JP4238701B2 - Rough rolling roll and rough rolling method used for manufacturing steel sheet piles having protrusions on joints - Google Patents

Description

  The present invention is a rough rolling roll and a steel sheet pile rough rolling method used in the manufacture of steel sheet piles having protrusions on joints, which are often used in civil engineering and construction work, and particularly for joints having a wide effective width. The present invention relates to a technique for manufacturing a steel sheet pile having

  As a steel sheet pile having protrusions on the joint, a steel sheet pile having a left-right asymmetric shape as shown in FIG. 11 is often used for civil engineering and construction work.

  A U-shaped steel sheet pile having a left-right asymmetrical joint has protrusions 201 and 202 as shown in FIG. 11A (Patent Document 1). Moreover, the linear steel sheet pile which has a right-and-left asymmetrical joint has the protrusion 301 as shown in FIG.11 (B) (patent document 2). Here, FIG. 11 (C) shows a hat-shaped steel sheet pile having a left-right asymmetric joint described in JP-A-2001-248152, and the hat-shaped steel sheet pile has protrusions 401 and 402 on the joint. (Patent Document 3)

The ridges of these steel sheet piles are formed by filling a metal of a rolled material into a hole-shaped ridge forming groove constituted by upper and lower rolls by hot rolling. At that time, it is known that the metal flow of steel becomes easier in a hot state as the thickness of the rolled material increases.
JP-A-2-240319 JP-A-11-140864 JP 2001-248152 A

  However, when it becomes a hole type that produces a steel sheet pile having a ridge on a joint having a wide effective width, the metal of the rolled material is drawn by stretching on both sides in the roll axis direction of the ridge forming groove, and is constituted by upper and lower rolls. In some cases, it becomes difficult to satisfy the metal of the rolled material in the hole-shaped protrusion forming grooves by hot rolling. In such a case, it is common to hold extra metal in advance, and a thick slab was applied as the material.

  For this reason, when trying to manufacture a steel sheet pile having a ridge on a joint with a wide effective width from a slab with a large thickness, the thickness of the hot rolled sheet is determined as long as the cross-sectional dimensions such as the web thickness of the steel sheet pile product are determined. In some cases, the amount of reduction increases, making manufacture difficult.

  When a thick slab is used, not only the rolling work in rough rolling is increased, but in the same shape of the hole shape, the hole-shaped protrusion forming groove constituted by upper and lower rolls and the thickness on both sides in the roll axial direction are used. As the rolling reduction difference increases, the metal remaining ratio in the ridge forming groove decreases, and there is a disadvantage in that the hole-shaped ridge forming groove cannot be efficiently filled with metal.

  The present invention uses a thin flat slab as a raw material, in particular, a rough rolling roll capable of producing a steel sheet pile having a protrusion on a joint having a wide effective width, and a rough rolling of a steel sheet pile having a protrusion on the joint It aims to provide a method.

  The present inventor has intensively studied, and in manufacturing a steel sheet pile having a ridge on a joint having a wide effective width, the roll cylinder length of a hot rolling mill for manufacturing the steel sheet pile is limited, and a small number of It is not efficient to increase the height of the ridge by the hole mold, and further, a bulge having a height corresponding to the ridge of the product is formed in the rough rolling process, and after the rough rolling process, the rough rolling is performed. The present invention was made based on the knowledge that the bulge of the height formed in the process is preserved according to the thickness reduction ratio.

  The present invention is as follows.

The present invention is a rough rolling roll used when manufacturing a steel sheet pile having protrusions on a joint, and among the inclined walls on the left and right of the roll circumferential groove facing each other, a step is formed on one inclined wall that is different in each of the upper and lower rolls. There is constituted by being formed vertically rolls, a stepped box grooved you pressure the slab in the width direction, in the same vertical roll, after width rolling ridges forming grooves are formed for forming the ridge of the joint portion slabs possess a draw caliber to reduction in the thickness direction, distance measured from the groove bottom of the step of the stepped box hole type, bulge formed in a width reduction after the slab by the level difference, after width rolling a rough rolling roll, characterized in Rukoto slabs while disposed in the draw caliber have been determined to match the ridges forming grooves.

Further, the present invention is a method for rough rolling a steel sheet pile when producing a steel sheet pile having a protrusion on a joint using the rough rolling roll described above, and the stepped box hole at the beginning of the rough rolling. performs width reduction of flat slabs by type over the slab longitudinal entire length, after form form a bulge station locations in respective different side slab surface vertical width end portion of the slab, ridge formation of the draw caliber joint, characterized in that had rows reduction in the thickness direction of the width reduction after the slab over a slub length entire length by the stretching hole type were allowed to coincide bulges before Symbol station locations in the groove to form a ridge on the joint portion It is a rough rolling method of the steel sheet pile which has a protrusion.
In that case, it is preferable that a slab having a slab thickness of 200 to 250 mm is used as a material, and a predetermined width reduction is performed in a plurality of times.

  According to the present invention, it is possible to manufacture a steel sheet pile having a protrusion on a joint having a wide effective width, using a flat slab having a smaller thickness as a material.

  In the present invention, a flat slab is pressed down in the slab width direction under light pressure to suppress stretching in the slab length direction, and the pressed metal swells in the thickness direction of the slab in the immediate vicinity of the roll (bulging deformation). By utilizing this, the protrusions of steel sheet pile products having protrusions on the joint are efficiently formed.

  Hereinafter, as a rough rolling method of a steel sheet pile having ridges on the joint according to the embodiment of the present invention, a case of manufacturing a hat-shaped steel sheet pile having ridges on the left and right as shown in FIG. 10 will be described as an example. .

  First, rough rolling rolls 10a and 10b used for rough rolling of a hat-shaped steel sheet pile according to an embodiment of the present invention will be described with reference to FIGS.

  The rough rolling rolls 10a and 10b used for the rough rolling of the hat-shaped steel sheet pile according to the embodiment of the present invention, as shown in FIG. 1, are stepped box hole molds K0 having stepped portions 1a and 1b composed of upper and lower rolls, An extending hole type K8 having the ridge forming grooves 4a and 4b is provided. The stepped box hole type K0 is a hole type used to reduce the width of a flat slab S as shown in FIG. 2 in the width direction, and the steps 1a and 1b have a distance measured from each groove bottom 2. It is formed in the predetermined roll radial direction position of one inclined wall 3 used as a and b, respectively.

  Note that the roll circumferential grooves of the upper and lower rolls have an appropriate inclination and a groove bottom interval W, and are formed so that the flat slab S is reduced in width in the width direction, and then the slab reduced in width is easily pulled out. Yes.

  Further, the extending hole mold K8 having the protrusion forming grooves 4a and 4b is a hole mold that first reduces the thickness of the slab in the thickness direction after the width reduction, and the protrusion forming grooves 4a and 4b are the extending hole mold K8. Are formed at predetermined positions in the roll axis direction. Reference numeral 4c indicates an inclined wall of the upper roll 10a. As shown in FIG. 3, the distances a and b measured from the groove bottoms 2 of the steps 1a and 1b are reduced in width when the flat slab S is reduced in the width direction and bulges 5a and 5b are formed at the width ends. As shown in FIG. 4, the swells 5a and 5b are determined so as to match the ridge forming grooves 4a and 4b of the drawing hole mold K8 in a state where the rear slab 5 is disposed in the inclined wall 4c of the upper roll 10a. .

In addition, the flat slab S has a substantially rectangular shape, and for the production of a hat-shaped steel sheet pile having an effective width of 900 mm, which will be described later, as the flat slab S, the slab B _S = 950 to 1050 mm and the slab thickness H _S = 200. The thing of -250mm is applicable.

  Thus, the rough rolling method of the hat-shaped steel sheet pile according to the embodiment of the present invention uses the stepped box hole type K0 as shown in FIG. 1 and the slab 5 after width reduction in the thickness direction as the rough rolling rolls 10a and 10b. Using a roll having a drawing hole mold K8 in which the ridge forming grooves 4a and 4b to be reduced are formed, the flat slab S is reduced in width over the entire length of the slab by the stepped box hole type K0. After forming the bulges 5a and 5b at the width end of the slab 5, the bulges 5a and 5b are matched with the ridge forming grooves 4a and 4b of the drawing hole mold K8, and then the width of the slab is reduced by the drawing hole mold K8. Thickness reduction is performed over the entire length of the slab.

  Next, it will be described that the bulges 5a and 5b can be formed at the width end portion of the slab 5 after the width reduction efficiently when the stepped box hole type K0 is used.

  FIG. 5 is an explanatory diagram showing the occurrence of bulges when rolls of various shapes are used and the flat slab S is lightly reduced in the width direction. Since the width reduction of the flat slab S according to the present invention is performed in a plurality of times under light pressure, it is a schematic diagram showing a state in the final pass when width reduction is performed under similar width reduction conditions.

  The total width reduction amount was set to the same value Δb regardless of which roll was used.

FIG. 5A shows a case where width reduction is performed using a flat roll, and FIG. 5B shows that width reduction is performed by a hole mold in which a roll circumferential groove having a height h ₀ of an inclined wall is formed in the upper and lower rolls. If you have made, FIG. 5 (C) is a case where the height h ₁ of the opposite inclined _walls, h ₂ was subjected to width reduction by grooved with engraved roll circumferential groove above and below the rolls to each other. In the case of FIG. 5C, h ₁ = h ₀ was set.

When the flat slab S is reduced in width by multiple times under light pressure, as shown in FIG. 5A, a bulge 5c is generated near the width end of the slab 5 by the metal flow in the slab thickness direction after the width reduction. However, it was found that the slab width direction position where the swelling occurs can be changed by regulating the metal flow in the slab thickness direction by the inclined wall as shown in FIG. Further, as shown in FIG. 5 (C), swelling by increasing the one inclined wall height h ₂ than the height h ₁ of the other inclined wall is formed in the lower inclined wall heights 5e It has also been found that can be made larger than the bulge 5f formed on the higher inclined wall, and a high bulge 5e can be obtained.

  Furthermore, in the case of FIG. 5C, it has been found that the height of the bulge 5e is higher than the bulge 5d formed by the box hole mold shown in FIG. 5B.

  The case of FIG. 5C corresponds to the case where the stepped box hole type shown in FIG. 1 is used. As described above, by using the stepped box hole mold K0 according to the present invention, the slab width direction position for forming the bulges 5a and 5b can be changed, and the conventional box hole shown in FIG. It can be seen that a bulge that is taller than the mold can be formed.

  By the way, in the production of the hat-shaped steel sheet pile described above, the rough rolling state shown in FIG. 4 is when the contact ratio between the slab 5 and the roll after the width reduction is small and the stretching is also small. The bulges 5a and 5b are deformed by the ridge formation grooves 4a and 4b, the cross-sectional area of the bulge portion remains at a high rate, and the degree of satisfaction of the ridge formation grooves 4a and 4b can be increased.

  Further, the width of the flat slab S is reduced by the stepped box hole type K0, and as shown in FIG. 3, after forming the bulges 5a and 5b at the width end of the slab 5 after the width reduction, as shown in FIG. When the ridges 5a and 5b are matched with the ridge forming grooves of the drawing hole mold K8 and then the slab 5 is pressed down in the thickness direction after the width reduction by the drawing hole mold K8, the product ridge is formed. In contrast, when trying to form product ridges of the same height, the thickness of the flat slab S is reduced and compared with the case where the metal is filled in the U-shaped or V-shaped grooves provided on the rough rolling roll. Thus, the rolling load can be reduced.

  As described above, according to the method for rough rolling steel sheet piles according to the present invention, it is possible to efficiently form a ridge of a steel sheet pile product having a ridge at a joint portion using a slab S having a flat cross section. As a result, a flat material such as a continuously cast slab can be applied.

A flat continuous cast slab (slab width B _S = 1000 mm, slab thickness H _S = 215 mm) is used as a material, and rough rolling, intermediate rolling, and finish rolling are performed, and an effective width B ₀ in the product cross section shown in FIG. Manufactured 900 mm. At that time, the stepped box hole type K0 shown in FIG. 1 was provided adjacent to the drawing hole type K7 as shown in FIG. The cross-sectional dimensions of the roll circumferential grooves formed on the upper and lower rolls are groove bottom interval W = 214 mm, height of the higher inclined wall = 120 mm, distance a = 48 mm measured from the step groove bottom, and measured from the step groove bottom. The distance b was 48 mm. In rough rolling, the flat slab width is reduced by the stepped box hole mold K0 over the entire length of the slab, and after the width reduction, a bulge is formed at the width end of the slab, and then the ridge forming groove of the extending hole mold K8 is formed. After the bulges 5a and 5b were matched with 4a and 4b, the width of the slab was reduced over the entire length of the slab after the width reduction by the drawing hole mold K8, and then the thickness reduction was performed by the drawing hole mold K7.

  In addition, the width reduction of the slab was performed three times every 20 mm, and the width of the slab was 940 mm after the width reduction.

Thickness reduction by the drawing hole mold K8 is performed by rolling a 215 mm thick slab four times, the web center thickness is set to 60 mm (average reduction ratio 27.3%), and the thickness reduction by the drawing hole mold K7 is 3 times. The center thickness of the web was set to 26 mm (average rolling reduction of 24.3%) by rolling. After the rough rolling, the material to be rolled is continuously subjected to intermediate rolling by the first and second intermediate rolling mills 11 and 12 arranged close to each other as shown in FIG. 6, and then finish rolling by the finishing mill 13. Went. The used rolling rolls are as follows.
Coarse rolling rolls 10a and 10b: body length 2800 mm, number of hole types 3, hole shape (see FIG. 7)
First intermediate rolls 11a, 11b: body length 2500 mm, number of hole types 2, hole shape (see FIG. 8)
Second intermediate rolls 12a, 12b: body length 2500 mm, number of hole types 2, hole shape (see FIG. 8)
Finishing rolls 13a and 13b: body length 2500 mm, number of hole types 2, hole shape (see FIG. 9)
Further, the order of passage of the hole mold after the rough rolling was K5 (empty pass) → K6 → K6 → K5 → K4 → K3 in the intermediate rolling, and then K2 → K1 → K1 in the finish rolling.

  In this hot rolling process, the height of the slab bulge 5a after the width reduction is about 10 mm, and after that, the bulge 5a is matched with the ridge forming groove 4a of the drawing hole mold K8, and then the thickness by the drawing hole mold K8 is reached. At the end of the reduction, the protrusion forming groove 4a having a depth of 25 mm of the drawing hole mold K8 was raised to about 90%. Further, at the end of the thickness reduction by the drawing hole mold K7, the ridge forming groove 5a can be filled with nearly 100%. In the intermediate rolling after the rough rolling, the height of the bulge formed in the rough rolling process is reduced by the thickness reduction. Saved to meet the rate.

As a result, the protrusion of the hat-shaped steel sheet pile having an effective width of 900 mm could be formed to a predetermined height. In the cross-sectional view shown in FIG. 10, in the product having the web width B _W = 290 mm, the total height H ₀ = 240 mm, the web thickness t _W = 11.0 mm, and the flange thickness = 8 mm, the height H _B of the obtained protrusion 101 is obtained. Is 8 mm, and the height _HA of the protrusion 102 is 10 mm. Prior to the application of the present invention, when manufacturing a hat-shaped steel sheet pile having an effective width of 900 mm, when a slab made of continuous casting having a slab width B _S = 1000 mm and a slab thickness H _S = 215 mm was used as a material, The strip 101 could not be stably molded over the entire length in the product length direction with a predetermined height of 8 mm and the protrusion 102 with a predetermined height of 10 mm.

It is explanatory drawing which shows the hole shape of the rough rolling roll which concerns on embodiment of this invention. It is explanatory drawing which shows the flat slab which concerns on embodiment of this invention. It is explanatory drawing which shows the width reduction state in embodiment of this invention. It is explanatory drawing which shows the thickness reduction state in embodiment of this invention, and is a figure of the state which match | combined the swelling part of the slab after width reduction with the groove part formed in the hole mold | type of the rough rolling roll. It is explanatory drawing which shows the swelling generation | occurrence | production situation at the time of using a roll of various shapes. It is explanatory drawing which shows the rolling mill arrangement | sequence of an Example. It is explanatory drawing which shows the hole mold | type of the rough rolling roll used for the Example. It is explanatory drawing which shows the hole mold | type of the intermediate rolling roll used for the Example. It is explanatory drawing which shows the hole mold | type of the finishing rolling roll used for the Example. It is sectional drawing of the hat-shaped steel sheet pile which has the coupling of the left-right asymmetric shape manufactured in the Example. It is sectional drawing which illustrated the steel sheet pile of the left-right asymmetric shape which has a protrusion in a joint, (A) is a U-shaped steel sheet pile which has a right-left asymmetric shape joint, (B) is a straight steel which has a right-left asymmetric shape joint. A sheet pile (C) is a hat-shaped steel sheet pile having a left-right asymmetrical joint.

Explanation of symbols

101, 102, 201, 202, 301, 402 Projection 10a, 10b Rough rolling roll 1a, 1b Step 2 Groove bottom 3 Inclined wall a, b Distance measured from groove bottom 2 S Slab (material)
4a, 4b, 4a ', 4b ' ridges forming grooves 4c inclined wall 5 width reduction after the slab 5a, 5b, 5c, 5d, 5e, 5f bulge H _S slab thickness B _S slab width Δb slab width reduction ratio 10 roughing mill 11, 12 1st, 2nd intermediate rolling mill 13 Finishing rolling mill 11a, 11b, 12a, 12b, Intermediate rolling roll 13a, 13b, Finishing rolling roll K1, K2, K3, K4, K5, K6, K7, K8, K0 Hole type h ₀ Height of inclined wall h ₁ Height of lower inclined wall (h ₁ = h ₀ )
h ₂ Height of higher inclined wall B ₀ Effective width B _W Web width H ₀ Total height t _W Web thickness

Claims (3)

It is a rough rolling roll used when manufacturing a steel sheet pile having protrusions on a joint,
Of face each other left and right inclined walls of the roll circumferential groove is constituted by the upper and lower rolls of a step formed in each upper and lower rolls different one of the inclined walls, the stepped box grooved you pressure the slab in the width direction, in the same vertical roll, it possesses a draw caliber for rolling width reduction after the slab in the thickness direction ridges forming grooves are formed for forming the ridge of the joint portion,
The distance measured from the groove bottom of the step of the stepped box hole type is that the bulge formed in the slab after width reduction by the step is in the state in which the slab is placed in the drawing hole mold after width reduction. rough rolling roll characterized that you have decided to match the forming groove. Using the rough rolling roll according to claim 1, a method for rough rolling a steel sheet pile when producing a steel sheet pile having a protrusion on a joint,
The first rough rolling performed across the width reduction of the slab longitudinal direction the entire length of the flat slab by the stepped box grooved to form the shape of the bulge station locations in respective different side slab surface vertical width end portion of the slab after the have rows reduction in the thickness direction over a slub length entire length of the width reduction after the slab by the draw caliber after align your bulge before Symbol station offices in ridges forming grooves of draw caliber, the joint portion A method of rough rolling a steel sheet pile having a protrusion on a joint, characterized by forming a protrusion .   The method for rough rolling a steel sheet pile having protrusions on a joint according to claim 2, wherein a slab having a slab thickness of 200 to 250 mm is used as a raw material, and a predetermined width reduction is performed in a plurality of times.

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