JP3098877B2 - Rolling method for H-section steel - 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 method capable of freely producing H-shaped steels having different sizes (especially, a web height) without frequently changing rolling rolls.

[0002]

2. Description of the Related Art An H-section steel having a web and a flange is usually provided in a rolling mill row in which a breakdown rolling mill, an intermediate universal rolling mill (coarse universal rolling mill), an edger rolling mill and a finishing universal rolling mill are sequentially arranged. ,
Alternatively, in order to improve the rolling efficiency, the second intermediate universal rolling mill is manufactured in a rolling mill row arranged on the exit side of the edger rolling mill, and reverse rolling is performed except for the finishing universal rolling mill. This was common (see FIGS. 9 and 10).

Here, in a breakdown rolling mill, a rolled material is rolled into a substantially H-shape, and in a subsequent rough rolling step (or intermediate rolling), a web of the material is reduced by a pair of upper and lower horizontal rolls and a pair of left and right vertical rolls is formed. The material flange is rolled down by a roll, and the material is rolled to a shape close to the product size by this rolling (see FIG. 13). The flange of the material at this stage has fallen outward from the viewpoint of avoiding damage caused by the side surface of the horizontal roll of the rolling mill contacting the inner surface of the flange of the material, and the angle between the web and the flange is generally In many cases, it is about 95 °, and in the subsequent finish rolling, the web and flange of the raw material are rolled down to a predetermined thickness, and at the same time, rolling that also serves as flange raising is finished to a predetermined cross-sectional dimension (see FIG. 14). ). By the way, when it is going to roll H-shaped steel of different sizes using such a rolling mill row, when changing the thickness of the web, the thickness of the flange or the width of the flange, it is necessary to change the roll of each roll of the universal rolling mill. There is no particular problem because it can be dealt with by changing the position, but when rolling such as changing the inner width of the web because the inner width of the web is equal to the roll width of the horizontal roll, it can not be handled with the same roll. The exchange (replacement of the rolls of the breakdown rolling mill, the coarse universal rolling mill, and the finishing universal rolling mill) was required.

[0004] In actual operation, the roll exchange of a rolling mill requires a great deal of time and man-hours, so that it is common to try to make various kinds of products by avoiding the exchange as much as possible. The H-shaped steel manufactured in this manner is a so-called H-shaped steel having a constant inner diameter and a different thickness of the flange even when the web height is the same as the same size.

[0005] By the way, the above-mentioned H-section steels having a constant inner law have different web heights even if they have the same name, so that the outer surfaces of the flanges are used, for example, when they are used for columns or beams as building steel. When used in conjunction with each other, a step is generated, and it is essential to insert a plate to eliminate the step, which has a drawback in terms of workability.

[0006] For this reason, the H-section steel used as a building steel material is manufactured by welding a plate to a so-called H-shaped steel having a constant outer method.
Shaped steel is used, but this welded H-shaped steel has a problem that the manufacturing cost and selling price are higher than the H-shaped steel manufactured by rolling, and the H-shaped steel with a constant external method can be manufactured at a low cost by rolling. The development of a method was desired.

[0007] There have been many proposals for a method of rolling an H-section steel in which the inner width of the web can be adjusted. For example, Japanese Unexamined Patent Publication No. Sho 59-202101 discloses a method of skew before finishing universal rolling. A technique has been proposed in which the inner width of the web is increased by a roll.

Further, Japanese Patent Application Laid-Open No. 58-135705 and
Japanese Patent No. 80102 proposes a technique in which a horizontal roll of a universal rolling mill is divided into two parts on the left and right sides and the inner width of the web of the material for H-section steel is adjusted by appropriately moving this in the axial direction. These technologies have been developed as disclosed in JP-A-3-258401, which lubricates the roll end surface of a horizontal roll when the inner width of the web is changed, and in a method of rolling an H-section steel using a variable width horizontal roll. Kaihei 3-1846
See No. 01 publication.

[0009]

SUMMARY OF THE INVENTION Incidentally, Japanese Patent Application Laid-Open No.
The technique disclosed in Japanese Patent Publication No. 02101 has a disadvantage that a dedicated rolling mill needs to be separately installed and equipment cost is high, and the technique disclosed in Japanese Patent Application Laid-Open Nos. 58-135705 and 2-80102 In the operation, when the inner width of the web is reduced for a thin object, there is a concern that the web buckles and the cross-sectional shape is deteriorated, and there is a disadvantage that the adjustment amount of the inner width of the web cannot be increased.

An object of the present invention is to propose a novel method by which H-section steels of various sizes can be separately formed without frequently changing rolls by applying a reduction to increase the inner width of the web. It is in.

[0011]

SUMMARY OF THE INVENTION According to the present invention, when manufacturing an H-section steel having a web and a flange, the material after rough shaping obtained by breakdown rolling is passed through a universal rolling mill to form a flange of the material. Make an angle of 100 with the web
Rough rolling is performed within the range of ~ 135 °, and then the web is rolled down along with the flange in the thickness direction by a universal rolling mill equipped with a horizontal roll having a roll width exceeding the inner width of the material web. This is a method for rolling an H-section steel characterized by increasing the width. In the present invention, the rolling for expanding the inner width of the web may be performed in any of a rough rolling stage and a finish rolling stage.

1 to 3 show a rolling procedure according to the present invention. In the drawings, reference numeral 1 denotes a material to be rolled, and 2 denotes a horizontal roll of a universal rolling mill (shown as a split type variable width roll). ), 3 is a vertical roll of a universal rolling mill. In order to manufacture an H-section steel according to the present invention, first, as shown in FIG.
The flange 1a is tilted so that the angle す between the web and the web 1b is 100 to 135 °. In a subsequent rough rolling or finish rolling, as shown in FIG. 2, the web 1b is rolled down together with the flange 1a in the thickness direction by a universal rolling mill having a horizontal roll having a roll width exceeding the web inner width L of the raw material 1. By doing so, the inner width of the web is enlarged to finish the H-section steel having a predetermined web height in the finish rolling stage.

[0013]

In the rolling in which the inner width of the web is enlarged in the middle of the rolling to change the web height, the relationship between each roll of the universal rolling mill and the rolled material is shown by taking a finishing universal rolling mill as an example. When the amount of expansion of the inner width of the web is too large, the flange 1a of the material 1 is formed.
The tip of the roll collides with the surface of the horizontal roll to prevent the material from entering the rolling mill, causing poor biting. In addition, even if the amount of expansion is not so large, the material 1 is left or right as shown in FIG. When entering the rolling mill in a displaced state, a similar biting failure is caused. Such a biting failure can also occur when rolling is not performed so as to increase the inner width of the web, but in particular, in a rolling method in which the area is actively reduced by rolling, the roll width of the horizontal roll is increased. So the danger is much greater.

[0014] The poor biting of such a material is caused by the material 1
It is clear that in the case of FIG. 6 where the web 1b at the front end is tongue-shaped and the width of the flange narrows toward the front end, the width of the horizontal roll is increased. Flange 1a
As shown in FIG. 7, it is conceivable that the roll is forcibly bitten by the horizontal roll, and if this occurs in actual operation, there is a risk that the roll may break and cause a serious accident.

In the present invention, the material after the rough shaping obtained by breakdown rolling is passed through a universal rolling mill so that the angle Θ between the flange of the material and the web is 100 to 135 °.
Rough rolling is performed so as to fall within the range of, and then the web of the material is reduced in the thickness direction by a universal rolling mill having a horizontal roll having a roll width exceeding the inner width of the web to reduce the inner width of the web. Because of the enlargement, the above-mentioned problems are extremely rare, and H-shaped steels of various sizes can be stably manufactured without requiring frequent replacement of rolls. Further, in the present invention, there is an advantage that the H-section steel having a constant web height can be rolled for a long time by adjusting the roll width and the roll interval of the rolling mill in accordance with the wear amount of the roll.

In the present invention, it is important that the flange 1a of the raw material 1 be reliably turned outward in the rough rolling step.
For that purpose, it is better to increase the angle Θ as shown in FIG. However, if this angle is too large, as shown in FIG.
Since the joint between the web 1a and the web 1b cannot be pushed outward, the flange 1a falls significantly outward (two layers), and if this area is caught by the horizontal roll, the horizontal roll may be seriously damaged. . For this reason, in the present invention, the angle Θ between the flange 1a and the web 1b is defined to be 100 to 135 °.

In order to perform the rolling at the above angle Θ, the roll shapes of the rolls (horizontal roll and vertical roll) incorporated in the universal rolling mill may be changed in advance.

FIGS. 10 and 11 show rolling mills suitable for rolling an H-beam. Rolling of an H-beam by such a rolling mill row is performed in the following manner.

First, when a rolling mill train as shown in FIG. 10 is used, a raw material is roughly formed by a breakdown rolling mill, and then a plurality of intermediate rolling mills for rough rolling are equipped with an edger rolling mill. Material 1 after rolling many times
The angle の between the flange 1a and the web 1b is 100 to 13
Keep within 5 °. Then, the web of the raw material 1 is reduced in the thickness direction by a finishing universal rolling mill provided with a horizontal roll having a roll width exceeding the inner width of the web of the raw material 1 so as to enlarge the inner width of the web. When a rolling mill row as shown in FIG. 11 is used, a horizontal roll capable of changing the roll width is arranged on a rolling mill installed on the exit side of the edger rolling mill, and the inner width of the web is set in the rough rolling stage. May be enlarged.

In the row of rolling mills as described above, the horizontal rolls of the finishing universal rolling mill may be any horizontal rolls as long as they become roll cylinders larger than the inner width of the web of the material subjected to rough rolling. In order to cope with the production of section steels, those in which the roll width can be changed are particularly advantageous.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A universal rolling mill (hereinafter, referred to as a first rolling mill) incorporating a horizontal roll having a taper at both ends of a roll, and a universal rolling mill having a horizontal roll whose roll width can be changed on an output side of the rolling mill ( In the following, a lead model was used as a raw material using a row of rolling mills (hereinafter referred to as a second rolling mill) (because, in actual rolling equipment, poor biting of a flange may cause a serious accident). Do
The occurrence of biting and falling of the flange (double rolling) at that time was investigated.

In the rolling using a lead model as a raw material, the angle between the web and the flange of the raw material in the first rolling mill of the above-mentioned rolling mill row is variously changed in the range of 5 ° to 160 °, and the web of the raw material is changed. 80 for all inner widths
mm, flange width 40 mm, web thickness 1.2 mm
And the flange thickness was rolled to 2.4 mm. Then, in the subsequent second rolling mill, the inner width of the web was changed to adjust the web height of the H-section steel, and the rolling was performed with the roll width of the horizontal roll changed variously. FIG. 12 shows the result.

In FIG. 12, ○ indicates a case where rolling was possible without any problem, △ indicates a case where a flange biting trouble occurred, and × indicates a case where a flange breaking problem occurred. Things.

FIG. 12 shows that the angle between the flange and the web Θ
If the angle is close to a right angle, the flange easily falls down to the web side, and the jamming of the flange tends to occur,
If the angle Θ is too large, the flange will fall out too much and the flange will be easily broken, but if the angle Θ is adjusted to the appropriate range, it will be confirmed that the flange will not be jammed or fall down at all. Was.

However, in the rolling of the H-section steel, the larger the amount of increase in the inner width of the web, the narrower the appropriate range of the angle Θ becomes. In rolling using this lead model, materials with various angles were produced by bending the flange, but in the actual rolling process, the angle Θ is determined by the taper angle of each roll of the rough rolling mill (intermediate universal rolling mill). Since it is impossible to change it easily, the angle あ ら か じ め
You need to know the proper range. In Fig. 12 above, the angle at which the trouble of breaking the flange can be avoided is Θ ≧
This is at 100 °, which indicates that it needs to be considerably larger than at the time of normal rolling (° = 95 ° in normal rolling). Further, when the amount of expansion of the inner width of the web is set to 10 mm or less, if the angle is set to Θ ≦ 135 °, it is apparent that trouble such as breakage of the flange does not occur. Here, the expansion amount of the inner width of the web of 10 mm is equivalent to the expansion of 60 mm in the actual machine size, and it is necessary to roll an H-beam of a constant outer size or to roll an H-beam of several sizes. This is a sufficient range.

[0026]

According to the present invention, in performing the rolling for freely expanding and changing the inner width of the web of the H-section steel without replacing the rolling roll, the flange of the material is engaged with the horizontal roll of the universal rolling mill. A stable operation can be realized without causing a serious accident that may be caused.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a rolling procedure according to the present invention.

FIG. 2 is an explanatory diagram of a rolling procedure according to the present invention.

FIG. 3 is an explanatory view of a rolling procedure according to the present invention.

FIG. 4 is a diagram showing a situation where a flange portion of a material is bitten by a horizontal roll of a universal rolling mill.

FIG. 5 is a diagram showing a state where a material is bitten into a rolling mill in a state where the material is shifted left and right.

FIG. 6 is a diagram showing a tip portion of a material.

FIG. 7 is a diagram showing a situation where a flange portion of a material is bitten by a horizontal roll.

FIG. 8 is a diagram showing a state in which a flange of a material has fallen;

FIG. 9 is a diagram showing a situation where a flange portion is folded and rolled.

FIG. 10 is a diagram showing a rolling mill train suitable for rolling an H-section steel.

FIG. 11 is a view showing another example of a rolling mill train suitable for rolling an H-section steel.

FIG. 12 is a graph showing the relationship between the amount of enlargement of the inner web width and the angle Θ.

FIG. 13 is a view showing a rolling state by a coarse universal rolling mill.

FIG. 14 is a diagram showing a rolling state by a finishing universal rolling mill.

[Explanation of symbols]

 1 Material 2 Horizontal roll 3 Vertical roll (A) Web thickness (A) Flange thickness (C) Flange width (D) Web inner width (E) Roll width (F) Web height 1'Material 2 'Horizontal roll 3 ′ Vertical roll

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B21B 1/08-1/14

Claims (2)

(57) [Claims] When manufacturing an H-section steel having a web and a flange, a raw material roughly formed by breakdown rolling is passed through a universal rolling mill to determine the angle between the flange of the material and the web.
Rough rolling is performed within the range of 100 to 135 °, and then rolling is performed by rolling down the web together with the flange in the thickness direction with a universal rolling mill equipped with horizontal rolls that have a roll width that exceeds the inner width of the material web. A method for rolling an H-section steel, wherein the inner width is increased. 2. The method according to claim 1, wherein the rolling for expanding the inner width of the web is performed in a rough rolling step or a finish rolling step.