JPH0381003A - Hot rolling method for shape having flange - Google Patents

Abstract

PURPOSE:To dissipate the buckling of constricted part generated on a web by specifically setting the radius dimension of the fillet part of a rolled stock, the circular arc shape of the radius of the side face outer peripheral end of a horizontal roll and the barrel length of the horizontal roll. CONSTITUTION:A rolled stock is rolled up to a beam blank by a breakdown rolling mill 20. The rolled stock is finished to the flange width, flange thickness and web thickness close to the final dimension by the intermediate rolling in which a roughing universal mill 22 and an edging mill 24 are used thereafter. The R dimension of the fillet part 182 of a rolled stock 180, the circular arc shape of the radius (r) of the side face outer peripheral edge 184 of a horizontal roll 82 and a horizontal roll WR are properly set based on an equation 1. As a result, the buckling of constricted part generated on the web face is dissipated by being rolled while being interposed by upper and lower horizontal rolls 86, 86. A drastic web height change becomes possible by optimizing the fillet part shape of the rolled stock or the horizontal roll side face outer peripheral end shape in a rolling line.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for hot rolling a section having a flange, typified by an H-beam used in fields such as construction and civil engineering.

(Prior art) Sections with parallel flanges, such as H-section steel and parallel flange channel steel (hereinafter collectively referred to as "parallel flange section steel"), have traditionally been manufactured by the rolling method. has been
The names of each part of these parallel flange steel sections are shown in Figure 1 (a
) and (b) will be explained by taking representative examples of H-beam steel and parallel flange channel steel as examples.

As shown in the figure, the mutually parallel flange portions 10 and IO are connected and integrated by a coupling portion 12 between them. In the case of the H-beam steel shown in Fig. 1(a), the joint part 12 is the flange part 1.
In the case of the channel steel shown in FIG. 1(b), the center is located at one end of the flange portion IO. This joint 12 is also referred to as a web 14 in the case of H-section steel and flange channel steel.

The length of each flange portion 10 is defined as the flange width (flange width).
The distance between the parallel flange parts is called the web height (tlo), and as shown in the figure, the flange internal width is S0, and the flange internal width is -0.
Define. According to the JIS standard, in the case of H-beam steel, the web height I (. is 100 to 900 at intervals of 25 to 100
Approximately 33 sizes are defined within the am range.

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

That is, the conventional H perfect rolling method is the same for channel steel, but as shown in FIG.
2) Intermediate rolling by the universal rough mill group 26, which is based on the old FJA electric mill 24, and finish rolling by the universal finishing mill 28 have been carried out.

In rough rolling, rolled materials such as heated steel ingots and continuously cast slabs are rolled through two holes of a breakdown mill 20, which is a double reversible rough rolling mill, to form a heel blank.
Use it as a modeling material.

In the subsequent intermediate rolling, the shaping material is first rolled in a mill group consisting of a universal rough mill 22 and a double edger mill 24 to form an intermediate rolled H-beam. That is, first, as shown in the schematic side view of FIG. 3, the universal rough mill 22 uses its horizontal rolls 30 to reduce the web thickness of the intermediate rolled H-shaped 1g 131, and the side surfaces of the horizontal rolls 30 and the vertical rolls 32 reduce the flange thickness. The above-mentioned forming material is elongated into intermediate rolled H-beam steel in multiple passes.

In each pass at this stage of intermediate rolling, as shown in the schematic side view in FIG. Let be a predetermined value.

In finishing rolling, as shown in FIG. 5, the thickness of the web 56 and flange 58 is reduced in one pass or in multiple passes by the horizontal roll 52 and vertical roll 54 of the universal finishing mill 50, as in the case of the universal rough mill 22. , the outer surface of the flange is made flat, and the angle between the flange 58 and the web 56 is made a right angle.

In this way, according to the conventional rolling method, even in finish rolling, the inner surface of the flange 58 is covered with the side surface of the horizontal roll 52, and the flange 58 is
8 are rolled down by vertical rolls 54, respectively.

Of course, the web 56 is rolled down by the horizontal roll 52 in the same manner. Therefore, the web inner width -0 of the H-section steel to be rolled is equal to the horizontal roll 52 of the universal finishing mill.
determined by the width of

For this reason, the following problems arise in the conventional method of rolling H-beam steel.

(1) Figure 6 shows changes in the cross-sectional shape of one series of H-beam steel with the same flange radius (for example, H600 Because of the flange thickness (
US, th, tfi) are different from each other, and the web height ■ for each size.

The external dimensions (H, 7, and lb in Figure 6) also have different values. That is, tfi <tf+ <tf
i, It.

<HH<Hx.

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

(2> When rolling steel sections with different sizes of flange inner width -0, the horizontal roll of the universal finishing mill must be replaced. In order to manufacture all of these H-shaped steel sections, it is necessary to have at least two sets of 47 types of horizontal rolls.Even at current prices, the cost of these rolls reaches hundreds of millions of yen. In order to maintain the rolling stock at all times, a large space comparable to that of the rolling building is required, and a large investment is also required for the roll shop building.

(3) The horizontal rolls of the same universal finishing mill can only roll one series of H-beams 20,001 rounds/rolling chance x 3 times - 6,000 tons. This is 10
This is because the width of the horizontal roll is worn out by about 1 inch per roll, and the usable width of the roll is 6 mm even if the tolerance is effectively used. Therefore, when a horizontal roll is no longer usable in a certain series, its width is cut by several tens of degrees and the roll is modified for the next series with a smaller web height.

Therefore, compared to rolls for steel plates, the amount of product rolled per roll is significantly smaller, that is, the roll cost per ton of product is higher.

(4) If the web height Ho is out of the standard, it is necessary to prepare a dedicated horizontal roll for universal finishing and change the roll, which is not economically viable for small lot orders. Often declines orders.

(Problems to be Solved by the Invention) The general object of the present invention is to make it possible to make it practical by making it possible to freely change the inner width of the web and to manufacture parallel flange sections of multiple series using a universal finishing rolling mill. The object of the present invention is to provide a rolling method.

Another object of the present invention is to be able to roll two or more series of parallel flange sections with one type of horizontal roll in a universal finishing rolling mill, to reduce the number of rolls in half, and to roll the same series with the outer dimension of web height. To provide a method for rolling a parallel flange section steel, which can be made constant, and which can be manufactured at a low cost using a rolling machine of another series even if the outside dimensions are outside the standard.

Still another object of the present invention is to provide constant outer dimensions of web height for different thickness sizes, square outer corners, and non-standard dimensions using the same universal finishing rolling horizontal roll. It is an object of the present invention to provide a method for rolling a parallel flange channel steel that can be manufactured at low cost even in sizes of .

Still another object of the present invention is to be able to roll different series of H-section steel using one type of parallel rolls in a universal finishing rolling mill, to make the outer dimensions of the web height constant in the same series, and to roll non-standard H-beams. To provide a method for rolling an H-section steel that can be manufactured at the same cost as a standard size and can greatly reduce the number of rolls owned.

Therefore, as a means to solve the numerous problems related to the conventional method of rolling sections with flanges mentioned above, a patent application
The applicant proposed the technique disclosed in No. 3-235388. This involves breakdown rolling as shown in Figure 2.
This method of rolling a section having a flange is performed through intermediate rolling and finish rolling, and its characteristics include: first, the rolled material is roughly rolled by a breakdown rolling mill 20;
Next, the intermediate rolling mill (coarse universal rough mill group) 26 completes rolling of the flange portion and the joint portion of both flanges, and in finishing rolling, a universal mill 86 as shown in FIG. 8 is used to finish the inner surface of the flange portion. The purpose is to finish the width dimension of the joint portion 80 between both flanges by rolling down the outer surface of the flange portion with the vertical roll 84 without contacting the side surface of the universal horizontal roll 82.

Furthermore, the applicant has proposed a variable width 2 as shown in FIG.
A universal mill 96 having a split horizontal roll 90 and a vertical roll 92 is applied to a rolling line equipped with primary and secondary roughing universal mills 22.22° as shown in FIGS. 10(a) and 10(b). Finishing universal mill 9
Japanese Patent Application No. 1-149 discloses a method of reducing the web height by performing one pass or multiple passes of reverse rolling in 6.
It was proposed in issue 851. Furthermore, the same patent application Hei 1-1498
No. 51, as shown in FIGS. 11(a) and 11(b), a finishing universal machine consisting of fixed width horizontal rolls [Le 11
This paper proposes a method for performing web height reduction rolling using two finishing universal mills: a finishing universal mill 112 consisting of a zero roll and a finishing universal mill 112 consisting of variable width horizontal rolls.

According to these inventions, it is possible to make constant the outer web height dimensions of sections with flanges such as horizontal flange section steel of the same series with one type of roll, and also to make the horizontal roll width of a rough universal rolling mill constant. without being restricted by
H-beam steel, channel steel, etc. with a free web height can be manufactured using the same roll in the same rolling chance, and it is possible to significantly reduce the number of rolls owned and greatly improve the roll consumption rate.

Regarding the method of rolling a section having a flange previously proposed by the present applicant, the present inventor has repeatedly conducted a large number of model mill experiments, and has now clarified the following problems.

■When manufacturing H-beam steel using the method of rolling sections with flanges proposed by the applicant, depending on the amount of reduction in web height, the problem of web center deviation of the product as shown in Figure 12 may occur. (The central deviation is expressed as 1s=(ab)/2.

In other words, when the amount of web height reduction exceeds a certain range,
The center deviation of the web increases rapidly, resulting in a product that does not satisfy the predetermined tolerance. (JIS, G 3192 specifies the allowable range of center deviation as ±3.0 mg+ for webs with a height of 300m or less, and ±4.5mm for webs with a height of over 300m.) Furthermore, if we examine in detail the manufacturing conditions when the web center deviation exceeds the allowable range as described in (■), we find that in addition to the size of the web height reduction, the shape of the fillet part of the material during the web height reduction process (for example, R dimension) and the shape of the outer circumferential edge of the side surface of the horizontal roll of the universal mill (for example, one dimension), which has caused problems in rolling pass schedule design and roll shape design.

Therefore, the specific purpose of the present invention is to: (1) make the inner dimensions of the web freely changeable so that multiple series of H-section steel and parallel flange channel steel, etc. In the case of manufacturing using horizontal rolls of the same universal finishing mill, when manufacturing sections with flanges with constant external dimensions of the web height even for sizes with different thicknesses, the web center deviation of the product It is an object of the present invention to provide a hot rolling method that makes it possible to suppress the amount of heat to a small level so that it does not deviate from a predetermined tolerance.

(Means for Solving the Problems) Thus, with the aim of solving the problems, the present inventors have conducted various studies and obtained the following findings through extensive rolling experiments.

(1) Using a universal mill as shown in Figure 8,
When reducing the web height by rolling down the outer surface of the flange with vertical rolls without making the inner surface of the flange contact the side surface of the universal horizontal roll, as the amount of web height reduction is gradually increased, Figure 13 (6
) to (C), the web portion begins to buckle between the side surface of the horizontal roll and the vertical roll (see Figure 13 (b)),
Eventually, the web portion buckles significantly and a constriction occurs (Fig. 13(C)).

(2) After reducing the web height with the unipersalumi JL =- shown in Fig. 8, according to the technique disclosed in Japanese Patent Application No. 63-235388, the web is shaped and rolled with a variable width universal forming wheel as shown in Fig. 9. or when filing a patent application
As disclosed in No. 149851, when finishing a product by further reducing the web height in one pass or multiple passes using a variable width universal mill as shown in FIG.
For those that have undergone the rolling process shown in Figure (a), middle), the rolling conditions in the final pass of the variable width universal mill (or shaping mill) are as shown in Figure 14 (a), where the web center deviation is small and good. Finished product with dimensions and shape.

However, in the case where the aforementioned constriction occurs in the web portion as shown in Fig. 13(C), the subsequent rolling process does not reduce the web height, but instead aims to correct the angle of the flange and flatten the web. Even with shaping rolling, the finished product has a large deviation in the center of the web, as shown in Fig. 14).

In other words, even if the web center deviation occurs due to slight buckling as shown in Fig. 13 in the unrolled portion of the web surface during the process of reducing the web height, the process of subsequent shaping rolling or reducing the web height may occur. (However, with a slight reduction), the fillet portion (inside the corner) of the material is held and rolled between the outer peripheral edges of the side surfaces of the upper and lower horizontal rolls, thereby correcting the material. On the other hand, in the process of reducing the web height, the unrolled part of the web surface (see Fig. 13)
In the case of a web with cracks as shown in C), even if the fillet area of the material is held between the outer circumferential edges of the upper and lower horizontal rolls in the subsequent shaping rolling, the neck part will not be corrected and the web will not be straightened. Center bias remains. In addition, it was found that in some cases, the constricted portion may become folded and remain on the product.

(3) The above facts (1) and (2) are based on the
As disclosed in No. 5388, the rolling method of dividing the horizontal roll of the universal mill shown in Fig. 8 into two to create a variable width roll and reducing the web height with vertical rolls so that the inner surface of the flange does not come into contact with the side surface of the horizontal roll is also discussed. I knew I could see it.

(4) Furthermore, the facts of (1) and (2) are
It has been found that the same phenomenon occurs when the web height is reduced by reverse rolling in one pass or multiple passes in a universal mill using variable width horizontal rolls as disclosed in No. 9851. That is, in this case, the feature is that the web height is reduced by rolling down the outer surface of the flange portion with vertical rolls so that the inner surface of the flange portion is in contact with the side surface of the universal mill horizontal roll.
Depending on the shape of the fillet part of the rolled material (for example, R dimension) or the shape of the outer peripheral edge of the side surface of the horizontal roll (for example, 1 dimension), when the amount of web height reduction is increased, the constriction that occurs near the fillet part during rolling may be reduced. It has been found that even if the web is rolled while being held between upper and lower horizontal rolls, the correction may not be completed and the finished web may be left with a deviation in its center.

Based on the above findings, the present inventor has created the following means as a method for suppressing web center deviation in web height reduction rolling.

FIGS. 18(a) to (C) show web height reduction rolling of H-section steel using the universal mill 86 shown in FIG. 8 based on the method of the present invention.
The web height can be reduced by optimizing the shape of the fillet part 182 of the rolled material 180 and the shape of the outer peripheral edge 184 of the side surface of the horizontal roll. Even if constriction-like buckling occurs on the web surface at a distance of 1.0 mm from the inner surface of the flange when it is reduced by Δl (C) from the start, as shown in FIG. It has become possible to roll the web 186 while sandwiching it between the horizontal rolls of the present invention, thereby preventing the residual constriction and, therefore, suppressing the occurrence of deviation in the center of the web.

Fig. 18 shows an example in which the web height is reduced without bringing the inner surface of the flange into contact with the side surface of the universal horizontal roll. The same applies when reducing the web height by rolling down the outer surface of the flange with a vertical roll until the inner surface of the flange comes into contact with the side surface of a universal horizontal roll. It has also been found that by rolling the web while sandwiching it between upper and lower horizontal rolls until the end of rolling, the remaining constrictions can be prevented and the occurrence of web center deviation can be suppressed.

Furthermore, in FIG. 18, the fillet portion 1 of the rolled material 180 is
The shape of 82 is made into an R shape as shown in FIG. 17(a),
The shape of the outer circumferential end 184 of the side surface of the horizontal roll was also r-shaped, but the fillet shape was tapered as shown in box 17) and (C), and an extra thickness of constant thickness was provided for a predetermined length. It can also be shaped.

Alternatively, the fillet portion may have a chamfered shape as shown in FIG. 22, which will be described later, and the outer peripheral end shape of the side surface of the horizontal roll may also be chamfered.

Here, when a rolled material having a fillet shape as shown in FIG. 17 (B) or (C) is subjected to web height reduction rolling with a universal mill consisting of variable width horizontal rolls as shown in FIG. It is necessary to ensure that the position of the constriction due to buckling that occurs on the web surface as the web height is reduced does not lie in the hollowed out portion of the two-part horizontal roll, as shown in FIG. 21, which will be described later. That is, if a constriction occurs in the hollow portion of the two-part horizontal roll, wrinkle-like defects will remain on the product, causing a quality problem.

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

FIG. 11(a) shows an example of a rolling line for realizing the rolling method according to the present invention. First, according to the rolling method according to the present invention, a breakdown rolling mill (BD) 2
The zero breakdown rolling may be performed in the same manner as in the conventional method, whereby the rolled material is rolled into a beam blank. After that, during intermediate rolling using a rough universal rolling mill (UR) 22 and an edging rolling mill II CB〉24, the rolled material has a flange width and a flange thickness close to the final dimensions.
Can be finished to web thickness. In this intermediate rolling process, the shape of the fillet part of the rolled material is also changed as shown in Fig. 17 (
6)-(C) It can be arranged into various shapes as shown in L.

The web height of the thus obtained intermediate rolled section is adjusted by a first finishing universal rolling mill 110 consisting of horizontal rolls and vertical rolls. That is, by changing the opening degree of the vertical rolls in the universal mill 86 shown in FIG. 8, the outer dimension of the web height of the H-section steel can be freely changed within the range of several 10-1.

Figures 18 and 19 are partially enlarged views of Figure 8;
Each of the figures (a) to (C) schematically shows the state of the rolled material at the start of rolling, during rolling, and at the end of rolling, respectively.

FIG. 18 shows a web height reduction rolling process when the present invention is applied, and FIG. 19 shows a conventional web height reduction rolling process. That is, in each figure (a), when the fillet shape of the rolled material before web height reduction rolling is an arc of radius R and the inner dimension of the web height is Hio, the web height is reduced by the web height reduction amount ΔHc. Figure (b) shows a state in which constriction-like buckling has occurred at a distance M11 from the inside of the flange when the web surface is reduced, and the horizontal roll 82 at this time has not reached the point where the web surface is completely clamped. The characteristic is that there is no

In FIG. 18, based on the method of the present invention, the R dimension of the fillet portion 182 of the rolled material 180, the arcuate shape of the radius r of the side surface outer peripheral end 184 of the horizontal roll 82, and the horizontal roll body length Wl are appropriately set. As a result, the constriction-like buckling that occurs on the web surface in the state shown in each figure (b) is
As shown in C), it is rolled while being held between upper and lower horizontal rolls 86 and 86 and disappears. That is, ΔH
The condition for transitioning to the state shown in Figure (C) is that the position where the fin-like buckling occurs is in the area where the upper and lower horizontal rolls face each other parallel to each other at the time when the web height is reduced as shown in Figure (C). , which can be formulated as follows.

That is, from Figure 18 (b), j! , ≧(old 0-ΔHc-11m +2r)/2...
・■Here, old 0 is the internal web height dimension of the rolled material before the web height is reduced by the finishing universal rolling, ΔHc is the limit web height reduction amount that causes buckling, and W true is The horizontal roll width (body length) of the finishing universal rolling mill, r indicates one dimension of the outer peripheral edge of the side surface of the horizontal roll, and i indicates the distance from the buckling position that occurs on the web surface as the web height is reduced to the inner surface of the flange. This is the distance to.

FIGS. 19(6) to (C) are cases where web height reduction rolling is performed under conditions that do not satisfy the above relationship of equation 0,
This shows a state in which constriction-like buckling that occurred during rolling remains on the web surface after rolling.

Now, the limit web height reduction amount ΔHc for occurrence of constriction-like buckling
As for the buckling occurrence position 1 m, the present inventor has fixed it as a function of various rolling conditions based on extensive experimental results. As an example, FIG. 15 shows the relationship between ΔHe and the web thickness tI4 of the rolled material, FIG. 16 illustrates the relationship between f and the fillet R dimension. H in Fig. 15 indicates the outer height of the web before rolling, and from the figure, the web thickness t of the rolled material is
. It can be seen that as the ratio of the outer dimension to the web height increases, the critical reduction ratio of the web height (ΔH/HX100%) increases. Also, from Fig. 16, buckling occurrence position 1. increases in proportion to the increase in the fillet R dimension, and it can be seen that the relationship between the two is expressed by Ilm = 2/3 R. If ΔHe and 11 are found for a given pass schedule from these relationships, it is only necessary to design the fillet shape and roll dimensions so as to satisfy the above equation 0. ===K W l is determined in advance by the pass schedule and rolling mill.

That is, in order to perform rolling according to Equation 0, first, the buckling limit ΔHe is determined from the relationship shown in FIG. Buckling occurrence position 1. The relationship between this and one dimension of the roll is determined, and the fillet shape and roll shape are designed based on the relationship shown in FIG. 16, for example.

20(a) to 20(C) show that an H-beam steel having a tapered fillet portion 202 as shown in FIG. This is a partially enlarged view of the rolling process when the web height is reduced in the mill 86. In this case as well, the shape of the fillet portion 202 or one dimension of the outer circumferential end 204 of the side surface of the horizontal roll is adjusted so as to satisfy the relationship of the above equation 0. By setting this, residual constriction buckling can be suppressed. - The constrictions caused by the alternating buckling (see Fig. 20) disappear by further continuing rolling (Fig. 20 (C)).

Further, FIG. 22 shows that the finishing universal mill 86 of FIG. This figure shows a mechanism for suppressing the residual constriction buckling during web height reduction rolling.

That is, from FIG. 22(b), h≧(Hio-ΔHc-WR+2G)/2...■
Here, Hio is the internal web height dimension of the rolled material before the web height is reduced by the finishing universal rolling, Δ[lc is the limit web height reduction amount that causes buckling, and WI is the finishing universal rolling. The horizontal roll width (body length) of the universal rolling mill, C, indicates the chamfer C dimension of the outer peripheral end 224 of the side surface of the horizontal roll, and 1. is the distance from the buckling position that occurs on the web surface to the inner surface of the flange as the web height is reduced.

In the case of this formula (■), the fillet shape and roll shape can be designed in the same manner as in the case of the above-mentioned formula 0. By the way, if the fillet shape is as shown in Fig. 17 (b) or (C), When a rolled material is rolled to reduce the web height, the position of the constriction due to buckling that occurs on the web surface as the web height is reduced shifts from the joint between the web and the flange to the center of the web. Therefore, when reducing the web height with a universal mill 96 consisting of a variable width horizontal roll as shown in Fig. 9, the hollow part (web unrestricted part) of the two-split horizontal roll as shown in Fig. 21 is used to reduce the web height. When the constriction position is reached, wrinkle-like defects remain on the product, so in such a case, the following relationship must be satisfied.

That is, the following relationship only needs to hold in the state shown in FIG. 21(C).

WR≧lB≧21 ...■ Here, W3 is the length of each part of the horizontal roll after division of the variable width finishing universal mill, and 16 is the length of the flange from the buckling position that occurs on the web surface as the web height is reduced. Represents the distance to the inner surface.

From the above, in the rolling method in which the horizontal roll width of the finishing universal rolling mill is divided into two and the width can be adjusted online, and the web height is reduced using the finishing universal rolling mill, In order to satisfy the relationship of formula (2), depending on the web height reduction amount and horizontal roll width (body length), the shape of the fillet part of the rolled material or the body length of each part of the horizontal roll after being divided into two WR≧lB and the horizontal One dimension or C dimension of the outer peripheral end of the roll side surface may be designed respectively.

Specifically, when the present invention is applied to a rolling line as shown in FIG. 11(a), the web height reduction amount in the first finishing universal rolling mill (UPI) 110 is According to the horizontal roll width (body length), the shape of the fillet portion of the rolled material or the shape of the outer circumferential end of the side surface of the horizontal roll is optimized based on the above formula 0 or formula (2). Then the second finishing universal rolling mill (UF2)
When performing web height reduction rolling in step 112, the variable width horizontal roll width, the body length of each part after division, and the shape of the roll side outer peripheral edge are optimized based on the formulas (1) and (2) or (2) and (2). good.

However, when web height reduction rolling is reverse rolling in multiple passes in UPI or UF2, f) Hi o , ΔHc, j!
1 is newly set based on a predetermined path schedule,
It is necessary to consider the shape of the fillet part of the rolled material or the shape of the outer peripheral edge of the side surface of the horizontal roll.

The above describes the case where the present invention is applied to the process of reducing the web height on a rolling line as shown in FIG. 11(C), or the rolling line as shown in FIGS. The same problem applies when the present invention is applied to the process of reducing the web height.

In addition, although the above has specifically described H-beam steel, the process of reducing the web height of other flanged sections, such as parallel flange channel steel, and manufacturing products with arbitrary web heights is also applicable. The present invention is also applicable to the present invention, and it is possible to improve the shape and dimensional accuracy of the product when rolling is performed to significantly reduce the web height.

(Example) The present invention will be explained in detail by examples.

Example 1 The following describes an example in which the method of the present invention was applied to hot rolling an H-beam steel of the H400x200 series with a constant external dimension of web height on the rolling line shown in FIG. 11 (0).

First, after heating the continuous casting plume, reverse rolling is performed in a breakdown rolling mill 20 having a roll hole type to form a beam blank. Furthermore, rough universal rolling 1a
(uR) 22 and edger rolling mill ([1) 24] perform reverse rolling to finish the product to a shape and size close to the flange thickness, web thickness, and flange width of the product.

Here, the horizontal roll width of UR is the target web height outer dimension (
-400v++) to the minimum flange thickness in the series (=
9ms), i.e. 400-2X
It may be set equal to 9=382+s-; however, in this embodiment, considering wear on the side surface of the horizontal roll, an additional 4cm is added, and the width of the horizontal roll is set to 386--.

Next, the material after OR rolling is passed through a first finishing universal rolling mill (UPI) 110, where the web height is reduced in one pass with vertical rolls so that the inner surface of the flange does not touch the side surface of horizontal rolls, and then 2. Finishing Using a universal rolling mill (IIF2) 112, shaping rolling was performed with the main purpose of making the web thickness uniform and correcting the perpendicularity between the flange and the web to produce a product.

Here, the UPI horizontal roll width WR is set to the value obtained by subtracting twice the maximum flange thickness in the series (-22 mm) from the target web height outer dimension (=400 m++w), that is, 400 2 X 22 = 356 mts. .

As an example, the product web thickness t. The present invention was carried out to determine the shape of the fillet portion of the rolled material of υF1 when the flange thickness and t took the values shown in Table 1.

The rolled material of UPI, that is, the web height inside dimension of the rolled material after the final pass of UR, is o-386vpyg, t
It is assumed that the r dimension of the outer peripheral edge of the side surface of the horizontal roll of lFl = 6 mm. The required amount of web height reduction ΔH for each size is the first
As shown in the table. Table 1 also shows the buckling limit web height reduction amount ΔHe'' estimated for each size, and the range of distance 11 from the buckling position to the inner surface of the flange that satisfies the above equation. The fillet shape of the rolled material is ΔH〉ΔHc”
For tw-6mm, Lr=16a++, lB
20R so that it falls within the specified range (≧12.5mm+)
(l m '= 13.3 mm).

Table 2 Table 2 shows the web center deviation determination status for the three sizes of the H400X200 series when the present invention is applied, and for all sizes of products, the center deviation falls within the tolerance and the quality is good. there were. Also, Fig. 23 (a
) to (C) schematically show the rolling process up to υR-11F2 based on the method of the present invention for tw=61WR and tr-16 open.

For comparison, the fillet shape of the UPI rolled material is
Table 3 shows the product quality status when SR was used and web height reduction rolling was performed on the rolling line shown in Figure 11(a) for three sizes of the H400x 200 series.
From this table, it can be seen that the amount of reduction in web height exceeds the buckling limit t
It can be seen that for the sizes w=6a+s+ and tt=16IIl-, deviations from the tolerance of web center deviation occur frequently.

Table 3 Example 2 8400 x 20 on the rolling line shown in Figure 10(a)
An example in which the method of the present invention is applied to hot rolling a 0 series H-beam steel with a constant external dimension of web height will be described below.

In the case of this example, the steps from breakdown rolling to rough universal rolling and edger rolling are the same as in Example 1 described above, and the horizontal roll width of uR = 386I
It was set as III. 01? After rolling, the rolled material is rolled in a finishing universal rolling mill 96 consisting of two horizontal rolls with variable width, to reduce the web height in one pass so that the inner surface of the flange is in contact with the side surface of the horizontal roll of the finishing universal rolling mill, and at the same time. Shaping rolling is performed with the main purpose of making the web thickness uniform and correcting the perpendicularity between the flange and the web to produce the product.

Here, the variable width horizontal roll width (Wq length) WR of the finishing universal rolling mill 96 is changed for each flange thickness as shown in Table 5. Also, the horizontal roll is 1. The later length of each section was set at 173 Kai.

As an example, when the product web thickness t and the flange thickness tf each took the values shown in Table 4, the present invention was implemented to determine one dimension of the outer peripheral end of the side surface of the variable width horizontal roll.

Table 4 Finishing universal rolling! a! 96 rolled material, i.e. web height internal dimension system of rolled material after final pass of UR 0
=386 +wm, and the fillet shape was an arc of 20R. The required amount of web height reduction ΔH for each size is as shown in Table 4. The table shows the amount of buckling limit web height reduction ΔHc' estimated for each size.
T, the distance 11 from the buckling position to the inner surface of the flange, and the range r0 of one dimension of the outer peripheral end of the side surface of the horizontal roll that satisfies the above formula 0. In addition, in the case of this example, as shown in Table 4, the trunk length of each part after dividing the horizontal roll w, >
1. ”, which satisfies the relationship in equation (2) above.

From the relationship in Table 4, ΔH>ΔHc” t.=6 open,
Regarding Lt-161pm, it is necessary to set one dimension of the variable width horizontal roll within a predetermined range, so this is set as r=1.
It was set to 0.

Table 5 Table 5 shows the web center bias determination status when the present invention is applied to three sizes of the )1400 x 200 series.The center bias for all products was within the tolerance and the quality was good. Ta. Also, Fig. 24(a) ~
(C) schematically shows the rolling process from <UR to UP based on the method of the present invention for L, x5+u+, Lt=16 mm.

For comparison, one dimension of the horizontal roll of the variable width finishing universal mill is assumed to be 16+ww, and the product quality is obtained when web height reduction rolling is similarly performed on the rolling line shown in Figure 10(a) for three sizes of the I+400X200 series. The situation is shown in Table 6.

Table 6 From this table, it can be seen that the amount of reduction in web height exceeds the buckling limit
It can be seen that for the size w-6+u+, tr=16m-, deviations from the tolerance of the web center deviation occur frequently.

Example 3 In the rolling line shown in Figure 11 (b), the same roll as the JIS standard H450X 300 series was used to
An example in which the method of the present invention is applied to rolling a 0x300 series product will be described below.

First, in the breakdown rolling mill (BD) 20,
An intermediate rolling mill group consisting of a rough universal rolling mill (UR) 22 with a zero-order horizontal roll width of 404 cm and an edge rolling mill (E) 24, which roll heated rolled materials such as CC slabs and blooms into beam blanks. By H450
x300 series intermediate rolling, UR at this time
The side taper of the horizontal roll was 5° as before. H
When rolling 450X300 series H-section steel, it is shaped into a shape and size close to the product through the intermediate rolling process, and then
The flange surface is raised in a first universal finishing mill (UPI) 110, and then shaped and rolled into a predetermined shape and size in a second variable width finishing universal mill (tlF2) 112 to produce a product.

Next, when rolling 11400X300 series on the same rolling line, for example, when manufacturing H386X297X9/14 size, first use OR to roll a web thickness of 9 m.
(The flange thickness is 14-1, and the outer web height dimension is 432-mm. Then, the web height is reduced by 30 m in one pass using UPI, and the outer web height dimension is 402. In UF2, the web height is reduced by 16 m in one pass, and at the same time, shaping rolling is performed to finish the web into a product.

Table 7 Here, as shown in Table 7, the horizontal roll width (body length) WR of the 11 FI! 358-, and the horizontal roll width (body length) -WR of UF2 was also set to 35 hw, and the body length w1 of each portion of the horizontal roll after division was 179 arms. The web height internal dimensions of the rolled material of UF1, i.e., the rolled material after the final pass of IJR, are 0'''404 m-, and the web height internal dimensions of the rolled material of UF4, i.e., the web height dimensions after the web height reduction in UPI. o = 374 +u+, and the fillet shape is finished in a tapered shape with [I[l].

Table 7 shows the estimated buckling limit web height reduction amount ΔHe for each UP≧ru, the distance from the buckling position to the inner surface of the flange I!1IlI11, and the level of each UP mill that satisfies the above formula 0. Range of one dimension of the outer peripheral edge of the roll side surface r8
is also listed. In addition, in the case of this embodiment, the trunk length of each section after division of the horizontal roll of tIF2 >wl>j!B'' and satisfies the relationship of formula (2) above.

From the relationship in Table 7, ΔH>Δ11C0 [For IFl, it is necessary to set one dimension of the horizontal roll within a predetermined range, so r = 18 mm. Regarding UF4, ΔH<Δl(c"), and there is no need to take measures against buckling; however, as disclosed by the present applicant in Japanese Patent Application No. 1-14985, one dimension of the horizontal roll of UF2 is tlFl. It needs to be equal to or smaller than one dimension of the horizontal roll, and in this example, r=15a+m of UF2.

Table 8 Table 8 shows the web center deviation determination status of the product when the present invention was applied to the production of 11386 x 297 x 9/14 size, and the center deviation was within the tolerance and the quality was good. Moreover, FIGS. 25(a) to 25(C) schematically show the rolling process up to <0R-UF2 based on the method of the present invention.

For comparison, one dimension of UPI's horizontal roll is 25111
Table 9 shows the product quality status when web height reduction rolling was similarly performed on the rolling line shown in FIG. 11 (b), with 20 questions per dimension of the variable width horizontal roll of UF2.

Table 9 From this table, it can be seen that the amount of web height reduction exceeds the buckling limit
The constriction of the fillet part in the Fl mill remains in the product,
It can be seen that deviations from the tolerance of web center deviation occur frequently.

(Effects of the Invention) As detailed above, according to the present invention, when multiple series of sections having flanges, such as H-beams and parallel-flange channel steels, are manufactured using the same universal finishing mill. Or, when manufacturing sections with flanges with constant external dimensions of web height for sizes with different thicknesses using horizontal rolls of the same universal finishing mill, the product change due to the reduction in web height. It is possible to realize a hot rolling method that suppresses deviation from the predetermined dimensional tolerance due to the occurrence of web center deviation, and enables a significant change in web height, which has extremely high industrial utility value.

[Brief explanation of drawings]

Figures 1 (a) and -) are explanatory diagrams of the names of each part of H-beam steel and parallel flange channel steel, respectively; Figure 2 is the layout of a conventional rolling mill for parallel flange steel; Figure 3 is Figure 4 is an explanatory diagram of rolling by a conventional universal roughing mill; Figure 4 is an explanatory diagram of rolling by a conventional edger rolling mill; Figure 5 is a diagram of rolling by a universal finishing mill. Explanatory diagram; Figures 6 and 7 are explanatory diagrams of the current product dimensions and types of H-beam steel and parallel flange channel steel, respectively; Figure 8 is a diagram showing the state of rolling by the universal finishing rolling mill according to the present invention. FIG. 9 is an explanatory diagram showing the state of rolling by the variable width universal finishing mill according to the present invention; FIGS. 10(a), (b) and 11
Figures (a) and (b) are the layout of a rolling mill for parallel flange steel according to the present invention; Figure 12 is an explanatory diagram of web center deviation of H-shaped steel; Figures 13 (a) to (C) 14(a) and 14(b) are explanatory diagrams showing the state of web buckling that occurs in universal finish rolling according to the present invention. FIGS. FIG. 15 is a diagram showing the relationship between web thickness and buckling limit web height reduction amount in universal finish rolling according to the present invention; FIG. 16 is a diagram showing the R dimension of the fillet portion in universal finish rolling according to the present invention 17(a) to (C) are explanatory diagrams of the fillet shape of the H-beam steel; FIG. 18(a) to (C), and FIG. 20(a) to (C)
, and FIGS. 22(a) to (C) are enlarged views of the fillet portion in universal finish rolling according to the present invention. FIGS. 19(a) to (C) are enlarged views of the fillet portion in conventional universal finish rolling. Figures; Figure 21 (C) is an illustration of web buckling in conventional universal finish rolling; Figures 23, 24, and 25 are illustrations of the rolling process in the embodiment of the present invention; 20: 22: 24: 22": 96: 110: 112 Ni breakdown rolling mill (primary) rough universal rolling mill edger rolling mill secondary rough universal rolling mill finishing universal rolling mill 1 finishing universal rolling machine 2nd finishing universal rolling machine

Claims (2)

[Claims] (1) A method for hot rolling a section having a flange through breakdown rolling, rough universal rolling, edger rolling, and finish rolling, in which the rolled material after edger rolling is subjected to finishing universal rolling with horizontal rolls of fixed width. When rolling with a machine, the web height is reduced in one pass or multiple passes by rolling down the outer surface of the flange part with vertical rolls without making the inner surface of the flange part come into contact with the side surfaces of the horizontal rolls of the universal rolling machine. In the method, the fillet shape of the rolled material before the finishing universal rolling is determined so as to satisfy the following relationship, and the fillet shape is formed in the rolling step before the finishing universal rolling so as to have the fillet shape, and then the finishing is performed. A method for hot rolling a section having a flange, the method comprising rolling with a universal rolling mill. l_B≧(Hio-ΔHc-W_R+2r)/2 or l_B≧(Hio-ΔHc-W_R+2c)/2 where Hio is the internal web height dimension of the rolled material before the finishing universal rolling, and ΔHc is the buckling limit web Height reduction amount, W_R is the horizontal roll width (body length) of the finishing universal rolling mill, r is the r dimension of the outer peripheral edge of the side surface of the horizontal roll, c is the c dimension of the outer peripheral edge of the side surface of the horizontal roll, and l_B is the reduction of the web height. It represents the distance from the buckling position that occurs on the web surface to the inner surface of the flange. (2) A method for hot rolling a section having a flange through breakdown rolling, rough universal rolling, edger rolling, and finishing rolling, in which the horizontal roll width of the finishing universal rolling mill is divided into two and the width is adjusted online. 1 in the universal rolling mill with possible structure and finishing
In a rolling method in which the web height is reduced by pass or multiple passes of reverse rolling, the shape of the fillet portion of the rolled material before the finishing universal rolling is determined so as to satisfy the following relationship, and the shape of the fillet portion of the rolled material is determined so as to satisfy the following relationship. A method for hot rolling a shaped material having a flange, characterized in that the material is formed in a rolling process prior to the finishing universal rolling, and then rolled in a finishing universal rolling mill consisting of the two-part horizontal rolls. W_R≧l_B≧(Hio−ΔHc−W_R+2r)/
2 or W_R≧l_B≧(Hio−ΔHc−W_R+2c)/
2 Here, Hio is the internal height dimension of the rolled material web before finishing universal rolling consisting of the two-divided horizontal rolls,
ΔHc is the amount of reduction in the buckling limit web height, W_R is the width of the horizontal roll divided into two parts of the finishing universal rolling mill, W_R is the body length of each part of the horizontal roll after division, r is the r dimension of the outer peripheral edge of the side surface of the horizontal roll, and c is the width of the horizontal roll divided into two parts of the finishing universal rolling mill. Horizontal roll side outer peripheral end c dimension, l_
B represents the distance from the buckling position that occurs on the web surface to the inner surface of the flange as the web height is reduced.