JPH07214101A - Flexible rolling method of shaped steel with flange - Google Patents

Abstract

(57) [Abstract] [Objective] A rolling method for a shaped steel having a flange, and more particularly to a rolling method for efficiently and flexibly forming the web height of an H-shaped steel without any defect in the shape. [Composition] In a rolling method in which an oblique roll is installed between a middle rolling step and a finish rolling step of a rolling process of a shaped steel having a flange, the web height is widened, and the inner surface of the flange 1a of the material to be rolled is contacted. The outer side surface of the roll is formed in a truncated cone shape, and the oblique rolls 15, 15 ', 16 in which the angle γ formed by the outer side surface of the roll and the surface perpendicular to the central axis of the roll are formed to be 15 to 45 ° , 16 'are used to widen the height of the web while rolling down the extra thickness portion 18 of the material to be rolled, and the extra thickness 1 which is the cause of the constriction of the web is reduced.
The amount of widening of the height of the web after rolling 8 is reduced, and the constriction of the web at the time of large widening rolling is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rolling a section steel having a flange, and more particularly to a method for efficiently and flexibly forming the web height of an H-section steel without any defect in shape.

[0002]

2. Description of the Related Art Shaped steel currently manufactured by rolling is
The feature is that the number of varieties and sizes is very large, and with the diversification of customer needs, there is an increasing tendency for more varieties and sizes. In order to manufacture these various types and sizes of shaped steels by the conventional rolling method, a large number of dedicated rolling rolls and dedicated guides corresponding to the shaped steels are required, and the number of times of roll / guide reassembly increases. Therefore, time loss increases and productivity is significantly impaired.

As a concrete example of this, the case of H-section steel will be described below. FIG. 10 (a) shows a typical example of a conventional H-shaped steel rolling equipment train, in which one breakdown rolling mill 1 (BD) and subsequently a four-roll universal rolling mill (RU) are used. And a single or plural RU-E group 2 including an edger rolling mill (E), and a finishing 4-roll universal rolling mill 3 (FU).

FIG. 10 (b) shows each shape 4, of the rolled material formed by each of the rolling mills 1, 2, 3 in FIG. 10 (a).
5 and 6 are shown. FIG. 11 shows the relationship between the rolling roll of the universal rolling method for rolling H-section steel and the material to be rolled. Due to the function of the universal rolling mill, it is possible to freely change it with the same set of roll pairs during rolling. The dimensions are only the gap 9 between the upper horizontal roll 7 and the lower horizontal roll 8 and the gaps 12 and 13 between the left and right vertical rolls 10 and 11. Therefore, the H-section steel web thickness 9 and flange thickness 12, 13
Can vary, but the inner web width IW
Has to be constant. As a result, when rolling the series in which the thickness 9 of the H-section steel product is different, if the left and right flange thicknesses 12 and 13 are changed, the web height OW which is the total of the inner web width IW and the left and right flange thicknesses 12 and 13 is naturally obtained. Will have to change to various dimensions.

That is, in the H-section steel rolled by the conventional rolling method, the inner web width IW is constant as shown in FIG. 12, and the flange height Tf1 is changed to Tf2 so that the web height OW1 is changed to OW2. This is a product series with a so-called constant web width. If the web height is constant H
When trying to manufacture a shaped steel product series by the conventional rolling method using a universal rolling mill, it is necessary to prepare most of the upper and lower horizontal rolls in all the processes of rough rolling to intermediate rolling to finish rolling according to the change in the web inner width. Therefore, a large number of rolls are required and frequent roll reassembling work must be performed, resulting in a significant increase in manufacturing cost.
It is virtually impossible to adopt this method.

The applicant of the present application has found that as one method for solving the above-mentioned drawbacks in the conventional method, Japanese Patent Publication No. 3-1212.
The rolling method of a profile having a flange by the skew roll method of Japanese Patent No. 2 has been proposed previously. As shown in FIGS. 7 (a) and 7 (b), the characteristic of the "oblique roll type rolling method" is that two upper and lower skew rolls 15, 15 'and 1 are provided.
The outer surfaces 19, 19 ', 20, 20' of 6, 16 'are in contact with the inner flanges 21, 22 of the material 17 and the roll axis S
Is θ _H with respect to the plane perpendicular to the rolling direction in the plane parallel to the rolling direction, and θ _V with respect to the plane horizontal to the rolling direction in the plane perpendicular to the rolling direction. A function to spread the web in the width direction by causing the material in the pressed portion to flow in the width direction by pressing the excess thickness portion 18 formed to be thicker than the central portion of the web without causing any wave of the web. Have.

FIG. 8 (a) shows an example in which the rolling mill 14 adopting the "oblique roll type rolling method" is incorporated in a hot rolling equipment train for H-section steel. By combining an intermediate universal rolling mill (RU-E) 2, an oblique roll type rolling mill (SS) 14 and a finishing rolling mill (FU) 3 in which the horizontal width of the horizontal roll is variable in the figure, It is basically possible to manufacture the “H-shaped steel product series with a constant web height (OW)” shown in FIG. 3C with a small number of rolls.

Further, referring to FIGS. 8 (a), 8 (b) and 8 (c), an example in which the oblique roll method is applied to the production of the H-section steel product series having a constant web height (OW) will be described in detail. .
First, in the intermediate universal rolling mill group 2 (RU-E), the beam blank 4 supplied from the rough rolling mill 1 (BD) is shaped up to a cross-sectional shape 25 having extra thickness portions 18 at both ends of the web. That is, recesses are provided on the left and right peripheral surfaces of the upper and lower horizontal rolls of the intermediate universal rolling mill (RU), and the recesses are rolled so as to fill the steel material, and a cross-sectional shape 25 is formed. Cross-sectional shape 2 molded in this way
The number of 5 types is not limited. That is, since the material is rolled and shaped by the universal rolling mill in the intermediate process, the web thickness and the flange thickness can be freely changed, and the required number of different cross-sectional shapes can be shaped according to the product series. . The inner web width IW1 is constant and the web height OW1 is not always constant. Cross-sectional shape 25 formed by the intermediate universal rolling mill group 2,
Alternatively, if necessary, the rolling material formed into a cross-sectional shape in which the web thickness and the flange thickness are further different is sent to the skew roll type rolling mill 14 (SS). Each of these rolled materials has a cross-sectional shape 27 that has been widened and rolled into various web internal width dimensions IW2 necessary for the product series by the skew roll type rolling mill 14 (SS).

The cross-sectional shape 27 produced by the oblique roll type rolling mill 14 (SS) has various web inner widths IW4 according to the product series by the finishing rolling mill 3 (FU) in which the body width of the horizontal roll is variable. The product 29 is shaped and rolled into a cross-sectional shape 28 having a constant web height OW and a web inner width IW6 according to the product series. In addition, the product 31 having the largest flange thickness and the smallest web inner width in the product series is not subjected to web widening by the oblique roll type rolling mill 14 (SS), but finish rolling in which the body width of the horizontal roll is variable. It can be manufactured by directly using the cross-sectional shape 25 of the intermediate universal rolling mill group 2 in the rolling mill 3 (FU). However, in this case, the web inner width IW3 of the cross-sectional shape 30 corresponding to the product web inner width IW5 and the web inner width IW1 of the cross-sectional shape 25 of the intermediate universal rolling mill group 2 are set to mutually compatible values. .

As described above, the oblique roll type rolling method of Japanese Patent Publication No. 3-42122 has a good web widening function, but a large web widening is required in order to manufacture products of different series from the same set of rolls. If it is attempted, (a) a large amount of extra thickness is generated in order to prevent a local thickness reduction (hereinafter referred to as a constriction) at the boundary 43 between the corner R portion 41 and the extra thickness portion and the central portion 42 as shown in FIG. (B) Since the amount of surplus is the same for each size of the profile, if the web height is not widened, a very large surplus must be reduced by the finishing mill. (C) The finish rolling mill must have a structure in which the body width of the horizontal roll can be changed in response to changes in the web width of the profile, so the rigidity and strength of the roll are lower than those of conventional integrated rolls. Have to There, for three reasons above, the problem of excess thickness to the product web remains occurs.

[0011]

SUMMARY OF THE INVENTION In order to manufacture products of different series from the same set of rolls without causing the problems described above, the present invention does not increase the amount of surplus and performs skewing. An object of the present invention is to provide a method for performing large web widening on a roll rolling mill.

[0012]

The gist of the present invention is (1)
Between the intermediate rolling step and the finish rolling step of the shaped steel rolling process consisting of the rough rolling step, the intermediate rolling step, and the finish rolling step, the central axis is in a plane horizontal to the rolling direction and perpendicular to the rolling direction. A pair of left and right skew rolls having a predetermined angle θ _H with respect to the surface are arranged inside the upper and lower flanges of the material to be rolled, and the width of the web is increased while the excess thickness at both ends of the web is reduced by the skew roll. In the rolling method of the shaped steel, the outer side surface of the roll, which comes into contact with the inner side surface of the flange of the material to be rolled, is formed into a truncated cone shape, and the angle formed by the outer side surface of the roll and the surface perpendicular to the central axis of the roll. γ from 15 °
A method of freely rolling a shaped steel having a flange for widening the web height by using a skew roll formed at 45 °, (2)
Angle θ _V between the center axis of the skew roll and the plane parallel to the web
And a difference (γ−θ _V ) between a surface perpendicular to the central axis of the skew roll and a surface in contact with the outer circumference of the skew roll (γ−θ _V ) is 0 °.
The width of the web is widened by setting it to 20 ° (1).
A method of freely rolling a shaped steel having a flange according to paragraph
(3) After widening the web height with the skew roll,
A method for freely rolling a shaped steel having a flange according to the above items (1) and (2), in which the flange outer surface is pressed by a pair of left and right vertical rollers to correct the flange angle.

[0013]

The basic rolling process of the present invention is as shown in FIG.
As shown in (b), a rough rolling mill 1 (BD) that supplies a beam blank 4, a universal rolling mill that rolls the beam blank 4 into a substantially H shape and forms a surplus portion 18 at both ends of the web 2a. 2-1 (RU), an edger rolling machine 2-2 (E) for forming the width F of the flange portion 1a,
It is configured by an oblique roll type rolling mill 14 (SS) installed after the intermediate rolling process and having a function of adjusting the web height, and a finish rolling mill 3 (FU) that rolls to a final product.

In the following, a method for widening a large web height without increasing the amount of surplus in the present rolling process will be described. FIG. 13 shows the constriction occurrence state when the web height is widened by the skew roll. The web height widening process is composed of three regions, region I, region II, and region III. The region I is a region in which the web height is slightly widened before the excess thickness reduction due to the web being pushed and expanded from the inner side due to the contact between the inner surface of the flange and the outer surface of the roll. The region II is a region where the web height is significantly widened by rolling the excess thickness diagonally while applying tension in the width direction to the web via the flange.
The region III is a region in which the web height is widened after the excess thickness reduction by the same action as the region I. In the widening process described above, the constriction occurs in the region III, and the generation site in the cross section is the corner R portion 41 and the boundary 43 between the extra thickness portion and the central portion 42 as shown in FIG. That is, the constriction is region III.
Due to the amount of widening in the area III, if the amount of widening in the region III exceeds a certain allowable value, it occurs in the portion where the cross-sectional shape changes rapidly at high temperature.

Therefore, the present invention has been devised to improve the shape of the oblique roll to reduce the amount of widening in the region III. 4 to 6 show schematic views of the oblique roll shape. Equations (1) to (7) for obtaining the shape of the outer surface of the roll are derived using these figures.

First, FIGS. 4 (a) to 4 (c) schematically show the shape of the oblique roll 15m of the present invention which serves as a reference when the angles θ _H = 0 ° and θ _V = 0 °. It is a thing. 4A is a front view and FIG. 4B is a side view.
The cross section AA is shown in FIG. In the AA cross section,
Distance L ₁ from the origin 0 to the end face of the roll, and overhang amount L of the skew roll 15 m at the distance X from the origin
₂ (X) can be represented by the formulas (1) to (3) using the symbols in FIGS. 4 (a) to 4 (c).

[0017]

[Equation 1]

Here, R is the radius of the skew roll, γ is the side angle of the skew roll, and other symbols are defined as shown in FIGS. The skew roll side face angle γ is an angle formed by the roll outer side face in contact with the flange inner side face of the material to be rolled with respect to the face orthogonal to the roll axis S. In the present invention, the shape of the skew roll is referred to as a frusto-conical shape, which means that the shape of the skew roll used in the present invention set in a specific skew roll side face angle γ range is a flange of a material to be rolled as described later. This is because the outer side surface of the roll, which is in contact with the inner side surface, is formed as a conical roll whose head portion is not sharp.

FIG. 5 schematically shows the shape of the skew roll 15m when it is rotated by θ _H (> 0 °) at the radius of rotation C _R around the center of rotation with reference to FIG. is there.
From FIG. 5 and the above equation (3), the outer shape of the skew roll 15m in the coordinate system (X ′, Y ′) after rotation is (4)
It can be represented by a formula. Y '= L ₂ (X') (-L ₁ ≤X '≤L ₁ ) (4)

Here, the equation (4) is converted into the coordinate system (X,
In order to represent Y), the coordinates may be converted by the equation (5).

[Equation 2]

FIG. 6 shows a radius of gyration C _R ′ around the center of rotation in a plane perpendicular to the web surface in accordance with the rotation shown in FIG.
3 schematically shows a skew roll shape when rotated by θ _V (> 0 °). According to FIG. 6, the outer diameter of the skew roll can be expressed by the equation (6).

[Equation 3]

Here, as Y ″, Y obtained by the equations (4) and (5) is substituted, and since the X coordinate does not change even if the roll is rotated in the plane perpendicular to the web surface, the equation (5) is obtained. It is sufficient to use X as it is.

Further, since the position of the slice plane (A-A cross section) is displaced by performing the rotation shown in FIG. 6, in equation (6), h ₀ ′ obtained by correcting h ₀ as in equation (7) is used. . h ₀ ′ = h ₀ · cos θ _V / cos (γ−θ _V ) (7) The coordinates (X, Y) of the outer shape of the skew roll can be obtained from the above equations (1) to (7).

In FIG. 3, the skew roll 15m (15m ', 1
An example of calculating the outer shape of the skew roll using the above formulas (1) to (7) when 6 m, 16 m ′) is cut on a surface parallel to the web surface and separated from the web surface by a distance h ₀ = 30 mm showed that. However, θ _H = 10 °, γ = 25 °, θ
_V = 5 ° and R = 450 mm were set. Since the material to be rolled is widened almost along the roll, the widening amount in the region III in this case (the widening amount after the completion of the excess thickness reduction) is ΔWIII in FIG.
Equivalent to. FIG. 2 shows the case where the skew roll angle θ _H is 5 ° and 10 °, and the skew roll side angle γ and the skew roll angle θ _V are changed to calculate the outer shape of the skew roll. Obtain the widening amount in Region III as shown below,
FIG. 6 is a diagram showing the relationship between the side angle γ of the skew roll and the angle θ _{V of the} skew roll and the widening amount in region III. From this figure, it can be seen that the larger the skew roll side surface angle γ, the smaller the amount of widening in the region III and the more effective it is in preventing necking. Further, it can be seen that the amount of widening in the region III does not change even if the angle θ _{V of the} skew roll is changed. The proper value of the skew roll side angle γ is determined by the target widening amount, the skew roll angle θ _H , the skew roll diameter, etc., but as a result of repeated experiments at various levels, the skew roll side angle γ is 15 ° ~
It was found that the constriction can be sufficiently suppressed by selecting within the range of 45 °. That is, when γ is less than 15 °, the region
The widening amount in III exceeds the permissible amount and constriction occurs, 45
This is because when the temperature exceeds 50 ° C., the effect of reducing the amount of widening in region III becomes saturated and the flange is tilted outwards more than necessary, which causes a problem in molding.

Even within the range of the side angle γ of the skew roll according to the present invention, the flange tilt after the γ is set to a large value to widen the web height is increased, and the flange of the finishing rolling mill in the post-process is increased. When the problem that the rolled material does not get caught occurs in the present invention, a method of increasing the skew roll angle θ _V , that is, a method of reducing the angle (γ-θ _V ) to suppress the flange tilt within the allowable value (Fig. As shown in FIG. 3, the widening amount in the region III does not change even if θ _V is increased), or a means for correcting a flange fall by providing a vertical roller after widening rolling with a skew roll may be applied.

[0026]

[Example] H-shaped member having a web height of 600 mm and a flange width of 200 mm and H-shaped member having a web height of 700 mm and a flange width of 200 mm
The effectiveness of the present invention will be described by comparing the case where the conventional method is used and the case where the present invention is applied, taking as an example the case where the profile is manufactured by the same roll.

Table 1 shows the case where the conventional method in which the side angle γ of the skew roll is 0 ° is applied. In this embodiment, in order to suppress the remaining surplus within an allowable value, the sectional area of the surplus is set to 5 which is the maximum required amount.
Since it was set to 0%, the necking during the large widening rolling was extremely large and remained after the finish rolling.

[0028]

[Table 1]

On the other hand, Table 2 shows the case where the present invention is applied. Even if rolling is performed under the same conditions as described above, the side angle .gamma. Of the oblique roll is set to 35.degree., And the widening amount in the region III is reduced. As a result, it was confirmed that the constriction was suppressed within the allowable value, and a product with good dimensional accuracy was obtained.

[0030]

[Table 2]

[0031]

By applying the present invention to a manufacturing process of a profile having a flange by a skew roll system, no web constriction occurs even if an extremely large web widening is performed by the skew roll, and the web is Even if the width is not widened, finish rolling can be performed on a product having a good web thickness distribution, and an H-shaped product series having an arbitrary web height can be manufactured with good quality and an extremely small number of rolls.

[Brief description of drawings]

1A and 1B are schematic views of a rolling method of an H-shaped material according to the present invention.

FIG. 2 is an explanatory diagram of a relationship between a side angle γ of a skew roll and a width expansion amount in a region III.

FIG. 3 is an explanatory view of the outer shape of a skew roll.

4 (a), (b), (c): Angle θ of skew roll
FIG. 3 is a schematic view showing a skew roll shape when _H and θ _V are 0 °.

FIG. 5 is a schematic diagram showing a skew roll shape when the skew roll angles θ _H > 0 ° and θ _V = 0 °.

FIG. 6 is a schematic diagram showing a skew roll shape in the case where the skew roll angles θ _H > 0 ° and θ _V > 0 °.

7 (a) and 7 (b): an explanatory view of a skew roll rolling method.

8 (a) and 8 (b): Functional explanatory views of an apparatus and a rolling mill for skew roll rolling. (C): Schematic drawing of the product by the oblique roll type rolling method.

FIG. 9 is an explanatory diagram of web constriction.

10 (a) and 10 (b): Explanatory views of a typical example of a conventional H-shaped material rolling apparatus train and cross-sectional shapes of respective materials rolled by rough, intermediate, and finishing rolling mills.

FIG. 11 is a functional explanatory view of a universal rolling mill based on a relationship between a universal rolling roll for rolling an H-shaped material and a material to be rolled.

FIG. 12 is an explanatory diagram of a product series with a constant web inner width.

FIG. 13 is an explanatory diagram showing a web constriction occurrence state.

[Explanation of symbols]

 1 Breakdown rolling mill 2 RU-E group 2-1 Intermediate universal rolling mill 2-2 Edger rolling mill 3 Finishing universal rolling mill 4-6 Rolled material 14 Oblique roll type rolling mill 15, 15 'Oblique roll (conventional) 16, 16 'Oblique Roll (Conventional) 15m, 15m' Oblique Roll (Invention) 16m, 16m 'Oblique Roll (Invention) 17 Shaped Material 18 Extra Thickness

Claims (3)

[Claims] 1. A center axis of a shaped steel rolling process comprising a rough rolling process, an intermediate rolling process, and a finish rolling process between the intermediate rolling process and the finish rolling process is in a plane horizontal to the rolling direction, and A pair of left and right skew rolls having a predetermined angle θ _H with respect to a plane perpendicular to the rolling direction are arranged inside the upper and lower flanges of the material to be rolled, and the skew rolls are used to reduce the excess thickness at both end portions of the web. In the rolling method of a shaped steel for widening the web height, the roll outer surface that comes into contact with the flange inner surface of the material to be rolled is formed into a truncated cone shape, and the roll outer surface and the center axis of the roll are perpendicular to each other. A method for universally rolling a shaped steel having a flange, characterized in that the web height is widened by using an oblique roll formed with an angle γ formed by the plane of 15 ° to 45 °. 2. An angle θ _V between the central axis of the skew roll and a plane parallel to the web, and an angle γ between a plane perpendicular to the central axis of the skew roll and a surface in contact with the outer circumference of the skew roll. Difference (γ
2. The method of universally rolling a shaped steel having a flange according to claim 1, wherein the width of the web is widened by setting −θ _V ) to 0 ° to 20 °. 3. The width of the web is widened by a skew roll, and then the flange outer surface is pressed by a pair of left and right vertical rollers to correct the flange angle.
Alternatively, a method of freely rolling a shaped steel having a flange according to claim 2.