JP2006289465A - Method and apparatus for manufacturing steel plate using universal mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing apparatus having excellent practicability capable of manufacturing the product width of a steel plate with the excellent dimensional accuracy at the same opportunity so as to be suitable for a four-sided box pillar for a building structure. <P>SOLUTION: In the steel plate manufacturing method, a first step including a step of restricting or rolling down a part of the width direction of a work to be rolled in the thickness direction of the work by a horizontal roll of a universal mill having a pair of horizontal rolls and a pair of vertical rolls, and a second step including a step of rolling down the work in the work by a thickness reduction mill having a pair of horizontal rolls are repeatedly performed. A third step including a step of rolling down the width direction of the work by a vertical roll of another universal mill while restricting or rolling down the work in the thickness direction by a horizontal roll of another universal mill having a pair of horizontal rolls and a pair of vertical rolls separately from the universal mill in the first step with respect to the work rolling direction is added at least once in the first step and the second step. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a universal mill and a method for producing a steel plate using the universal mill. Specifically, a universal mill including a pair of horizontal rolls and a pair of vertical rolls and a rolling process including the universal mill, for example, a steel plate such as a thick steel plate, a flat steel plate, and a wide flat steel plate as defined in JIS G0204, The present invention relates to a method for producing a steel plate suitable for use as a box column for a building structure.

  In hot rolling of shaped steel, using a universal mill that has been widely used in the past, for example, a thick steel plate that is a hot-rolled steel plate having a thickness of 3 mm or more, a steel bar having a rectangular cross section, as defined in JIS G0204 It has been studied to perform hot rolling of a steel plate such as a flat steel having a width of more than 150 mm and a width of more than 4 mm.

  Specifically, reciprocating rolling of multiple passes (hereinafter sometimes referred to as reverse rolling) using a universal mill and a horizontal mill arranged on the outlet side thereof, flat steel, wide flat steel, etc. It has been attracting attention because it is possible to produce various types of steel sheets having different widths and thicknesses by simply rolling the steel sheet and changing the roll interval of the universal mill. Various methods have been proposed so far for this method. 10 and 11 schematically show a conventional method for producing a typical steel sheet. FIG. 10 is a diagram schematically showing an intermediate / finish rolling mill 550 used in an example of a conventional steel plate manufacturing method using one universal mill. Moreover, FIG. 11 is the figure which showed typically the intermediate | middle and finishing rolling mill 650 used for one example of the manufacturing method of the conventional steel plate when not using a universal mill.

  The intermediate / finishing mill has the role of finishing the material to be rolled (rough shaped steel slab) obtained by heating and rough rolling of the slab, which is the upper process of the rolling line, to a predetermined size. It is. The intermediate / finish rolling mill 550 shown in FIG. 10 includes a universal mill 551 and a double mill 552 in this order from the upper process side of the rolling line. In the intermediate / finish rolling mill 550, a material to be rolled (rough shaped steel slab) is introduced from the left side of the paper which is the upper process side, and after the processing is finished, the material to be rolled comes out to the right side of the paper which is the lower process side. . Further, the intermediate / finish rolling mill 650 shown in FIG. 11 includes a vertical mill 651 and two double mills 652 and 653 in this order from the upper process side of the rolling line. In the intermediate / finish rolling mill 650, the material to be rolled (rough shaped steel slab) is introduced from the left side of the paper on the upper process side, and after the processing is finished, the material to be rolled comes out to the right side of the paper on the lower process side.

  For such conventional intermediate / finish rolling mills, various proposals focusing on the universal mill have been disclosed for the above reasons. For example, in Patent Document 1, flat steel is rolled using a universal mill including a flat vertical roll and a horizontal roll gradually reduced in diameter from a central portion to an end portion in the roll body length direction. The invention is disclosed. Further, in Patent Document 2, the width of each roll of a universal mill having a variable width type horizontal roll and an edger mill having a variable width type roll is adjusted online, and the horizontal roll of this universal mill is used to adjust the width of each roll. A method of rolling flat steel by rolling a material to be rolled for steel along the longitudinal direction thereof, and then rolling at least three uncompressed lower portions formed on the material to be rolled in the edger mill. And an invention relating to the apparatus is disclosed.

Patent Document 3 discloses an invention relating to a method of rolling flat steel by slightly modifying a plurality of universal roll stands arranged in tandem for rolling H-section steel. Patent Document 4 describes a method of assembling an as-rolled flat bar and assembling it into a box column for building structure, and a method of manufacturing the flat bar using a breakdown mill, a coarse universal mill and an edger mill. Patent Document 5 discloses an invention relating to a flat bar manufacturing method and manufacturing equipment in which a rough bar after rough rolling is finish-rolled into flat bar using at least two universal mills.
Japanese Patent Laid-Open No. Sho 62-21402 JP-A-5-329503 JP-A-10-277602 JP 2000-35068 A JP 2004-98102 A

  However, according to the method described in Patent Document 1, in addition to both ends of the flat steel that is uncompressed by the horizontal roll of the universal mill, the thick portions at both ends in the width direction of the horizontal roll are reduced in thickness by a horizontal roll rolling mill. At that time, there has been a problem that the tensile force acts in the rolling direction due to the stretching accompanying the thickness reduction of the other portion of the flat steel in the width direction, and the thickness becomes thinner than a predetermined thickness. On the other hand, a portion other than the central portion has a problem in that the thickness variation in the width direction of the flat steel increases due to the compressive force acting in the rolling direction and becoming thicker than a predetermined thickness.

  Further, according to the method described in Patent Document 2, since the universal mill horizontal roll is a roll divided in the width direction, the process of repeatedly rolling down the uncompressed portion with the horizontal roll with the edger mill is performed. 1, there was a problem that the thickness variation in the width direction of the flat steel increased.

  According to the method described in Patent Document 3, vertical rollers are installed on the front and back of a tandem universal stand, and the width of the flat steel is reduced by the vertical rollers. In contrast, due to the rigidity of the machine part that supports the roller, a significant reduction in width cannot be expected, and since the roller is not driven, the flat bar that is the material to be rolled bites into the roller during repeated rolling of the flat bar. There was a problem that defective trouble was likely to occur.

  The method described in Patent Document 5 is characterized in that the material to be rolled is chamfered and chamfered by a hole die provided in a vertical roll of one of the two universal rolling mills. However, such chamfering has a problem that it becomes harmful when manufacturing a steel plate (flat steel) used for a four-sided box column for a building structure.

  Further, the flat steel rolling method described in Patent Document 4 is considered to be substantially the same as the rolling methods described in Patent Documents 1, 2, and 5 described above, and is necessary when welding after assembling into a four-sided box column. It is thought that there is a feature in that a groove is formed by rolling. However, even if such a groove is formed by hot rolling, there is a problem in that it cannot be used for welding as it is because the scale adheres to the groove surface.

  FIG. 12 is a schematic diagram for explaining the assembly state of the four-sided box 200. A steel plate (flat steel) for a four-sided box column includes four steel plates 201, 202, 203, and 204 (flat steel) as main members. The four steel plates 201, 202, 203, and 204 have substantially the same thickness, but the steel plates 201 and 202 that are horizontally arranged on the paper and the steel plates 203 and 204 that are arranged vertically on the paper. And the width is different. Since the four-sided box needs to be formed in a square cross-sectional shape, the width of the plate changes with the difference in the plate thickness of the steel plates 201, 202, 203, and 204 constituting the four-sided box 200. In providing a four-sided box with different plate thicknesses, the plate width must also be changed. This means that many types of steel plates have to be made separately, which has been one of the problems in the manufacturing process. There is no description in Patent Document 4 about the making. That is, the same applies to other Patent Documents 1, 2, 3, and 5, but there is no disclosure of a technique related to rolling the material to be rolled up to about several tens of millimeters per pass in the width direction. If it becomes possible to perform a maximum reduction of several tens of mm per pass in the width direction, the above problem can be solved.

  Accordingly, the present invention makes it possible to finely produce product widths at the same opportunity so that steel plates such as thick steel plates, flat steels, and wide flat steels can be used with excellent dimensional accuracy, particularly for four-sided box columns for building structures. It is an object of the present invention to provide a manufacturing method and an apparatus therefor that can be used and have excellent practicality.

  The inventors of the present application have found the following knowledge through an enormous field experiment on a manufacturing technology of a steel plate having a relatively narrow product width such as flat steel (approximately 1000 mm or less).

  1. Using a universal mill consisting of a horizontal roll and a vertical roll, the steel sheet is hot rolled in the width direction. In other words, while performing appropriate reduction in the thickness direction of the material to be rolled with a horizontal roll having a width smaller than the entire width of the material to be rolled, it is covered with a vertical roll having an opening smaller than the width before rolling of the material to be rolled. By rolling down the rolled material in the width direction, the width can be reduced up to several tens of mm per pass, and no buckling deformation of the material to be rolled is observed at that time.

  2. The vertical roll of the universal mill is provided with a hole shape, and the width direction reduction (width reduction) of the material to be rolled is performed while constraining the width direction end of the material to be rolled with the hole shape. As a result, compared to a flat roll that does not have a perforated shape, there is less width return when the thickness is reduced by another mill having a horizontal roll, and as a result, the width can be efficiently reduced and There is also an effect of suppressing buckling deformation of the rolled material.

  Therefore, the inventors of the present application, in addition to hot rolling using a conventional universal mill (or vertical mill) and a double mill consisting of a pair of upper and lower horizontal rolls for a relatively narrow steel plate such as flat steel. Further, a new universal mill is disposed in the vicinity of the universal mill. The new universal mill exclusively performs the reduction (width reduction) of the material to be rolled in the width direction, and the conventional universal mill (or vertical mill) mainly keeps the material to be rolled in the light width direction. As a result, steel sheets with different widths of up to several tens of millimeters can be freely created without changing the rolls and guides at the same rolling opportunity, and the end shape of the product is adjusted (the four corners are kept at right angles). It has been found that the dimensional accuracy with respect to the width can be increased.

  The present invention has been completed based on the above findings, and the gist thereof is as follows. The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings may be added in parentheses, but the present invention is not limited to the illustrated form.

  According to the first aspect of the present invention, there is provided a horizontal roll of a universal mill (51) having a pair of horizontal rolls (51a, 51b) and a pair of vertical rolls (51c, 51d). Reduction in the thickness direction of the material to be rolled by the first step including the step of constraining or reducing the part in the thickness direction of the material to be rolled and the thickness rolling mill (52) provided with a pair of horizontal rolls (52a, 52b). A method of manufacturing a steel sheet including repeatedly performing a second step including a step of performing a pair of horizontal rolls (53a, 53a, 53b) and a horizontal roll of another universal mill (53) provided with a pair of vertical rolls (53c, 53d), while constraining or reducing the material to be rolled in the thickness direction, The above-mentioned problem is solved by providing a method of manufacturing a steel sheet, characterized in that a third step including a step of rolling the material to be rolled in the width direction is added to the first step and the second step at least once. To do.

  Invention of Claim 2 is the thickness reduction mill provided with the 1st process including the process of rolling down the width direction of a to-be-rolled material with this vertical roll of the vertical mill provided with a pair of vertical rolls, and a pair of horizontal rolls A steel plate manufacturing method including repeatedly performing a second step including a step of reducing the thickness of the material to be rolled, with respect to the direction in which the material to be rolled is rolled, a pair of horizontal rolls and a pair of vertical rolls, A third step including a step of performing a reduction in the width direction of the material to be rolled by a vertical roll of the universal mill while being constrained or reduced in the thickness direction of the material to be rolled by a horizontal roll of the universal mill comprising: The said subject is solved by the manufacturing method of the steel plate characterized by adding to a 2nd process at least once.

  Invention of Claim 3 is a manufacturing method of the steel plate of Claim 1 or Claim 2, The vertical roll of the universal mill with which the 3rd process was equipped with the 3rd process is a rolling material in a thickness direction. It comprises a hole mold that can be constrained and includes a step of rolling the material to be rolled in the width direction by the vertical roll.

  The invention according to claim 4 includes a first universal mill (51) having a pair of horizontal rolls (51a, 51b) and a pair of vertical rolls (51c, 51d), and a pair of horizontal rolls (53a, 53b). And a pair of vertical rolls (53c, 53d), and a second universal mill provided with a hole mold that restrains the end in the width direction in the thickness direction when the vertical roll is subjected to the width reduction of the material to be rolled (11). (53) and a steel sheet having different plate widths made from the same size base material slab by a manufacturing facility (50) including a thickness reduction mill (52) provided with a pair of horizontal rolls (52a, 52b). The first universal mill is used for fine adjustment of the plate width which is 2% or less of the plate width of the steel plate and reduction of the plate thickness of the steel plate. Used to reduce the plate thickness, When it is necessary to reduce the plate width or more integer solves the problems by providing a method for manufacturing a steel sheet characterized by using a second universal mill in a plate width reduction of the steel sheet.

  Invention of Claim 5 is a manufacturing method of the steel plate of Claim 4, It is necessary to reduce plate width more than fine adjustment of plate width, performing reverse rolling with the 1st universal mill and thickness reduction mill When there is, there is a feature that rolling by the second universal mill is performed in addition to reverse rolling.

  Invention of Claim 6 is a manufacturing method of the steel plate as described in any one of Claim 4 or Claim 5, and rolling by a 1st universal mill carries out rolling of a material to be rolled by the horizontal roll of this 1st universal mill. Rolling to adjust the sheet width by the vertical roll of the first universal mill and / or rolling to reduce the sheet thickness by the horizontal roll while constraining the material to be rolled in the thickness direction for a part of the width direction. The rolling by the universal mill is characterized in that the sheet width is reduced by the vertical roll while restraining and / or reducing a part in the thickness direction of the material to be rolled by the horizontal roll of the second universal mill.

  Invention of Claim 7 is a manufacturing method of the steel plate as described in any one of Claims 4-6, Comprising: The last pass is performed by the said thickness reduction mill, It is characterized by the above-mentioned.

  The invention according to claim 8 is a first universal mill comprising a pair of horizontal rolls and a pair of vertical rolls, a thickness reduction mill comprising a pair of horizontal rolls, a pair of vertical rolls and a pair of horizontal rolls, The said subject is solved by providing the manufacturing apparatus of the steel plate containing the 2nd universal mill provided with.

  The invention according to claim 9 is a second universal mill comprising a vertical mill having a pair of vertical rolls, a thickness reduction mill having a pair of horizontal rolls, and a pair of horizontal rolls and a pair of vertical rolls. The said subject is solved by providing the manufacturing apparatus of the steel plate containing these.

  Invention of Claim 10 is a manufacturing apparatus of the steel plate as described in any one of Claim 8 or Claim 9, and the vertical roll of a 2nd universal mill is in the case of the reduction of the width direction of a to-be-rolled material. It has the hole type which restrains the end part in the width direction in the thickness direction.

  According to the manufacturing method and manufacturing apparatus of a steel plate of the present invention, it is possible to efficiently manufacture a steel plate or flat steel suitable for use in a building structure four-sided box column. Therefore, the present invention is an industrially highly valuable invention.

  Such an operation and gain of the present invention will be made clear from the best mode for carrying out the invention described below.

  Hereinafter, embodiments of a universal mill according to the present invention and a method of manufacturing a steel plate using the universal mill will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram schematically showing a rolling line 100 to which a steel plate manufacturing method using a universal mill of the present invention according to one embodiment is applied. The production line 100 includes a heating furnace 20, a rough rolling mill 30 (hereinafter sometimes referred to as a breakdown mill), and an intermediate / finish rolling mill 50 as main equipments in this order from the above process. The slab 10 as a raw material is processed into a steel plate having a predetermined plate thickness, plate width, and surface properties. As the slab 10, a continuous casting slab, a block slab, or the like can be used. The slab 10 is heated to 1200 to 1300 ° C. in the heating furnace 20. Thereafter, the slab 10 is subjected to a plurality of reciprocating rollings (reverse rolling) in which a plate mill direction reduction and a plate width direction reduction are repeated by a breakdown mill 30 having a double horizontal roll engraved with a plurality of perforations. By performing “rough shaped steel slab” (the “rough shaped steel slab” was originally a slab 10 but its shape and name changed by processing to become the “rough shaped steel slab”. Further, the name changes depending on the position in the subsequent process, but for the sake of easy understanding, in the following, the material to be processed in the subsequent process including the “rough shaped steel slab” will be referred to as “rolled material 11”. ”In a unified manner). An example of the breakdown mill 30 is shown in FIG. The breakdown mill 30 shown in FIG. 2 has two breakdown mills 31 and 32. The breakdown mill 31 reduces the rolling material 11 in the thickness direction, and the breakdown mill 32 reduces the rolling material 11 in the sheet width direction. It is carried out. As the breakdown mill 30, any rough rolling mill that is normally used can be applied, and is not particularly limited in the present invention.

  Next, the material to be rolled 11 is supplied to the intermediate / finishing mill 50 and subjected to reciprocal rolling (reverse rolling) in a plurality of passes, thereby forming a steel plate that is a material to be rolled having a predetermined plate width and plate thickness. Finish.

  The intermediate / finish rolling mill 50 will be described in detail. FIG. 3 is a perspective view schematically showing an intermediate / finish rolling mill 50 according to one embodiment of the present invention. The intermediate / finish rolling mill 50 includes a first universal mill 51, a thickness reduction mill 52, and a second universal mill 53 in this order from the upper process side of the line on the left side of the drawing. In FIG. 4, the figure which looked at the 1st universal mill 51 from the front (rolling line lower process side) was shown. The first universal mill 51 includes a pair of upper and lower horizontal rolls 51 a and 51 b having a roll width smaller than that of the material to be rolled 11, and a pair of left and right vertical rolls 51 c and 51 d. Normally, the horizontal rolls 51a and 51b are driven rolls, and the vertical rolls 51c and 51d are non-driven rolls. In the first universal mill 51, the horizontal rolls 51a and 51b are rolled down in the thickness direction at the center in the width direction excluding the portions where the horizontal rolls 51a and 51b at both ends of the material to be rolled 11 (steel plate) do not contact (in the thickness direction). (Partial pressure reduction). Further, the rolls 11 are slightly reduced in the sheet width direction by the vertical rolls 51c and 51d (a slight reduction that prevents the width from being increased due to the thickness reduction by the horizontal rolls 51a and 51b. That is, the width reduction rate is 2). % Reduction or less). Thereby, the end face shape of the width direction which the vertical rolls 51c and 51d contacted can be prepared.

  The thickness reduction mill 52 is disposed on the line lower process side of the first universal mill 51. The figure which looked at the thickness reduction mill 52 from the front (rolling line lower process side) in FIG. 5 was shown. The thickness reduction mill 51 includes horizontal rolls 52 a and 52 b having a roll width larger than the width of the material 11 to be rolled, and the horizontal rolls 52 a and 52 b do not perform reduction in the thickness direction in the first universal mill 51. The reduction in the plate thickness direction is performed over the entire region in the plate width direction including both ends in the width direction. Thereby, the thickness of the material 11 to be rolled is made uniform in the width direction.

  As described above, by repeating the reduction in the plate thickness direction and the reduction in the plate width direction by the first universal mill 51 and the thickness reduction mill 52 described above, the material to be rolled 11 has a predetermined plate thickness and plate width to be obtained in this step. Finished into a steel plate with In the present embodiment, one each of the first universal mill 51 and the thickness reduction mill 52 are arranged, but two or more of the first universal mill and the thickness reduction mill are arranged to reduce the plate in the thickness direction and the plate. The reduction in the width direction may be performed. Examples of configurations at this time include thickness reduction mill-first universal mill-thickness reduction mill, first universal mill-thickness reduction mill-first universal mill, first universal mill-thickness reduction mill-first universal mill-thickness. A rolling mill etc. are mentioned, and free combinations are possible.

  A second universal mill 53 is provided on the rolling line lower process side of the thickness reduction mill 52. In FIG. 6, the figure which looked at the 2nd universal mill 53 from the front (rolling line lower process side) was shown. The second universal mill 53 includes a pair of upper and lower horizontal rolls 53 a and 53 b having a roll width smaller than the sheet width of the material 11 to be rolled, and a pair of left and right vertical rolls 53 c and 53 d. Normally, the horizontal rolls 51a and 51b are driven rolls, and the vertical rolls 51c and 51d are non-driven rolls. In the second universal mill 53, the vertical rolls 53c and 53d have a hole shape. FIG. 7 is an enlarged view of only one vertical roll 53c. As shown in FIG. 7, a groove-shaped hole mold 53e having a depth direction in the direction from the outer periphery of the roll to the roll axis is engraved at the center of the vertical roll 53c in the body length direction. The groove of the hole mold 53 has a so-called taper shape that is gradually widened from the axis of the vertical roll 53c toward the outer peripheral side. Further, the width of the bottom portion of the hole mold 53e is approximately the same as the thickness of the material 11 to be rolled. The vertical roll 53d on the other side of the vertical roll 53c shown in FIG. 7 has the same configuration. By arranging the material to be rolled 11 in the hole mold 53e as shown in FIG. 7, the end in the width direction of the material to be rolled 11 is deformed so as to fill the hole 53e. Part of the upper and lower surfaces in the plate thickness direction is constrained in the plate thickness direction by the tapered surface 53e. As a result, compared to a flat roll that does not have a perforated shape, there is less width return when the thickness is reduced by another mill having a horizontal roll, and as a result, the width can be efficiently reduced and The buckling deformation of the rolled material 11 can be suppressed.

  In addition, the horizontal rolls 53a and 53b of the second universal mill 53 make the rolled material 11 smoothly bite into the vertical rolls 53c and 53d, and also the width of the rolled material 11 by the vertical rolls 53c and 53d. It has the effect of preventing buckling during reduction (width reduction). In addition, by adjusting the amount of rolling in the width direction per pass of the material to be rolled 11 and the number of passes, a dimension corresponding to twice the difference in thickness between two materials to be rolled with different thickness after rolling finish, Without changing the horizontal rolls 53a, 53b and the vertical rolls 53c, 53d of the second universal mill 53 in the middle from the same size material, the width difference between the two materials to be rolled can be obtained in one rolling chance. Reduction is possible.

  The number of the second universal mill 53 is not limited to one, and two or more of the second universal mills 53 are arranged close to each other, and each second universal mill shares the reduction amount in the width direction of the material to be rolled per pass. It is also possible to increase the amount of reduction in the width direction.

  Returning to FIG. 3, the description will be continued. The second universal mill 53 is intended to reduce the material to be rolled 11 obtained by the first universal mill 51 and the thickness reduction mill 52 in any appropriate amount (up to several tens of mm) in the width direction. . As seen in FIG. 3, the material to be rolled 11 passes through the second universal mill 53 even when reverse rolling is performed by the first universal mill 51 and the thickness reduction mill 52. However, when the second universal mill 53 is not used, the size of the opening of each roll (the opening degree of the roll) of the second universal mill 53 is set to be larger than that of the material to be rolled. 53 can be invalidated. And when using the 2nd universal mill 53, the opening degree of a roll is adjusted and the 2nd universal mill 53 is validated.

  By using the intermediate / finishing mill 50 having the above-described configuration, the material to be rolled 11 introduced into the intermediate / finishing mill 50 as a rough steel slab first includes a first universal mill 51, a thickness reduction mill 52, The second universal mill 53 is invalidated by adjusting the roll opening degree of the second universal mill 53 at that time. Next, the second universal mill 53 is made effective and the reduction in the width direction is performed. With the above-described configuration of the second universal mill 53, it is possible to reduce the width direction by up to several tens of mm per pass. As a result, trouble shops such as buckling and width return are alleviated and the width direction can be reduced efficiently. As a result, rolled materials such as steel plates and flat steels can be manufactured with high accuracy and efficiency. And just before leaving the intermediate / finishing mill 50, the upper and lower surfaces in the thickness direction of the material to be rolled 11 are smoothed by the thickness reduction mill 52.

  The same effect can be obtained even when a vertical mill is used as a rolling mill for reducing the material to be rolled in the width direction instead of the first universal mill 51 in the intermediate / finishing rolling mill 50 described above. FIG. 8 schematically shows the intermediate / finish rolling mill 150 when the vertical mill 151 is used. The intermediate / finish rolling mill 150 includes a vertical mill 151, a thickness reduction mill 152, and a second universal mill 153 in this order from the upper process side. The vertical mill 151 is a mill having only a pair of vertical rolls, and performs only the reduction in the width direction and does not control the change in the thickness direction associated therewith. In the intermediate / finishing mill 150, reverse rolling is performed by the vertical mill 151 and the thickness reduction mill 152, and the second universal mill 153 is effectively used as necessary. In this step, if the rolling reduction of the vertical mill 151 and the thickness reduction mill 152 is smaller than a predetermined value, the vertical mill 151 does not buckle even if it is not restrained in the thickness direction. Therefore, the intermediate / finish rolling mill 150 is effective when reverse rolling, which is a combination of a vertical mill and a thickness reduction mill, in which the amount of reduction in the thickness direction is relatively small and the change in the width direction is also relatively small. It is.

  Moreover, as a thickness reduction mill, it is good also as a universal mill 252 as shown in FIG. 9 instead of the double mill 52 shown in FIG. In this case, the interval between the vertical rolls 252c and 252d (the opening degree of the vertical roll) may be increased, or a dummy chock may be incorporated in place of the vertical rolls 252c and 252d. In short, as the thickness reduction mill, the configuration is not limited as long as the rolling mill has a configuration capable of reducing the thickness over the entire width direction of the steel sheet.

  While the present invention has been described in connection with embodiments that are presently the most practical and preferred, the present invention is not limited to the embodiments disclosed herein. However, it can be changed as appropriate without departing from the scope or spirit of the invention that can be read from the claims and the entire specification, and a method and an apparatus for manufacturing a steel plate using a universal mill with such changes are also included in the present invention. Should be understood as being included in the technical scope of

(Example 1)
Below, using the rolling line 100 shown in FIG. 1, two types of steel plates (product standard: SN490B) having a thickness of 36 mm and a width of 600 mm and a width of 528 mm (= 600 mm−36 mm × 2) of the product to be manufactured at the main rolling opportunity. The example which manufactured manufacture of) is shown. A continuous cast slab having a width of 650 mm and a thickness of 250 mm was used as a raw material, heated to 1250 ° C. in a heating furnace, and subjected to rolling.

  First, in a breakdown mill, the material to be rolled (coarse steel slab) having a width of 610 mm and a thickness of 80 mm was obtained after rolling for ten or more passes. Next, 9-pass reverse rolling was performed using a first universal mill (horizontal roll drum length: 550 mm), a thickness reduction mill (horizontal roll drum length: 700 mm), and a second universal mill (horizontal roll drum length: 500 mm). Finished product. In the case of an odd number of passes, the material to be rolled is passed in the order of the first universal mill-thickness reduction mill-second universal mill. Material. At this time, in the pass in which the width of the material to be rolled is not reduced by the second universal mill, the roll opening is set large so that the material to be rolled can easily pass through.

  Table 1 shows the rolling pass schedule. The numerical values in parentheses in Table 1 indicate the width and thickness of the material to be rolled when a product width of 528 mm is produced. That is, only when manufacturing a product width of 528 mm, in addition to the first universal mill and the thickness reduction mill, the second universal mill is used in 3 to 6 passes to reduce the width (reduction in width) of the material to be rolled. When a product width of 600 mm is manufactured, the width of the material to be rolled is constant at 600 mm in all 3 to 9 passes, and reverse rolling is performed only by the first universal mill and the thickness reduction mill without using the second universal mill. Went.

(Example 2)
Similarly, using the rolling line 100 shown in FIG. 1, two types of steel plates (product standard: SN490B) having a thickness of 22 mm and a width of 600 mm and a width of 556 mm (= 600 mm−22 mm × 2) of a product to be manufactured at the main rolling opportunity are used. The example which manufactured was shown. As a raw material, a continuous cast slab having a width of 650 mm and a thickness of 250 mm was used, heated to 1250 ° C. in a heating furnace, and subjected to rolling.

  First, in a breakdown mill, the material to be rolled (coarse steel slab) having a width of 610 mm and a thickness of 80 mm was obtained after rolling for several dozen passes. Next, 11-pass reverse rolling was performed using a first universal mill (horizontal roll drum length: 550 mm), a thickness reduction mill (horizontal roll drum length: 700 mm), and a second universal mill (horizontal roll drum length: 500 mm). Finished product. Also in this case, as described above, in the case of odd-numbered passes, the material to be rolled is passed in the order of the first universal mill-thickness reduction mill-second universal mill, and in the case of even-numbered passes, the second universal mill-thickness reduction mill. -The material was passed through in the order of the first universal mill. At this time, in the pass in which the width of the material to be rolled is not reduced by the second universal mill, the roll opening is set to be large so that the material to be rolled can easily pass through.

  Table 2 shows the rolling pass schedule at this time. In Table 2, numerical values in parentheses indicate the width and thickness of the material to be rolled when a product width of 556 mm is produced. That is, only when manufacturing a product width of 556 mm, in addition to the first universal mill and the thickness reduction mill, the second universal mill is used to reduce the width (width reduction) of the material to be rolled in 3 to 4 passes. When producing a product width of 600 mm, reverse rolling was performed only with the first universal mill and the thickness reduction mill without using the second universal 2 mill.

  Here, in both cases of Table 1 and Table 2, the breakdown mill, the first universal mill, the thickness reduction mill, and the second universal mill use the same specification roll and guide, and the roll is changed at the same chance. The width and thickness of the product could be created without having to In addition, the hole type of the vertical roll of the 2nd universal mill at this time is a hole type bottom dimension (thickness direction of the material to be rolled) such that the material to be rolled fills the hole shape in the third pass of Tables 1 and 2. ), Which is 60 mm.

  As can be seen from Tables 1 and 2, according to the steel sheet manufacturing method of the present invention, two types of steel sheets having product widths of 528 mm and 556 mm can be manufactured at the same rolling chance without changing rolls or guides. That is, a dimension corresponding to twice the thickness difference between the two rolled materials of the rolled material after the finish rolling ((36 mm−22 mm) × 2 = 28 mm) without changing the roll from the material of the same dimension, It can be seen that it is possible to realize the difference between the widths of the two rolled materials after the finish rolling of the rolled material at the same rolling chance (556 mm−528 mm = 28 mm).

  The above is an example of the case where the steel sheet manufacturing method of the present invention is carried out using the rolling line shown in FIG. 1, but each mill in the intermediate / finishing rolling mill has a vertical roll-thickness composed of a pair of vertical rolls. It is possible to implement the present invention by arranging the rolling mill-second universal mill-thickness rolling mill, and performing reverse rolling of the steel sheet with an intermediate / finish rolling mill consisting of a total of four mills. The effect of can be demonstrated.

  Further, in the above embodiment using the rolling line of FIG. 1, a new finishing mill for carrying out the finishing rolling in the intermediate / finishing mill is unnecessary, but the finishing mill is used as a lower process of the intermediate / finishing mill. It may be provided on the side.

It is a figure which shows typically the rolling line 100 to which the manufacturing method of the steel plate using the universal mill of this invention which concerns on one embodiment is applied. It is the figure which showed an example of the rough rolling mill in a rolling line. It is the perspective view which showed typically the intermediate | middle and finishing mill 50 which concerns on one Embodiment of this invention. It is the figure which looked at the 1st universal mill from the front (rolling line lower process side). It is the figure which looked at the thickness reduction mill from the front (rolling line lower process side). It is the figure which looked at the 2nd universal mill from the front (rolling line lower process side). It is the figure which expanded and showed only one vertical roll of the 2nd universal mill. It is the perspective view which showed typically the intermediate | middle and finishing rolling mill 150 which concerns on one Embodiment of this invention. It is the figure which showed typically the positional relationship of a to-be-rolled material and a roll in the case of using a universal mill instead of a double mill. It is the figure which showed typically the intermediate | middle and finishing rolling mill used for one example of the manufacturing method of the conventional steel plate at the time of using a universal mill. It is the figure which showed typically the intermediate | middle and finishing rolling mill used for one example of the manufacturing method of the conventional steel plate when not using a universal mill. It is a typical figure in order to explain the assembly situation of a 4-sided box.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Slab 11 Rolled material 20 Heating furnace 30 Rough rolling mill 50 Intermediate and finishing rolling mill 51 First universal mill 52 Thickness reduction mill 53 Second universal mill 100 Rolling line

Claims (10)

A first step including a step of constraining or reducing a part in the width direction of the material to be rolled in the thickness direction of the material to be rolled by the horizontal roll of the universal mill including a pair of horizontal rolls and a pair of vertical rolls; ,
A second step including a step of reducing in the thickness direction of the material to be rolled by a thickness reduction mill having a pair of horizontal rolls;
A method of manufacturing a steel sheet including repeatedly performing
Regarding the direction in which the material to be rolled is rolled, separately from the universal mill in the first step, the material to be rolled is obtained by the horizontal roll of another universal mill having a pair of horizontal rolls and a pair of vertical rolls. A third step including a step of reducing the width direction of the material to be rolled by the vertical roll of the other universal mill while restraining or reducing in the thickness direction,
A method for producing a steel sheet, wherein the steel plate is added to the first step and the second step at least once. A first step including a step of rolling the material to be rolled in the width direction by the vertical roll of a vertical mill having a pair of vertical rolls;
A second step including a step of reducing the thickness of the material to be rolled by a thickness reduction mill provided with a pair of horizontal rolls;
A method of manufacturing a steel sheet including repeatedly performing,
With respect to the direction in which the material to be rolled is rolled, the horizontal roll of the universal mill including a pair of horizontal rolls and a pair of vertical rolls is restrained or reduced in the thickness direction of the material to be rolled, and the universal mill A third step including a step of rolling the material to be rolled in the width direction with a vertical roll;
A method for producing a steel sheet, wherein the steel plate is added to the first step and the second step at least once.   The third step includes a hole mold in which the vertical roll of the universal mill provided in the third step can restrain the material to be rolled in the thickness direction, and the vertical roll extends in the width direction of the material to be rolled. The manufacturing method of the steel plate as described in any one of Claim 1 or 2 including the process of performing reduction. A first universal mill comprising a pair of horizontal rolls and a pair of vertical rolls;
A second universal mill comprising a pair of horizontal rolls and a pair of vertical rolls, the vertical rolls having a hole shape that constrains the widthwise end portions in the thickness direction when the material to be rolled is subjected to width reduction;
A thickness reduction mill with a pair of horizontal rolls;
A manufacturing method of a steel sheet that separates steel sheets of different sheet widths from a base steel piece of the same size by a manufacturing facility including:
The first universal mill is used for fine adjustment of the plate width that is 2% or less of the plate width of the steel plate, and reduction of the plate thickness of the steel plate, and the thickness reduction mill is Used for reduction,
When it is necessary to reduce the plate width more than the fine adjustment of the plate width, the second universal mill is used for reducing the plate width of the steel plate.   While performing reverse rolling with the first universal mill and the thickness reduction mill, when it is necessary to reduce the plate width beyond the fine adjustment of the plate width, rolling by the second universal mill is added to the reverse rolling. The manufacturing method of the steel plate of Claim 4 to perform. In the rolling by the first universal mill, the width of the material to be rolled is constrained in the thickness direction by a horizontal roll of the first universal mill, and the plate width is obtained by the vertical roll of the first universal mill. Rolling to adjust the thickness and / or rolling to reduce the plate thickness by the horizontal roll,
The rolling by the second universal mill is rolling that reduces the sheet width by the vertical roll while constraining and / or reducing a part in the thickness direction of the material to be rolled by the horizontal roll of the second universal mill. The manufacturing method of the steel plate as described in any one of Claim 4 or 5.   The method for manufacturing a steel sheet according to any one of claims 4 to 6, wherein the final pass is performed by the thickness reduction mill. A first universal mill comprising a pair of horizontal rolls and a pair of vertical rolls;
A thickness reduction mill with a pair of horizontal rolls;
A second universal mill comprising a pair of vertical rolls and a pair of horizontal rolls;
Steel sheet manufacturing equipment including A vertical mill with a pair of vertical rolls;
A thickness reduction mill with a pair of horizontal rolls;
A second universal mill comprising a pair of horizontal rolls and a pair of vertical rolls;
Steel sheet manufacturing equipment including   The vertical roll of said 2nd universal mill has a hole type | mold which restrains the width direction edge part in the thickness direction at the time of the reduction of the width direction of the said to-be-rolled material, either. The manufacturing apparatus of the steel plate as described in a term.

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