JPH07314003A - Method for hot-rolling wide flange shape - Google Patents

Abstract

PURPOSE:To manufacture many sizes of wide flange shapes at the same timing of rolling. CONSTITUTION:Material is cut in length after break down rolling it and, using a group U of universal mills including universal mills U2, UF whose horizontal rolls are variable in width, respective cut materials are manufactured into plural wide flange shapes having different web height at the same rolling chance. In the final rolling mill UF, idle passes are executed to the final pass of finish rolling and the width of the horizontal rolls of the mills U2, UF is changed into the width corresponding to the product size. Then, division is executed by cutting the length of a rough shaped material in the middle of rolling, so the min. weight of the lot of manufacture is reduced and various sizes of the wide flange shapes are manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling method for H-section steel used as beams and columns of buildings.

[0002]

2. Description of the Related Art H-section steels are used as beams and columns of buildings, and the weight of steel materials used has been reduced with the increase in the height of buildings.

FIG. 6 is a view showing a cross section of an H-section steel, W
Is a web and F is a flange. The size of the H-section steel is represented by the cross-sectional dimensions of the web height a, the flange width b, the web thickness c, and the flange thickness d.

The shape of the H-section steel manufactured by hot rolling is restricted by the manufacturing equipment, and the web height a is set to 50 mm intervals (450 mm to 500 mm) in the JIS standard. 475 mm H-section steel is not manufactured.
When an H-section steel with a web height of 475 mm was absolutely necessary, a welded H-section steel in which the web and the flange were joined by welding was used. However, the welded H-section steel has a drawback that it is about 20% more expensive than the hot-rolled H-section steel.

FIG. 3 is a view showing a conventional rolling line for producing hot-rolled H-section steel with a universal rolling mill. B is a breakdown mill, C is a tongsaw, U1 is a universal rough rolling mill, E is a 2Hi edger rolling mill, and UF is a universal finishing mill.

FIG. 4 is a diagram showing a roll hole type of the breakdown mill. The rolls of the breakdown mill B are formed with a plurality of hole dies, and in this case, three hole dies (a, b, and c) are arranged on a pair of upper and lower rolls, and the material is reciprocally rolled by these hole dies. By doing so, reduction in the thickness direction of the web is mainly performed to form a dogbone-shaped rough material of H-section steel.

FIG. 5 is a view showing a conventional roll arrangement by a universal rolling mill, (a) shows a roll arrangement of a rough rolling mill, (b) shows a roll arrangement of an edger rolling mill, c) is a diagram showing the roll arrangement of the finish rolling mill.
1 is a horizontal roll, 2 is a vertical roll, 3 is an edger roll, 3'is a lower edger roll, and M is a rolled material.

As shown in FIG. 3, the heated rolled material M has three hole types (a, b, c) of the breakdown mill B.
(See FIG. 4), it is rolled into a dogbone-shaped crude H-shaped steel and sent to a universal rolling machine. As shown in FIG. 5 (a), the rough shape material is rolled down by the rough rolling mill U1 by the upper and lower horizontal rolls 1 and the left and right vertical rolls 2 in the web thickness direction of the H-section steel and the thickness direction of the flange, As shown in (b), the flange width is made constant with a 2Hi edger rolling mill E, and with the finishing rolling mill UF, the right angle between the flange and the web is formed as shown in (c). Height, flange width, web thickness and flange thickness).

[0009]

Since each horizontal roll of the conventional universal rolling mill is constituted by an integral roll (width is not variable) as shown in FIG. 5, the H of one kind of web height is used. Dedicated rolls are required for shaped steels (though different thicknesses are considered the same size). And it takes about 2 hours to prepare for roll change,
It is planned to roll as much as possible after one roll change. For example, web height 500
mm, flange width 200 mm, web thickness 10 mm and flange thickness 16 mm, H-section steel rolled for 2 hours will produce about 100 tons. If less than 100 tons, the mill will be stopped and operation will start. The rate will decrease. That is, a small lot,
Since rolling of multi-size H-section steel reduces the productivity of rolling mills, cross-sectional dimensions that are not in accordance with JIS standards have not been produced.

An object of the present invention is to provide a method for manufacturing multi-size H-section steels (including H-section steels having a cross-sectional dimension not in JIS standard) from the same material at the same rolling timing.

[0011]

The present inventor has found that
We have researched a manufacturing method that can reduce the number of roll reshuffling without lowering the mill's rolling ability even when rolling multi-size H-section steel, and when the length of the rolled material is cut, the width of the horizontal roll is variable. It was confirmed that the H-section steel in which the web height was changed to the interval of 25 mm could be obtained by applying the above method, and the present invention was completed.

The gist of the present invention resides in a method for manufacturing an H-section steel shown below (see FIGS. 1 and 2).

(1) Universal rolling mill (U2, U) with variable horizontal roll width after cutting the material after breaking rolling
A hot rolling method for producing a plurality of H-section steels having different web heights from each cut material at the same rolling chance using a universal rolling mill group U including F).

(2) 1 of the last stage of universal rolling mill group U
Horizontal edger roll (1 ') with variable roll width is used for the previous rolling mill U2, and shaped horizontal roll (1 ") with variable roll width is used for the final stage rolling mill (UF). However, the final rolling mill (UF) is an empty pass until the final pass of finish rolling, (U1)
In the final pass of finish rolling, horizontal rolls of the final two rolling mills (U2, UF) are performed by simultaneously reducing the web thickness and flange thickness and making the flange width constant in the rolling mill and (U2) rolling mill. The method for hot rolling H-section steel, in which the width of the H-section steel is adjusted to a width corresponding to the product size and the web height of the H-section steel is adjusted.

[0015]

1 is a view showing a hot rolling line for H-section steel for carrying out the method of the present invention.

[0016] B is a breakdown mill, C is a tongsaw, A is a heat-retaining furnace (or heat-retaining cover), U is a universal rolling mill group, and U1 is a universal rough rolling mill (hereinafter simply referred to as rough rolling mill). , U2 is a universal edger rolling mill (hereinafter simply referred to as edger rolling mill), UF is a universal finish rolling mill (hereinafter simply referred to as finish rolling mill), and M is a rolled material.

The rolled material M is subjected to a plurality of reciprocal rollings in a hole type as shown in FIG.
It is formed into a dogbone-shaped rough material, and then is subjected to multi-pass reciprocal rolling by the universal rolling mill group U to be finished into an H-shaped steel product. The one pass referred to here means that the material passes through the die of the breakdown mill or passes through the universal rolling mill group.

In the rolling method of the present invention, the rolled material M (bloom) is made into an H-shaped steel of a certain size (H-shaped steel in JIS standard).
Then, a dog-bone-shaped rough material suitable for the above is rolled by a breakdown mill B having a hole shape as shown in FIG. The obtained rough shaped material is used as an H-shaped steel of a specific size (H
The required weight of shaped steel) is used to cut the length with a tongue and cut saw C (intermediate crop cutting saw), and in some cases heat retention furnace A
Store in. In the past, because the product lot of small weight was handled in bloom condition, the length of the raw material was short and it could not be charged into the heating furnace.

FIG. 2 is a view showing the roll arrangement of the universal rolling mill group. FIG. 2 (a) is a view showing the arrangement of an integral fixed-width horizontal roll and vertical roll arranged on the rough rolling mill, and FIG.
FIG. 6 is a diagram showing the arrangement of edge-width horizontal rolls and vertical rolls arranged on the edger rolling mill, and FIG. 7 (c) is a diagram showing the arrangement of width-variable horizontal rolls and vertical rolls arranged on the finishing mill.

The horizontal roll 1 of the rough rolling mill is a roll having a fixed width and is the same as a conventional roll. Horizontal rolls 1 ', 1 "with variable width are used for the edger rolling mill and finish rolling mill, and the horizontal rolls 1'of the edger rolling mill are provided with steps so as to be rolled down in the width direction of the flange of the H-section steel. The variable-width horizontal rolls have a structure in which the upper or lower left and right horizontal rolls are supported by, for example, a spline shaft, and the distance between the rolls can be adjusted in a short time by hydraulic pressure or the like. It is possible to quickly reduce or increase the roll interval in the middle of.

Among the cut rough shape materials, the rough shape material which is not stored in the heat-retaining furnace is immediately sent to the universal rolling mill group U and is subjected to reciprocating rolling in a plurality of passes as described above.

In the method of the present invention, the finishing rolling mill UF is used as an empty pass and rolling is performed by the rough rolling mill U1 and the edger rolling mill U2 up to one pass before the final pass. The rolled material is reduced by the rough rolling mill U1 in the web thickness direction and the flange thickness direction of the H-section steel, and by the edger rolling mill U2 in the web thickness direction, the flange thickness direction, and the flange width direction. In the edger rolling of this edger rolling machine U2, the purpose is mainly to reduce the flange width, and the web thickness and the flange thickness are preferably lightly reduced or zero reduced (the same roll opening as the inlet side thickness). .

In the final pass, the widths of the horizontal rolls of the universal rolling mills U2 and UF are set to the product web size (JIS standard size), and the web height of the H-shaped steel material rolled by U1 is set. Is made uniform with U2 so as to become the dimension of the web height of the product, and is further shape-rolled with UF to produce H-section steel of the target size.

Next, the rough material cut and put in the heat-retaining furnace is rolled into an H-section steel of another size (for example, a size not in JIS standard). First, up to one pass before the final pass, the same rolling as the H-section steel of the above size (JIS standard size) is performed, and in the final pass, the roll width of U2 and UF is changed to the web height of the H-section steel of another size. Shrink or expand to the dimensions of
It is stabilized and shaped and rolled in the same manner as above. That is, the above H
It is possible to manufacture H-section steels having different web heights from section steels.

[0025]

EXAMPLES To carry out the method of the present invention, rolling equipment shown in FIG. 1 was used.

[Example 1] H-section steel according to JIS standards [web height 500 mm, flange width 200 mm, web thickness 10 mm, flange thickness 16 mm (hereinafter referred to as H500 x 200 x 10 x 16)] And H-section steel that does not meet JIS standards [web height 475 mm
, Flange width 200mm, web thickness 10mm, flange thickness 16m
m (hereinafter referred to as H475 × 200 × 10 × 16)] were produced at the same rolling chance.

As the rolled material, a continuously cast slab having a thickness of 300 mm, a width of 700 mm, a length of 5 m and a weight of 8 tons was used.

The breakdown mill is provided with hole types a, b, and c as shown in FIG. 4 as a hole type for rolling the H500 × 200 rough material. Using a breakdown mill, the pass schedule shown in Table 1 and a web thickness of 60
mm, a web height of 720 mm, and a length of 30 m were formed.
Roughly shaped material with a length of 30 m was cut into two with a length of 22 m and a length of 8 m with a tongs and cutsaw C, the 22 m material was immediately sent to the universal rolling mill group U, and the 8 m material was placed in a heat-retaining furnace on the traveling table. .

[0029]

[Table 1]

Immediately after that, the crude shaped material sent to the universal rolling mill group was rolled into H500 × 200 × 10 × 16 H-section steel. Figure 2
With the roll arrangement of the universal rolling mill group as shown in
Roll widths (e, e ') of the horizontal rolls were both set to 468 mm, and reciprocating rolling was performed according to the pass schedule shown in Table 2. That is, from the 1st pass to the 8th pass, the finish rolling mill UF is used as an empty pass, and the rough rolling mill U1 and the edger rolling mill U2 perform reduction in the web thickness direction, the flange thickness direction, and the flange width direction, and finally. On the 9th pass of the above, the roll width of the finishing mill is 468 mm, and it is H-rolled by H500 × 200 × 10 × 16.
Finished into shaped steel products.

[0031]

[Table 2]

Next, the rough material put in the heat-retaining furnace is treated with H475 ×
Rolled to 200 x 10 x 16 product. From the 1st pass before the final pass (1st pass to 8th pass), it is the same as the rolling pass of the rough material described above, and in the final pass (9th pass), the rolls of the edger rolling mill U2 and finish rolling mill UF Width (e ') 4
Reduced from 68mm to 443mm. And Edger rolling mill U2
The web height of the rolled material was reduced by, and it was shape-rolled by a finishing rolling mill UF and rolled to a predetermined H-section steel dimension.

The weight of the rolled product H-section steel was 8 tons, and the minimum weight of the production lot could be reduced to 2 tons.

[Embodiment 2] Similar to Embodiment 1, H-shaped steel (H500 × 200 × 10 × 16) in JIS standard and H not in JIS standard
Shaped steel (H510 × 200 × 10 × 16) was manufactured with the same rolling chance.

The rolling schedule up to the final pass of the breakdown mill and the universal rolling mill group is the same as in Example 1, and is the same as shown in Tables 1 and 2.

After the break mill rolling, the 30 m rough shaped material is cut into two pieces each having a length of 15 m, and the preceding material is immediately sent to the universal rolling mill group, and the rolling widths of all the rolling mills U1, U2 and UF are adjusted. H500 × 200 without changing to the final pass
A × 10 × 16 H-section steel was produced.

Next, the following material is sent to the group of universal rolling mills, and until the pass before the final pass, the above H500 × 200 ×
Rolled with the same pass schedule as when manufacturing 10 × 16 H-section steel, and in the final 9th pass, edger rolling mill
Horizontal roll width of U2 and finish rolling mill UF from 468mm to 478m
Expand the web height of the material rolled by the edger rolling mill U2 by the rough rolling mill U1 by 10 mm and set the flange width and flange thickness to the target values, and then finish mill UF.
It was finished in H510 × 200 × 10 × 16 H-section steel.

The method of the present invention uses a universal rolling mill group in which an edger rolling mill and a finishing rolling mill, each of which has a horizontal roll whose width can be changed by cutting the length of the rolled material during rolling, are arranged. Since the same rolling is performed up to the rolling pass and the width of the horizontal roll is changed in the final rolling pass, it is possible to manufacture H-section steels of different sizes in small lots.

In the final pass of the universal rolling mill group, the horizontal roll width of the edger rolling mill U2 and the horizontal roll width of the finishing rolling mill UF were expanded from 468 mm to 478 mm.

[0040]

According to the hot rolling method for H-section steel of the present invention, since the length of the crude material in the middle of rolling is cut and divided, the minimum weight of the production lot can be reduced (about 2 tons). As a result, H-shaped steels of various sizes can be manufactured at the same rolling chance.

[Brief description of drawings]

FIG. 1 is a diagram showing a hot rolling line for H-section steel for carrying out the method of the present invention.

FIG. 2 is a view showing a roll arrangement of a universal rolling mill group for carrying out the method of the present invention.

FIG. 3 is a view showing a hot rolling line for producing a conventional H-section steel.

FIG. 4 is a view showing a hole die arranged in a breakdown mill.

FIG. 5 is a view showing a roll arrangement of a universal rolling mill group for producing a conventional H-section steel.

FIG. 6 is a view showing a cross-sectional shape of H-section steel.

[Explanation of symbols]

A. Heat insulation furnace B. Breakdown mill
C. Tong cut and sewn U. Universal rolling mill group
U1. Rough rolling mill U2. Edger rolling mill UF. Finish rolling machine
M. Rolled material W. Web F. Flange
a. Web height b. Flange width c. Web thickness
d. Flange thickness e. Horizontal roll width 1. Horizontal roll
2. Vertical roll 3. Upper edger roll 3 '. Lower edger roll

Claims (2)

[Claims] 1. A method for producing H-section steel by hot rolling, comprising: a universal rolling mill group including a universal rolling mill having horizontal rolls with variable roll widths, which is obtained by breaking down a material and then cutting the length thereof. A method for hot rolling H-section steel, wherein a plurality of H-section steels having different web heights are produced from each of the cut materials at the same rolling chance. 2. A horizontal edger roll having a variable roll width is used for the rolling mill immediately before the final stage of the universal rolling mill group, and a shaped horizontal roll having a variable roll width for the final rolling mill. The final rolling mill uses an empty path until the final pass of finish rolling, and in the final pass of finish rolling,
The hot rolling of the H-section steel according to claim 1, wherein the width of the horizontal rolls of the last two rolling mills is changed to a width corresponding to the product size to adjust the web height of the H-section steel. Rolling method.