Method for rolling a metallic material using at least one rolling stand

Abstract

The invention relates to a method for rolling a metallic material using at least one rolling stand (1), wherein two mounting elements (2, 3) for two cooperating work rolls (4, 5; 6, 7) are arranged in the rolling stand (1). In order to enable the flexible processing of different rolling tasks, the invention provides that two sets of work rolls (4, 5;6, 7) with large and small diameters are provided, wherein an adjustment system (8) for applying a rolling force to a work roll is arranged in the rolling stand (1), the adjustment system (8) comprising a first piston-cylinder unit (9) with a large piston diameter (DK1) and a second piston-cylinder unit (11) with a small piston diameter (DK2), selectively carrying out the following rolling processes: a) skin rolling of a first metallic material using the work rolls (4, 5) with first work roll diameter (D1), wherein the rolling force is applied by the second piston-cylinder unit (11); b) skin rolling of a second metallic material using the work rolls (6, 7) with second work roll diameter (D2), wherein the rolling force is applied by the first piston-cylinder unit (9);c) Cold rolling of the second metallic material using the work rolls (6, 7) with a second work roll diameter (D2), wherein the rolling force is applied by the first piston-cylinder unit (9). The invention further relates to a rolling stand for carrying out this process.

Description

[0001] The invention relates to a method for rolling a metallic material using at least one rolling stand, wherein two mounting elements for two cooperating work rolls are arranged in the rolling stand. The invention further relates to a rolling stand for carrying out this method.

[0002] Such a rolling process is well known in the prior art. Up to now, specially designed rolling stands have been used for the various rolling tasks, taking into account different grades or products.

[0003] Conventional methods usually only allow the use of an average diameter of the work rollers, which, compared to the use of particularly large or particularly small diameter work rollers, has the following disadvantages: In reversing operation during cold rolling, the required high-strength grades cannot be rolled to the required thin final thicknesses with average-sized work rolls.

[0004] When dressing strips of high-strength grades, the required dressing levels cannot be achieved with an excessively large working roll.

[0005] However, when dressing relatively soft materials (IF grades) during rolling with average-sized work rolls, there is a risk that the required rolling force becomes so small that the control accuracy can no longer be guaranteed.

[0006] Finally, when dressing standard grades of material using average-sized work rollers, the disadvantage is a poorer roughness imprint and shorter service life compared to using larger work rollers.

[0007] Accordingly, a disadvantage of the previously known solutions is that significant retooling of the rolling stand is required for the different tasks, which is time-consuming and therefore expensive. Previously known solutions cannot (satisfactorily) roll and skin the broad product range with a single set of work rolls. Typically, two separate rolling mills are therefore required.

[0008] The invention is based on the objective of further developing a method of the type mentioned above in such a way as to avoid the aforementioned disadvantages. Accordingly, the proposed method should enable the processing of different rolling tasks in a flexible manner.

[0009] The solution to this problem by the invention is characterized in that at least two sets of work rolls are provided, wherein a first set of work rolls has a first work roll diameter and wherein a second set of work rolls has a second work roll diameter, the first work roll diameter being larger than the second work roll diameter, wherein at least one adjustment system for applying a rolling force to a work roll is arranged in the rolling stand, wherein the adjustment system has a first piston-cylinder unit with a first piston diameter, wherein a second piston-cylinder unit with a second piston diameter is arranged in or on the piston of the first piston-cylinder unit, the first piston diameter being larger than the second piston diameter, wherein the following rolling processes are optionally carried out: a) Dressing of a first metallic material using the work rolls with first work roll diameter, wherein the rolling force is applied by the second piston-cylinder unit; b) Dressing a second metallic material using the work rolls with a second work roll diameter, wherein the rolling force is applied by the first piston-cylinder unit; c) Cold rolling of the second metallic material using the work rolls with the second work roll diameter, the rolling force being applied by the first piston-cylinder unit.

[0010] Preferably, the roller diameter of the second, smaller work roller set is always smaller than the roller diameter of a ground-down large work roller. Preferably, the roller diameter of the first, large work roller set is in the range of 580 mm to 360 mm, particularly preferably in the range of 550 mm to 450 mm. Preferably, the roller diameter of the second, small work roller set is in the range of 500 mm to 300 mm, particularly preferably in the range of 400 mm to 360 mm.

[0011] The first metallic material used is preferably a mild steel. Specifically, an IF steel is being considered. An IF steel is typically characterized by a yield strength of up to 200 N / mm². 2 out of.

[0012] The second metallic material is preferably a high-strength steel. A high-strength steel is typically characterized by a yield strength of at least 500 N / mm². 2 out of.

[0013] The rolling line preferably remains constant during rolling according to the above-mentioned steps a), b) and c).

[0014] When rolling according to the above-mentioned steps a), b) and c), the same inserts are preferably used for the first set of work rolls and for the second set of work rolls.

[0015] When rolling according to the above-mentioned steps a), b) and c), the same bearings in the rolling stand are preferably used for the first set of work rolls and for the second set of work rolls.

[0016] Drive pins are arranged for the drive of the work rolls, and preferably the same drive pins are used for the first set of work rolls and for the second set of work rolls when rolling according to the above-mentioned steps a), b) and c).

[0017] Preferably, the drive system features a so-called twin drive, allowing each work roll to be driven individually. The use of a twin drive helps to limit torque distortions, particularly during the dressing process, which can otherwise lead to surface defects.

[0018] A work roller twin drive also allows for a particularly simple decoupling of one working mode from the drive, so that dressing with only one driven working mode becomes possible.

[0019] One preferred further development involves the use of an adjustment system in which the first piston-cylinder unit and the second piston-cylinder unit interact telescopically.

[0020] Finally, it is also preferably provided that a roll bending system is arranged, wherein the same roll bending system is used for the first set of work rolls and for the second set of work rolls when rolling according to the above-mentioned steps a), b) and c).

[0021] The proposed rolling stand for carrying out the described method comprises two installation pieces for two cooperating work rolls, wherein, according to the invention, at least one adjustment system for applying a rolling force to a work roll is arranged in the rolling stand, wherein the adjustment system has a first piston-cylinder unit with a first piston diameter, wherein a second piston-cylinder unit with a second piston diameter is arranged in or on the piston of the first piston-cylinder unit, wherein the first piston diameter is larger than the second piston diameter.

[0022] Preferably, the work roll mounting pieces are designed to accommodate work rolls of different diameters.

[0023] In the aforementioned temper rolling process, the metallic material is cold-rolled to a degree of rolling, preferably between 0.4% and 2.5% (based on the thickness of the rolled material). Tempering with deformation within this range eliminates the pronounced yield point and / or imparts a desired surface structure to the metallic material.

[0024] Cold rolling involves a reduction in thickness with complete plastic deformation.

[0025] The use of adjusting cylinders with two different usable piston diameters offers advantageous application possibilities: The larger piston diameter is used for high required rolling forces. The smaller piston diameter is used when relatively low rolling forces are required in the tempering process, thus enabling sufficiently precise control of the rolling force or tempering degree. At low rolling forces, this avoids the so-called control sump, which leads to inaccuracies in the rolling force adjustment. This is prevented by switching from the actuation of the first piston-cylinder unit to the second.

[0026] The proposed method advantageously allows cold rolling and skin forming of strip steel on a single combined rolling stand, as it can address both the geometric and rolling force-related requirements of the forming task.

[0027] This provides an expansion of the product range that can be rolled and dressed, from very soft to very firm and thin strips on a rolling stand, to increase efficiency in comparatively small production quantities.

[0028] The proposed concept enables the provision of a rolling stand for the use of at least two different work roll diameters. The individual assemblies are designed to ensure a constant rolling line for all combinations of backup and work roll diameters (strokes of the adjusting cylinders, work roll bending cylinders, and wedge adjustment). Preferably, identical bearings, mounting components, and drive journals are used for both or all work roll diameters. Changing between the at least two different work rolls of different diameters is possible within the scope of a standard work roll change. No additional effort is required.

[0029] This results in short changeover times between the different work roll diameters.

[0030] This advantageously enables a wide range of products that can be rolled and dressed using a single rolling mill.

[0031] Furthermore, only a small number of interchangeable operating parts are required, particularly with regard to roll bearings and mounting components. Instead, a large number of identical parts can be used, which simplifies and makes the manufacture and operation of the rolling mill stand more economical.

[0032] The drawing shows an embodiment of the invention. Fig. Figure 1 shows the side view of a rolling mill in which large work rolls are used, and Fig. Figure 2 shows the side view of the rolling mill according to Fig. 1, in which small working rollers are used.

[0033] The figures show a rolling mill 1, in which Fig. 1 relatively large work rolls 4 and 5 with a first work roll diameter D1 are mounted, while in Fig. Two relatively small work rolls, 6 and 7, are mounted on a second work roll diameter D2. The work roll diameter D1 is therefore larger than the work roll diameter D2. Otherwise, the same mounting blocks 2 and 3 are always used for the work rolls in the rolling stand 1.

[0034] To apply a rolling force (i.e., a force acting between the two work rolls 4 and 5 or 6 and 7), an adjustment system 8 is provided. This is formed by a piston-cylinder system in which two piston-cylinder units are used that interact in a telescopic manner.

[0035] The first piston-cylinder unit 9 has a relatively large piston diameter DK1 and is therefore suitable for generating a high rolling force. A second piston-cylinder unit 11 is arranged in the base region of the piston 10 of this first piston-cylinder unit 9, which has a relatively small piston diameter DK2. The second piston diameter DK2 is thus smaller than the first piston diameter DK1.

[0036] In Fig. Figure 1, in the left half of the figure, illustrates the situation where the rolling stand 1 is at its maximum height. Here, the large work rolls 4 and 5 are mounted, and relatively large backup rolls 12 and 13 are also in use. The roll gap between the two work rolls 4 and 5 is at its maximum height (i.e., they are in the changeover position). Meanwhile, in the right half of the figure... Fig. Figure 1 illustrates the situation when the two cooperating work rolls 4 and 5 are brought together, i.e., in the rolling position. Ground-down backup rolls 14 and 15 are mounted here.

[0037] In Fig. 2 is the analogous representation to Fig. Figure 1 is given, although here the smaller work rollers 6 and 7 are mounted. Due to the small work rollers 6 and 7 and the ground-down backup rollers 14 and 15, the right half of the figure shows... Fig. 2 the situation is given when the positioning system 8 exerts the maximum closing stroke.

[0038] It becomes clear that the small working roller is made of Fig. 2 has a smaller diameter than the ground-down working roller made of Fig. 1.

[0039] It should be noted that the rolling line WL always remains constant, i.e. the material to be rolled is always at the same height, so that the work rolls act symmetrically on the material to be rolled.

[0040] Depending on the rolling task to be performed, i.e., in particular a) Dressing of soft steel with large diameter work rolls 4, 5 using the second piston-cylinder unit 11 of the adjustment system 8 to generate a small rolling force, b) Dressing of high-strength steels with small-diameter work rolls 6, 7 using the first piston-cylinder unit 9 of the adjustment system 8 to generate a large rolling force and c) Cold rolling of a strip with small-diameter work rolls 6, 7 using the first piston-cylinder unit 9 of the adjustment system 8 to generate a large rolling force A relatively wide range of tasks can now be accomplished simply by replacing the work rollers.

[0041] In this respect, high-strength grades with small work roll diameters are reduced (method c), while equally high-strength grades with small work roll diameters can also be dressed (method b).

[0042] Soft IF grades are dressed with large work roll diameters (method a), which allows for better control accuracy. Otherwise, with medium-sized work roll diameters, the rolling force would be so low that control accuracy could not be guaranteed.

[0043] Furthermore, standard grades can be dressed when using large work roll diameters, which allows for better roughness imprinting and better service life.

[0044] A high degree of surface finishing can be achieved with the piston-cylinder system with a small piston diameter, using large-diameter work rollers. This results in good roughness transfer through a large indentation.

[0045] High-strength steels can be processed advantageously when using a piston-cylinder system with a small piston diameter and when using work rollers with a small diameter.

[0046] In general, the working roll diameters and piston diameters of the aforementioned piston-cylinder systems can be combined in any way to meet different product requirements.

[0047] This makes it possible to produce a large product portfolio cost-effectively on one plant. Reference symbol list: 1 rolling mill 2 Installation piece 3 Installation piece 4 Working roller (working roller) 5 (large work roller (large work roller) 6 Working roller (small working roller) 7 Working roller (small working roller) 8-position system 9 first piston-cylinder unit 10 pistons of the first piston-cylinder unit 11 second piston-cylinder unit 12 large support rollers / support rollers with maximum diameter 13 large support rollers / support rollers with maximum diameter 14 small support rollers / ground-down support rollers with minimal diameter 15 small support rollers / ground-down support rollers with minimal diameter D1 first working roller diameter (large diameter) D2 second working roller diameter (smaller diameter) DK1 first piston diameter (large piston diameter) DK2 second piston diameter (smaller piston diameter) WL rolling line

Claims

[1] Method for rolling a metallic material using at least one rolling stand (1), wherein two installation pieces (2, 3) for two cooperating work rolls (4, 5; 6, 7) are arranged in the rolling stand (1), characterized by , that at least two sets of work rolls (4, 5; 6, 7) are provided, wherein a first set of work rolls (4, 5) has a first work roll diameter (D1) and wherein a second set of work rolls (7, 8) has a second work roll diameter (D2), wherein the first work roll diameter (D1) is larger than the second work roll diameter (D2), wherein at least one adjustment system (8) for applying a rolling force to a work roll is arranged in the rolling stand (1), wherein the adjustment system (8) has a first piston-cylinder unit (9) with a first piston diameter (DK1), wherein a second piston-cylinder unit (11) with a second piston diameter (DK2) is arranged in or on the piston (10) of the first piston-cylinder unit (9), wherein the first piston diameter (DK1) is larger than the second piston diameter (DK2), where the following rolling processes are optionally carried out: a) Dressing of a first metallic material using the work rolls (4, 5) with first work roll diameter (D1), wherein the rolling force is applied by the second piston-cylinder unit (11); b) Dressing a second metallic material using the work rolls (6, 7) with a second work roll diameter (D2), wherein the rolling force is applied by the first piston-cylinder unit (9); c) Cold rolling of the second metallic material using the work rolls (6, 7) with second work roll diameter (D2), wherein the rolling force is applied by the first piston-cylinder unit (9). [2] Method according to claim 1, characterized by that the first metallic material is a soft steel. [3] Method according to claim 2, characterized by , that the first metallic good is an IF steel. [4] Method according to claim 1, characterized by that the second metallic material is a higher-strength steel. [5] Method according to any one of claims 1 to 4, characterized by , that the rolling line (WL) remains constant during rolling according to steps a), b) and c) according to claim 1. [6] Method according to any one of claims 1 to 5, characterized by , that during the rolling process according to steps a), b) and c) according to claim 1, the same inserts (2, 3) are used for the first set of work rolls (4, 5) and for the second set of work rolls (6, 7). [7] Method according to any one of claims 1 to 6, characterized by , that during rolling according to steps a), b) and c) according to claim 1, the same bearings are used in the rolling stand (1) for the first set of work rolls (4, 5) and for the second set of work rolls (6, 7). [8] Method according to any one of claims 1 to 7, characterized by , that drive pins are arranged for the drive of the work rolls (4, 5; 6, 7), wherein the same drive pins are used for the first set of work rolls (4, 5) and for the second set of work rolls (6, 7) during rolling according to steps a), b) and c) according to claim 1. [9] Method according to any one of claims 1 to 8, characterized by, that an adjustment system (8) is used in which the first piston-cylinder unit (9) and the second piston-cylinder unit (11) act telescopically together. [10] Method according to any one of claims 1 to 9, characterized by , that a roll bending system is arranged, wherein the same roll bending system is used for the first set of work rolls (4, 5) and for the second set of work rolls (6, 7) during the rolling process according to steps a), b) and c) according to claim 1. [11] Rolling stand (1) for carrying out the method according to one of claims 1 to 10, wherein two installation pieces (2, 3) for two cooperating work rolls (4, 5; 6, 7) are arranged in the rolling stand (1), characterized by, that in the rolling stand (1) at least one adjusting system (8) for applying a rolling force to a work roll is arranged, wherein the adjusting system (8) has a first piston-cylinder unit (9) with a first piston diameter (DK1), wherein a second piston-cylinder unit (11) with a second piston diameter (DK2) is arranged in or on the piston (10) of the first piston-cylinder unit (9), wherein the first piston diameter (DK1) is larger than the second piston diameter (DK2). [12] Rolling mill according to claim 11, characterized by , that the work roll mounting pieces (2, 3) are designed to accommodate work rolls of different diameters.

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