JPH0813363B2 - 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 an H-section steel used in fields such as construction and civil engineering.

(Prior Art) Shaped steel with a parallel flange portion such as H-shaped steel and parallel flange grooved steel (hereinafter collectively referred to as "parallel flange shaped steel")
Is manufactured by the rolling method,
The names of the respective parts of these parallel flange section steels will be described with reference to FIGS. 1 (a) and 1 (b) by taking the H section steels and parallel flange channel steels as typical examples.

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. 1 (a), the joint portion 12 is located at the center of the flange portion 10, and in the case of the channel steel shown in FIG. 1 (b), it is located at 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 (flange length, L ₀ ), the distance between parallel flanges is the web height (web height, H ₀ ), and as shown in the figure, the flange internal method S ₀ , flange Define the inner width W ₀ . According to the JIS standard, in the case of H-section steel, the web height H
Approximately 33 sizes are defined in the range of ₀ to 25 to 100 mm and 100 to 900 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. 2, the rough rolling by the breakdown mill (rolling machine) 20 and the universal rough mill 22 are performed.
Universal coarse mill group 2 consisting of 2Hi edger mill 24
6 by intermediate rolling, and by universal finishing mill 28 by finish rolling.

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. 3, 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 the side face of the horizontal roll 30 and the vertical roll 32 are used to form the flange. The thickness is reduced and the above-described modeling material is stretch-rolled into an intermediate rolled H-section steel in multiple passes. Then, in each pass in the intermediate rolling stage, as shown in the schematic side view in FIG. 4, the flange tip of the intermediate rolled H-section steel 31 is pressed down by the hole-shaped roll 42 of the ender mill 40 to reduce the flange width L ₀ . Set to a predetermined value.

In the finish rolling, as shown in FIG. 5, the horizontal roll 52 and the vertical roll 54 of the universal finishing mill 50 are used to make the thickness of the web 56 and the flange 58 in one pass or in multiple passes as in the case of the universal rough mill 22. Subtract each,
Moreover, 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.

As described above, according to 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 reduction of the web 56 by the horizontal roll 52 is similarly performed. Therefore, the web width W ₀ of the rolled H-section steel is
Determined by the width of the horizontal roll 52 of the universal finishing mill.

For this reason, the conventional H-section steel rolling method has the following problems.

(1) FIG. 6 illustrates changes in sectional shape in one series of H-section steels (for example, H600 × 200) having the same flange width L ₀ . Current of the flange thickness for in the same series is a flange within the width W ₀ is constant in the standard of (tf _0, t
f ₁ and tf ₂ ) are different from each other, and the outer dimensions of the web height H ₀ (H ₀ , H ₁ ,
H ₂ ) also have different values. That is, tf ₀ <tf ₁
<Tf ₂ and H ₀ <H ₁ <H ₂ .

The same relationship applies to the channel steel shown in FIG.

(2) When rolling shaped steel with different sizes of the inner flange width W ₀ , the horizontal roll 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 constantly hold this, a large space comparable to the building for rolling is required, so a large investment is also 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. As a result, horizontal rolls that can no longer be used in one series are cut into widths of several tens of millimeters and are reworked for the next series with smaller web heights. Therefore, compared to the case of rolls for steel sheets, roll 1
The amount of product rolled per book is extremely small. In other words, the roll cost per ton of product is high.

(4) If the web height H ₀ is out of specification, it is naturally necessary to prepare a dedicated horizontal roll for the universal finishing mill and change the rolls, so it is not economically viable for small lot orders. Often declined orders.

(Problems to be Solved by the Invention) Here, a general object of the present invention is to make it possible to change web width dimensions and to manufacture a plurality of series of parallel flange section steels in the same universal finish rolling mill. It 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 section steels with one type of horizontal roll in a universal finish rolling mill, halving the number of rolls possessed, and maintaining the outer dimensions of the web height constant in the same series. It is possible to provide a method for rolling a parallel flange section steel which can be manufactured at a low cost with other series rolling chances even if the outer dimensions are out of specification.

Still another object of the present invention is to use the same universal finish rolling horizontal roll to keep the outer dimensions of the web height constant even for different thicknesses, to make the outer corners at right angles, and to have non-standard dimensions. It is an object of the present invention to provide a method for rolling parallel flange channel steel that enables manufacturing at low cost even in the size of.

Still another object of the present invention is to make it possible to roll different series of H-section steels by using one kind of parallel rolls in a universal finish rolling mill, to make the outer dimensions of the web height constant in the same series, and to make them out of specification. It is an object of the present invention to provide a rolling method of H-section steel which can be manufactured in the same size as the standard size at the same cost and in which the number of held rolls can be significantly reduced.

Therefore, as a means for solving various problems related to the above-described conventional rolling method of a profile having a flange, Japanese Patent Application No.
The applicant has proposed the technology disclosed in 63-235388. This is a method of rolling a profile having a flange which is subjected to breakdown rolling, intermediate rolling and finish rolling as shown in FIG. 2, and is characterized in that the rolled material is a break-down rolling machine 20. Rough rolling, and then the intermediate rolling mill (coarse universal rough mill group) 26 completes rolling of the flange portion and the joint portion of both flange portions, and in the finish rolling, a universal mill 86 as shown in FIG. 8 is used. The point is that the width dimension of the joint portion 80 between both flange portions is finished by pressing the outer surface of the flange portion with the vertical roll 84 without contacting the inner surface of the flange portion with the side surface of the universal horizontal roll 82.

Furthermore, the applicant of the present invention has developed a universal mill 96 having a variable width two-division horizontal roll 90 and a vertical roll 92 as shown in FIG. 9 into a primary mill and a secondary mill as shown in FIGS. Japanese Patent Application No. 1-149851, which is applied to a rolling line provided with rough universal mills 22 and 22 ', and the web height is reduced by performing reverse rolling in one pass or multiple passes in the finishing universal mill 96. Proposed in.
Further, in Japanese Patent Application No. 1-149851, there are two finishing universal mills 110 consisting of fixed-width horizontal rolls and finishing universal mills 112 consisting of variable-width horizontal rolls, as shown in FIGS. 11 (a) and 11 (b). We have proposed a method for reducing the web height using a base universal mill.

According to these inventions, it is possible to make the outer dimension of the web height of a profile having a flange such as a horizontal flange shaped steel of the same series in one type of roll uniform, and to make the horizontal roll width of the rough universal rolling mill uniform. Without being constrained
H-shaped steel and channel steel with free web height can be manufactured with the same roll at the same rolling opportunity, and the number of rolls held can be greatly reduced and the unit consumption of rolls can be greatly improved.

As described above, the present inventor repeatedly carried out a large number of model mill experiments on the method of rolling a profile having a flange proposed by the present applicant, and this time, the following problems were clarified.

When the H-section steel is manufactured 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. 12 becomes a problem depending on the reduction amount of the height of the web. . (Amount of center deviation S = (ab) / 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. (JIS.G 3192 stipulates that the allowable range of center deviation is ± 3.0 mm for webs with a height of 300 mm or less and ± 4.5 mm for webs with a height of 300 mm or more.) If we carefully examine the manufacturing conditions when the deviation of the web center exceeds the allowable range, in addition to the size reduction of the web height, the fillet shape (for example, R dimension) of the material in the process of reducing the web height and the universal mill The outer peripheral edge shape (for example, r dimension) of the horizontal roll has a large influence, which hinders the rolling pass schedule design and roll shape design.

Therefore, the specific object of the present invention is to
When the profile with flanges typified by multiple series of H-section steels and parallel flange channel steels is manufactured by the same universal finishing mill with the dimensions in the web being variable, horizontal rolls of the same universal finishing mill When manufacturing a profile with a flange with a constant outer dimension of the web height even for different thicknesses, the web center deviation of the product was suppressed to a small level so as not to deviate from the specified tolerance. It is to provide a hot rolling method that enables the above.

(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 problem.

(1) When reducing the web height by using a barge universal mill as shown in Fig. 8 to press down the outer surface of the flange with a vertical roll without contacting the side of the universal horizontal roll with the inner surface of the flange As the web height is gradually reduced, as shown in FIGS. 13 (a) to 13 (c), the web portion begins to buckle between the horizontal roll side surface and the vertical roll (see FIG. (See b)), and then the web portion buckles greatly and a constriction occurs (13th (c)).

(2) After reducing the height of the web with the universal mill shown in FIG. 8, according to the technique disclosed in Japanese Patent Application No. 63-235388,
In the case of performing the shaping rolling with the variable width universal shaping mill as shown in FIG. 9, or as disclosed in Japanese Patent Application No. 1-149851, the variable width universal mill as shown in FIG. When the web height is further reduced in order to finish into a product, the rolling conditions in the final pass of the variable width universal mill (or shaping mill) are those that have undergone the rolling process of Figs. 13 (a) and (b). Figure 14 (a)
As shown in, the product is finished with good dimensions and shape with a small deviation of the center of the web.

However, in the case where the above-mentioned constriction occurs in the web portion as shown in Fig. 13 (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,
As shown in FIG. 2B, a product having a large deviation in the center of the web is finished.

That is, even if the web center is deviated due to a slight buckling in the unrolled portion of the web surface in the process of reducing the height of the web as shown in Fig. 13 (b), the subsequent shaping rolling or the reduction of the height of the web is performed. In the rolling process (however, with a slight reduction), the fillet portion (fillet portion) of the material is clamped by the outer peripheral edges of the side faces of the upper and lower horizontal rolls and rolled to correct it. On the other hand, in the process of reducing the web height,
As for the one with the sharpness as shown in Figure (c),
In the subsequent shaping rolling, even if the material is rolled while sandwiching the vicinity of the fillet portion between the outer peripheral edges of the upper and lower horizontal rolls, the constricted portion is not corrected and the center deviation 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. 63-135388.
See also the rolling method in which the horizontal roll of the universal mill shown in FIG. 8 is divided into two as variable width rolls, and the vertical roll is used to reduce the web height so that the inner surface of the flange does not contact the horizontal roll side. I found out that

(4) Furthermore, the facts of (1) and (2) apply to Japanese Patent Application No. 1-1498.
It was found that the same can be seen when the web height is reduced by one-pass or multi-pass reverse rolling in a universal mill using variable width horizontal rolls as disclosed in No. 51. That is, in this case, by pressing the outer surface of the flange portion with a vertical roll so that the inner surface of the flange portion contacts the side surface of the universal mill horizontal roll,
It is characterized by performing reduction rolling of the web height, but depending on the shape of the fillet portion 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, r dimension),
When the reduction amount of the web height is increased, the constriction generated near the fillet part during the rolling may not be corrected even if it is rolled while being sandwiched by the upper and lower horizontal rolls, and the finish of the web may occur with the deviation of the web center. It turned out to be.

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

18 (a) to 18 (c) are schematic views of material deformation in the vicinity of the fillet portion when the web height reduction rolling of H-section steel is performed by using the universal mill 86 of FIG. 8 based on the method of the present invention. Shown in. By optimizing the shape of the fillet portion 182 of the rolling stock 180 and the shape of the horizontal roll side outer peripheral edge 184, the web away from the flange inner surface by a distance l _B at the time of the reduction by ΔHc to start reduction of web height Even if a buckling like a neck occurs on the surface, as shown in FIG. 18 (c), it is possible to roll the web 186 while sandwiching the web 186 by the upper and lower horizontal rolls until the end of rolling, and the remaining neck is left. It was clarified that this can be prevented, and thus the deviation of the web center can be suppressed.

FIG. 18 illustrates the case where the height of the web is reduced without contacting the inner surface of the flange with the side surface of the universal horizontal roll. However, as described in (4) above, a universal mill equipped with a variable width horizontal roll is used. The same applies 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. It was also found that by rolling while holding the web between the upper and lower horizontal rolls until the end of rolling, the constriction is prevented from remaining and the deviation of the center of the web is suppressed.

Furthermore, in FIG. 18, the shape of the fillet portion 182 of the rolled material 180 is the R shape as shown in FIG. 17 (a), and the shape of the outer peripheral edge 184 of the side surface of the horizontal roll is also the r shape. As for the above, a taper shape as shown in FIGS. 17 (b) and 17 (c) and a shape in which a surplus thickness of a predetermined thickness is provided for a predetermined length may be adopted. Alternatively, a chamfered fillet portion as shown in FIG.
The outer peripheral edge of the horizontal roll may be chamfered.

Here, when a rolling material having a fillet portion 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. 9, It is necessary to prevent the position of the constriction due to buckling generated on the web surface due to the reduction of the height of the web from reaching the hollow portion of the two-division horizontal roll as shown in FIG. That is, if a constriction occurs in the hollow portion of the two-division horizontal roll, wrinkle-like defects remain on the product, which is a quality problem.

(Operation) Next, the present invention will be described more specifically 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 of the present invention, the breakdown rolling by the breakdown rolling mill (BD) 20 may be performed in the same manner as the conventional method,
Thereby, the rolled material is rolled into a beam blank.
After that, in the intermediate rolling using the rough universal rolling mill (UR) 22 and the edging rolling mill (E) 24, the rolled material is finished to a flange width, a flange thickness, and a web thickness close to the final dimension. In this intermediate rolling step, the fillet shape of the rolled material is also provided with various shapes as shown in FIGS. 17 (a) to (c).

The web height of the intermediate rolled shape steel thus obtained is adjusted by the first finishing universal mill 110 composed of horizontal rolls and vertical rolls. That is, by changing the opening degree of the vertical roll 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 tens mm.

FIG. 18 and FIG. 19 are partially enlarged views of FIG. 8, and each of FIGS. (A) to (c) mechanically shows the state of the rolled material at the start of rolling, during rolling, and at the end of rolling. ing.

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 shape of the fillet portion of the rolled material before the web height reduction rolling is an arc of radius R and the inner dimension of the web height is Hio, the web height reduction amount ΔHc is equal to the web height reduction amount ΔHc. Figure (b) shows the state where necking buckling occurs at the distance l _B from the inside of the flange when the height is reduced. At this time, the horizontal roll 82 does not completely clamp the web surface. The feature is that there is no.

In FIG. 18, the rolled material is based on the method of the present invention.
The R dimension of the fillet part 182 of 180, the arc shape of the radius r of the side surface outer peripheral end 184 of the horizontal roll 82, and the horizontal roll body length W
By properly setting _R , the constriction buckling generated on the web surface in the state of each figure (b) is rolled while being sandwiched by the upper and lower horizontal rolls 86, 86 as shown in each figure (c). It will disappear. That is, when the web height reduction of ΔHc is performed, the position where the constriction buckling occurs is in the region where the upper and lower horizontal rolls face each other in parallel. Yes, the formulation is as follows.

That is, FIG. 18 (b) from _{l B ≧ (Hio-ΔHc-} W R + 2r) / 2 ··· Here, the web height of the front of the rolling stock Hio is to reduce the web height by the finishing universal rolling ΔHc is the limit of web height reduction that causes buckling, W _R is the horizontal roll width (body length) of the finishing universal rolling mill, and r is the r dimension of the outer peripheral side of the horizontal roll. In the figure, l _B is the distance from the buckling position generated on the web surface to the inner surface of the flange as the web height is reduced.

FIGS. 19 (a) to (c) show the case where the web height reduction rolling is performed under the condition that the relation of the above equation is not satisfied,
The figure shows a state in which the necked buckling generated during rolling remains on the web surface after rolling.

By the way, the amount of reduction in the web height at which the constriction-like buckling occurs is limited ΔHc
Regarding the buckling occurrence position l _B , the present inventor has quantified various rolling conditions as a function from a huge amount of experimental results,
As an example, FIG. 15 shows the relationship between ΔHc and the web thickness t _w of the rolled material, and FIG. 16 illustrates the relationship between l _B and the dimension of fillet R. H in FIG. 15 shows the outer dimension of the web height before rolling. From the figure, as the ratio of the web pressure t _{w of the} rolled material to the outer dimension of the web height increases, the limit reduction rate of the web height (ΔH / H X100%) increases. Further, it can be seen from FIG. 16 that the buckling occurrence position l _B increases in proportion to the size of the fillet R, and the relationship between the two is expressed by l _B = 2 / 3R. When these ΔHc and l _B from the relationship is determined for a given pass schedule, it is sufficient to design the r dimension of the fillet portion shape or a roll so as to satisfy the relationship of the above formula. Hio and W _R are obtained in advance by the pass schedule and rolling mill.

That is, in order to perform rolling according to the formula, first, the buckling limit ΔHc is obtained from the relationship shown in FIG. 15, and this is calculated in advance with the web height inside dimension Hio and horizontal roll width W of the rolled material.
And a _R, obtained relation seat屈発raw position l _B and role of r dimension by formula, fillet shape from the relationship Te based cerebrospinal example Figure 16 thereto, and it is to design a roll form.

20 (a) to 20 (c), the H-section steel having the shape of the tapered fillet portion 202 as shown in FIG. 17 (b) is based on the method of the present invention and the finish universal of FIG. The partially enlarged view of the rolling process at the time of web height reduction rolling with the mill 86 is shown. Also in this case, residual neck buckling can be suppressed by setting the shape of the fillet portion 202 or the r dimension of the outer peripheral edge 204 of the side surface of the horizontal roll so as to satisfy the relationship of the above expression. The constriction caused by buckling (FIG. 29 (b)) once disappears by continuing rolling (FIG. 20 (c)).

Further, in FIG. 22, by setting the chamfering dimension (C dimension) of the outer peripheral edge 224 of the side surface of the horizontal roll so as to satisfy the following relationship based on the method of the present invention, the finishing universal mill 86 of FIG. It shows a mechanism for suppressing the remaining buckling buckling during web height reduction rolling.

That is, FIG. 22 (b) from _{l B ≧ (Hio-ΔHc-} W R + 2c) / 2 ··· Here, the web height of the rolling stock before Hio is to reduce the web height by the finishing universal rolling web height reduction ratio of a internal dimensions ,, .DELTA.Hc generates a buckling limit, W _R is the horizontal roll width of the finishing universal rolling machine (barrel length), C chamfer C of the horizontal roll side outer peripheral end 224
The dimension is shown, and l _B is the distance from the buckling position generated on the web surface to the inner surface of the flange as the web height is reduced.

Also in this case, the shape of the fillet portion and the shape of the roll may be designed in the same manner as in the case of the above-mentioned expression.

By the way, when performing web height reduction rolling of a rolling material having a fillet portion shape as shown in FIG. 17 (b) or (c), the buckling caused by buckling that occurs on the web surface as the web height is reduced. The position shifts from the web-flange joint to the center of the web. Therefore, when the height of the web is reduced by the universal mill 96 composed of the variable width horizontal rolls as shown in FIG. 9, the hollow part of the two-division horizontal roll as shown in FIG. When the necked position comes, the product remains as wrinkle-like defects, and in this case, it is necessary to satisfy the following relationship.

That is, the following relationship may be established in the state of FIG.

w _R ≧ l _B ... where w _R is the body length of each horizontal roll of the variable width finishing universal mill after splitting, and l _B is the buckling position generated on the web surface as the web height is reduced. Indicates the distance to the inner surface of the flange.

From the above, in the rolling method in which the horizontal roll width of the finishing universal rolling mill is divided into two, the width can be adjusted online, and the web height is reduced by the finishing universal rolling mill, In order to satisfy the relationship, depending on the web height reduction amount and the horizontal roll width (cylinder length), the fillet shape of the rolled material or the cylinder length w _R of each part of the horizontal roll after splitting and The r dimension or the C dimension may be designed respectively.

When the present invention is specifically applied to a rolling line as shown in FIG. 11 (a), the web height reduction rolling in the first finish universal rolling mill (UF1) 110 is as follows.
The shape of the fillet portion of the rolled material or the shape of the outer peripheral edge of the side surface of the horizontal roll is optimized based on the above formula or the formula according to the web height reduction amount and the horizontal roll width (cylinder length). Next, when performing the web height reduction rolling in the second finish universal rolling mill (UF2) 112, the variable width horizontal roll width, the body length after division, and the roll side surface are based on the above formula or The outer peripheral edge shape may be optimized.

However, when the web height reduction rolling and reverse rolling of a plurality of passes in the UF1 or UF2, Hio in the ~ formula for each path, .DELTA.Hc, l _B is newly set Ki not a preparative to predetermined pass schedule However, it is necessary to consider the shape of the fillet portion of the rolled material or the shape of the outer peripheral edge of the side surface of the horizontal roll.

The above is the case where the present invention is applied to the process of reducing the web height in the rolling line as shown in FIG. 11 (b), or the rolling line as shown in FIG. 10 (a), (b). The same applies when the present invention is applied to the process of reducing the height of the web.

In addition, although the above has described H-section steel in particular, the process of reducing the web height of a profile having another flange represented by parallel flange channel steel and manufacturing a product having an arbitrary web height is described. The present invention can also be applied to the present invention, and it is possible to improve the shape and dimensional accuracy of a product when a reduction of a web height is significantly reduced.

(Examples) The present invention will be described in detail with reference to Examples.

Example 1 When hot rolling H-section steel of H400 × 200 series with a constant outside height of web in the rolling line shown in FIG. 11 (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 the breakdown rolling machine 20 having a roll hole type. Coarse universal rolling mill (U
R) 22 and edger rolling machine (E) 24 are used for lever rolling 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 400-2 × 9382 mm, which is the value obtained by subtracting 2 times. 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 a first finishing universal rolling mill (UF1) 110, the height of the web is reduced by a vertical roll in one pass without contacting the inner surface of the flange with the side surface of the horizontal roll, and then the first 2 finish universal rolling mill (UF
2) At 112, the product was formed by forming and rolling with the main purpose of making the web thickness uniform and correcting the squareness of the flange and the web.

Here, the horizontal roll width W _R of the UF1 is calculated from the outer dimension of the target web height (= 400 mm) to the minimum flange thickness (= 2 mm) in the series.
2mm) minus twice, ie 400-2 × 22 = 35
Keep 6 mm.

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 were taken, the present invention was used as an example to determine the shape of the frets of the rolled material of UF1.

The inside height of the UF1 rolled material, that is, the rolled material after the final pass of UR, is Hio = 386 mm, and the UF1 horizontal roll side outer peripheral edge r dimension is 6 mm. The required reduction amount ΔH of the web height for each size is as shown in Table 1. Table 1 shows the buckling limit web height reduction amount ΔHc ^* estimated for each size, and the range of the distance l _B ^* from the buckling position to the inner surface of the flange that satisfies the above expression. From now on, the fillet shape of the rolled material of UF1 is 20R so that l _B is within a predetermined range (≧ 12.5 mm) for t _w = 6 mm and t _f = 16 mm where ΔH> ΔHc ^*.
It has an arc shape of (l _B ≈ 13.3 mm).

Table 2 shows three sizes of H400 × 200 series.
The web center deviation determination situation in the case of applying the present invention is shown, and the center deviation of the products of any size is within the tolerance and the quality is good. Also, FIG. 23 (a)-
(C) schematically shows the rolling steps from UR to UF2 based on the method of the present invention for t _w = 6 mm and t _r = 16 mm.

For comparison, the fillet shape of the UF1 rolled material is 15R.
The same applies to the 3 sizes of the H400 × 200 series and the 11th
Table 3 shows the product quality situation when the web height reduction rolling is performed on the rolling line shown in FIG. From this table, the web height reduction exceeds the buckling limit t _w = 6 mm, t _r = 16 m
It can be seen that the deviation of the deviation of the center of the web about the size of m frequently occurs.

Example 2 When hot rolling H-section steel of H400 × 200 series having a constant outside height of web in the rolling line shown in FIG. 10 (a),
An example of applying the method of the present invention will be described below.

In the case of this example, the steps from breakdown rolling to rough universal rolling and edger rolling were the same as in the case of Example 1 described above, and the horizontal roll width of UR was 386 mm. The material after UR rolling is a finish universal rolling mill 96 consisting of variable-width two-division horizontal rolls, and the web height is reduced and rolled in one pass so that the inner surface of the flange is in contact with the side of the horizontal roll of the finish universal rolling mill, and At the same time, shaping rolling is carried out mainly for the purpose of making the web thickness uniform and straightening the squareness of the flange and the web to obtain a product.

Wherein the width of variable horizontal roll width of the finishing universal rolling machine 96 (cylinder length) W _R will be changed for each flange thickness as shown in Table 5. The body length W _R of each part of the horizontal roll after division was 173 mm.

As an example, the product web thickness t _w and the flange thickness t _f are each 4th
When the values shown in the table were taken, the present invention was carried out to determine the r dimension of the side surface outer peripheral edge of the variable width horizontal roll.

The inside diameter of the rolled material of the finish universal rolling mill 96, that is, the rolled material after the final pass of the UR was Hio = 386 mm, and the fillet shape was an inner arc of 20R. The required reduction amount ΔH of the web height for each size was as shown in Table 4. In the same table, the buckling limit web height reduction amount ΔHc ^* estimated for each size, the distance from the buckling position to the flange inner surface l _B ^*, and the range of the r dimension of the horizontal roll side outer peripheral edge that satisfies the above formula r ^* is also shown. In the case of the present embodiment, as shown in Table 4, the body lengths w _R > l _B ^* of the horizontal rolls after division are satisfied, which satisfies the relationship of the above equation.

From the relationship in Table 4. ΔH> ΔHc ^* , t _w = 6 mm, t _f =
Since it is necessary to set the r dimension of the variable width horizontal roll to a predetermined range for 16 mm, this is set to r = 10 mm.

Table 5 shows three sizes of H400 × 200 series.
The web center deviation determination situation when the present invention is applied is shown. The center deviation of all products was within the tolerance and the quality was good. Further, in FIGS. 24 (a) to 24 (c), t _w
= 6 mm, the t _r = 16 mm, based on the method of the present invention UR~U
The rolling process up to F is schematically shown.

For comparison, when the horizontal roll of the variable width finish universal mill is set to 16 mm and the r size is 16 mm, the three sizes of the H400 × 200 series are similarly subjected to web height reduction rolling at the rolling line shown in FIG. 10 (a). Table 6 shows the product quality status.

From this table, the reduction amount of the web height exceeds the buckling limit.
It can be seen that for the sizes t _w = 6 mm and t _r = 16 mm, the deviation of the center of the web is frequently out of tolerance.

Example 3 In the rolling line shown in FIG. 11 (b), JIS standard H
An example of applying the method of the present invention when rolling a product of H400 × 300 series on the same roll as that of 450 × 300 series will be described below.

First, in a breakdown rolling machine (BD) 20, a heated rolling material such as CC slab or bloom is rolled to beam black. Next, H450 × 300 series intermediate rolling is performed by an intermediate rolling mill group consisting of a rough universal rolling mill (UR) 22 and an edger rolling mill (E) 24 having a horizontal roll width of 404 mm. At this time, the side taper of the horizontal roll of UR was 5 ° as before. When rolling H450 × 300 series H-section steel, the first finish universal rolling mill (UF1) 1
The flange surface is raised at 10 and further shaped and rolled into a predetermined shape and size by the second variable width finish universal rolling mill (UF2) 112 to obtain 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 To model. But later, in UF1 1
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 (body length) W _R of the UF1 as shown in Table 7 and 358 mm, the horizontal roll width of UF2 (body length) W _R
Is also set to 358 mm. The body length w _R of each part of the horizontal roll after division was 179 mm. UF1 rolled material, that is, rolled material after the final pass of UR, inside the web height Hio = 404
mm, the UF2 rolled material, that is, UF1 has a web height inside dimension after reduction of the web height of Hio = 374 mm, and the fillet shape is finished to be tapered by UR. Table 7 shows
Buckling limit web height reduction amount estimated for each UF mill Δ
Hc ^* , the distance l _B ^* from the buckling position to the inner surface of the flange, and the range r ^* of the r dimension of the outer peripheral edge of the horizontal roll side surface of each UF mill satisfying the above formula are also shown. In the case of this embodiment, the body lengths w _R > l _B ^* of each part of the horizontal roll of the UF2 after division are satisfied, which satisfies the relationship of the above formula.

From the relationship in Table 7. For UF1 with ΔH> ΔHc ^* ,
Since it is necessary to set the r dimension of the horizontal roll within a predetermined range, r = 18 mm. For UF2, ΔH <ΔHc ^*
Therefore, it is not necessary to take measures against buckling, but as disclosed by the present applicant in Japanese Patent Application No. 1-14985, r of the horizontal roll of UF2
The dimension must be equal to or smaller than the r dimension of the horizontal roll of UF1, and in this example, r = 15 mm of UF2.

Table 8 shows the web center deviation of the product when the present invention was applied to the production of H386 × 297 × 9/14 size. The center deviation was within the tolerance and the quality was good. In addition, UR based on the method of the present invention is shown in FIGS.
~ The UF2 rolling process is schematically shown.

For comparison, the r dimension of the UF1 horizontal roll is set to 25 mm and U
F2 width variable horizontal roll with r size of 20mm
Table 9 shows the product quality status when web height reduction rolling is performed on the rolling line shown in Fig. 11 (b).

From this table, the UF where the reduction amount of the web height exceeds the buckling limit
It can be seen that the constriction of the fillet part at 1 mil remains in the product and the deviation of the web center deviation frequently occurs.

(Effects of the Invention) As described in detail above, according to the present invention, when a profile having a flange represented by a plurality of series H-section steels and parallel flange channel steels is manufactured by the same universal finishing mill. Alternatively, when manufacturing a profile with a flange with a constant outside dimension of the web height for different thickness sizes using the same horizontal roll of the Univar finishing mill, the product with the reduction of the web height A hot rolling method can be realized in which deviation of the center of the web is generated and deviation from a predetermined dimensional tolerance is prevented, and the web height can be significantly changed, which is extremely useful in industry.

[Brief description of drawings]

1 (a) and 1 (b) are explanatory views of the names of the respective parts of the H-section steel and the parallel flange channel steel; FIG. 2 is the layout of a conventional parallel flange section rolling mill; , Fig. 4 is an explanatory view of the state of rolling by the conventional universal rough rolling mill; Fig. 4 is an explanatory view of the state of rolling by the conventional method of edger rolling mill; Fig. 5 is the same as the state of rolling by the universal finish rolling mill. Explanatory drawing; FIG. 6 and FIG. 7 are explanatory drawings of the current product size type of H-section steel and parallel flange channel steel, respectively. FIG. 8 shows the state of rolling by the universal finish rolling mill according to the present invention. FIG. 9 is an explanatory view showing a state of rolling by a variable width universal finishing mill according to the present invention; FIG. 10 (a), (b) and FIG. 11 (a), (b) are ,
Layout of a parallel flange section rolling mill according to the present invention; Fig. 12 is an explanatory view of web center deviation of H section steel; Figs. 13 (a) to (c) are universal finish rolling mills according to the present invention. 14 (a) and 14 (b) are explanatory views showing the state of web center deviation occurring in the universal finish rolling according to the present invention; FIG. 15 is FIG. 16 is a diagram showing the relation between the web thickness and the buckling limit web height reduction amount in the universal finish rolling according to the present invention; FIG. 16 is a diagram showing the relation between the R dimension of the fillet portion and the buckling occurrence position in the universal finish rolling according to the present invention. FIG. 17 (a) to (c) are explanatory views of the fillet portion shape of H-section steel; FIG. 18 (a) to (c), FIG. 20 (a) to (c), and 22. Figures (a) to (c) show a universal device according to the present invention. Fig. 19 (a) to (c) are enlarged views of the fillet part in the conventional universal finish rolling; Figs. 21 (a) to (c) are conventional universal finishes. Explanatory drawing of web buckling during rolling; FIGS. 23, 24, and 25 are explanatory views of the rolling process in the example of the present invention. 20: Breakdown rolling mill 22: (Primary) rough universal rolling mill 24: Edger rolling mill 22 ': Secondary rough universal rolling mill 96: Finishing universal rolling mill 110: 1st finishing universal rolling mill 112: 2nd finishing universal rolling mill Rolling mill

Claims (2)

[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 the rolled material after edger rolling is finished with horizontal rolls of fixed width. When rolling with a universal rolling mill, the outer surface of the flange portion is rolled down by a vertical roll without contacting the inner surface of the flange portion with the side surface of the horizontal roll of the universal rolling mill, thereby reducing the web height in one or more passes. In the method of performing, after determining the fillet portion shape of the rolling material before the finish universal rolling so as to satisfy the following relationship, after forming in the rolling step before the finish universal rolling to be the fillet portion shape,
A method for hot rolling a profile having a flange, which comprises rolling with the finishing universal rolling mill. l _B ≧ (Hio−ΔHc−W _R + 2r) / 2 or l _B ≧ (Hio−ΔHc−W _R + 2c) / 2, where Hio is the inside dimension of the web height of the rolled material before the finish universal rolling, ΔHc is the buckling limit web height reduction amount, W _R is the horizontal roll width (cylinder length) of the finishing universal rolling mill, r is the horizontal roll side outer peripheral edge r dimension, c is the horizontal roll side peripheral edge c dimension, l _B represents the distance from the buckling position generated on the web surface to the inner surface of the flange as the web height is reduced. 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, wherein a horizontal roll width of a finish universal rolling mill is divided into two, and is online. In a rolling method in which the width is adjustable and the web height is reduced by one-pass or multi-pass reverse rolling in the finishing universal rolling mill, the rolling material fillet before the finishing universal rolling is made to satisfy the following relations. A shape having a flange, characterized in that the shape of the part is determined, and the shape of the fillet is formed in the rolling step before the finish universal rolling, and then rolled by the finish universal rolling machine consisting of the two-division horizontal rolls. Hot rolling method for material. w _R ≧ l _B ≧ (Hio-ΔHc-W _R + 2r) / 2 or w _R ≧ l _B ≧ (Hio-ΔHc-W _R + 2c) / 2 where Hio is the finishing universal consisting of the two-division horizontal rolls Rolling material before rolling Web height inside dimension, ΔHc
Is the amount of reduction of the buckling limit web height, W _R is the width of two horizontal rolls of the finishing universal rolling mill, w _R is the body length of each horizontal roll after splitting, r is the outer peripheral edge r dimension of the horizontal roll,
Represents the distance of the horizontal roll side outer peripheral edge dimension c, l _B from buckling position generated on the web surface with the reduction of the web height to the flange inner surface.