JPS6141641B2 - - Google Patents

Description

Detailed Description of the Invention The present invention involves the rolling of H-beam steel by a universal mill. The present invention relates to a method of rolling H-section steel to obtain a product H-section steel having a flange.

As is well known, H-beam steel is made of a material steel piece 1 or 1', such as a bloom shown in a perspective view in FIG. 1 or a beam blank shown in a perspective view in FIG. 2, and an example of the layout shown in FIG. After heating to 1150°C to 1300°C in the heating furnaces 2 and 2' in the rolling line shown in , the rough rolling mill 3, the rough universal mill 4 and the edge mill 5, the rough universal mill 4' and the edge mill 5', and the finishing process are performed. It is rolled and formed through a universal mill 6.

Although the rough universal mill 4 may have only one stage, it usually has two or more stages.

In the rough rolling mill 3, the raw steel piece 1 or 1' is formed into a rough H-beam 7, an example of which is shown in a perspective view in FIG. The rough _H -section steel usually has a flange width B ₂ smaller than the flange width B 1 of the beam blank 1'.

The rough H-shaped steel 7 is processed in the next step, the rough universal mill 4, as shown in FIG. 5 with some parts omitted.
The web 1 is rolled down by a pair of upper and lower horizontal rolls 8, 8 and a pair of left and right vertical rolls 9, 9 to form flanges 10A, 10A of a predetermined width and a web 1 of a predetermined thickness.
It is formed into a semi-formed H-section steel 10 with 0B. In this case, the vertical roll 9 generally has a maximum diameter at the center of the body length (length in the axial direction), and tapers at both upper and lower sides with a sweepback angle θ of 3 to 10 degrees. _W1 is the width of the flange 10A of the semi-formed H section steel 10
It is designed so that it is no smaller than B ₃ .

The semi-formed H-beam 10 has a flange 1 as described above.
After 0A, 10A and web 10B are formed,
In an edge mill 5 (see FIG. 3) consisting of a pair of upper and lower edge rolling rolls 11, 11 partially omitted in FIG. 6, the flanges 10A, 10
The tip of A is shaped to become a semi-formed H-beam 10' with a flange width of _B4 .

The semi-formed H-beam 10' that has passed through Etsugi Mill 5 is
As shown in FIG. 7, a pair of upper and lower horizontal rolls 12,1
The finished product is sent to a finishing universal mill 6 consisting of 2 and vertical rolls 13, 13, and becomes a finished product H-beam 14. Product H-beam 14 flange width B ₅
is determined by the flange width B ₂ of the rough H-section steel 7 and the balance between the subsequent rolling reduction ratio of the flange and web.

That is, coarse universal mill 4, Etsuya mill 5
By performing rolling reduction using a series of universal mills, the flange thickness t _F changes to t _F ' from the state shown in FIG. 8 to the state shown in FIG. 9, and the web thickness t _W
When changes to t _W ', the change from flange width B to B' is as follows: If the rolling reduction of the flange becomes larger than the rolling reduction of the web, the flange width B' becomes larger,
In the opposite case, the flange width B' will become smaller.

Furthermore, it is known that the change in flange width due to the difference in rolling balance between the web and the flange is also related to the ratio between the height H of the web of the material to be rolled and the flange width B. In other words, the larger the value of H/B,
The flange width fluctuation due to the difference in balance between the web and the flange becomes large, and if the value of H/B is small, the flange width fluctuation due to the difference in rolling balance becomes small.

Assume now that the product H-section steel 14 shown in FIG. 10 is stably manufactured from the rough H-section steel 7 shown in FIG. 4 through rolling with a universal mill. If the flange width of this product H-beam 14 is B ₅
According to the conventional method, first, when rolling down the rough H-shaped steel 7 shown in FIG. 4 in the rough universal mill 4, the rough universal The distance between the horizontal rolls 8, 8 in the mill 4 is narrowed by the required dimension, and the distance between the vertical rolls 9, 9 is as follows:
Leave as usual.

As a result, the semi-formed H-beam 10 becomes the web 10
B becomes thinner than in the conventional semi-formed H-section steel, and only the width _B3 increases with almost no change in the thickness of the flange 10A.

At this stage, the half-formed H with increased flange width _B3
The tip of the shaped steel 10 is shaped in the next process, the edge mill 5, and the width dimension is determined (of course, the edge rolling roll 1 in the conventional edge mill 5 is used).
1 and 11, the edge shaping portion 11A,
11A), and then a finishing universal mill 6 is used to flatten the flange and make the desired product H-beam 14 with a larger flange width.

However, even if the flange width is increased in this way, when rolling with the rough universal mill 4, the amount of increase in the flange width will be small if the H/B is small and the rolling reduction balance is slightly changed. However, although it is possible to increase the flange width by increasing the flange reduction rate to a certain level or more than the web reduction rate, the web, on which a large tensile force acts, becomes extremely thin, and the horizontal roll There is a risk that the material may pass through without coming into contact with the material. In particular, if a large tensile force is applied, web breakage may occur.

Therefore, in the past, a dedicated rough H-beam was required for each rolling series, and if the web height and flange ratio changed, the size and shape of all the rough H-beams had to be changed. Ta.

Based on the above-mentioned viewpoint, this invention makes it possible to increase only the flange width by using rough H-shaped steel rolled into the same shape from the same material steel piece within a certain range in each rolling series. This method provides a rolling method for H-beam steel, in which the tip of the flange is formed thickly in the rolling process using a rough universal mill, and the thickness of the tip of the thickened flange is equal to the thickness of the flange base. The feature is that the flange width is increased by rolling down the flange so that the width of the flange is increased.

Next, embodiments of the method of the present invention will be described with reference to the drawings.

FIG. 11 shows a front view of the vertical roll 15 of a rough universal mill used in carrying out the method of the invention, and FIG. 12 shows a plan view.

Like the conventional vertical roll 9, the vertical roll 15 has the maximum diameter at the center of the body length (length in the axial direction), and is tapered at a predetermined receding angle θ3 to 10° on both upper and lower sides. However, both ends of the body 15A, which is shorter than the length of the flange 10A of the semi-formed H-beam 10 to be rolled in a rough universal mill, are connected to a stepped portion 15B,
15B, and the end portions beyond the stepped portions 15B, 15B are formed into small diameter portions 15C, 15C.

The length W ₂ of the body portion 15A is determined to be around 250 mm, for example, assuming that the flange width B ₂ of the rough H-shaped steel 7 shown in FIG.
C is designed so that the diameter difference between the stepped portions 15B and 15B is approximately 60 mm.

FIG. 13 is a front view showing the rolling state of a material to be rolled by a rough universal mill 4' comprising the vertical rolls 15, 15 and conventional horizontal rolls 8, 8.

The semi-formed H-section steel 10 obtained by rolling in this rough universal mill 4' has flanges 10A,
The tips 10C of the flanges 10A and 10A are thick, respectively, and intersect with the web 10B.
The tip portion 10C is thicker by, for example, 30 mm than the base portion A.

From this state, as the next step, the tips 10C of the flanges 10A, 10A are processed using a rough universal mill 4 consisting of vertical rolls 9, 9 and horizontal rolls 8, 8 as in the past, without reducing the thickness of the web 10B. Roll down the chisel until it is the same thickness as the base.

As a result, the widths of the flanges 10A, 10A are greatly expanded, but since rolling is performed only at the tips of the flanges, compression occurs in the flanges 10A, 10A in the direction of the flange base, and the web 10B
Although compressive force may be applied to the web, no tensile force is generated at all, so there is no phenomenon in which the web 10B becomes thin and passes through between the horizontal rolls 8, 8, or becomes too thin and breaks. .

Thereafter, the semi-formed H-section steel 10 is rolled by an edge mill and a finishing universal mill to become a product H-section steel, which is the same as in the conventional method. In addition, the tip part 1
Although the 0C reduction may be performed at the same time as the flange rolling in the finishing universal mill 6, in that case, there is a limit to the amount of flange widening.

Flange 10A having the thick tip portion 10C
The warp roll 15 used for rolling may be a warp roll 16 shown in a front view in FIG. 14 and in a plan view in FIG. 15.

A roughing universal mill 4'' using vertical rolls 16 is shown in FIG.

As shown in the figure, the vertical roll 16 is a conventional vertical roll formed to have the same length as the body 15A of the vertical roll 15 described above, and is a 16th vertical roll.
As shown in the figure, a flange 1 of a semi-formed H-beam 10
The same applies to the vertical roll 15 in that the tip portions 10C and 10C of 0A and 10A can be formed thick.

Next, FIG. 17, which shows changes in the shape of the rolled material in each step of the conventional method, and FIG. 18, which shows the changes in the shape of the rolled material in each step of the method of the present invention, will be compared and explained. do.

The raw steel pieces 1' and 1' shown in Fig. 17a and Fig. 18a, respectively, are beam blanks having the same shape and size, and both have a width _B1 of the flange 1'A.
The thickness t _W1 of the web 1'B is 120 mm, and the thickness t _F1 of the flange 1'A is 105 mm.

The rough H-section steels 7, 7 shown in FIGS. 17b and 18b, which are obtained by finishing the raw steel pieces 1', 1' with rough rolling rolls, respectively, have the same shape and size, and
In both cases, the width _B2 of flange 7A is 380 mm, and the web 7
Thickness t _W7 of B is 50 mm, thickness t _F7 of flange 7A is
It is 95mm.

Next, as shown in Figures 17C and 18C,
Regarding the semi-formed H-section steel 10 obtained by rolling the rough H-section steels 7, 7 in a rough universal mill,
There is a big difference between the conventional method and the method of the present invention.

That is, according to the conventional method, the semi-formed H-beam 10
The flange 10A has a uniform thickness throughout from the base to the tip, but according to the method of the present invention, the flange 10A has a thickness equal to the thickness of the thick tip part of the tip 10C and the thickness of the flange base. The difference Δt is approximately
The flange width _B3 is the same although the thickness is mixed by 30mm.

Following the step in FIG. 17C, there is an edge shaping step using an edge mill, followed by flange shaping rolling using a finishing universal mill to obtain the product H-section steel 14 shown in FIG. 17d. In this case, the product H-beam 14 has a width _B5 of the flange 14A.
380-390mm, thickness t _W14 of web 14B is 13mm,
The thickness t _F14 of flange 14A was 21 mm.

On the other hand, following the process shown in FIG. 18C, the tip part 10C is rolled at the same height as the base part by a rough universal mill, the edge shaping rolling is performed by an edge mill, and the flanges 14A, 14A are flattened by a finishing universal mill. By rolling, a product H-shaped steel 14 shown in FIG. 18d is obtained. In this case, the width _B5 of the flange 14A is 400~
The thickness t _W14 of the web 14B was 13 mm, and the thickness t _F14 of the flange 14B was 21 mm.

In the semi-formed _H -section steel 10 shown in FIG.
The width ₃ ' excluding 0C and 10C is preferably 1/ _5B3 < _B3 '< _B3 . That is, if the width B ₃ ' of the flange 10A excluding the thick end portions 10C, 10C is less than 1/5 of the width B ₃ of the flange 10A, the effects of the present invention cannot be fully expected.

In addition, the difference Δt between the thickness of the thick end portion of the flange 10A and the thickness of the flange base is determined in relation to the thickness t _F1 of the intermediate portion of the flange 1'A of the rough H-shaped steel 7 shown in FIG. 18a. , Δt<0.9×t _F1
It is preferable that Set the upper limit of Δt to 0.9×t _F1
This is because it is impossible to form a thickness difference greater than the flange thickness of the rough H-shaped steel.

As is clear from the above explanation, according to the method of the present invention, the product H For shaped steel, the flange width is
It can be expanded by 20 to 30 mm compared to the conventional model, and the thickness of both the web and flange can be kept the same as before. In particular, for each series, a rough H-beam steel is prepared specifically for that series. Excellent effects can be obtained that help achieve rationalization of production, such as no need.

[Brief explanation of the drawing]

Figures 1 and 2 are perspective views showing examples of raw steel slabs, Figure 3 is a schematic diagram of a rolling line, Figure 4 is a perspective view of a rough H-beam, and Figure 5 is a conventional rough H-beam. FIG. 6 is a front view showing rolling in the universal mill, FIG. 7 is a front view showing rolling in the finishing universal mill, and FIGS. 8, 9, and 10 are the roughing universal mill. Fig. 11 is a front view of the vertical roll for the first stage of the rough universal mill used to carry out the method of the present invention; 13 is a plan view, FIG. 13 is a front view showing the rolling state of the roughing universal mill equipped with the vertical rolls of FIGS. 11 and 12, and FIG. A front view of the vertical roll for the first stage of the universal mill, FIG. 15 is a plan view, and FIG. 16 is a front view showing the rolling state in the rough universal mill equipped with the vertical rolls of FIGS. 14 and 15.
Figures 17a, b, c, and d are front views showing changes in the shape of the rolled material in each rolling process of the conventional method, and Figures 18a, b, c, and d are front views showing changes in the shape of the rolled material in each rolling process of the method of the present invention. FIG. 3 is a front view showing a change in shape of a rolled material with some steps removed. In the drawings, 1,1'...Material steel piece, 1'A...Flange,
1'B...Web, 2,2'...Heating furnace, 3...Roughing mill, 4,4',4''...Roughing universal mill,
5... Etsugi mill, 6... Finishing universal mill, 7... Rough H-shaped steel, 7A... Flange, 7B
...Web, 8...Horizontal roll, 9...Vertical roll, 10, 10'...Semi-formed H-shaped steel, 10A...
Flange, 10B... web, 11... rolling roll, 12... horizontal roll, 13... vertical roll,
14...Product H-shaped steel, 14A...Flange, 14
B...Web, 15...Vertical roll, 15A...
Body part, 15B...Step part, 15C...Small diameter part, 16
...Vertical roll, B, B', B ₁ , B ₂ , B ₃ , B ₄ , B ₅
...Flange width, t ₁ , t _W , t _W ′, t _W1 , t _W7 ,
t _W14 ...Thickness of the web, t ₂ , t _F , t _F ′, t _F1 ,
t _F7 , t _F14 ... Thickness of flange, W ₁ , W ₂ ... Length of trunk, H ... Height of web.

Claims (1)

[Claims] 1 In the rolling process using a rough universal mill, the flange tip is formed into a thick wall, and then rolled down so that the thickness of the thickened flange tip is equal to the thickness of the flange base, thereby increasing the flange width. A method for rolling H-section steel, characterized in that: