (claim 3); depending on the operating conditions, it may also be expedient to arrange the 180 ° deflection unit between the two intermediate rolling sections (claim 4).

To reduce the effort for the displacement drive, the roll stands of the roughing section have a stationary rolling drive (claim 5).

In a preferred embodiment of the subject matter of the invention, the rolling stands of the roughing section are each arranged on their own sliding frame and connected to their rolling drive via cardan shafts (claim 6).

If the casting and rolling plant is used for wire production, it additionally has the features of claim 7 and / or claim 8.

The invention is explained in detail below using an exemplary embodiment shown in the drawing.

• Figur 1 schematisch den Aufbau der erfindungsgemäßen Gießwalzanlage und
• Figur 2 schematisch den Aufbau eines quer zur Gießrichtung verschiebbaren Walzgerüstes des in Fig. 1 dargestellten Vorwalzabschnitts.

Show it :

• Figure 1 schematically shows the structure of the casting and rolling plant according to the invention
• Figure 2 schematically shows the structure of a rolling stand which can be moved transversely to the casting direction of the roughing section shown in Fig. 1.

The casting and rolling system according to the invention (see FIG. 1) has two mutually independent casting devices 1 and 1a, each consisting of a casting machine 2 or 2a, a mutually exclusive secondary cooling section 3 or 3a, a temperature compensation section 4 or 4a, and a drive unit 5 or 5a and a pair of scissors 6 or 6a.

The casting devices 1 and 1a constructed in this way are followed by a single roughing section 7 common to both casting devices, which in the exemplary embodiment shown is composed of three roll stands 8, 9 and 10. The roughing section 7 is transverse movable to the casting direction in such a way that it lies either in the region of the longitudinal axis 12 of the casting device 1 or in the region of the longitudinal axis 12a of the casting device 1a. The two operating positions mentioned are denoted in the drawing with solid or dash-dotted lines; the transverse displaceability of the roughing section 7 is indicated by a double arrow 13.

The use of two mutually independent, independent casting devices 1 and 1a is intended to ensure that the production of the casting and rolling system can be maintained in the event of a casting device failure. The casting machines 2 and 2a are designed in a manner known per se; they can in particular consist of two casting belts delimiting a casting cross section or of a casting wheel which interacts with a suitably designed casting belt.

The liquid steel to be processed is cast in one of the two casting machines - for example in casting machine 2 - to form a casting strand, where it receives an approximately 10 to 20 mm thick shell. In the subsequent secondary cooling section 3, the casting strand solidifies completely under the action of water cooling before the temperature gradient between the strand shell and the strand core is reduced in the temperature compensation section 4.

The two goat devices 1 and 1a are followed by a rolling mill which consists of the previously mentioned roughing section 7, a first intermediate rolling section 14, a 180 ° deflection unit 15, a second intermediate rolling section 16, a finishing rolling section 17, a primary cooling section 18, a winding layer 19, a secondary cooling section 20 and a collecting station 21. The casting strand pre-rolled in the roughing section 7 and reduced to a suitable cross section is further deformed in the intermediate rolling sections 14 and 16 before it receives the desired wire cross section when it passes through the finishing rolling section 17. In the area between the roughing section 7 and the finishing section 17 - in the exemplary embodiment shown between the two intermediate rolling sections 14 and 16 - the casting strand passes through the 180 ° deflection unit 15; he thereby receives a movement direction 22 opposite to the casting direction 11, which remains during the subsequent treatment processes. After the finish rolling, the casting strand runs through the primary cooling section 18, for example in wire form, is turned into turns by means of the winding layer 19 and passed over the secondary cooling section 20 before it is collected in the collecting station 21 in the form of wire rings.

The deflection of the casting strand - which, depending on the cross section, can be carried out before, between or after the two intermediate rolling sections 14 and 16 - leads to a reduction in the space requirement and the installation costs for the supply facilities of the casting and rolling system. The displaceable arrangement of the roughing section 7 makes deflection of the casting strand, which still has the full casting cross section in this area, superfluous.

FIG. 1 shows an example of the roll stand 8 of the roughing section 7, which is at the front in the casting direction, and which is displaceable in the direction of the double arrow 13. The schematically represented rollers 8 'and 8 "are connected via the cardan shafts 23 to a gear 24 and, with the interposition of a clutch 25, to a motor 26 serving as a roller drive. In contrast to the roll stand 8, the parts 24, 25 and 26 are fixed on a foundation 27. The roll stand 8 (like the other roll stands 9 and 10 of the roughing section 7, not shown) is movably held on a sliding frame 28 within a fixed guide 29. The sliding frame 28 is articulated with the piston rod 30 'of a cylinder unit 30 in connection, which serves as a displacement drive and which in turn is held stationary via a bracket 31. It is also equipped with a clamping device 32 which clamps it in the selected operating position with the guide 29 and thus holds it stationary in the operating position shown in FIG the roll stand 8 (and the subsequent roll stands of the roughing section) takes a St ellung in which the roller center 33 coincides with the longitudinal axis 12 indicated in Figure 1; the second operating position of the roll stand 8 is indicated by dash-dotted lines in FIG. 1.

Deviating from the design of the roll stands of the roughing section 7 just explained, under certain circumstances these can also be arranged in a plurality on a common displacement frame; it is possible, for example, to arrange two directly successive roll stands of the roughing section on a common sliding frame.

The stationary arrangement of the roller drive and the displacement drive with respect to the roll stands has the advantage that the installation of these drives is simplified and the size of the masses to be moved is kept as small as possible.

The casting and rolling system and possibly the 180 ° deflection unit can - in contrast to the application example shown in Fig. (Downstream wire rod mill) - also cooperate with a rolling mill for the production of fine steel.

Claims (8)

1. Installation for the casting-rolling of steel at high speeds, in which the continuously produced cast length is completely solidified, after passing through a temperature-equalisation path (4 and 4a) is fed to a pre-rolling section (7) and thereupon rolled in several intermediate and final rolling sections (14, 16, 17), before it is subjected in bar or wire form to further treatment operations, characterised by two mutually independent casting apparatuses (1 and 1a) each consisting of a casting machine (2 and 2a) with a secondary cooling path (3 and 3a), following temperature-equalisation path (4 and 4a) and a guillotine (6 and 6a), and by a prerolling section (7) movable transversely of the casting direction (double arrow 13), which can be driven according to choice into the region of the longitudinal axis (12 and 12a) of one of the two casting apparatuses (1 and 1a).

2. Installation according to Claim 1, characterised in that a 180° reversal unit (15) is arranged in the region between the pre-rolling section (7) and the final rolling section (17) which concludes the rolling treatment.

3. Installation according to Claims 1 to 2, characterised in that two intermediate rolling sections (14 and 16) follow the pre-rolling section (7) and in that the 180° reversal unit (15) is situated before the first intermediate rolling section (14), but possibly after the second intermediate rolling section (16).

4. Installation according to Claim 3, characterised in that the 180° reversal unit (15) is arranged between the two intermediate rolling sections (14, 16).

5. Installation according to Claims 1 to 4, characterised in that the roll stands (8, 9, 10) of the pre-rolling section (7) are displaceable in relation to their non-displaceable rolling drive (24, 25, 26).

6. Installation according to Claims 1 to 5, characterised in that the roll stands (8, 9, 10) of the pre-rolling section (7) are arranged each on its own displacement frame (28) and connected with their rolling drive (24, 25, 26) through universal-joint shafts (23).

7. Installation for wire production according to Claims 1 to 6, characterised in that the final- rolling section (17) is followed by at least one cooling path (18), a coiler (19) and a gathering station (21).

8. Installation according to Claim 7, characterised in that the coiler (19) is preceded by a primary cooling path (18) and followed by a secondary cooling path (20).

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