JPH0655201A - Method for controlling and rolling web center bias of h-shape steel - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Providing a method that can reliably control the center deviation when reducing the inner width of the H-section steel web. [Configuration] Web center deviation measurement value S over the entire length of the rolled material
[= (Ab) / 2; a and b measure the inner width of the upper and lower flanges of each H-section steel. An offset position e of the flange center with respect to the mill pass center or a correction amount Δe of e with respect to the measured value of the web center deviation on the exit side is obtained by the following formula. Feedforward or feedback control is performed according to the offset position e or Δe. e = S · (1-100 / η), Δe = −S · 100 / η
Formula 1 Center deviation control efficiency η = K ₁ · (1 _df · I _z ^1/4 ) / (1 _dw
・ L) + K ₂ 1 _df , 1 _dw is the projected contact length between the flange outer surface of each material to be rolled and the vertical and horizontal rolls of the universal rolling mill, I _z is the second moment of the cross section, and K ₁ and K ₂ are constants. Is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling method for H-section steel used in fields such as construction and civil engineering, and more particularly to a method for controlling web center deviation of H-section steel.

[0002]

2. Description of the Related Art Conventionally, when manufacturing H-section steel by rolling,
Since rolls of the same width are used in the same rolling chance,
The inner width of the flange of H-section steel can be made constant, but when the cross-sectional dimensions such as the flange thickness are changed, the web height changes accordingly, so the nominal size and the web height are the same series. There are many things that do not match. These relationships are shown in FIG. 1 by taking the H-section steel 60 as an example. In the figure, H ₀ , H ₁ and H ₂ are web heights and W ₀ is the web inner width. If the plate thickness is tf ₀ <tf ₁ <tf ₂ , then H ₀ <H ₁ <H ₂ when W ₀ is constant.

On the other hand, when the H-section steel is manufactured by welding, the plate thickness can be selected and used so as to have a predetermined size, so that the cross-sectional dimension changes in the same series. Can make the web height all constant. These relationships are shown in FIG. 2 by taking the H-section steel 62 as an example, and the reference numerals in the figure are the same as those in FIG. Since W ₀ , W ₁ and W ₂ can be changed by changing the plate thicknesses tf ₀ , tf ₁ and tf ₂ , H ₀ , H ₁ and H ₂ can be made constant.

The present applicant has already proposed some techniques as means for solving the above-mentioned problems relating to the method of rolling a profile having a conventional flange. In Japanese Patent Application No. 1-149851, a universal rolling mill (universal mill, hereinafter the same) 90 having a vertical roll 94 and a variable width split horizontal roll 92 as shown in FIG. 3 is shown in FIGS. 4 (a) and 4 (b). We have proposed a method to reduce the height of the web (inner width of the web) by applying it to such a rolling line and performing reverse rolling of one pass or multiple passes in the finishing universal mill at that time.

Further, in Japanese Patent Application No. 1-149851, as shown in FIGS. 5 (a) and 5 (b), a finishing universal mill (UF ₁ ) consisting of fixed width horizontal rolls and a finishing universal mill consisting of variable width horizontal rolls are shown. We proposed a web height (web inner width) reduction rolling method using two finishing universal mills of a mill (UF ₂ ).

Furthermore, the applicant of the present invention has disclosed in Japanese Patent Application No. 4-44934 UR ₁ (first rough universal rolling mill) -E (edger rolling mill) -UR ₂ (second rough universal rolling mill) or UR. (Coarse Universal Rolling Mill) -E (Edger Rolling Mill) -UF (Finishing Universal Rolling Mill) etc. In a H-shaped steel hot rolling line consisting of three rolling mill rows, the horizontal rolls of each rolling mill are divided. The width of each pass can be adjusted online, and when the rough-shaped steel slab after breakdown rolling is rolled in multiple passes with this rolling mill train, the inner width of the web is reduced or expanded for each rolling pass. , A method of manufacturing H-section steels of various sizes with the same rolling chance with the same roll was proposed.

According to these inventions, the height of the web of the H series steels of the same series, that is, the outer dimension can be made constant by one type of roll, and the horizontal roll width of the rough universal rolling mill is restricted. It is possible to manufacture H-section steel with a free web height on the same roll with the same rolling chance without being cut, and it is possible to significantly reduce the number of rolls possessed and significantly improve the basic unit of roll.

[0008]

With respect to the various hot rolling methods for H-section steels as proposed by the present applicant, the present inventor repeatedly carried out enormous model mill experiments and found the following problems. Revealed.

(1) When manufacturing an H-section steel by the method of rolling a section having a flange proposed by the present applicant, depending on the reduction amount of the web height, the H-section steel product as shown in FIG.
The web center deviation of 60 is a problem. Here, the central deviation amount S is represented by S = (a−b) / 2. Here, a and b are the inner widths of the upper and lower flanges of the H-section steel, respectively.

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 is rapidly increased, and the product does not satisfy the predetermined tolerance. According to JIS G 3192, the tolerance of center deviation is ± 3.0 m for webs with a height of 300 mm or less.
m and web height over 300 mm are specified as ± 4.5 mm.

(2) As a method for preventing the reduction of the web center deviation of the H-section steel in the above web height reduction rolling, the present applicant has developed the technique disclosed in, for example, Japanese Patent Application No. 2-7812. Is a method for preventing the web center deviation of the H-shaped steel material before the web height reduction rolling from being deteriorated by the web height reduction rolling, and not for correcting the center deviation. Therefore, a large web center deviation generated in the rolling process before finish rolling is not corrected even if the above-mentioned web height reduction rolling proposed by the present applicant is adopted, and remains as the web center deviation of the product. Doing so may cause deviation from the dimensional tolerance.

(3) Further, the applicant of the present invention, in Japanese Patent Application No. 2-265691, divides the horizontal roll width of the finishing universal rolling mill into two, and has a structure in which the width can be adjusted online. Alternatively, in a rolling method in which the web height is reduced by rolling in a plurality of passes, the inlet side of the finishing universal rolling mill is determined based on the web center deviation measurement value installed on the upstream side and / or the downstream side of the rolling mill. Has disclosed a web center deviation control rolling method for H-section steel in which the vertical position is adjusted during rolling by means of a roller guide arranged in close proximity. This method can be a solution to the problem described in (2) above, but since the relationship between the web center deviation measurement value of the material to be rolled and the position adjustment amount of the roller guide has not been clarified quantitatively, it is actually In many cases, inconvenience occurred in controlling the center deviation. Further, the application target is limited to the finishing universal rolling machine having the variable width horizontal rolls divided into two, and the above-mentioned H
It could not be applied to various rolling methods of shaped steel.

It is an object of the present invention to make it possible to reliably control the deviation of the center of the web during the reduction of the inner width of the web at any stage of rough universal rolling or finish universal rolling. It is an object of the present invention to provide a method for controlling rolling with center deviation.

[0014]

In order to solve such a problem, the present inventor conducted a web height reduction rolling experiment of H-section steel using a universal rolling machine having a variable width horizontal roll and carried out an enormous amount of experiments. The following facts were found from the experimental data.

In a universal mill 74 having a vertical roll 70 and a variable width horizontal roll 72 (in this case, a roll which is divided into two and whose width can be adjusted in the axial direction) as shown in FIG.
The flange center (center point of the flange width) of the H-section steel 76 having the web 75 to be rolled is vertically shifted by e with respect to the path center of the rolling mill to perform web height reduction rolling,
The change in the web center deviation of the H-section steel before and after rolling was investigated. 7 (b) is a sectional view taken along the line AA 'of FIG. 7 (a), FIG. 7 (c) is a sectional view taken along CC', and FIG. 7 (d) is a sectional view taken along BB '.

The result at this time is shown in FIG.
₀ is the web center deviation of the material to be rolled on the entrance side of the rolling mill
[= (Ab) / 2, where a is the inner width of the upper flange, b
Indicates the inner width of the lower flange. ], And S _{1 on} the vertical axis represents the web center deviation value on the delivery side of the rolling mill.

As shown in FIG. 8, S ₀ and S ₁ are in a substantially linear relationship, and the gradient thereof is the rolling condition (web thickness, flange thickness, flange width, web width, flange height, reduction of web height). Amount, rolling material, rolling temperature, etc.)
Moreover, it was found that the intercept (vertical position) of the straight line changes depending on e. That is, it was found that S ₁ can be mathematically expressed by the following equation by S ₀ and e.

S ₁ = S ₀ × (1−η / 100) + e × η / 100 (1) where η is the web center deviation control efficiency and is defined by the following equation. is there. η = (Change in center deviation before and after universal rolling / Amount of deviation in the vertical direction of the web center of the rolled material from the mill pass center) × 100 (unit:%) ··· (2) Web represented by this equation (2) It can be seen from the relationship of the equation (1) that the slope of the straight line in FIG. 8 becomes smaller when the center deviation control efficiency η is large, and conversely the slope of the straight line becomes larger when η is small. If e is large, the straight line in FIG.
The value of S ₁ is increased with respect to _0, conversely, that the value of S ₁ is decreased relative to S ₀ when the value of e is reduced (1)
It is easy to understand from the relation of the formula. The following control is possible by experimentally or theoretically obtaining η in Eq. (2) based on various rolling conditions in web height reduction rolling.

The center deviation S ₀ of the rolled material before the web height reduction rolling by the universal rolling mill is detected, and the center deviation S ₁ after rolling can be set to 0 based on the detected value.
It is calculated using equation (1). After that, the position of the flange roller guide, which is installed close to the entrance side of the rolling mill, is adjusted to feed-forward control the vertical position of the flange portion of the material to be rolled with respect to the mill pass center during rolling.

Detecting the web center deviation S ₁ of the H-shaped steel after rolling, and based on the detected value, the correction amount Δe of e necessary for making the S ₁ to 0 is expressed by the equation (1). Calculate using.
After that, the position of the flange roller guide, which is installed close to the entrance side of the rolling mill, is adjusted, and the vertical position of the flange portion of the material to be rolled with respect to the mill pass center is feedback-controlled during rolling.

By performing such feedforward control and feedback control at the same time, more reliable and highly accurate web center deviation control becomes possible. Here, the control efficiency (%) η of the center deviation in the equation (2) is calculated from the model mill experiment conducted by the present inventor and the rolling result using the actual rolling mill as shown in FIG. 9 as an example. η is (1 _df・ I _z ^1/4 ) /
It was found to have a linear relationship with (1 _dw · L).

That is, it has been found that η can be generally formulated as follows. η = K ₁ · (1 _df · I _z ^1/4 ) / (1 _dw · L) + K ₂ (3) where 1 _df and 1 _dw are the outer surface of the flange of the rolled material and the universal rolling mill, respectively. Is the projected contact length with the vertical rolls, the projected contact length between the web and the horizontal rolls of the universal rolling mill, I _z is the second moment of area of the rolled material, and L is the universal rolling mill as shown in FIG. Represents the distance between the roller center of the roll and the roller of the flange roller guide. Also,
Both K ₁ and K ₂ are constants experimentally obtained.
The projected contact lengths 1 _df , 1 _dw and the second moment of area I _z can be calculated if the rolling schedule is determined, and therefore η can be calculated by the above equation (3) before rolling.

As a result of the above, the present inventor has completed a web center deviation controlled rolling method for H-section steel in which the web center deviation is small over the entire length of the material to be rolled and no products are out of the dimensional tolerance. .

Here, the gist of the present invention is a control rolling method of the web center deviation in the hot rolling method of H-section steel using a universal rolling mill, in which the horizontal rolls of the universal rolling mill are divided. The width of the web can be adjusted online by means of one-pass or multi-pass rolling in the universal rolling mill to reduce the inner width of the web: Rolling is performed by a web center deviation measuring device installed on the upstream side of the universal rolling mill. Web center deviation measurement value S [= (ab) / 2; a and b are the upper and lower flange inner widths of H-section steel] over the entire length of the material; From the detected web center deviation measurement value S The offset position e of the center of the flange of the rolled material with respect to the mill pass center is calculated by the following formula; and the flange of the rolled material is placed at the obtained offset position e. H-shaped steel characterized in that the vertical position of the material to be rolled is adjusted during rolling by a roller guide (eg, a flange roller guide, a web roller guide) disposed close to the entrance side of the universal rolling machine so as to bring the mind to mind. Is a web center deviation controlled rolling method.

E = S · (1−100 / η) (4) However, when e> 0, the offset is upward, and when e <0, the offset is downward.

Here, η is the web center deviation control efficiency, and is represented by the above-mentioned equation (3). η = K ₁ · (1 _df · I _z ^1/4 ) / (1 _dw · L) + K ₂ (3) where 1 _df and 1 _dw are the outer surface of the flange of the rolled material and the universal rolling mill, respectively. Is the projected contact length of the roll with the vertical roll, the projected contact length of the web with the horizontal roll of the universal rolling mill, I _z is the second moment of area of the rolled material, and L is the roll of the universal rolling mill and the roller of the roller guide. Shows the distance between axes. Further, both K ₁ and K ₂ are constants experimentally obtained.

Further, from another aspect, the present invention is a method for controlling the web center deviation in a hot rolling method for H-section steel using a universal rolling mill, in which the horizontal rolls of the universal rolling mill are divided. The width of the web can be adjusted online by means of one-pass or multiple-pass rolling in the universal rolling mill to reduce the inner width of the web: rolling by a web center deviation measuring device installed on the downstream side of the universal rolling mill Web center deviation measurement value S [= (ab) / 2; a and b are the upper and lower flange inner widths of H-section steel] over the entire length of the material; From the detected web center deviation measurement value S Determining a correction amount Δe of the offset position of the flange center of the material to be rolled on the entrance side of the universal rolling mill with respect to the mill pass center by the following formula; A web center of H-section steel characterized in that the vertical position of the material to be rolled with respect to the mill pass center is adjusted by the correction amount Δe during rolling by means of a roller guide (eg, a flange roller guide) arranged close to the upstream side of the Versal rolling mill. This is a bias control rolling method.

Δe = −S · 100 / η (5) However, if e> 0, the position is adjusted upward, and if e <0, the position is adjusted downward. Here, η is as described above.

As described above, the present invention performs feedforward control of the offset position e described above, and feedback control of the correction amount Δe of the offset position described above after rolling. It can also be said to be a rolling method with controlled center deviation.

[0030]

The present invention will be described more specifically with reference to the accompanying drawings. The rolling method according to the present invention is, for example, as shown in FIG.
It can be carried out by the rolling line shown in.

First, according to the rolling method of the present invention,
Breakdown rolling may be performed in the same manner as in the past, and this allows rolling material (slab) to be beam blank (rough shaped billet).
Roll to. Subsequent intermediate rolling using a rough universal mill (coarse universal mill: UR) and an edging mill (edger mill: E) finishes the rolled material to a flange width, flange thickness, and web thickness close to the final dimensions.

The intermediate rolled shape steel thus obtained is
Finishing universal rolling machine consisting of horizontal rolls and vertical rolls with variable split width (Finishing universal mill: UF)
As a result, the web height reduction rolling is performed in one pass or a plurality of passes, and the outer dimension of the web height of the H-section steel can be freely changed within the range of several tens mm. If necessary, the finishing universal rolling mill may perform plural revers rolling.

The web center deviation controlled rolling according to the present invention may be applied to rough universal rolling or finish universal rolling. Further, in that case, the divided horizontal rolls may be two or more divided rolls, and there is no particular limitation in this respect, but generally, two or three divided rolls are used, and the width adjustment mechanism is also included for them. Since they are already known, they may be appropriately used if necessary.

FIGS. 10 (a) and 10 (b) show a side view of the web height reduction rolling process in the present invention. Finishing universal rolling mill 74 with variable width horizontal rolls 72
The upper and lower ends of the flange of the H-shaped steel 76, which is the material to be rolled, are constrained by the flange roller guide 82, which is a vertical position changing means installed close to the entry side of the, while the vertical position of the flange is adjusted during rolling. is there.

FIG. 10 (a) shows a case where the web center deviation S ₀ (= (a ₀ −b ₀ ) / 2) of the material to be rolled before rolling is negative (a ₀ <b ₀ ). 10 (b) represents the case where the web center deviation S ₀ (= (a ₀ −b ₀ ) / 2) of the rolled material before rolling is positive (a ₀ > b ₀ ).

Here, since S ₀ <0 in FIG. 10 (a), the flange roller guide is held so that e> 0, that is, the flange center is held at a position separated by | e | above the mill path center. adjust. Also, in FIG. 10 (b), S ₀ > 0
Therefore, the flange roller guide is adjusted so that e <0, that is, the flange center is held at a position downwardly | e | from the mill pass center.

The adjustment amount e at this time is calculated as follows with S ₁ = 0 in the above equation (1). e = S ₀ · (1-100 / η) (6) Therefore, the web center deviation value of the material to be rolled is measured on the upstream side of the universal rolling mill and the flange roller guide, and based on the measurement result. Then, by calculating the value e by the above formula (6) and controlling the vertical position of the flange roller guide, the center deviation value S ₁ after rolling can be brought close to "0". Note that Equation (6) is equivalent to Equation (4) when generalized.

The means for measuring the web center deviation value is not particularly limited, but as will be apparent to those skilled in the art from the above description, mechanical means (eg, magnescale) or optical means can be used. (Example: laser range finder)

Other examples of the web center deviation measuring device used for practicing the present invention include, for example, JP-A-58-17.
The device disclosed in Japanese Patent No. 9515 can also be used.
Here, η in the equation (6) is the control efficiency (%) of the center deviation already described in connection with FIG. 9, and can be obtained by the equation (3) before rolling.

Next, according to another embodiment of the present invention, the measured value of the web center deviation over the entire length of the rolled material detected by the web center deviation measuring device installed on the downstream side of the universal rolling mill is used. A method for controlling the center deviation of the rolled and rolled material will be described.

Now, in a universal rolling mill having a flange roller guide installed on the entrance side as shown in FIGS. 10 (a) and 10 (b), specific positions of the material to be rolled before and after rolling in an arbitrary pass
The web center deviations _{(denoted by i)} are S _{0 (i)} and S _{1 (i), respectively,} and the offset amount with respect to the flange center and the mill pass line at this time is e _(i) . Then, the following equation is obtained from the relational expression of the above equation (1).

S _{1 (i)} = S _{0 (i)} × (1−η / 100) + e _(i) × η / 100 (7) Then, from the specific position (i) of the rolled material, The position adjacent to the upstream side (rolling bottom side) is defined as (i + 1), and the center deviation at the specific position (i + 1) of the material to be rolled after universal rolling is defined as S1 _{(i + 1)} . Then, the vertical position adjustment amount of the flange roller guide for setting S _{1 (i + 1)} to “0” is Δe.
Then, the following equation holds from the relation of equation (7).

0 = S _{0 (i + 1)} × (1−η / 100) + (e _(i) + Δe) × η / 100 (8) In the formula (6), the rolled material before rolling is Center deviation of material S _{0 (i + 1)}
Assuming that is equal to the central deviation S _{0 (i)} at the adjacent position, S _{0 (i)} and S _{0 (i + 1)} are eliminated from the equations (7) and (8 _), and the relation of the following equation Is obtained.

Δe = −S _{1 (i)} · 100 / η ··· (9) Therefore, the web center deviation value of the material to be rolled is measured on the downstream side of the universal rolling mill and the flange roller guide, and the measurement result is obtained. On the basis of this, by calculating the Δe value by the above equation (9) and controlling the vertical position of the flange roller guide, the center deviation value S ₁ after rolling can be brought close to “0”. Note that this equation (9) is generalized to equation (5)
Is equivalent to.

When Δe calculated by the equation (9) is a positive value, the position is adjusted upward, and when it is a negative value, the position is adjusted downward. Further, η in the equation (9) is the web center deviation control efficiency, and is represented by the equation (3).

The case where the flange roller guide as shown in FIGS. 10 (a) and 10 (b) is installed on the inlet side of the universal rolling mill has been described above. However, instead of the flange roller guide, the web of the material to be rolled is replaced. A guide structure having a web roller that adjusts the vertical position of the material to be rolled by constraining the surface from above and below may be used.

Further, the flange roller guide and the web roller guide constituting the vertical position changing means are provided with one or more upper and lower rollers (in FIG. 10, the upper and lower rollers 2 and 2 respectively) so that the H-shaped steel web and the flange can be pressed in the vertical direction. One) is not particularly limited.

The web center deviation control rolling method of the H-section steel of the present invention is a flange installed on the entrance side of the rolling machine when the web height reduction rolling of the H-section steel is performed by the universal rolling machine having the variable width horizontal rolls. It is characterized in that the roller guide or the web roller guide adjusts the vertical position of the material to be rolled by feedforward control and / or feedback control. Therefore, the form of the universal rolling mill is not limited to the finish rolling mill, and may be an intermediate rolling mill as long as it takes a rolling process involving reduction of the web height.

Specifically, as a group of intermediate rolling mills as shown in FIG. 4 (b), two primary and secondary rough universal mills (coarse universal mills: UR ₁ and UR ₂ ) and edging rolling are used. Machine (edger mill: E) is installed and the finishing universal rolling machine is located downstream (Finishing universal mill: UF)
In the case of a rolling line in which is arranged, the coarse universal rolling may be subjected to the web center deviation controlled rolling according to the present invention, and the case to which the present invention is applied will be described below as an example.

In FIG. 11 (a), among the group of intermediate rolling mills, the horizontal rolls of the edger rolling mill (edger mill) and the secondary rough universal mill (secondary rough universal mill) have a variable width structure, and the finishing universal rolling mill ( An example of incorporating a variable width horizontal roll in the finishing universal mill) is also shown.
In this case, the beam blank (coarse shaped steel slab) after breakdown rolling is subjected to Levers rolling with the group of intermediate rolling mills, drawn to the shape of the specified flange thickness, web thickness and flange width, and then the final pass of the intermediate rolling. Then, the web height of the rolled material is reduced and rolled in the secondary coarse universal mill.
After that, in the finish universal rolling mill, the reduction of the web height of the rolled material is performed and the shaping rolling is performed to raise the flange angle.

Two flanges or web roller guides
By installing the secondary coarse universal rolling mill (secondary coarse universal mill) and finishing universal rolling mill (finishing universal mill) on the upstream side, the web center deviation control rolling method of the present invention can be implemented by the secondary rough universal mill and finishing. It becomes possible in the universal mill. In addition,
The web center deviation measuring device is preferably installed on the downstream side of the secondary coarse universal mill and on the upstream side or downstream side of the finishing universal mill.

FIG. 11 (b) shows a primary rough universal rolling mill (primary rough universal mill), an edging rolling mill (edger mill) and a secondary rough universal rolling mill (secondary rough universal mill) in the intermediate rolling mill group. The following shows an example in which the horizontal rolls of No. 1 have a variable width structure, and the variable width horizontal rolls are incorporated into the finishing universal mill. In this case, the beam blank (coarse shaped slab) after breakdown rolling is reversed by the intermediate rolling mill group, but the horizontal roll width of the secondary coarse universal mill is changed to the horizontal roll of the primary coarse universal mill and the horizontal roll of the edger mill. The web width of the material to be rolled is reduced by the secondary rough universal mill in an odd number of passes in which the material is rolled from the edger mill toward the secondary rough universal mill by setting the roll width smaller than the roll width. At the same time, the material to be rolled is drawn in the intermediate rolling mill group into a shape having a predetermined flange thickness, web thickness and flange width. In the post-finishing universal mill, however, the web height of the rolled material is slightly reduced, and the shape rolling is performed to raise the flange angle.

By installing the flange or the web roller guide on the upstream side of the secondary rough universal mill and the finishing universal mill, the web center deviation control rolling method of the present invention can be carried out in the secondary rough universal mill and the finishing universal mill. Becomes The web center deviation measuring device is preferably installed downstream of the secondary rough universal mill and upstream or downstream of the finishing universal mill.

12 and 13 are control block diagrams for carrying out the web center deviation control method according to the present invention. In FIG. 12, a web center deviation measuring device 90 is installed on the upstream side of the universal rolling mill 74, and based on the measured value of the web center deviation S over the entire length of the rolling material (H-shaped steel) detected by this measuring device, The opening of the flange roller guide 82 is controlled during rolling through a flange guide position adjusting device 92 arranged near the entrance side of the rolling mill to minimize the deviation of the web center of the H-section steel after rolling. .

In the opening command of the flange guide position adjusting device 92, the inward web center deviation detection value, the rolling condition instructed for each pass from the main process computer, and the material temperature during rolling measured by the thermometer. Based on this, an appropriate upper and lower position of the guide is calculated by the arithmetic unit, and a command is issued in a timely manner so that the guide position is adjusted when the measured position of the web center deviation S is rolled by the rolling mill. .

In FIG. 13, a web center deviation measuring device is installed on the downstream side of the finishing universal rolling mill, and based on the web center deviation measuring value over the entire length of the material to be rolled (H-shaped steel) detected by this measurement device. The opening of the flange roller guide is controlled during rolling through a flange guide position adjusting device arranged close to the entrance side of the rolling mill to minimize the deviation of the web center of the H-section steel after rolling.

Based on the detected value of the deviation of the web center on the delivery side of the rolling mill, the rolling conditions instructed from the main process computer for each rolling pass, and the material temperature during rolling measured by the thermometer, an appropriate value is calculated by the computing unit. The vertical position adjustment amount of the guide is calculated, and the opening command is given to the flange guide position adjusting device without delay. In the case of FIG. 13, since the feedback control is performed, it is desirable that the web center deviation measuring device installed on the exit side of the rolling mill be as close as possible to the rolling mill. As a result, it is necessary to shorten the processing time of the computing unit and the adjustment time of the necessary guide adjusting device as much as possible.

Although not shown, a web center deviation measuring device is provided on both the upstream side and the downstream side of the universal rolling mill, and a calculated value of the web center deviation over the entire length of the rolled material obtained by each measuring device is calculated by a calculator. To enter. Therefore, based on the rolling conditions input from the main process computer for each rolling pass and the material temperature during rolling measured by a thermometer, it is appropriate to minimize the deviation of the web center of the H-section steel after rolling. The guide vertical position setting value and the correction amount are calculated, and the opening command is given to the flange guide position adjusting device at an appropriate timing. According to the control system of this configuration,
It is possible to control the web center deviation with higher accuracy.

In the above description, the method of controlling the deviation of the center of the web by adjusting the position of the flange vertically by the flange guide has been described. However, by adjusting the position of the flange center vertically by the guide of the web as described above, The above description also applies to controlling the web center deviation.

Further, in the above description, the case where the web height is reduced in one pass by the universal mill having the variable width horizontal rolls has been described as an example. However, when the web height reduction rolling is performed in a plurality of passes. The same applies to the above, and the present invention may be implemented with the configurations shown in FIGS. 12 and 13 for each rolling pass.

[0061]

EXAMPLES Next, the function and effect of the present invention will be described more specifically based on its examples. (Example 1) In this example, H4 was used in the rolling line shown in Fig. 11 (a).
The method of the present invention is applied when hot rolling H-section steel of the 00 × 200 series having a constant outer height of web. First, the continuous casting bloom is heated, and then reverse rolling is performed by a breakdown mill having a roll hole die. Then, the beam blank was formed. Further, reverse rolling is performed with a primary coarse universal mill (UR ₁ ) having a fixed width horizontal roll, an edger mill having a variable width horizontal roll and a secondary coarse universal mill (UR ₂ ), and the product flange thickness, web thickness, Stretch rolling to a shape and dimensions close to the flange width. Then, in the final pass of the intermediate rolling, the horizontal roll width of UR ₂ is set narrower by a predetermined amount, and the web height of the material to be rolled is reduced and rolled by the UR ₂ mill. Finally, a finishing universal mill (UF) was used for shaping rolling that reduced the height of the web and raised the flange, to finish the material to be rolled.

Table 1 shows the results of measuring the web center deviation of the products when the present invention was carried out, in the form of average values (average absolute values of the web center deviations) and standard deviations. In the present embodiment employs the arrangement of the roller guide shown in FIG. 11 (a), performs detection of the center deviation on the web center deviation measuring device which is provided on the downstream side of the UR ₂ and UF, the UR ₂ and UF entry side Web center deviation control was performed by adjusting the vertical position of the flange roller guides placed close to each other. Applying the feedback control shown in FIG. 13 for UR ₂ as a control system in this case, FIG feedforward control shown in FIG. 12 for UF (combination of downstream center deviation measurement instrument of UR ₂₎ Both feedback control systems shown in 13 were applied. In the same table, the results of measuring the web center deviation when only the flange roller guide is used and rolling is performed without performing the control of the present invention are also shown for comparison.

From Table 1, when the control of the present invention is carried out, the average value and standard deviation of the web center deviations are significantly smaller than those in the case where the control is not carried out, and a product having good dimensional accuracy can be obtained. I can see that

[0064]

[Table 1]

Example 2 In this example, the method of the present invention was applied when hot rolling H600 × 300 series JIS / H section steel in the rolling line shown in FIG. 11 (b).

First, after heating the continuous casting bloom, reverse rolling is performed with a breakdown mill having a roll hole type,
Modeled into a beam blank. The shape of the beam blank at this time was for rolling H700 × 300 series H-section steel.
Furthermore, a primary coarse universal mill (UR ₁ ) with a variable width horizontal roll, an edger mill and a secondary coarse universal mill (U
Reverse rolling with R ₂ ) and stretch rolling to a shape and size close to the product's flange thickness, web thickness, flange width, and web height. At this time, the horizontal roll width of UR ₂ is set to be narrower than the horizontal roll width of UR _{1 by} a predetermined amount in the odd numbered passes of the intermediate rolling, and the reduction of the web height of the material to be rolled is performed by the UR ₂ mill. To do. Finally, a finishing universal mill (UF) was used for shaping rolling that reduced the height of the web and raised the flange, to finish the material to be rolled. At this time, the web height on both UR ₂ and UF mills
(Web width) The total reduction amount is 104 mm.

Table 2 shows the results of measuring the web center deviation of the entire product length in the case of carrying out the present invention in the form of an average value (average absolute value of the web center deviation) and a standard deviation. In the present embodiment employs the arrangement of the roller guide shown in FIG. 11 (b), performs detection of the center deviation at the web center deviation measuring device which is provided on the downstream side of the UR ₂ and UF, the UR ₂ and UF entry side Web center deviation control was performed by adjusting the vertical position of the flange roller guides arranged close to each other. As the control system in this case, by applying the feedback control shown in FIG. 13 for UR _2, (a combination of the downstream-side center deviation measurement instrument of UR ₂₎ feedforward control shown in FIG. 12 for UF and Both control systems of the feedback control shown in Fig. 13 were applied. The table also shows, for comparison, web center deviation measurement results when rolling was performed without using the control of the present invention, using only the flange roller guide.

It can be seen from Table 2 that when the control of the present invention is carried out, the average value and standard deviation of the deviation of the center of the web are much smaller than that in the case where the control is not carried out, and a product having good dimensional accuracy can be obtained. I can see that

[0069]

[Table 2]

[0070]

As described in detail above, according to the present invention,
When manufacturing H-section steels with different web heights in a universal rolling mill with the same variable horizontal rolls, or using the same variable horizontal rolls, H with a constant outer dimension of the web height for different sizes In the case of manufacturing a shaped steel, the H-shaped steel can be hot-rolled while maintaining the web center deviation of the product at an extremely low level. Therefore, products with excellent dimensional accuracy can be rolled with a high yield, and H-section steels of various sizes can be manufactured with the same chance using the same roll, which leads to improvement in efficiency and operating rate of rolling mills. , The number of rolls owned can be reduced significantly. Therefore, the present invention has extremely high industrial utility value.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a current product dimension system of H-shaped steel by rolling.

FIG. 2 is an explanatory diagram of a current product dimension system of H-section steel by welding.

FIG. 3 is an explanatory view showing a state of a variable width universal finish rolling mill according to the present invention.

4 (a) and 4 (b) are explanatory views showing an example of the layout of a rolling mill for H-section steel when carrying out the present invention.

5 (a) and 5 (b) are explanatory views showing an example of a rolling mill layout of an H-section steel when carrying out the present invention.

FIG. 6 is an explanatory diagram of the deviation of the web center of the H-section steel.

7 (a), (b), (c) and (d) are explanatory views showing changes in web center deviation due to web height reduction rolling of H-section steel.

FIG. 8 is a diagram showing the influence of the vertical movement of the flange in the web height reduction rolling of H-section steel on the change in web center deviation before and after rolling.

FIG. 9 is an explanatory diagram showing the relationship between web center deviation control efficiency and web height reduction rolling conditions for H-section steel according to the present invention.

10 (a) and 10 (b) are explanatory views showing a state of rolling H-section steel according to the present invention.

FIGS. 13 (a) and 13 (b) are explanatory views showing an example of a rolling mill layout of H-section steel to which the present invention is applied.

FIG. 12 is a block diagram of a web center deviation control when implementing the present invention.

FIG. 13 is a block diagram of a web center deviation control when implementing the present invention.

[Explanation of symbols]

70: Vertical roll 72: Horizontal roll 74: Universal rolling mill 76: H-section steel 82: Flange roller guide

Claims (2)

[Claims] 1. A method for controlling web center deviation in a hot rolling method for H-section steel using a universal rolling mill, wherein a horizontal roll of the universal rolling mill is divided to have a structure in which width can be adjusted online. When reducing the inner width of the web by rolling in one pass or in multiple passes in the universal rolling mill: A web center deviation measuring value S over the entire length of the material to be rolled is measured by a web center deviation measuring device installed on the upstream side of the universal rolling mill. [= (A-b) / 2; a and b are the inner widths of the upper and lower flanges of the H-section steel]; Obtaining an offset position e of the center with respect to the mill pass center; and performing the universal rolling so that the flange center of the material to be rolled comes to the obtained offset position e. Web center bias control rolling method of H-beams, characterized in that the roller guides disposed close to the entrance side of the adjusted during rolling the vertical position of the rolled material. e = S · (1-100 / η) However, when e> 0, the offset is upward, and when e <0, the offset is downward. Here, η is the web center deviation control efficiency and is represented by the following equation. η = K ₁ · (1 _df · I _z ^1/4 ) / (1 _dw · L) + K ₂ where 1 _df and 1 _dw are projections of the outer surface of the flange of the material to be rolled and the vertical roll of the universal rolling mill, respectively. The contact length is the projected contact length between the web and the horizontal roll of the universal rolling mill, I _z is the second moment of area of the material to be rolled, and L is the distance between the axes of the rolls of the universal rolling mill and the rollers of the roller guides. . Further, both K ₁ and K ₂ are constants experimentally obtained. 2. A method for controlling web center deviation in a hot rolling method for H-section steel using a universal rolling mill, wherein a horizontal roll of the universal rolling mill is divided into a structure capable of adjusting the width online. When reducing the inner width of the web by rolling in one pass or in multiple passes in the universal rolling mill: A web center deviation measuring value S over the entire length of the rolled material is measured by a web center deviation measuring device installed on the downstream side of the universal rolling mill. [= (Ab) / 2; a and b are inner widths of the upper and lower flanges of the H-section steel] from the detected web center deviation measurement value S according to the following formula: Obtaining a correction amount Δe of the offset position of the flange center of the rolled material on the entry side with respect to the mill pass center; and near the upstream side of the universal rolling mill. A method for controlling web center deviation of H-section steel, characterized in that the vertical position of a material to be rolled with respect to a mill pass center is adjusted by the correction amount Δe during rolling by means of a roller guide arranged. Δe = −S · 100 / η However, if e> 0, the position is adjusted upward, and if e <0, the position is adjusted downward. Here, η is the web center deviation control efficiency and is represented by the following equation. η = K ₁ · (1 _df · I _z ^1/4 ) / (1 _dw · L) + K ₂ where 1 _df and 1 _dw are projections of the outer surface of the flange of the material to be rolled and the vertical roll of the universal rolling mill, respectively. The contact length is the projected contact length between the web and the horizontal roll of the universal rolling mill, I _z is the second moment of area of the material to be rolled, and L is the distance between the axes of the rolls of the universal rolling mill and the rollers of the roller guides. . Further, both K ₁ and K ₂ are constants experimentally obtained.