JP5214326B2 - Rolled material manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a rolled material that is rolled while gradually reducing a gap between rolling rolls while passing a material between the rolling rolls a plurality of times.

  When producing a plate-shaped rolled material from an ingot (slab) such as aluminum having a thickness of about 300 to 650 mm, first, as rough rolling, a temperature of 400 to 550 ° C. or more, for example, above the recrystallization temperature using a reversible rolling mill. Then, it is hot-rolled to a thickness of several tens of mm, further rolled to a thickness of 20 mm or less with a finish rolling mill, and wound into a cylindrical shape to form a coil.

Hot rolling by the reversible rolling mill is performed by gradually reducing the gap between the rolling rolls while allowing the material to reciprocate between the rolling rolls before and after the rolling roll. This is a method of reducing the thickness. In this hot rolling, the deformation of the raw material during rolling is not uniform in the sheet thickness direction, the portion near the surface in the sheet thickness direction is greatly deformed near the entrance of the rolling roll, and the deformation of the central portion proceeds with a delay. For this reason, when rolling the slab so as to reduce the wall thickness sequentially, a material crack called a mouth crack that becomes a crocodile shape when the material is viewed from the side tends to occur at the front and rear ends of the material. . When such a crack is generated, the generated end portion is cut and removed by a predetermined length (see Patent Document 1).
Japanese Patent Laid-Open No. 9-329428

  Normally, a stripper guide is installed near the rolling roll of a reversible hot rolling mill so that the material can easily enter between the rolling rolls. If it is sent to, it will be caught by the stripper guide and the stripper guide will be damaged. For this reason, the operation to advance, stop, and retract the tip part by operator operation is repeated several times to correct it, but it requires subtle operation and may cause damage to the stripper guide due to operation mistake There is also.

  The present invention has been made in view of such circumstances, and provides a method for manufacturing a rolled material that can automatically correct a crack and prevent automatic continuation and operator error. Objective.

The method for producing a rolled material according to the present invention is a method for producing a rolled material that is rolled by gradually reducing a gap between rolling rolls while passing the material a plurality of times between the rolling rolls. In addition to having a straightening step, the material edge straightening step sets the gap between the rolling rolls to a range of 90 to 110% of the actual gap value at the previous pass, and bites the edge of the raw material between the two rolling rolls. After feeding a predetermined length, the direction of movement of the material is reversed, and the material is drawn from between the rolling rolls while reducing the gap between the two rolling rolls to a gap that is 0-10 mm narrower than the setting gap at the next pass. Thereafter, the material is fed between the rolling rolls set as the setting gap at the next pass, and is rolled.

That is, by feeding the raw material as a gap in the range of 90 to 110% of the actual gap value at the time of the previous pass for both rolling rolls, there is a risk that a crack will occur in a state where no crack is generated and biting is detectable. By moving the material while reducing the gap between the two rolling rolls to a gap 0 to 10 mm narrower than the setting gap of the next pass when reversing, the roll is allowed to pass through to a certain length range. The part can be crushed and repaired. And by this operation, the tip end portion is crushed by a predetermined length, and then when it is fed to the rolling roll, since the tip end portion is already crushed, it smoothly enters between the rolling rolls. In the crushed tip, the phenomenon of being peeled off at the exit side of the rolling roll is also suppressed, and the occurrence of cracks is prevented.

The operation of reducing the gap between the rolling rolls to a gap narrower than the setting gap of the next pass when reversing the material may be performed over the entire length of the predetermined length, or during the reverse rotation, the predetermined length You may make it carry out in the specific part within the range. In the former case, the thickness of the material is gradually reduced over the entire length of the predetermined length, and in the latter case, the thickness is reduced as if a step is provided in the middle of the predetermined length. The predetermined length is, for example, about 2 m to 3 m.

  Moreover, the manufacturing method of the rolled material which concerns on this invention WHEREIN: The said raw material edge part correction process is implemented when rolling a raw material below to the preset roll gap. In other words, the plate thickness that may cause cracking is empirically grasped, and is corrected when rolling below the plate thickness. The plate thickness at which the cracks may occur differs depending on the material type (alloy, slab size, slab shape, etc.), and is set for each material type.

  Moreover, according to the manufacturing method of the rolling material which concerns on this invention, first, as a gap of 90 to 110% of the actual gap value at the time of the last pass, the rate of change is reduced to within ± 10%, and the material between both rolling rolls. Since the tip is crushed by feeding it in reverse, the cracked part is crushed and repaired. Moreover, while smoothly entering between the rolling rolls, it is possible to prevent the occurrence of another cracking. Therefore, automatic rolling can be continued without damaging the stripper guide.

  Hereinafter, one embodiment of a manufacturing method of a rolling material concerning the present invention is described, referring to drawings.

  FIG. 1 shows a rolled material manufacturing apparatus used for carrying out the manufacturing method of the present embodiment, and reference numeral 1 indicates a rolling mill. The rolling mill 1 is provided with a pair of rolling rolls 2 at the top and bottom, and these rolling rolls 2 are driven in both forward and reverse directions by a rotary drive motor 3. Constitutes a so-called four-high rolling mill in which large-diameter backup rolls 4 are in contact with each other. Further, before and after the rolling mill 1, table rollers 5 for conveying the material A are provided.

Then, the upper backup roll 4 is provided with a reduction screw 6 for pressing it, and a reduction means 8 including a position control motor 7 for moving the reduction screw 6 to set the distance between the rolling rolls 2. It has been. Further, a rolling load detecting means 9 such as a load cell for detecting a rolling load from the rolling roll 2 to the material A is provided.
Further, the rotation drive motor 3 of the rolling roll 2 is provided with a roll rotation detector 11, a position control motor 7 of the reduction screw 6 is provided with a roll gap position detector 12, and a roller drive motor 13 of the table roller 5 is provided. A roller rotation detector 14 is provided.

Further, in FIG. 1, reference numeral 15 denotes a setup computer. This setup computer 15 includes the interval between the rolling rolls 2 for each pass, the rotational direction and rotational speed of the rolling roll 2, the rolling load, and the table roller 5. It is connected to a controller 16 that executes and manages target values such as a conveyance speed in accordance with a preset pass schedule. Based on the target value of the controller 16, the position control motor 7, the rotary drive motor 3 for the rolling roll 2, the reduction screw 6, the roller drive motor 13 for the table roller 5, etc., output values such as rolling speed and roll gap value. Control with feedback.
In FIG. 1, reference numeral 17 denotes a stripper guide, which is provided before and after the rolling roll 2.

Next, a method for manufacturing a rolled material from an aluminum ingot by the manufacturing apparatus configured as described above will be described.
The aluminum ingot has a thickness of, for example, 300 to 650 mm, and is fed into the rolling mill 1 through a heating furnace (not shown) at a temperature of, for example, 400 to 550 ° C. that is equal to or higher than the recrystallization temperature. . And in this rolling mill 1, it rolls by making an ingot pass between both rolling rolls 2 in multiple times, reducing the gap between the rolling rolls 2 gradually according to the set pass schedule. In the first stage, the gap between the rolling rolls 2 is controlled so as to reduce the thickness by about 5 to 60 mm for each pass. Then, by repeating this rolling a plurality of times, the following control is performed as a material edge correction process when the progress of the pass schedule falls below a preset roll gap.

  This material edge correction process is a control that is performed when a roll gap that may cause a crack at the edge of the material when the material is rolled, and automatically controls the generated crack. To do. The roll gap that may cause cracks varies depending on the type of material. For example, when the material is 99% or more of the AL component, the slab thickness is 600 mm, and the slab side surface shape is straight, the roll gap value is 200 mm or less. Is automatically given by the setup computer 15 before the start of rolling.

  This material edge correction process will be described in order from FIG. 2 to FIG. 5. As shown in FIG. 2, the gap between both rolling rolls 2 is bitten as 90 to 110% of the actual gap value at the previous pass. The gap GA can be detected, and the end of the material A is fed between the two rolls 2. Then, after both rolling rolls 2 have bitten the end of the material A and moved a predetermined length L, the driving of the table roller 5 and the rolling roll 2 is stopped, and the movement of the material A is stopped as shown in FIG. Let

Next, by reversing both the rolling rolls 2 from the state shown in FIG. 3, the material A is moved in the direction of pulling out between the two rolling rolls 2, and the gap between the two rolling rolls 2 is changed in the next pass at that time. while gradually reduced to a narrower gap than the set gap G ₁ is rolled material a as shown in FIG. In the material A after rolling, as shown in FIG. 6A, the tip portion E in the range of the predetermined length L is in a state where the plate thickness gradually decreases toward the tip. Further, after this rolling, the gap between the two rolling rolls 2 is narrower by 0 to ₁₀ mm than the next pass setting gap G1.

Then, rolling the entire by feeding back material A as shown in FIG. 5 the gap between the two rolling rolls 2 as a set gap G ₁ of the next pass between the rolling rolls 2. After passing through this series of material edge correction processes, the process returns to the normal pass schedule, and the material is rolled to a target plate thickness while narrowing the gap between the rolling rolls 2 by a predetermined amount, and the process proceeds to the next finish rolling process. .

That is, in this material edge correction process, as shown in FIG. 2 to FIG. 3, the gap between both rolls 2 is 90 to 110% of the actual gap value of the previous pass (change rate is within ± 10%). When the material A is fed as GA, the rolling roll 2 is once passed to the range of a length (predetermined length L) that may cause a crack, and the gap between both the rolling rolls 2 is passed next time when it is reversed. By moving the narrow material A while reducing it to a gap narrower by 0 to ₁₀ mm than the set gap G ₁ , the cracked portion is crushed and repaired. Then, through this operation, the material A is in a state where the tip E is crushed by a predetermined length L as shown in FIG. Since the tip E has already been crushed, the phenomenon of smoothly entering between the rolling rolls 2 and being peeled off at the exit side of the rolling roll 2 is also suppressed, and the generation of new cracks is prevented. It is done.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention. For example, in the above embodiment, when the rolling roll is reversed and the material is pulled out, the gap is gradually reduced to a narrow gap of 0 to ₁₀ mm from the set gap G1 at the next pass over the entire length of the predetermined length L. However, it suffices to reduce the gap within the range of the predetermined length L, or a method of reducing the gap at a specific position in the middle. FIG. 6B shows the material when the gap of the rolling roll is reduced to a gap 0 to ₁₀ mm narrower than the set gap G1 at the next pass in the first portion (the portion indicated by B) of the predetermined length L. Such a control may be used.

It is a whole block diagram which shows the manufacturing apparatus used in order to implement one Embodiment of the manufacturing method of the rolling material which concerns on this invention. It is sectional drawing which demonstrates the raw material edge part correction process in the manufacturing method of one Embodiment later on to FIG. 5, and shows the state before a raw material is sent to a rolling roll. It is sectional drawing which shows the state which the edge part of the raw material was sent between rolling rolls and stopped from the state shown in FIG. FIG. 4 is a cross-sectional view showing a state in which the rolling roll is reversed from the state shown in FIG. 3 and the material is being rolled down by the rolling roll. FIG. 5 is a cross-sectional view showing a state in which a material is pulled out from the state shown in FIG. 4 and then fed again between rolling rolls. FIGS. 4A and 4B show cross-sections of the raw materials when the reduction control shown in FIG. 4 is different. FIG. 4A shows a case in which the gap of the rolling roll is gradually reduced over the entire length of the predetermined length, and FIG. The case where the gap of a rolling roll is reduced in the specific position is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling machine 1 Rolling machine 2 Rolling roll 3 Rotation drive motor 4 Backup roll 5 Table roller 6 Screw for reduction 7 Position control motor 8 Reduction means 9 Rolling load detection means 11 Roll rotation detector 12 Roll gap position detector 13 Roller drive motor 14 Roller rotation detector 15 Calculator for setup 16 Controller 17 Stripper guide A Material E Crushed edge GA Set gap between rolling rolls before being fed

Claims (2)

In the manufacturing method of the rolled material, while rolling the material while gradually passing the material between the rolling rolls, gradually reducing the gap between the rolling rolls,
While having at least one material edge correction step, the material edge correction step sets the gap between the rolling rolls to a range of 90 to 110% of the actual gap value at the previous pass, While the end of the material is bitten and fed to a predetermined length, the direction of movement of the material is reversed and the gap between the two rolling rolls is reduced to a gap that is narrower by 0 to 10 mm than the set gap at the next pass. A method for producing a rolled material, wherein the material is drawn from between the rolling rolls, and then the material is fed between the rolling rolls that are set as a gap at the time of the next pass and rolled.   The method for producing a rolled material according to claim 1, wherein the material edge correction step is performed when the material is rolled to a roll gap or less that is set in advance.

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