JPH06508A - Rolling mill line and manufacture of shapes having flange - Google Patents

Abstract

PURPOSE:To stably manufacture shapes having fixed web hight, good dimensional accuracy of a cross-section and fixed outside measurements by rolling. CONSTITUTION:This rolling mill line is provided with a roughing universal mill group which consists of a roughing universal mill 12 and edger mill 14, web expanding mill 18 and finishing universal mill 16 in the order of the above- mentioned from the upstream side. In the web expanding mill 18, a pair of upper and lower horizontal rolls is positioned in a inclined state so that the directions that are orthogonally crossed to the axes of rotation of the rolls form a prescribed angle alpha to the rolling direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a section steel having a rolling mill train and a flange. For more details,
INDUSTRIAL APPLICABILITY The present invention provides a method for stably manufacturing a shaped steel having a flange having a constant outer diameter, which has a constant web height and good cross-sectional dimensional accuracy, and a rolling mill that can be used when carrying out this method. Regarding columns.

[0002]

2. Description of the Related Art Generally, a section steel having a flange such as an H-section steel, a channel section steel and an angle section steel is manufactured by a universal rolling method. As is well known, the universal rolling method is a rolling method in which a universal mill having a combination of horizontal rolls and vertical rolls is used to simultaneously reduce the flange of the shaped steel and the web.

FIG. 3 schematically shows an example of a rolling mill train for carrying out the universal rolling method. As shown in the figure, a double rolling mill called a breakdown mill 30 equipped with rolls having a hole shape is used to roll a crude steel strip, and a rough universal mill 32 and an edger mill 34 roll down the web surface and the flange surface. Reversed, finished with a universal mill 36 to a specified size to make a finished product.

The universal rolling method carried out in this way has the advantage that the same roll can be shared by several kinds of products having different cross-sectional dimensions. Further, since the rolls having the same width are used in the same rolling chance, the inner width of the web of the H-section steel (the distance between the inner surfaces of the flanges) can be made constant. However, even with the same rolling chance, if the cross-sectional dimension of the material to be rolled, especially the flange thickness, changes, the web height (distance between the outer surfaces of both flanges) also changes. However, there is a problem that the web height of the H-shaped steel product cannot be made constant.

Conventionally, various techniques for adjusting the web height of the H-section steel have been proposed in order to improve the dimensional accuracy of the H-section steel.

In Japanese Patent Laid-Open Nos. 60-206502 and 61-262403, two horizontal rolls having a small diameter are provided so as to come into contact with the flange inner surface and the web surface of the material to be rolled,
A technique has been proposed in which the web height is set to a predetermined constant value by rolling while expanding the web height. However, in these techniques, since the metal flow of the material to be rolled does not proceed smoothly, there is a risk of necking in the fillet portion of the material to be rolled.

On the other hand, it is conceivable that a roll is provided so as to come into contact with the outer surface of the flange of the material to be rolled and rolling is performed while compressing the web height to bring the web height to a predetermined value.
In this case, since the web bends to the inner surface side, a large amount of compression cannot be taken. In order to obtain a large amount of compression, it is necessary to install a web restraint roll on the inner surface of the flange to prevent web deflection, but in order to achieve a sufficient web deflection prevention effect, the web restraint roll must have a large diameter. It must be a horizontal roll, which results in the same as using a universal mill.

As a method for expanding or reducing the height of the web using a universal mill, Japanese Patent Laid-Open Nos. 58-135705 and 61-262404 use a finishing universal mill equipped with a variable width horizontal roll. There has been proposed a method for producing an H-section steel having a constant outer-web method by increasing or reducing the inner width of the web. However, in these methods, the width of the flange is likely to partially vary, and the product web may not be located at the center of the flange. Therefore, in the H-section steel manufactured using the universal mill, the center deviation of the web occurs.

That is, when a H-shaped steel having a constant outer method is manufactured by rolling the height of a web in a universal mill, particularly when performing a rolling to reduce the height of the web, a more severe center deviation than in the past occurs. To do. FIG. 4 schematically shows a situation in which the center deviation of the web occurs. In the figure, the distances from the joint of the web 42 to the flange 44 to the flange end are a and b (a> b), respectively, and are not constant,
It shows that the H-section steel 40 has a center deviation. Also,
In the worst case, since the deformation resistance of buckling is smaller than the deformation resistance that uniformly compresses the web height, the fillet portion c may buckle as shown in the figure.

Therefore, in recent years, a technique for securing a metal flow by providing a projection on the web of the material to be rolled before the finish universal rolling and pressing down the projection by the finish universal rolling is proposed. Has been done. For example, in Japanese Unexamined Patent Publication No. 59-178101, a protrusion is formed in the center of a web of a material to be rolled in a rough universal rolling process, and the protrusion is rolled down by a finishing universal mill equipped with a normal horizontal roll. Has proposed a technique for increasing the height of the web. However, with this technology, metal flow occurs in the rolling direction due to the reduction of the protrusions by the finishing universal mill, but the part where the web is not reduced and the flange cause the metal flow in the center of the web in the rolling direction. Restraint force (compressive stress)
Acts, and the corrugation phenomenon occurs in the web depending on the dimensions of the material to be rolled.

Further, in Japanese Patent Laid-Open No. 61-262404, protrusions are formed at both ends of a web of a material to be rolled in a rough universal rolling process, and the protrusions are formed by a finishing universal mill having variable width dividing rolls. By rolling down,
Techniques for increasing the web height have been proposed. According to this technology, the metal flow to the flange and the web naturally occurs due to the reduction of the protrusion, but the ratio of the amount of the metal flow is strongly affected by the temperature difference between the flange and the web, which makes it difficult to control. However, the dimensions of both the flange and the web fluctuate, the cross-sectional dimensional accuracy deteriorates, and center deviation occurs.

[0012]

As described above, according to these techniques for forming the protrusions on the web, since the metal flow is secured, it is possible to prevent buckling of the fillet portion to some extent. However, according to these techniques, since the projection is pressed down and the flange is raised and the flange is pressed down in the same manner, uneven metal flow occurs in the direction of the end of the flange, and the flange width is expanded.
Center deviation occurs. Therefore, the cross-sectional dimensional accuracy of the product is significantly reduced. Here, the object of the present invention is that the web height is constant and the cross-sectional dimension accuracy is good,
It is to stably manufacture a shaped steel having a constant outer method, more specifically, an H-shaped steel by rolling.

[0013]

DISCLOSURE OF THE INVENTION The present inventors have proposed a method of adjusting the web height by providing a protrusion in the web longitudinal direction and rolling the protrusion, which occurs during rolling of the protrusion. With the recognition that the above problems can be solved if the metal flow to be carried out can be optimized, the inventors have made earnest studies.

As a result, the inventors of the present invention provided a longitudinal projection on the web of the material to be rolled by rough universal rolling, and before the finish universal rolling, the direction orthogonal to the roll rotation axis in the horizontal plane was the rolling direction. In order to make a predetermined angle α to the, to expand the web height of the material to be rolled by rolling the protrusions using a web widening mill that is a pair of upper and lower horizontal rolls installed in an inclined state, By performing finish universal rolling on the flange and raising the angle of the flange and reducing the thickness of the web and flange,
The present invention has been completed by finding that a shaped steel having a constant web height and a good cross-sectional dimensional accuracy and a constant outer process can be stably manufactured by rolling.

Here, the gist of the present invention is to provide a coarse universal mill group consisting of a coarse universal mill and an edger mill, a web widening mill having at least one installed, and a finishing universal mill in this order from the upstream side. In the rolling mill row, the web widening mill is a pair of upper and lower horizontal rolls installed in an inclined state such that the direction orthogonal to the roll rotation axis in the horizontal plane forms a predetermined angle α with the rolling direction. It is a rolling mill train characterized by that.

[0016] From another point of view, the present invention is a method for manufacturing a shaped steel having a flange for performing rough universal rolling, edger rolling and finish universal rolling,
(i) By performing rough universal rolling and edger rolling to form protrusions in the longitudinal direction of the web of the material to be rolled, (ii) before performing finish universal rolling, the direction orthogonal to the roll rotation axis in the horizontal plane is The protrusion of the web is rolled at least once by a web widening mill, which is a pair of upper and lower horizontal rolls installed in an inclined state so as to form a predetermined angle α with respect to the rolling direction. And (iii) finishing universal rolling is performed to raise the angle of the flange and reduce the thickness of the web and the flange, which is a method for manufacturing a shaped steel having a flange.

In the present invention, the section steel refers to a section steel having a flange such as an H-section steel, a channel steel, an angle steel, an I-section steel and the like. The predetermined angle α is determined according to the amount of web to be expanded, and is generally about 10 to 35 degrees, although it is influenced by the size and material of the product.

[0018]

The operation of the present invention will be described in detail below. The present invention is, in brief, by performing rough universal rolling, edger rolling and finish universal rolling,
The present invention relates to a method for manufacturing a shaped steel having a flange.

The above-mentioned JP-A-59-178101
In the present invention, as in the technique proposed by Japanese Patent Laid-Open No. 61-262404, the protrusions are formed in the longitudinal direction of the web of the material to be rolled by rough universal rolling and edger rolling. The formation range, size, number of formations, etc. of the protrusions are not particularly limited, and may be approximately the same as known protrusions. For example, when forming one protrusion at the center of the web height direction, the width of the protrusion is about 10 to 30% of the web height, and the height of the protrusion is about 30 to 50% of the web thickness. Can be illustrated.

In the prior art, the rolling of the projection thus formed was carried out by a horizontal roll of a universal mill or a horizontal roll of variable width, but in the present invention, in order to improve and optimize the metal flow. Before the finish universal rolling, the web widening mill described later is used, and then the finish universal mill raises the angle of the flange and reduces the thickness of the web and the flange.

FIG. 1 is an explanatory view showing a structural example of a rolling mill train according to the present invention. In the figure, the breakdown mill 10, the rough universal mill 12, the edger mill 14, and the finishing universal mill 16 are arranged in this order from the upstream side, but these rolling mills may be the same as conventionally known rolling mills, The invention does not require any limitation. The rolling mill train according to the present invention includes a rough universal mill 12, an edger mill 14, a finishing universal mill 16, and a web widening mill 18 installed in a step directly above the finishing universal mill 16.

A structural example of the web widening mill 18 is shown in FIG.
Figure 2 (a) is a top view of the web widening mill during rolling.
(b) is a view on arrow A in FIG. 2 (a). In FIG. 2, the web 23 of the material 22 to be rolled has a protrusion 24 formed by rough universal rolling and edger rolling.

In the web widening mill 18, as shown in FIG. 2 (a), the direction orthogonal to the roll rotation axis (shown by the one-dot chain line) in the horizontal plane forms a predetermined angle α with respect to the rolling direction (shown by the two-dot chain line). It is a pair of upper and lower horizontal rolls 20 and 21 installed so as to be inclined. The difference from a normal pair of upper and lower horizontal rolls is that they are installed at an angle α on a horizontal plane, and other (roll shaft supporting means, driving means, etc.) may be the same as known horizontal rolls.

In the present invention, the purpose of installing the horizontal rolls 20 and 21 of the web widening mill in a slanting direction is orthogonal to the rolling direction of the material 22 to be rolled (the direction of the arrow with diagonal lines) in FIG. 2 (a). Direction, that is, the web height direction, the protrusion
The purpose of this is to increase the height of the web 23 of the material 22 to be rolled by applying the component force of the reduction of 24.

The predetermined angle α may be appropriately adjusted according to the amount of expansion of the height of the web, and it is not necessary to limit the range in the present invention. Generally, the web height H is about 600 mm.
To expand the shaped steel web about 10 mm, it is about 13 degrees, and to expand the web about 20 mm, it is about 20 degrees.

In other words, in the present invention, the web height is expanded without causing the center deviation by first performing the reduction of the protrusion 24, and then the raising of the flange 25 and the thickness reduction are performed by the finish universal rolling. By carrying out the above, it is possible to prevent the outside constant and the center deviation.

The direction in which the web height is increased is
As is clear from 2 (a), it is the same as the inclination direction of the web expanding mill (in FIG. 2 (a), it is the right direction toward the paper surface).
Therefore, as shown in FIG. 5, which is a top view showing another installation example of the web widening mill according to the present invention, rather than securing a desired web widening amount with one web widening mill,
Two or more web widening mills may be installed with the inclination directions of the two web widening mills 50 and 51 being opposite to each other. The reference numerals in FIG. 5 are the same as those in FIG.

As described above, when the shaped steel is manufactured according to the present invention, the metal flow to the flange of the rolled material does not occur,
Also, metal flow in the rolling direction can be suppressed,
Since the metal flow mainly occurs in the web height direction, the web can be efficiently widened. Further, the present invention will be described in detail with reference to examples, but this is an example of the present invention and the present invention is not limited thereto.

[0029]

EXAMPLES As an example of the present invention, a web widening mill shown in FIG.
With the rolling mill train shown in FIG.
H-section steel having a thickness of 600 mm, a flange width of 200 mm, a flange thickness of 16 mm and a web thickness of 9 mm was manufactured by rolling.

The predetermined angle α in FIG. 2 (a) is 10 degrees, and the protrusions 24 have a length of 100 mm and a height of 4 mm, and one protrusion is provided at the center in the web height direction. Rolling was performed by the web widening mill 18. Also breakdown mill
(BD mill), rough universal mill (UR mill), edger mill (E mill), web widening mill and finishing universal mill (UF mill).

[0031]

[Table 1]

On the other hand, as a comparative example, a method proposed by Japanese Patent Application Laid-Open No. 61-262404, that is, a rough universal mill and an edger mill are used to form protrusions on both ends of the web of the material to be rolled and a variable width horizontal roll Rolling was carried out with the target of H-section steel of the same cross-sectional dimension by a method of reducing or reducing the height of the projections by a finishing universal mill equipped with. Table 2 collectively shows the cross-sectional dimensional accuracy of the H-section steel obtained by rolling.

[0033]

[Table 2]

As is apparent from Table 2, according to the present invention, the occurrence of web deviation is significantly suppressed, and the H value which is constant outside the method is obtained.
It has become possible to manufacture shaped steel.

[0035]

As described in detail above, according to the present invention,
It has become possible to stably produce a shaped steel having a constant web height and good cross-sectional dimensional accuracy and a constant outer process by rolling.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration example of a rolling mill train according to the present invention.

FIG. 2 shows an example of the structure of a web widening mill 18. Figure 2
(a) is a top view of the web widening mill during rolling, and Fig. 2 (b).
FIG. 2 is a view on arrow A in FIG.

FIG. 3 is an explanatory view showing a conventional rolling mill train.

FIG. 4 is an explanatory diagram showing the occurrence of buckling that occurs in the fillet portion of H-section steel.

FIG. 5 is an explanatory view showing another arrangement example of the web widening mill.

[Explanation of symbols]

10, 30: Breakdown mill 12, 32: Coarse universal mill 14, 34: Edger mill 16, 36: Finishing universal mill 18: Web widening mill 20, 21: Horizontal roll 22: Rolled material 23: Web 24: Projection 25 : Flange 40: Rolled material 42: Web 44: Flange 50, 51: Web widening mill

Claims (2)

[Claims] 1. A rolling mill train comprising a coarse universal mill group consisting of a coarse universal mill and an edger mill, a web widening mill having at least one installed, and a finishing universal mill in this order from the upstream side, wherein the web widening is performed. The mill is such that the direction orthogonal to the roll rotation axis in the horizontal plane forms a predetermined angle α with the rolling direction,
A rolling mill train comprising a pair of upper and lower horizontal rolls installed in an inclined state. 2. A method for manufacturing a shaped steel having a flange for performing rough universal rolling, edger rolling and finish universal rolling, comprising: (i) performing the rough universal rolling and edger rolling to obtain a web of a material to be rolled. Form the protrusions in the longitudinal direction, and (ii) before finishing universal rolling, install in an inclined state so that the direction orthogonal to the roll rotation axis on the horizontal plane forms a predetermined angle α with the rolling direction. With the web widening mill which is a pair of upper and lower horizontal rolls, the protrusion is rolled at least once to increase the web height of the material to be rolled, and (iii) Finish universal rolling is performed to raise the angle of the flange and the web. And a method for manufacturing a shaped steel having a flange, characterized by performing thickness reduction of the flange.