JP2012200742A - Manufacturing method of steel sheet having uneven pattern on surface thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method which allows industrial production of a steel sheet with an uneven pattern at low cost without lowering durability of a work roll, regardless of an uneven pattern shape, when manufacturing the steel sheet with the uneven pattern, which requires functionality, such as design, slip resistance, or the like, by multistage rolling.SOLUTION: When rolling a surface of a metal slip by a multistage roller using the work roll having an uneven part on the surface thereof to form the uneven pattern on the surface of the metal slip, the multistage roller, which uses a roll having the uneven part at a portion whose part in a long-bodied direction becomes a minor diameter as at least one work roll, is used for rolling. As the work roll, it is preferable that a roll is used in which both side parts in the long-bodied direction of the roll are left and only the diameter of a central part becomes small.

Description

  The present invention relates to a method for manufacturing a steel sheet having a concavo-convex pattern having functions such as designability and anti-slip by multi-stage rolling, and relates to a manufacturing method that suppresses a decrease in durability of a work roll on which concavo-convex is formed.

In general, as a method for producing a steel sheet having a concavo-convex pattern such as an embossed pattern, a rolling method is adopted in which a work roll having a concavo-convex surface is incorporated into a rolling mill and the concavo-convex pattern is transferred to the steel sheet surface.
There are various types of rolling, from two-stage rolling consisting of a pair of work rolls to multi-stage rolling such as 20 stages. Which rolling type is selected depends on the type and dimensions of the material and the uneven pattern to be applied. It depends on conditions such as required rolling load. In rolling, the smaller the diameter of the work roll, the shorter the contact arc length with the material. Therefore, the rolling load can be reduced even at the same rolling rate. On the other hand, since the cross-sectional rigidity of the work roll is reduced, the work roll is likely to bend, and as a result, the plate thickness accuracy and shape of the rolled material are likely to deteriorate. In particular, the deflection of the work roll becomes more pronounced as the plate width of the material is wider.

Therefore, in order to suppress the deflection of the work roll, so-called multi-stage rolling, which is supported by a backup roll having an outer diameter equal to or greater than that of the work roll, is frequently used.
In multi-stage rolling, measures to improve work roll deflection using a work roll bender are also being used.
For example, in the conventional four-stage rolling as shown in FIG. 1, the work roll comes into contact with the material and the backup roll.

Usually, work rolls and backup rolls have a hardened layer on the surface in order to ensure durability such as wear resistance, and have higher hardness than the material. Due to this hardness difference, wear of the work roll is suppressed in normal rolling. On the other hand, since the surface hardness of the work roll and the backup roll are the same, the influence on wear is considered to be small.
However, when producing a concavo-convex steel sheet by multi-stage rolling, the influence of the outer diameter difference and the surface shape of the work roll has a great influence on the wear.

Regarding the outer diameter of the roll, since the work roll has an outer diameter equal to or smaller than that of the backup roll, the rotation speed is inevitably higher in the work roll, so that the work roll is more easily worn.
Further, regarding the surface shape, in the work roll having unevenness, the contact with the backup roll is only the convex part, so that the surface pressure applied to the convex part becomes high. At that time, the unevenness of the work roll causes remarkable wear of the convex portion, and the durability of the work roll may be significantly reduced.

For example, as shown in FIG. 2, when the area of the convex portion is relatively large with respect to the area of the concave portion formed on the surface of the work roll, it is difficult to cause an increase in local surface pressure. Wear is relatively small. On the other hand, as shown in FIG. 3, when the tip of the convex portion is sharp or the area of the convex portion is relatively small with respect to the area of the concave portion, the load tends to be concentrated. Wear becomes noticeable and the durability of the work roll is significantly reduced.
In this way, when a concavo-convex pattern is imparted to the steel sheet surface by multi-stage rolling, the durability of the work roll varies greatly depending on the contact state between the work roll and the backup roll. There were restrictions.

  By the way, although it is a manufacturing method of an irregular cross-section strip | belt plate material, in patent document 1, the reduced diameter part 31 which is non-contact to the circumferential protrusion 11 of this deformed work roll 10 on the deformed work roll 10 side, and its right-and-left both end area 13 A deformed backup roll 30 having a large-diameter portion 32 that abuts on the peripheral surface of the flat work roll 20 disposed on the side of the flat work roll 20 facing the deformed work roll. Has been proposed (see FIG. 4).

Japanese Patent Laid-Open No. 11-123488

With reference to the technique proposed in Patent Document 1 above, when a concavo-convex pattern is imparted to the steel sheet surface by a rolling method, concavo-convex is formed on the work roll surface, and the diameter of the part corresponding to the work roll concavo-convex of the backup roll is reduced. It can also be assumed.
However, since the diameter of the backup roll is usually equal to or greater than the diameter of the work roll, it is more costly to partially reduce the diameter of the backup roll by grinding than to reduce the diameter of the work roll. In addition, if the technique proposed in Patent Document 1 is to be used for forming a concavo-convex pattern, work rolls and backup rolls corresponding to concavo-convex patterns of various sizes are required, resulting in high costs.

  The present invention has been devised in order to solve such problems, and in producing a concavo-convex steel sheet that requires functionality such as design and anti-slip by multi-stage rolling, it has a concavo-convex pattern shape. Therefore, it aims at proposing the method which enables industrial production of the uneven | corrugated patterned steel plate at low cost, without reducing the durability of a work roll.

In order to achieve the object, the method for producing a steel sheet having a concavo-convex pattern on the surface of the present invention forms a concavo-convex pattern on the surface of the metal strip by rolling with a multi-stage rolling mill using a work roll having a concavo-convex part on the surface. When performing, it rolls with the multi-high rolling mill which used the roll which has an uneven | corrugated | grooved part in the site | part which reduced the diameter of a part of the trunk length direction as at least one work roll.
As a work roll, it is preferable to use a roll that satisfies the following formula (1).
(D−d) / 2 <t (1)
However, d: The maximum outer diameter of the work roll uneven part, D: The outer diameter of the work roll large diameter part, t: The plate thickness of the metal strip to be processed Note that the work roll leaves both side parts in the body length direction of the roll. A roll having a reduced diameter only in the center may be used.

In the present invention, since a roll having a concavo-convex portion is used as a work roll at a part where the diameter of a part in the body length direction is reduced, the convex portion does not contact the backup roll.
Therefore, even if a roll having a shape having a convex portion on the surface is used as a work roll, wear of the work roll convex portion as occurs conventionally is suppressed, without reducing the durability of the work roll, It becomes possible to form a concavo-convex pattern stably over a long period of time.

Schematic showing the conventional manufacturing method of uneven steel plate Schematic showing an example of a work roll when the area of the convex part is larger than the concave part Schematic showing an example of a work roll when the area of the convex part is smaller than the concave part Four-stage rolling roll proposed in Patent Document 1 Schematic showing four-stage rolling in the present invention Schematic showing six-stage rolling in the present invention Schematic which shows the work roll shape of this invention in an Example Schematic showing the conventional work roll shape in the examples In the examples, measurement results of unevenness of uneven steel plates rolled by the present invention and conventional work rolls

As described above, in order to suppress the wear of the uneven portion formed on the work roll surface, with reference to the technique proposed in Patent Document 1, the uneven surface is formed on the work roll surface, corresponding to the work roll unevenness of the backup roll. It can also be assumed that the diameter of the part is reduced.
However, there are various problems when trying to divert the technique proposed in Patent Document 1 to the formation of a concavo-convex pattern. As a result, the manufacturing cost of a steel sheet having a concavo-convex pattern on the surface increases.
Therefore, the present inventors decided to use a roll having an uneven portion formed in a part with a reduced diameter in the body length direction as a work roll and to perform multi-stage rolling using a normal flat roll as a backup roll. Thus, the wear of the convex portion was suppressed.
Details will be described below.

The concavo-convex pattern provided on the surface of the roll used as a work roll is formed in a portion where a part of the body length direction is reduced in diameter. As a means for reducing the diameter, an etching method or cutting may be used.
By reducing the diameter of the roll surface and forming the uneven portion, the maximum roll diameter d of the formed uneven portion (small diameter portion) is d <D with respect to the roll diameter D of the unprocessed portion (large diameter portion). Since contact with the roll can be avoided, wear of the convex portion is reduced.

  The position in the body length direction of the work roll forming the irregularities is not particularly limited. This is mainly determined by the position in the plate width direction of the uneven shape to be applied to the material. However, when trying to pass the steel plate to be processed through the center part in the body length direction of the roll, it is preferable that the position where the diameter of the work roll is reduced is only the center part while leaving both side parts in the body length direction of the roll. If the body length of the part that does not form uneven parts on both sides of the roll body length is extremely short, the area supported by the backup roll is reduced, making it difficult to perform the original function of suppressing deflection. The length of is preferably about 1/3 or less of the total body length.

Further, the reduction amount of the maximum outer diameter of the uneven portion with respect to the portion where the uneven portion is not formed (large diameter portion) is d (maximum outer diameter of the work roll uneven portion) and D (outer diameter of the work roll large diameter portion) shown in FIG. ) And t (plate thickness of the metal strip to be processed) are not particularly limited as long as (D−d) / 2 <t is satisfied. If this relationship is not established, rolling itself becomes impossible. As d << D, the cross-sectional rigidity of the work roll is lowered and bending is likely to occur. Therefore, it is desirable to set the reduction amount, that is, the step depth of the concave portion within a range not contacting the backup roll.
As described above, a normal flat roll is used as the backup roll.
The present invention may be applied to only one work roll, or both. Further, the rolling type is not particularly limited as long as it is multi-stage rolling such as 4 stages, 6 stages, and 20 stages as shown in FIG.

Embodiments of the present invention will be specifically described below with reference to the drawings.
As a material, a coil of SUS304 having a plate thickness of 2 mm and slit in advance to a plate width of 95 mm was used. As the rolling mill, a four-high rolling mill was used, and a roll having a conical protrusion shown in FIG. The conical protrusions were formed by etching with a maximum diameter of 5 mm, a height of 1 mm, and a pitch of 10 mm in both the circumferential direction and the trunk length direction.
A protrusion was provided in the region of the central portion of 100 mm for the overall length of the body portion of the work roll of 300 mm. In addition, the maximum outer diameter including the tip of the protrusion was set to φ108 mm, which is 2 mm smaller in diameter than the outer diameter φ110 mm of the region not provided with the uneven shape. In order to grasp the effect of the present invention, as shown in FIG. 8, a work roll having the same protrusion as that in FIG.

Each of the above two types of work rolls was used to roll a distance of 2000 m, and the depth of unevenness (unevenness difference) formed in the material was investigated for each rolling distance. A work roll bender was used for both of the two conditions, and the work roll bender force was appropriately adjusted so that the plate shapes on the rolling exit side were comparable. FIG. 9 shows the influence of the rolling distance on the unevenness difference formed on the rolled material.
In the case of rolling with the work roll of the present invention, the reduction in unevenness was about 0.1 mm at a rolling distance of 2000 m, whereas in the case of the conventional work roll, it was significantly about 0.8 mm at a rolling distance of 1000 m. The unevenness difference decreased.
In the conventional work roll after the end of the rolling process, the height of the protrusion is clearly reduced as compared with the work roll of the present invention.

Claims (3)

  When forming a concavo-convex pattern on the surface of a metal strip by rolling with a multi-stage rolling mill using a work roll having a concavo-convex portion on the surface, at least a roll having a concavo-convex portion at a part where the diameter in the body length direction is reduced The manufacturing method of the steel plate which has an uneven | corrugated pattern on the surface characterized by rolling with the multistage rolling mill used as one work roll. The manufacturing method of the steel plate which has an uneven | corrugated pattern on the surface of Claim 1 using the roll which satisfy | fills following (1) Formula as a work roll.
(D−d) / 2 <t (1)
However, d: The maximum outer diameter of a work roll uneven | corrugated | grooved part, D: Outer diameter of a work roll large diameter part, t: Plate | board thickness of a metal strip to be processed   The manufacturing method of the steel plate which has an uneven | corrugated pattern on the surface of Claim 1 or 2 using the roll which left the both sides of the trunk | drum length direction of the roll, and reduced the diameter of only the center part as a work roll.

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