JP3432634B2 - H-section rolling mill train - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling mill train for freely forming a plurality of sizes of H-section steel in a rolling process.

[0002]

2. Description of the Related Art Shaped steel currently manufactured has a wide variety of types, cross-sectional shapes and dimensions, and the number of types and sizes is very large. A large amount of rolling rolls are required to manufacture these various types and sizes of shaped steel. Therefore, the number of times of roll change is increased, the loss of required time is increased, and the productivity is significantly impaired. Also, according to the shape of the product. The rolls and guides need to be held exclusively, and there is a drawback that they cannot easily meet the needs such as diversification of product dimensions.

As a technique for solving this point and manufacturing shaped steels of a plurality of sizes without recombining, there is disclosed in JP-A-59-202.
101, JP-A-61-27900, and JP-A-4-288902. JP-A-59-2021
As shown in FIG. 11, the feature of the technology disclosed in Japanese Patent Publication No. 01 is that two upper and lower skew rolls 8 and 9 are in contact with the inside of the flange of the material, and the roll axis is in the horizontal direction with the rolling direction θ. _H , by pressing down the web close to the flange of the material while keeping the angle of θ _{v with} the horizontal axis in the horizontal plane, the material in the pressed part is caused to flow in the width direction, and the web is generated without generating web waves. To widen the width. In FIG. 11, it is possible to change the widening amount by adjusting the angle θ _H formed by the oblique rolls 8 and 9 with the rolling direction and the distance L between the oblique rolls 8 and 8 ′ and between 9 and 9 ′. is there.

FIG. 12 shows the relationship between the rolled material and the oblique rolls during widening rolling. The widening using the oblique roll can be divided into the following three stages. First, in the initial stage of widening, the side surface of the oblique roll 8 comes into contact with the inner surface of the flange of the material to be rolled, and the flange is pushed open to widen the outer width of the web of the material to be rolled. Next, the oblique rolls roll down the material (filling) at the base of the flange and the web, causing the material to flow in the width direction, so that the outer width of the web of the rolled material is widened.
After that, it is widened only by pushing and expanding the inner surface of the flange.
The amount by which the widening is performed only by expanding the flange is determined by the geometrical arrangement of the roll and the material, and increases as the amount of widening increases.

FIG. 13 shows an example of a rolling mill train for H-section steel, which adopts the above-mentioned technique and divides a plurality of sizes into different sizes. The intermediate rolling process 22 is composed of a universal rolling mill (RU) and an edger rolling mill (E), and the beam blank supplied from the breakdown process 1 is fed by the universal rolling mill (RU) to a web thickness close to the final product,
Modeling up to the flange thickness and applying the thickness needed for widening near the flange of the web. The horizontal rolls 6 and 6'of the universal rolling mill are provided with calibers for forming the meat corresponding to the maximum widening amount (maximum web inner width of sizes divided by the same roll-minimum web inner width). There is. The horizontal widths of the horizontal rolls 6 and 6'correspond to the smallest web inner width among product sizes produced by the same roll. Further, the horizontal roll side surface and the vertical rolls 23, 23 'are provided with a taper of about 5 ° in order to have commonality by reshaping the rolls. In the widening / rolling step 3, it is possible to produce products having different inner web widths by changing the amount of widening by the oblique rolls 8 and 9. Widening is not performed for sizes with the smallest internal web width. In the finishing process, the universal taper 4 makes the flange taper formed by the intermediate universal taper at a right angle and shapes the base portion of the flange and the web.
The horizontal rolls 10 and 10 'of the universal rolling mill are divided into two in the width direction so that the cylinder width can be changed so that shaping can be performed corresponding to different inner web widths.

The technique disclosed in Japanese Patent Application Laid-Open No. 61-279001 discloses a universal rolling machine with vertical rolls opened to reduce the material (thickness) applied near the flange of the web to widen the material. 4-288902
The technology disclosed in Japanese Patent Publication No. 1993-96952 widens by rolling down the meat with a universal rolling mill. For both technologies, rolling is shown in Fig. 10.
No. 59-202, in which a universal rolling mill arranged in place of the oblique rolls 8 and 9 is used.
The amount of widening possible is smaller than that of Japanese Patent No. 101, and the size range that can be produced by the same roll is narrow. However, JP-A-5
Even in the method of 9-202101, there is a limit to the product size that can be produced without modification.

[0007]

Problems to be Solved by the Invention JP-A-59-2021
In the technology of Japanese Patent Publication No. 01, the product size that can be manufactured separately without reassembling was investigated, and as the width of the oblique roll rolling mill was increased, the outer surface of the flange was shown in FIG. It was found that such a dent occurred. For example, FIG. 10 shows the results of an examination of the correspondence relationship between the flange thickness and the amount of widening in the widening rolling process and the amount of depression on the outer surface of the flange for a material having a web height of 600 mm, a flange width of 200 mm, and a web thickness of 9 mm. However, as shown in FIG. 9, the dents on the outer surface of the flange are determined by the tangents 18 and 1 of the outer surface of the flange drawn at the upper and lower flange tips.
It was defined by the distance between the intersection of 8'and the width center of the flange outline of the material to be rolled. Further, when the recess on the outer surface of the flange was 4 mm or more, it was impossible to erase it by the finishing mill as shown in FIG. From FIG. 9, it can be seen that when a flange thickness of 22 mm is widened by 60 mm or more, no dent is generated, but when a flange thickness of 12 mm is widened by 40 mm or more, it cannot be erased by a finishing mill. It can be seen that a dent occurs. Thus, for the size of this example, the range of web heights that can be built without modification is limited to 40 mm.

As described above, JP-A-59-202101
Also in the technique disclosed in Japanese Patent Laid-Open Publication No. 1994-331, when the flange thickness is small, a recess is formed on the outer surface of the flange, and the amount of widening is limited.

The present invention solves the above problems and comprises a breakdown step, an intermediate rolling step, a widening rolling step, and a finish rolling step. By widening the web in the widening rolling step, a plurality of rolls can be formed on the same roll. It is possible to manufacture a wide range of H-section steels without reassembling, by providing the technology to prevent the dents on the outer surface of the flange that occur during the widening rolling process in the rolling mill trains that produce different size H-section steels. The purpose is to

[0010]

The gist of the present invention is (1)
In an H-shaped steel rolling mill train comprising a breakdown process, an intermediate rolling process, a widening rolling process, and a finishing rolling process, a horizontal roll and a flange provided with a caliber for forming a meat in the intermediate rolling process near the flange of the web. A rolling mill train of H-section steel characterized by comprising a universal rolling mill having a vertical roll provided with a caliber for imparting meat to the widthwise central portion, and an edger rolling mill,
Preferably, (2) the vertical roll of the universal rolling mill is provided with a caliber for thickening the central portion of the flange width over a range of ¼ or more of the flange width.

[0011]

The present invention will be described in detail below. The inventors investigated the mechanism of the occurrence of dents on the outer surface of the flange. As a result of investigating the anti-bite material at the time when the dent on the outer side surface of the flange was generated, as shown in FIG.
The side surface of the flange contacts the inner surface of the flange, and the web is widened by expanding the flange,
It was found that the above-mentioned dent occurred. This is because the material having a small flange thickness has a low rigidity, and therefore only the portion in contact with the roll is deformed, and the central portion of the width of the flange is not deformed.

From this, the central portion of the width of the flange is thickened to increase the rigidity of the flange and prevent the depression of the outer surface of the flange. A hot rolling experiment was conducted in order to confirm the effect of increasing the thickness of the central portion of the flange width. In the experiment, the material was rolled with a universal rolling mill, the horizontal rolls were used to form a thickness near the flange of the web, and the vertical rolls were used to increase the thickness at the center of the width of the flange, followed by widening with an oblique roll widening mill. Then, the amount of dents was investigated. As an index showing the shape of the thickened portion at the center of the flange width, the flange thickened range and the flange thickened amount were defined in the longitudinal section of the H-section steel as shown in FIG. That is, the flange thickening range is the length of the thickened portion measured parallel to the flange, and the flange thickening amount is the width of the outer line of the flange and the intersection of the tangents of the flange outer surface drawn at the tip of the upper and lower flanges. It is the distance from the center. In the experiment, the shape of the caliber applied to the vertical roll of the universal rolling mill was changed, and the shape of the thickened portion at the center of the flange width was changed. The caliber shape used in the experiment is shown in FIG. Caliber is a vertical roll 1
An arc contacting with 2, 12 'was used to change the flange thickness increasing range. Because of the condition that the inclined portions 12 and 12 ′ of the vertical roll and the arc 13 are in contact with each other, if the flange thickness increasing range is determined, the flange thickness increasing amount and the radius of the arc 13 are uniquely determined. The meat added by the horizontal roll near the flange of the web was constant.

FIG. 6 shows a web height of 600 mm and a flange width of 20.
For a material having a thickness of 0 mm, a web thickness of 9 mm, and a flange thickness of 12 mm, the relationship between the amount of depression on the outer surface of the flange and the ratio of the flange thickness increase range to the flange width is shown. It can be seen from FIG. 6 that the flange depression is reduced by increasing the thickness of the central portion of the flange width.

However, since the amount of depression of the outer surface of the flange changes depending on the thickness of the flange and the amount of widening of the web,
It is necessary to determine the range of the thickened portion at the center of the flange width and the amount of thickening according to the size to be manufactured without rearrangement. Generally, the thinner the flange, the smaller the rigidity of the flange, and the more easily the dent is formed. Therefore, the flange thickness is the smallest among the sizes that are manufactured by the same roll,
In addition, for the size of the maximum width expansion of the web, determine the range of the thickened part at the center of the flange width that can prevent dents and the thickness increase amount, and use the caliber to form this as the vertical roll of the universal rolling mill in the intermediate rolling process. It is preferable to add.

The caliber shape for thickening the vertical roll will be described. In order to prevent the occurrence of flaws when rolling down the flange in the intermediate rolling step, it is preferable that the intersecting portion between the inclined portion of the vertical roll and the caliber provided for increasing the thickness be a tangential arc. For example, the inclined portion 1 shown in FIG.
An arc that touches 2,12 '(hereinafter called an arc caliber)
Alternatively, as shown in FIG. 4, there is a caliber (hereinafter referred to as a straight caliber) in which a flange thickening range is connected by a straight line 14 and an intersection of the vertical roll and the inclined part 12 is connected by a circular arc 15. On the other hand, a caliber as shown in FIG. 5 is not preferable because the central portion of the flange width of the material to be rolled overhangs in a convex shape and may cause a flaw. Therefore, from the viewpoint of preventing flaws in the intermediate rolling step, the caliber shape of the thickened portion which is preferable is between the arc caliber and the straight caliber, and when the thickening range of the flange is constant, the flange thickening amount is as shown in FIG. It becomes the minimum when the arc caliber shown in FIG. 4 is used, and becomes the maximum when the straight line caliber shown in FIG. 4 is used.

FIG. 7 shows a case in which a material having a minimum flange thickness of 9 mm among the H-section steels manufactured by rolling is currently widened, the ratio of the thickening range to the flange width is changed, and the widening amount and the dent are formed. The result of comparing the relationship between the arc caliber and the straight line caliber is shown. No matter which caliber is used from Fig. 7, if the thickness of the flange width is increased from the center of the flange width to ¼ or more of the flange width, it is possible to expand the width about twice as much as when the center width of the flange is not increased. It can be seen that the size range that can be created without modification is dramatically expanded.

The rolling mill train of the present invention is shown in FIG. Breakdown step 1 consists of upper and lower horizontal rolls with calibers. The intermediate rolling step 2 includes a universal rolling mill (RU) and an edger rolling mill (E) for reducing the flange width. In addition, the horizontal rolls 6 and 6'of the universal rolling mill have a cylinder width corresponding to the smallest inner web width among products manufactured by the same roll, the maximum expansion amount in the vicinity of the flange of the web, and the maximum size of different sizes produced by the same roll. Inner width of the web-providing a caliber for forming meat corresponding to the minimum inner width of the web. This caliber may be similar to the prior art. A taper of about 5 ° is attached to the side surface of the horizontal roll and the vertical roll. The vertical rolls 7 and 7'of the universal rolling mill are provided with a caliber for thickening the central portion of the flange width of the material to be rolled. The material to be rolled roughly shaped in the breakdown step is rolled by the universal rolling machine and the edger rolling machine in the intermediate rolling step. Therefore, in the material to be rolled after the intermediate rolling step, the material required for widening is applied to the root portion of the web and the flange, and the flange width center portion is further thickened.

The widening rolling step 3 is described in JP-A-59-2021.
As disclosed in Japanese Patent No. 01, the oblique roll 8,
It is constituted by a rolling mill having 8 ', 9 and 9'. With this oblique roll, the web inner width of the material to be rolled supplied from the intermediate rolling step 2 is widened to the web inner width of the product. At this time, since the central portion of the flange width of the material to be rolled is thickened in the intermediate rolling step, the flange outer surface dent does not occur even if the flange thickness is thin.

The finish rolling step 4 is composed of a universal rolling mill having horizontal rolls 10 and 10 'which are divided in the width direction and whose body widths are variable, and vertical rolls. In the finish rolling process, the material to be rolled whose inner width of the web is divided in the widening rolling process is
The flange taper is squared and the base of the flange and the web is shaped.

[0020]

EXAMPLE A product having a flange width of 200 mm, a web thickness of 9 mm and a flange thickness of 1 was used in the rolling mill train of the present invention shown in FIG.
For 2 mm H-section steel, the outer width of the web is from 400 mm to 46 mm.
I made it to 0 mm. The width of the horizontal rolls of the two universal rolling mills was 382 mm, which corresponds to the minimum width of the outer web of 400 mm and the inner width of the web. The horizontal roll of the universal rolling mill was provided with a caliber for forming a thickness of 360 mm ² required for widening the thickness of 60 mm for a web thickness of 6 mm. The vertical roll was provided with an arc having a radius of 285 mm at the center of the width so as to contact the inclined portion. As a result, the range of the thickened portion formed at the center of the flange width is 60
mm, the amount of thickness increase is 2 mm. A two-roll type edger rolling mill was arranged on the rear surface of the universal rolling mill. The results are shown in Table 1. Product web width is 450 mm (width expansion is 50
(mm) did not cause a dent. When the outer width of the web of the product was 460 mm (the amount of widening was 60 mm), slight dents were observed after the widening rolling, but they could be erased by the finishing mill.

[0021]

[Table 1]

[0022]

According to the present invention, it comprises a breakdown step, an intermediate rolling step, a widening rolling step and a finish rolling step. By widening the web in the widening rolling step, a plurality of sizes of shaped steel can be formed by the same roll. Since it is possible to prevent dents on the outer side surface of the flange in the rolling mill train to be manufactured separately, it is possible to manufacture shaped steels in a wide range of sizes without reassembling.

[Brief description of drawings]

FIG. 1 is a diagram showing a rolling mill train of the present invention.

FIG. 2 is a diagram showing a definition of a thickened shape of an outer surface of a flange.

FIG. 3 is a diagram showing an example of a caliber shape of a vertical roll of the universal rolling mill of the present invention.

FIG. 4 is a diagram showing another example of the caliber shape of the vertical rolls of the universal rolling mill of the present invention.

FIG. 5 is a view showing an example of an unfavorable shape as the caliber shape of the vertical roll of the universal rolling mill of the present invention.

FIG. 6 is a diagram showing the relationship between the amount of depression on the outer surface of the flange and the range of increase in thickness of the flange for a material having a web height of 600 mm, a flange width of 200 mm, a web thickness of 9 mm, and a flange thickness of 12 mm.

FIG. 7 is a diagram showing a relationship between the amount of depression of the outer surface of the flange and the thickness increasing range of the flange for a material having a web height of 400 mm, a flange width of 150 mm, a web thickness of 6 mm, and a flange thickness of 9 mm.

FIG. 8 is a diagram showing a relationship between a material and a roll when a dent on the outer surface of the flange occurs.

FIG. 9 is a schematic view of a recess on the outer surface of the flange.

FIG. 10 is a diagram showing the relationship between the amount of recess on the outer surface of the flange, the amount of widening, and the flange thickness.

11A and 11B are explanatory views of a technique for widening the inner width of the web by the oblique roll.

FIG. 12 is a view showing a relationship with a roll material during web widening by an oblique roll.

FIG. 13 is a view showing a conventional rolling mill train for universal forming of shaped steel using oblique rolls.

[Explanation of symbols]

1 Breakdown Step 2 Intermediate Rolling Step 3 of the Present Invention 3 Widening Rolling Step 4 Composed of Oblique Rolls 4 Finishing Rolling Step 5 Composed of Finishing Universal Rolling Machine H Section Steel 6 and 6 ′ During Rolling Horizontal rolls 7 and 7'of universal rolling machine with caliber Vertical rolls 8 and 9 of universal rolling machine with caliber for thickening the central part of the flange width Oblique rolls 10 and 10 'Cylinder of finishing universal rolling machine Variable-width horizontal rolls 11 and 11 'Vertical rolls 12 and 12' of finishing universal rolling mill Vertical rolls of universal rolling mill 13 Inclined portion of vertical rolls 13 Arcs given to vertical rolls to thicken the central portion of flange 14 Central portion of flange width Straight line applied to the vertical roll to increase the thickness of the vertical roll 15 An arc connecting the straight portion of the vertical roll and the caliber 16 H-section steel before widening 1 H-shaped steel with a dent on the outside surface of the flange 18, 18 'Tangential line drawn from the flange tip of the material to be rolled 19 H-shaped steel after widening 20 H-shaped steel at the beginning of widening 21 H-shaped steel in the middle of widening 22 Intermediate Rolling Process 23 Vertical Roll of Conventional Technology Universal Rolling Mill

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-114402 (JP, A) Japanese Patent Publication No. 42-1525 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 1/00-1/46 B21B 13/10 B21B 27/02

Claims (2)

(57) [Claims] 1. In a rolling mill train of H-section steel consisting of a breakdown process, an intermediate rolling process, a widening rolling process and a finish rolling process, the intermediate rolling process is provided with a caliber for forming meat in the vicinity of the flange of the web. Rolling mill train of H-section steel, which comprises a universal rolling mill having a horizontal roll and a vertical roll having a caliber for thickening the central portion of the flange width, and an edger rolling mill. 2. The rolling mill according to claim 1, wherein the vertical roll of the universal rolling mill is provided with a caliber for thickening the central portion of the flange width over a range of ¼ or more of the flange width. Row.