JP2508873B2 - Method for hot rolling profile with flange - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hot rolling method for a profile having a flange represented by H-section steel or channel steel used in the fields of construction, civil engineering and the like. Is.

(Prior Art) Most shaped steels having a parallel flange portion such as H-shaped steel and parallel flange grooved steel are conventionally manufactured by rolling, and the names of the parts of these parallel flange shaped steels are as follows:
22. FIGS. 22 (a) and 22 (b) will be described by taking H-section steel and parallel flange channel steel as typical examples thereof.

As shown in the figure, the flange portions 10 and 10 which are parallel to each other are connected and integrated by a coupling portion 12 therebetween. In the case of the H-shaped steel shown in FIG. 22 (a), the joint portion 12 comes to the center of the flange portion 10, and in the case of the channel steel shown in FIG. 22 (b), it comes to one end of the flange portion 10. This joint 12 is also referred to as a web 14 for H-section steel and flange channel steel. The length of each flange 10 is called the flange width (L ₀ ), and the distance between the parallel flanges is the web height (web height, L ₀ ).
H ₀ ), and the flange internal method (S ₀ ) and web internal width (W ₀ ) as shown. According to the JIS standard, in the case of H-section steel, about 33 sizes are specified in the range of 100 to 900 mm in web height (H ₀ ) at intervals of 25 to 100 mm.

However, for example, in the case of H-section steel, the conventional rolling method has the following problems.

That is, the conventional H-section steel rolling method is the same as in the case of channel steel, but as shown in FIG. 23, it is a universal rolling consisting of rough rolling by a breakdown mill 20, universal rough mill 22 and edger mill 24 of 2Hi. It has been carried out by intermediate rolling by the rough mill group 26 and finish rolling by the universal finishing mill 28.

In rough rolling, heated materials such as steel ingots and continuously cast slabs are processed by a double reversible rough rolling machine called Breakdown Mill 20.
Roll forming with a 2Hi hole die to shape a beam blank,
Use as a molding material.

In the intermediate rolling to be performed next, first, the shaping material is rolled in a mill group consisting of the universal rough mill 22 and the double type edger mill 24 to obtain an intermediate rolled H-section steel. That is, first, as shown in the schematic side view of FIG. 24, the web thickness of the intermediate rolling H-section steel 31 is reduced by the horizontal roll 30 in the universal rough mill 22, and by the side face of the horizontal roll 30 and the vertical roll 32. The thickness of the flange is reduced, and the above-described shaping material is stretch-rolled into an intermediate rolled H-section steel in multiple passes. Then, as shown in the schematic side view in FIG. 25, the flange tip of the intermediate rolled H-section steel 31 is pressed down by the hole-shaped roll 42 of the edger mill 24 in each pass in this intermediate rolling step, and the flange width (L ₀ ) Is a predetermined value.

In the finish rolling, as shown in FIG. 26, the horizontal roll 52 and the vertical roll 54 of the universal finishing mill 28
As in the case of the universal rough mill 22, the thickness of the web 56 and the flange 58 is reduced, the outer surface of the flange is flattened, and the angle between the flange 58 and the web 56 is a right angle.

As described above, in the conventional rolling method, even in the finish rolling, the inner surface of the flange 58 is the side surface of the horizontal roll 52 and the outer surface of the flange 58 is the vertical roll 54 as in the universal rough mill of the intermediate rolling. It is down. Of course, the web pressure is also reduced by the horizontal roll 52.
Therefore, the inner width (W ₀ ) of the rolled H-section steel is
Determined by the width of the horizontal roll 52 of the universal finishing mill.

Therefore, the following problems occur in the conventional H-section steel rolling method.

(1) FIG. 27 illustrates changes in cross-sectional shape in one series of H-section steels (for example, H600 × 200) having the same flange width (L ₀ ). According to the current standard, in the same series, the inner web width (W ₀ ) is constant, so the flange thickness (tf
₀ , tf ₁ , tf ₂ ) are different from each other, and for each size, the outer dimension of the web height (H ₀ ) (H _{0 in} FIG. 27, H ₀ ,
H ₁ and H ₂ ) also have different values. That is, tf ₀ <t
f ₁ <tf ₂ and H ₀ <H ₁ <H ₂ .

This relationship also applies to the channel steel shown in FIG. 28.

(2) When rolling shaped steels with different web inner widths (W ₀ ), the horizontal rolls of the universal finishing mill must be replaced as a matter of course. For example, there are 33 series of JIS standard and 14 series of H section steel according to ASTM standard. When manufacturing all these H section steels, it is necessary to have at least two sets of 47 types of horizontal rolls. The roll cost required for this is several hundred million yen even at the current price, and in order to keep this at all times, a large space comparable to the building for rolling is required, so a large investment is required in the roll shop building.

(3) 2000 tons / rolling chance of one series of H-section steel with horizontal rolls of the same universal finishing mill × 3
Rolling = 6000 tons only. This is because the width of the horizontal roll wears about 1 mm per 1000 tons, and the working width of the roll is 6 mm even if the tolerance is effectively used. Therefore 1
The horizontal roll that can no longer be used in one series,
The width is cut by several tens of millimeters and it is reworked for the next series with a small web height. Therefore, the amount of product rolled per roll is significantly smaller than that in the case of steel plate rolls. In other words, the roll cost per ton of product is high. (4) If the web height (H ₀ ) is out of the standard, it is naturally necessary to prepare a horizontal roll for a dedicated universal finishing mill and change the roll, so it is economically profitable for small lot orders. In many cases, he declines orders.

In particular, in recent years, it has become common to combine flange-shaped members into a box member, and many specifications have been made where the height of the web is constant and the inner width of the web can be freely changed. Cannot handle.

Therefore, the present applicant has developed the technique disclosed in Japanese Patent Application No. 63-235388 as a means for solving the above-mentioned problems associated with the conventional method of rolling a profile having a flange.
This is a rolling method of a profile having a flange which is subjected to breakdown rolling, intermediate rolling, and finish rolling as shown in FIG. 23, and its characteristic is that the rolling material is first roughly rolled by breakdown rolling, Then, rolling of the flange portion and the joint portion of both flange portions is completed by intermediate rolling (coarse universal rolling), and in finish rolling, a universal mill as shown in FIG. The point is to finish the width dimension of the joint between both flange parts by pressing down the outer surface of the flange part with a hard roll (vertical roll) without contacting the side surface of the roll.

Furthermore, the applicant has applied a universal mill having a variable width two-division horizontal roll as shown in FIG. 2 to a rolling line as shown in FIGS. In Japanese Patent Application No. 1-149851, a method of reducing the height of the web by performing reverse rolling in one pass or in multiple passes was proposed. Furthermore, in Japanese Patent Application No. 1-149851, as shown in FIGS. 4 (a) and 4 (b), a finishing universal mill (UF1) consisting of fixed-width horizontal rolls and a finishing universal mill consisting of variable-width horizontal rolls ( We proposed a method of performing web height reduction rolling using two finishing universal mills (UF2).

According to these inventions, it is possible to make the outside dimension of the web height of a profile having a flange such as a parallel flange section steel of the same series in one type of roll uniform, and to reduce the horizontal roll width of the rough universal rolling mill. It is possible to manufacture H-section steel and channel steel with a free web height from the same roll with the same rolling chance without being restricted by the above, and it is possible to significantly reduce the number of rolls possessed and significantly improve the roll unit consumption.

(Problems to be Solved by the Invention) Regarding these rolling methods of a profile having a flange proposed by the present applicant, the present inventor repeatedly carried out enormous model mill experiments and clarified the following problems. I chose

When manufacturing an H-section steel by the method of rolling a profile having a flange proposed by the applicant, the deviation of the web center of the product as shown in FIG. 5 becomes a problem depending on the reduction amount of the web height. . In the illustrated example, the center deviation amount S is S = (ab)
Expressed as / 2.

That is, when the amount of reduction in the height of the web exceeds a certain range, the deviation of the center of the web rapidly increases, and the product does not satisfy the predetermined tolerance. In JIS G 3192, the allowable range of center deviation is ± 3.0 mm for webs with a height of 300 mm or less,
It is specified as ± 4.5 mm for web heights over 300 mm.

Furthermore, when the manufacturing conditions when the deviation of the center of the web exceeds the allowable range as described above, the shape of the fillet part of the material in the process of reducing the web height (in addition to the reduction amount of the web height) is examined. For example, the R dimension) has a great influence on the rolling pass schedule and roll shape design.

Here, the object of the present invention is to manufacture a profile having a flange represented by a plurality of series H-section steels and parallel flange groove section steels in the same universal finishing mill, with the web inner width dimension being freely changeable. In the case of manufacturing a profile with a flange with a constant outer dimension of the web height for different sizes of flange thickness using the same horizontal roll of the universal finishing mill, the deviation of the web center of the product is It is an object of the present invention to provide a hot rolling method for a profile having a flange, which makes it possible to keep it at a small level so as not to miss the tolerance.

(Means for Solving the Problem) Thus, the present inventor has conducted various studies and has obtained the following knowledge through enormous rolling experiments in order to solve the technical problems.

(1) Using the universal mill 86 as shown in FIG. 1, the outer surface of the flange portion is reduced by the vertical roll 84 without contacting the inner surface of the flange portion with the side surface of the universal horizontal roll 82, thereby reducing the web height. Rolling,
When the reduction amount of the web height is gradually increased from the state shown in FIG. 6 (a), FIG. 6 (b) to FIG. 6 (c).
As shown in the schematic sectional view of Fig. 6, the web portion begins to buckle between the side surface of the horizontal roll and the vertical roll, and eventually the web portion largely buckles and a constriction occurs (Fig. 6 (c)).

(2) When the web height reduction rolling is performed according to the technique disclosed in Japanese Patent Application No. 63-235388 shown in FIG. 1 and then the shaping rolling is performed by a variable width universal shaping mill as shown in FIG. 2, or When the web height is further reduced in one pass or a plurality of passes by the variable width universal mill 90 as shown in FIG. 2 disclosed in Japanese Patent Application No. 1-149851, the product shown in FIG. Regarding the rolling process in the state shown in Fig. 6 (b), the rolling condition of the final pass of the variable width universal mill (or shaping mill) is good as shown in Fig. 7 (a) with small deviation of the web center. Finished products with various dimensions and shapes.

However, in the case where the above-mentioned constriction occurs in the web portion as shown in FIG. 6 (c), the subsequent rolling process does not reduce the web height, and the purpose is to correct the flange angle and flatten the web. Even in the process of shaping and rolling, the product is finished with a large deviation of the center of the web as shown in FIG. 7 (b).

That is, even if the web center is deviated due to a slight buckling in the unrolled portion of the web surface during the process of reducing the height of the web as shown in FIG. 6 (b), the subsequent shaping rolling or the reduction of the height of the web is performed. In the process (however, a slight reduction), the fillet portion of the material is clamped by the outer peripheral edges of the upper and lower horizontal roll side faces and rolled to be straightened. On the other hand, in the case where the unrolled portion of the web surface has a constriction as shown in FIG. 6 (c) in the process of reducing the height of the web, in the subsequent shaping and rolling, the material near the fillet portion is horizontally rolled up and down. Even if it is sandwiched by the outer peripheral edges of the side faces and rolled, the constriction is not corrected, and the deviation in the center of the web remains. In addition, it was found that the necked portion may be broken and remain on the product in some cases.

(3) The facts of (1) and (2) above are based on Japanese Patent Application No. 63-23.
The horizontal roll 82 of the universal mill of FIG. 1 disclosed in No. 5388 is divided into two to make a variable width roll, and the vertical roll 84 is used to reduce the web height so that the inner face of the flange does not contact the side face of the horizontal roll. It turns out that it holds even if there is.

(4) Furthermore, the facts of (1) and (2) are as follows:
1 in universal mill with variable width as disclosed in No. 149851
It has been found that the same applies to the case where the web height is reduced by reverse rolling of multiple passes or multiple passes. That is, in this case, it is characterized in that the outer surface of the flange portion is rolled down by a vertical roll so that the inner surface of the flange portion contacts the side surface of the universal horizontal roll, and the web height is reduced and rolled. Depending on the shape (for example, R dimension) or the shape of the outer peripheral edge of the side surface of the horizontal roll (for example, r dimension), when the amount of reduction in the height of the web is increased, the constriction generated near the fillet during rolling is sandwiched by the upper and lower horizontal rolls Then, it was found that even if rolled, the correction could not be completed and the web might be finished with a deviation in the center of the web.

(5) Based on the above findings, the present inventor further clarified the following facts by repeating enormous experiments for the purpose of suppressing the deviation of the web center in the reduction rolling of the web height. . That is, the present inventor conducted a rolling experiment using a universal mill as shown in FIG. 1 to reduce the web height of H-section steel. Material H-section steel (H200 x
Reduction of the web height (reduction amount: 18 mm) by variously changing the shape (for example, R dimension) of the fillet part of 100 × 6/12)
We conducted a survey on the occurrence of web center deviation after the above.

Fig. 8 summarizes the results of this model experiment, where the horizontal axis indicates the projected contact length between the web surface and the universal horizontal roll.
The difference between l _dw and the projected contact length l _df between the outer surface of the flange and the universal vertical roll is taken, and the vertical axis indicates the deviation of the web center. Are shown. From this, it was found that in the region where the difference between l _dw and l _df is a positive value of 0 or more, that is, the region satisfying the relationship of l _dw ≧ l _df , the web center deviation is extremely small.

(6) Furthermore, the relationship shown in FIG. 8 is not limited to the case where the height of the web is reduced by pressing down the outer surface of the flange with a vertical roll until the inner surface of the flange contacts the side surface of the universal horizontal roll. The same holds true for the case where the web height is reduced without contacting the side of the horizontal roll.When the web height is reduced by the vertical roll, the web face near the fillet is clamped by the horizontal roll. This is intended to suppress the deviation of the center of the web due to the buckling of the web surface during the web rolling process.

Further, in view of the above facts, the present invention provides the above (5),
As shown in FIG. 9, in the region satisfying the relationship l _dw ≧ l _df described in (6), among the shapes of the fillet portion of the H-shaped steel of the material, the angle θ between the straight portion of the fillet portion and the web surface is θ. , An arc radius R ₁ of the connecting portion between the fillet portion and the inner surface of the flange,
A large number of rolling experiments were conducted to reduce the height of the web by varying the arc radius R ₂ of the joint between the fillet portion and the web surface, and the following new facts were found.

That is, the present inventor conducted a rolling experiment using a universal mill as shown in FIG. 1 to reduce the web height of the H-section steel. At that time, the H-section steel (H200 ×
The shape of the fillet portion of 100 × 6/12) was changed to various shapes as described above, and the occurrence of web center deviation after reduction rolling of the web height (reduction amount 18 mm) was investigated.

Fig. 10 summarizes the results of this model experiment. The horizontal axis is the angle θ between the straight part of the fillet of the rolled material and the web surface, and the building axis is the deviation of the web center. Are shown.

From this, in the range of 10 ° ≤ θ ≤ 60 °, the web center deviation is relatively low and stable rolling is possible, while in the range of θ> 60 ° and θ <10 °, the web center deviation amount | S
It was found that | increased sharply and the web height reduction rolling condition became unstable.

Regarding the arc R ₁ of the joining portion between the straight portion of the fillet portion of the rolled material and the inner surface of the flange and the arc R ₂ of the joining portion between the straight portion of the fillet portion and the web surface, r of the outer peripheral edge of the horizontal roll of the universal mill is used. It has been found that if the value is not larger than the dimension, the joint remains as a linear flaw in the product after the web height reduction rolling liquid.

Here, the gist of the present invention is a method of hot rolling a profile having a flange that is subjected to breakdown rolling, rough universal rolling, edger rolling and finish rolling, in which the material to be rolled after edger rolling is When rolling with a finishing universal mill having a fixed width horizontal roll, the outer surface of the flange is pressed down by a vertical roll without contacting the inner surface of the flange with the side surface of the horizontal roll of the finishing universal mill. In the method of performing the web height reduction rolling, or the horizontal roll width of the finishing universal mill for finishing rolling the material to be rolled after the edger rolling is divided into two to have a structure in which the width can be adjusted online. Reduce web height by rolling in multiple passes or reverse rolling in multiple passes A method of performing a hot rolling method of profiles having flanges, characterized by molding the finish rolling earlier fillet shape of the rolled material so as to satisfy the following relationship.

ld _w ≧ ld _f and 10 ° ≦ θ ≦ 60 ° and R ₁ ≧ r and R ₂ ≧ r where ld _w is the projected contact length between the web surface and the universal horizontal roll, and ld _f is the outer surface of the flange and the universal vertical roll. Is the projected contact length with, θ is the angle formed by the straight portion of the fillet portion with respect to the web surface, R ₁ is the arc radius of the joint portion between the fillet portion and the inner surface of the flange, R ₂ is the fillet portion Represents the arc radius of the joint with the web surface, r
Is the arc radius of the outer peripheral edge of the horizontal roll of the finishing universal mill.

(Operation) Next, the present invention will be described more specifically with reference to the accompanying drawings.

The rolling line to which the rolling method according to the present invention is applied is not limited to a specific rolling line as long as it is capable of reducing the web height by vertical rolls in a finishing universal mill. ), And the fourth
It is preferably applied to a rolling line as shown in FIGS.

Hereinafter, the rolling method according to the present invention will be described in detail by taking the rolling line shown in FIG. 4 (a) as an example.

First, according to the rolling method of the present invention, the breakdown rolling may be performed in the same manner as the conventional method, whereby the rolling material is rolled into a beam blank. After that, by intermediate rolling using a rough universal rolling mill (UR) and an edging rolling mill (E), the rolled material is finished to a flange width, a flange thickness, and a web thickness close to the final dimensions. In this intermediate rolling process, the fillet shape of the rolled material is also adjusted to the shape shown in FIG.

The web height of the intermediate rolled steel thus obtained is adjusted by the first finishing universal rolling mill including horizontal rolls and vertical rolls. That is, by changing the opening degree of the vertical roll in FIG. 1, the outer dimension of the web height of the H-section steel can be freely changed within the range of several tens of mm. In this case, the second finishing universal mill is used as a shaping mill to make the web thickness and the flange thickness uniform and correct the squareness of the flange and the web.

FIGS. 11, 13, and 16 show the state in which the web height reduction rolling process of FIG. 1 is viewed from the side, and each cross-sectional view of (a) to (c) of FIG. 12 (a)-(c),
14 (a) to (c) and FIG. 17 (a) to (c).

In FIG. 16, FIGS. 17 (a) to (c) and FIG. 18 viewed from above, based on the method of the present invention, the shape of the fillet portion of the rolled material was set to an appropriate range. The material to be rolled is finished by a universal mill to reduce the height of the web. Even if wavy buckling occurs on the web surface during the web height reduction process as shown in the cross section (b), it is shown in the cross section (c). When being rolled by being sandwiched between the upper and lower horizontal rolls,
The web surface can be replaced vertically with respect to the flange surface,
The so-called web center deviation can be suppressed.

That is, in FIG. 9, the angle θ formed by the straight portion of the fillet portion and the web surface is set to 10 ° ≦ θ ≦ 60, and the arc radius of the joint portion between the straight portion of the fillet portion and the inner surface of the flange is set.
For each of R ₁ and the arc radius R ₂ of the joint with the web surface,
When materials with R ₁ ≧ r and R ₂ ≧ r (r is the radius of the circular arc of the outer peripheral edge of the horizontal roll) are used, as shown in FIGS. 16 and 18, the projected contact length l between the web and the horizontal roll is By setting _dw ≥ projected contact length l _df between the outer surface of the flange and the vertical roll, the web surface is always clamped by the horizontal rolls near the fillet during the process of reducing the web height, and the flange of the flange to the path center of the universal mill is The vertical movement is restricted, and as a result, the web center deviation of the material after rolling is reduced. Further, it is possible to prevent linear flaws from being generated in the fillet portion of the product after the web height is reduced and rolled.

On the other hand, FIG. 13, FIGS. 14 (a) to (c), and FIG. 15 as viewed from above in FIG. 15 show a material to be rolled having a fillet shape which does not satisfy the relationship of the present invention. This is an example of the case where the web height reduction rolling is performed. In this case, the cross section (a) is obtained because the shape of the fillet portion of the material to be rolled is not proper.
Since wavy buckling occurs on the web surface in the state of, when the web is clamped and rolled by the upper and lower horizontal rolls as shown in cross sections (b) and (c), the web surface is replaced with the flange surface, Web center deviation is likely to occur.

That is, when the shape of the fillet portion of the material to be rolled in FIG. 9 is θ <10 °, as shown in FIG. 14 and FIG. Wavy buckling occurs in the
_{Even if} the relationship of _dw ≥ l _df is satisfied, the effect of restraining the vertical movement of the flange with respect to the path center of the universal mill at the horizontal height of the roll during the web height reduction process is weakened, resulting in The deviation of the web center of the material becomes large. (FIG. 14 (c)) Further, FIG. 11 and FIG. 12 (a) to (c) are one example in the case where the reduction rolling of the web height is carried out under the condition that the relation of the present invention is not satisfied, In this case as well, since the shape of the fillet portion of the rolled material was not proper, if a wavy buckling occurs on the web surface in the state of the cross section (b), the cross section (b),
As shown in (c), when it is sandwiched between the upper and lower horizontal rolls and rolled, the web surface is replaced with the flange surface, and the deviation of the web center easily occurs.

That is, when the fillet shape of the rolled material in FIG. 9 is θ> 60 °, the relationship of l _dw ≧ l _df is satisfied due to the buckling of the web surface caused during the web height reduction process. However, the effect of restraining the vertical movement of the flange with respect to the pass center of the universal mill at the horizontal roll corners is weakened, and as a result, the deviation of the web center of the material after the rolling is increased. (Fig. 12 (c)) Furthermore,
As shown in the figure, when the rolling material bites into the path center of the universal mill in a state where it is vertically displaced, θ> in the fillet shape of the rolling material in FIG. 9>
When the angle is 60 °, even if the relationship of l _dw ≧ l _df is satisfied, the vertical position of the flange and the web relative to the universal mill pass center by the corners of the horizontal roll as shown in Fig. 12 (a). The function of correcting the deviation is weakened, and as a result, the web surface is replaced with the top and bottom with respect to the flange surface, and the deviation of the web center occurs.

The above has illustrated the case where the outer surface of the flange is pressed down by the vertical roll without contacting the inner surface of the flange with the side surface of the universal horizontal roll to reduce the height of the web. The same applies to the case where the height is reduced, and by designing the fillet shape of the rolled material for the finish universal mill by the method of the present invention, it becomes possible to suppress the deviation of the web center of the product.

Further, also in a rolling method in which the horizontal roll width of the finishing universal mill is divided into two, the width can be adjusted online, and the web height is reduced by the finishing universal mill, the same method as described above is used according to the method of the present invention. Finishing Universal Mill It is sufficient to design the fillet shape of the rolled material.

Finishing universal mill 1 or more may be provided,
In this specification, including those cases, it is referred to as "finishing universal mill". According to the present invention, the shape of the fillet portion may be formed and then the web height reduction rolling and the finish universal shaping rolling may be performed at the same time.

In the above, the H-section steel has been described in particular, but the present invention can be applied to a section material having another flange represented by a parallel flange channel steel, and in any case, the present invention can be greatly applied. It is possible to improve the shape and dimensional accuracy of products when reducing the height of the web.

Next, the function and effect of the present invention will be described more specifically by way of its examples.

Example 1 When hot rolling H-section steel of H400 × 200 series having a constant outside height of web in the rolling line shown in FIG. 4 (a),
An example of applying the method of the present invention will be described below.

First, after heating the continuous casting bloom, the beam blank is formed by performing revers rolling with a breakdown rolling machine having a roll hole type. Coarse universal rolling mill (UR)
And reversal rolling with an edger rolling machine to finish the product into a shape and dimensions close to the flange thickness, web thickness and flange width of the product.

Here, the horizontal roll width of the UR is the outer diameter of the target web height (= 400mm) to the minimum flange thickness in the series (= 9mm).
It should be set equal to the value obtained by subtracting 2 times, that is, 400-2 × 9 = 382 mm. However, in this example, the horizontal roll width was set to 386 mm by adding 4 mm in consideration of the wear of the side surface of the horizontal roll.

Next, the material after UR rolling is first finish universal rolling (UF1) so that the inner surface of the flange is not in contact with the side of the horizontal roll and the web height is reduced by a vertical roll in one pass,
Then, in the second finishing universal rolling mill (UF2), the product is subjected to shaping rolling for the purpose of making the web thickness and the flange thickness uniform and correcting the squareness of the flange and the web.

Here, the horizontal roll value of UF1 is calculated from the outside dimension of the target web height (= 400 mm) to the maximum flange thickness (= 22 m) in the series.
The value obtained by subtracting 2 times m), that is, 400-2 x 22 = 356m
Set to m.

As an example, the product web thickness t _w and the flange thickness t _f are the first
When the values shown in the table are taken, the present invention is applied to determine the shape of the fillet portion of the UF1 rolled material. Here, UF1 horizontal roll outer peripheral edge and r dimension = 15 mm. The required reduction amount ΔH of the web height for each size is as shown in the table.

In the table, the minimum fillet shape for satisfying the relationship of l _dw ≧ l _df is obtained for each size, and the angle θ formed by the linear part of the fillet shape with respect to the web surface is described. Further, the arc radius R ₁ of the connecting portion between the straight portion of the fillet portion and the inner surface of the flange and the arc radius R ₂ of the connecting portion with the web surface are required to be 15 mm or more, respectively, according to the method of the present invention.

Table 2 shows three sizes of H400 × 200 series.
The following describes the material fillet shape, the product web center deviation measurement value, and the quality determination result when the present invention is applied.
According to the method of the present invention, the shape of the fillet of the material to be rolled was θ = 13.4 ° and R ₁ = R ₂ = 20 mm. From the table, the center deviation was good for all sizes within the criteria (web center deviation ≤ ± 2.0 mm).

Further, in FIG. 19 (a), (b) and (c), t _w = 6 m
UR based on the method of the present invention for m, t _f = 16 mm
~ The UF2 rolling process is schematically shown.

For comparison, the fillet shape of UF1 rolled material is
As shown in the table, the product quality situation when the web height reduction rolling is similarly performed on the three sizes of the H400 × 200 series in the rolling line shown in FIG. 4 (a) is also shown in the table. From this table, as compared with the case where the present invention is applied, the deviation of the web center is worse when the present invention is not applied, and in particular, the web height reduction amount is large t _w = 6 mm, t _f = 1.
It can be seen that the product with 6 mm, t _w = 12 mm, and t _f = 22 mm is out of dimensional tolerance.

Example 2 When performing hot rolling of H400 × 200 series H-section steel with a constant outside height of web in the rolling line shown in FIG. 3 (a),
An example of applying the method of the present invention will be described below.

In the case of this embodiment, the steps from breakdown rolling to rough universal rolling and edger rolling are the same as in the case of the above-mentioned embodiment 1, and the horizontal roll width of UR = 386 mm. The material after UR rolling is a finishing universal rolling machine consisting of horizontal rolls with variable width and divided into two rolls with one pass to reduce the height of the web so that the inner surface of the flange contacts the side of the horizontal roll. The product is formed by forming and rolling mainly for the purpose of straightening and straightening the flange and web squareness.

Here, the width variable horizontal roll width (body length) of the finishing universal mill was changed from 356 to 382 mm according to each flange thickness.

As an example, when the web thickness t _w and the flange thickness t _f of the product take the values shown in Table 4, the present invention is applied to determine the shape of the fillet portion of the rolled material for the variable width universal mill. Here, the r dimension of the outer peripheral edge of the side surface of the two-division horizontal roll of the variable width universal mill (UF) is set to 15 mm. The required reduction amount ΔH of the web height for each size is as shown in the table.

In the same table, the minimum fillet shape for satisfying the relationship of l _dw ≧ l _df is obtained for each size, and the angle θ formed by the linear portion of the fillet shape with respect to the web surface is described. Further, the arc radius R ₁ of the joint between the straight portion of the fillet and the inner surface of the flange and the arc radius R ₂ of the joint between the web surface and the web surface are required to be 15 mm or more, respectively, according to the method of the present invention.

Table 5 shows three sizes of H400 × 200 series.
The material fillet shape in the case of applying the present invention, the measured value of the product web center deviation, and the quality judgment result are shown. According to the method of the present invention, the fillet shape of the rolled material is θ = 13.4
And R ₁ = R ₂ = 20 mm. From the table, the center deviation for all sizes is the criterion (web center deviation ≤ ± 2.0 m
Good quality within m).

In addition, in FIG. 20 (a), (b), t _w = 6 mm, t _f = 16 m
For the case of m, the rolling steps from UR to UF based on the method of the present invention are schematically shown.

For comparison, the fillet shape of UF rolled material is
As shown in the table, the product quality situation when the web height reduction rolling is similarly performed on the three sizes of the H400 × 200 series in the rolling line shown in FIG. 3 (a) is also shown in the table. From this table, compared to the case of applying the present invention,
When the present invention is not applied, the deviation of the center of the web is aggravated, and in particular, the web height reduction amount is large t _w = 6 m.
It can be seen that dimensional tolerance deviation occurs for products with m, t _f = 16 mm, t _w = 12 mm, and t _f = 22 mm.

Example 3 In the rolling line shown in FIG. 4 (b), JIS standard H45
An example in which the method of the present invention is applied to rolling a product of the H400 × 300 series on the same roll as the 0 × 300 series will be described below.

First, in a breakdown mill (BD mill), heated rolled materials such as CC slabs and blooms are rolled into beam blanks. Next, H450 × 300 series intermediate rolling is carried out by an intermediate rolling mill group consisting of a rough universal mill (UR mill) with a horizontal roll width of 404 mm and an edger mill (E mill). At this time, the side surface taper of the horizontal roll was 5 ° as in the conventional case. When rolling H450 × 300 series H-section steel, it is shaped into a shape and dimensions similar to the product by the above intermediate rolling, then the flange surface is raised by the 1st finishing universal mill (UF1), and then the 2nd A universal mill (UF2) with variable width finish is shape-rolled into a predetermined shape and size to make a product.

Next, when rolling the H400 × 300 series on the same rolling line, for example, when manufacturing H386 × 297 × 9/14 size, first UR web thickness 9 mm, flange thickness 14 mm, web height outside dimension 432 mm Modeling up to. After that, 1 at UF1
30mm web height reduction rolling is performed by pass, and the outer dimension of the web height is set to 402mm. Furthermore, in UF2, the product is finished by reducing the web height of 16 mm in one pass and performing shaping rolling at the same time.

Here, the horizontal roll width of the UF1 is set to 358 mm, and the variable horizontal roll width of the UF2 is also set to 358 mm. In addition, the r dimension of the outer peripheral edges of the horizontal rolls of UF1 and UF2 is 20 mm and 15 m respectively
Let m. Required reduction of web height ΔH for each mill
Is shown in Table 7.

In the same table, the minimum fillet shape for satisfying the relationship of l _dw ≧ l _df is obtained for each mill, and the angle θ formed by the linear portion of the fillet shape with respect to the web surface is described.
Further, according to the present invention, the arc radius R ₁ of the joint portion between the straight portion of the fillet and the inner surface of the flange needs to be 20 mm or more, and the arc radius R ₂ of the joint portion between the straight portion of the fillet and the web surface is 15 mm. More is required.

Table 8 shows the material fillet shape of UF1 when the present invention is applied to the manufacture of H-section steel of H386 × 297 × 9/14 size, the measured value of the web center deviation of each mill release, and the quality judgment result. According to the method of the present invention, the shape of the fillet portion of the material to be rolled was θ = 10.5 °, R ₁ = 25 mm, R ₂ = 25 mm. From the table, the center deviation of both UF1 and UF2 (product) was good within the criteria (web center deviation ≦ ± 4.5 mm).

21 (a), (b) and (c) schematically show the rolling process from UR to UF2 based on the method of the present invention.

For comparison, the material fillet shape of UF1 is as shown in Table 9, and the quality condition of each universal mill is the same when the web height reduction rolling is performed in the same manner on the rolling line shown in FIG. 4 (b). Shown in the table. As you can see
With both UF1 release and UF2 release, the web center deviation was worse than when the method of the present invention was carried out, and linear flaws were observed over the entire length near the fillet portion of the material after rolling.

(Effect of the Invention) As described in detail above, according to the present invention, a plurality of series H-shaped steels and a profile having a parallel flange with a flange typified by a channel steel are manufactured by the same universal finish rolling mill. In the case of manufacturing a profile with a flange with a constant outer dimension of the web height even for different sizes of thickness using the same horizontal roll of the universal finish rolling mill, It was possible to provide a method for hot rolling a shape having a flange while suppressing deviation of the center of the web and deviating from a predetermined dimensional tolerance. Therefore, the height of the web can be significantly changed, and the utility value in the industry is extremely high.

[Brief description of drawings]

1 is an explanatory view showing a state of rolling of a universal finish rolling mill according to the present invention; FIG. 2 is an explanatory view showing a state of a variable width universal finish rolling mill according to the present invention; FIG. 3 (a) And FIG. 3 (b) and FIG. 4 (a)
4 and FIG. 4 (b) are explanatory views showing an example of the rolling mill layout of the parallel flange section steel when carrying out the present invention; FIG. 5 is an explanatory view of the deviation of the web center of the H section steel; FIGS. 7 (a) to 6 (c) are explanatory views showing a state of web buckling that occurs in universal finish rolling; FIGS. 7 (a) and 7 (b) are universal finishes according to the present invention. FIG. 8 is an explanatory view showing a state of web center deviation generated in rolling; FIG. 8 is a relational diagram of web center deviation in web height reduction rolling of H-section steel and l _dw −l _df ; FIG. 10 is an explanatory view of the fillet shape of the H-shaped steel rolling material; FIG. 10 is a relational diagram between the web center deviation and θ in the web height reduction rolling of the H-shaped steel; FIGS. 11 to 15 are H-shaped. Occurrence of web center deviation in web height reduction rolling of steel FIG. 16 to FIG. 18 are explanatory views showing a rolling situation when the present invention is carried out in the web height reduction rolling of H-section steel; FIG. 19 (a) to FIG. (C), FIG. 20 (a) and FIG. 20 (b), FIG. 21 (a) to FIG. 21 (c) are explanatory views of the rolling step in the embodiment of the present invention; ) And FIG. 22 (b) are explanatory views of the names of the respective parts of the H-section steel and the parallel flange channel steel; respectively, FIG. 23 is the rolling mill layout of the conventional parallel flange section steel, and FIG. Fig. 25 is an explanatory view of the rolling state of the universal rough mill of Fig. 25; Fig. 25 is an explanatory view of the rolling state of the conventional edger mill; Fig. 26 is an explanatory view of the rolling state of the universal finishing mill; and Fig. 27 and FIG. 28 is an explanatory view of the current product dimension system of H-section steel and parallel flange channel steel. 82: Horizontal roll, 84 :: Vertical roll, 86: Universal mill, 90: Universal mill 92: Horizontal roll, 94: Vertical roll,

Claims (2)

(57) [Claims] 1. A hot rolling method for a profile having a flange, which is performed through breakdown rolling, rough universal rolling, edger rolling and finish rolling, wherein a material to be rolled after edger rolling has a horizontal roll of a fixed width. When rolling with a finishing universal mill, the outer surface of the flange portion is pressed down by a vertical roll without contacting the inner surface of the flange portion with the side surface of the horizontal roll of the finishing universal mill, thus reducing the height of the web in one or more passes. And a method for hot rolling a profile having a flange, characterized in that the fillet shape of the material to be rolled is formed before the finish rolling so as to satisfy the following relationship. 1d _W ≧ 1d _f and 10 ° ≦ θ ≦ 60 ° and R ₁ ≧ r and R ₂ ≧ r where 1d _W is the projected contact length between the web surface and the universal horizontal roll, and 1d _f is the outer surface of the flange and the universal vertical roll. Is the projected contact length with, θ is the angle formed by the straight portion of the fillet portion with respect to the web surface, R ₁ is the arc radius of the joint portion between the fillet portion and the inner surface of the flange, R ₂ is the fillet portion It represents the arc radius of the joint with the web surface, and r is the arc radius of the outer peripheral edge of the horizontal roll of the finishing universal mill. 2. A hot rolling method for a profile having a flange, which is carried out through breakdown rolling, rough universal rolling, edger rolling and finish rolling, which is a finish universal mill for finish rolling the material to be rolled after edger rolling. The horizontal roll width is divided into two, the width can be adjusted online, and the web height can be reduced by one-pass rolling or multiple-pass reverse rolling in the finishing universal mill, and the following relations can be satisfied. A hot rolling method for a profile having a flange, characterized in that the shape of the fillet portion of the material to be rolled is formed before the finish rolling. 1d _W ≧ 1d _f and 10 ° ≦ θ ≦ 60 ° and R ₁ ≧ r and R ₂ ≧ r where 1d _W is the projected contact length between the web surface and the universal horizontal roll, and 1d _f is the outer surface of the flange and the universal vertical roll. Is the projected contact length with, θ is the angle formed by the straight portion of the fillet portion with respect to the web surface, R ₁ is the arc radius of the joint portion between the fillet portion and the inner surface of the flange, R ₂ is the fillet portion It represents the arc radius of the joint with the web surface, and r is the arc radius of the outer peripheral edge of the two-division horizontal roll of the finishing universal mill.