JPH09239401A - Method for rolling wide flange shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the precision of flange thickness and web height by performing finish rolling after adjusting roll width and position in the roll axial direction and the positions of vertical rolls according to flange thicknesses and web heights in four places of both upper and lower sides, and the left and the right of a rolled stock to be rolled after rough rolling. SOLUTION: According to the actual result of the dimensional measurements of a rolled stock after rough rolling, in an arithmetic unit 6, the set quantity of a roll opening degree and a adjusting quantity in a universal rolling mill 4, are operated. 'The roll opening degree of a rolling mill 4, putting it concretely. the roll width and a position in the roll axial direction of a horizontal roll pair and the position of vertical rolls, are set and adjusted by a drawing down setting device 7 after receiving the result of an operation. After completing the setting and the adjustment of a roll gap the milled stock is rolled by a finish universal mill 4, and the product dimensions of the rolled stock are obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to further improve the accuracy of flange thickness and the accuracy of web height when rolling H-section steel.

[0002]

2. Description of the Related Art As shown in FIG. 1, a hot rolling facility for H-section steel comprises a breakdown rolling mill 1, a rough universal rolling mill 2, an edging rolling mill 3, and a finishing universal rolling mill 4 in this order from the upstream side of the process. The H-section steel having a predetermined cross-sectional dimension is manufactured by sequentially passing materials such as slabs, blooms, and beam blanks through the rolling mills in the arranged configuration.

In some of the above facilities, as shown in FIG. 2, another rough universal rolling mill 2 is installed on the exit side of the edging rolling mill 3, but any of the facilities has a breakdown rolling mill. Reference numeral 1 is a double-type rolling mill in which a pair of upper and lower rolls having a plurality of open or closed holes are arranged along the roll cylinder. In this rolling mill, the material has an H-shaped cross section. Coarse shaped billets are rolled.

Further, in the rough universal rolling mill 2 provided with a pair of upper and lower horizontal rolls 2a and 2b having a draft angle (taper angle) on the side faces and vertical rolls 2c and 2d paired on the left and right sides, the coarse universal rolling mill 2 is obtained by breakdown rolling. The web w of the rough-shaped billet thus formed is, as shown in FIG.
The flange f is pressed down in the thickness direction by a and 2b.
Is rolled down in the thickness direction by horizontal rolls 2a, 2b and vertical rolls 2c, 2d. Further, as for the flange width, as shown in FIG.
It is rolled down to a predetermined size by the edging rolling machine 3 used as a pair.

The above rough rolling is repeated a plurality of times until a predetermined cross-sectional dimension is reached, and thereafter, as shown in FIG. 3 (c), the finish universal rolling machine 4 performs reduction in the thickness direction of the flange and reduction in the thickness direction of the web. In addition to this, the angle of the flange is raised to complete the final product. In this finish universal rolling, the height of the web may be adjusted as shown in FIG. 3 (d).

In such rough rolling and finish rolling, a target thickness is usually set for each pass, and the roll clearance is usually adjusted so as to reach the target thickness. As a typical one,
So-called setup control was applied.

This setup control predicts the rolling reaction force (rolling load) from the fact that the rolling reaction force and the amount of increase in the roll clearance due to this are in a linear relationship, and the roll clearance without load is preliminarily determined accordingly. In particular, in finish rolling, the material size after finish rolling becomes the product size, so setting the roll clearance when there is no load was a very important factor. . As prior art documents relating to this point, reference is made to JP-A-63-104714 and JP-A-63-123510.

Further, from the viewpoint of equalizing the thickness of the four flanges of the H-section steel, in the rough universal rolling, the flange thickness of the raw material is measured at four positions, up, down, left and right, respectively, and the rough universal is determined from the measurement results. The deviation of the roll axial position of the upper and lower horizontal rolls of the rolling mill, the deviation of the roll opening of the left and right vertical rolls, and the deviation of the center of the gap between the upper and lower horizontal rolls with respect to the center of the gap between the vertical rolls are calculated, and these deviations are calculated to Alternatively, a technique disclosed in Japanese Patent Application Laid-Open No. 6-15327, which changes the position of each roll within an allowable range, is known.

[0009]

By the way, in the production of H-section steel, the height of the web is not affected by the wear of the rolls.
(Outer method) is always required to be rolled so as to have a desired size, and the above-mentioned JP-A-6-1532 is used.
The technique disclosed in Japanese Patent Laid-Open No. 7 cannot cope with this, and the techniques disclosed in Japanese Patent Laid-Open No. 63-104714 and Japanese Patent Laid-Open No. 6-104714.
The technique disclosed in Japanese Patent No.
Since the left and right are set up symmetrically, there is a problem that this deviation cannot be corrected when there is a difference in the thickness of the four flanges.

Incidentally, Japanese Patent Application Laid-Open No. 2-80102 discloses that
In the finish universal rolling of H-section steel, a universal rolling machine provided with a horizontal roll whose pair of upper and lower roll widths can be changed and a vertical roll which becomes a pair of left and right,
A technique has been proposed in which the roll width of the horizontal roll is made smaller than in the rough rolling stage to raise the angle of the flange, reduce the height of the web, and reduce the width of the flange to reduce the inner width of the web. However, even if this technology is applied, H
Regarding the accuracy of the thickness of each flange of shaped steel, it has not been possible to secure sufficiently satisfactory quality.

An object of the present invention is to solve the conventional problems that occur when H-section steel is manufactured by rolling, to improve the accuracy of the flange thickness of the four legs, and to improve the dimensional accuracy of the web height. The present invention is to propose a rolling method capable of stably producing various H-section steels.

[0012]

According to the present invention, a material to be roughly rolled is finish-rolled by using a universal rolling machine provided with a pair of horizontal rolls vertically and a pair of vertical rolls left and right. As a rolling mill for performing finish rolling, a universal rolling mill having a pair of horizontal rolls whose roll width can be changed in both upper and lower sides and at least one of the upper and lower rolls can be positionally adjusted along the roll axis. Using the roll width of the horizontal roll pair and the position of the roll axial direction and the position of the vertical roll taking into account the elastic deformation amount of each part during rolling of this rolling mill, the vertical and horizontal positions of the material to be rolled after rough rolling of a rolling method of H-beams, characterized in that the finish rolling After adjusted based on a flange thickness and web height of the four positions, the elastic deformation amount δ ₁ ~δ ₆ above, the following formula Therefore it predicts.

A. When rolling with reduction of the inner width of the web P ₁ = K ₁ · δ ₁ + K ₇ (δ ₁ + δ ₃ ) P ₂ = K ₂ · δ ₂ + K ₈ (δ ₂ + δ ₄ ) P ₃ = K ₃ · δ ₃ + K ₇ (δ ₁ + δ ₃ ) P ₄ = K ₄ · δ ₄ + K ₈ (δ ₂ + δ ₄ ) δ ₅ · K ₅ = P ₁ + P ₂ + P ₅ δ ₆ · K ₆ = P ₃ + P ₄ + P ₅ Here, P _{1 to} P ₅ : Rolling load at each part of the roll K ₁ : Elastic coefficient between the upper horizontal roll left side chock and the upper horizontal roll left side roll K ₂ : The upper horizontal roll left side chock and the lower horizontal roll left side roll elastic coefficient between K _3: modulus between right roll of the upper horizontal roll right chocks and the upper horizontal roll K _4: elastic modulus between right roll of the lower horizontal roll right chocks and lower horizontal roll K _5, K _6: left and right vertical Elastic moduli of rolls K ₇ and K ₈ : Elastic moduli between left and right rolls of horizontal rolls with variable vertical width

B. When Rolling with Expansion of Inner Width of Web P ₅ ′ = M ₅ ′ ΔB _W ′ P ₁ + P ₅ ′ / 2 = K ₁ δ ₁ + K ₇ (δ ₁ + δ ₃ ) P ₂ + P ₅ ′ / 2 = K ₂ δ ₂ + K ₈ (δ ₂ + δ ₄ ) P ₃ + P ₅ ′ / 2 = K ₃ δ ₃ + K ₇ (δ ₁ + δ ₃ ) P ₄ + P ₅ ′ / 2 = K ₄ δ ₄ + K ₈ ((δ ₂ + δ ₄ ) δ ₅ · K ₅ = P ₁ + P ₂ δ ₆ · K ₆ = P ₃ + P ₄ where P _{1 to} P ₅ ′: rolling load M ₅ ′: plastic constant K ₁ : upper Elastic coefficient between left horizontal roll of horizontal roll and upper horizontal roll K ₂ : Elastic coefficient between left horizontal roll of upper horizontal roll left chock and lower horizontal roll K ₃ : Between right horizontal roll of upper horizontal roll right chock and upper horizontal roll elastic coefficient K _4: elastic modulus between right roll of the lower horizontal roll right chocks and lower horizontal roll K _5, K _6: elastic modulus of the left and right vertical rolls K _7, K _8: vertical width allowed Modulus .DELTA.B _W between the left and right rolls of a horizontal roll ': oversize web within the width t ₁ ~t _4: Flange after rolling thickness H _2: web height after rolling

C. When performing rolling without shrinking or expanding the inner width of the web The rolling load P ₅ in the above A is 0 (reduction allowance ΔB _W is 0).
Alternatively, ΔB _W ′ in B is 0 (rolling load P ₅ ′ is 0).

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 4 shows an H suitable for carrying out the present invention.
1 shows a hot rolling facility for shaped steel, in which a material S that has undergone a breakdown rolling process is subjected to reverse rolling (rough rolling) in multiple passes by a rough universal rolling mill 2 and an edging rolling mill 3, After passing through the number of passes, the flange width after rough rolling, the flange leg length,
Flange thickness and web thickness are measured.

Based on the dimension measurement results of the raw material S after rough rolling, the calculation device 6 calculates the set amount and the adjustment amount of the roll opening (roll gap) in the finish universal rolling mill 4. On the basis of this calculation result, the reduction setting device 7 sets and adjusts the roll opening of the finishing universal rolling mill 4, specifically, the roll width of the horizontal roll pair, the position in the roll axial direction, and the position of the vertical roll.

The material S is rolled by the finishing universal rolling machine 4 after finishing the setting and adjustment of the roll gap to obtain the product size. Finishing Universal Rolling Machine 4 Horizontal Roll 4
a and 4b are variable width rolls in which the widths of the rolls can be changed in the upper and lower sides. Of these, in this example, the upper roll is
The thing which can also adjust the position of the whole roll in the axial direction is applied (the lower roll may also be one which can adjust the position of the whole roll in the axial direction).

The setting and adjustment procedure of the roll clearance of the finishing universal rolling mill 4 based on the dimensional results of the material is accompanied by the reduction of the inner width of the web, the enlargement of the inner width of the web and the reduction of the inner width of the web. A case without the above will be described more specifically with reference to FIGS. 5 to 8.

First, the case of carrying out rolling for reducing the inner width of the web by ΔB _W in the situation as shown in FIG.

The thickness of the four flanges before finish rolling is T
_{1 to} T ₄ , the target thickness after finish rolling is t ₁ to t ₄ (usually t ₁ = t ₂ = t ₃ = t ₄ ), and the gaps between the four flanges before rolling are S. _{1 to} S ₄ , and
Deformation amount (elastic deformation amount) of each roll during rolling is δ ₁ to δ ₆
Then, the thickness t ₁ to t ₄ of the flange after rolling is (1) to
It is expressed by equation (4). t ₁ = S ₁ + δ ₁ + δ ₅ --- (1) t ₂ = S ₂ + δ ₂ + δ ₅ --- (2) t ₃ = S ₃ + δ ₃ + δ ₆ --- (3) t ₄ = S ₄ + Δ ₄ + δ ₆ --- (4)

Further, the rolling load P in each part
₁~ P_FiveIs P₁= M₁(T₁-T₁) ---- (5) P_Two= M_Two(T_Two-T_Two) ---- (6) P_Three= M_Three(T_Three-T_Three) ---- (7) P_Four= M_Four(T_Four-T_Four) ---- (8) P_Five= M_FiveΔB_W ---- (9) Where, the height of the web before finish rolling is H₁Finish rolling
Rear web height is H_TwoIf so, ΔB_W= {H₁− (T₁+ T_Two/ 2)-(T_Three+ T_Four/
2)}-{H_Two− (T ₁+ T_Two/ 2)-(t_Three+ T_Four/
2)} It is expressed as --- (100).

In the above equations (5) to (9), M _{1 to} M ₄ are plastic constants when rolling the respective flanges, and M _{1 to} M ₄ are
₅ is the plastic constant when reducing the web height. Also,
Although each part is elastically deformed by rolling to change the roll gap, if the elastic coefficient of each part is K, the relationship between the elastic deformation amount and the rolling load can be expressed as follows. P ₁ = K ₁・ δ ₁ + K ₇ (δ ₁ + δ ₃ ) --- (10) P ₂ = K ₂・ δ ₂ + K ₈ (δ ₂ + δ ₄ ) --- (11) P ₃ = K ₃・δ ₃ + K ₇ (δ ₁ + δ ₃ ) --- (12) P ₄ = K ₄・ δ ₄ + K ₈ (δ ₂ + δ ₄ ) --- (13) δ ₅・ K ₅ = P ₁ + P ₂ + P ₅ --- (14) δ ₆ · K ₆ = P ₃ + P ₄ + P ₅ --- (15)

In the equations (10) to (15), K ₁ is the elastic coefficient between the upper horizontal roll left side chock and the upper horizontal roll left side roll, and K ₂ is the lower horizontal roll left side chock and the lower horizontal roll left side roll. Elastic coefficient, K ₃ is the elastic coefficient between the upper horizontal roll right chock and the upper horizontal roll right roll, K ₄
Is the elastic coefficient between the right lower chock of the lower horizontal roll and the right lateral roll of the lower horizontal roll, K ₅ and K ₆ are the elastic moduli of the left and right vertical rolls respectively, and K ₇ and K ₈ are the elastic properties between the left and right rolls of the horizontal rolls that are variable in the vertical width. This is a coefficient, and since the horizontal roll is a variable width roll, the left and right rolls are elastically deformed individually.

Based on the above equations (1) to (15), the roll clearances S _{1 to} S ₄ are obtained by combining the elastic deformation amounts δ _{1 to} δ ₆ and the rolling loads P _{1 to} P _{5 of} each part.

In order to set the height H ₂ of the web after rolling to a target dimension, the distance D between the left and right vertical rolls is calculated by the following equation. D = H ₂ −δ ₅ −δ ₆ --- (16)

When S _{1 to} S ₄ and D are obtained, the adjustment amount of the roll clearance is determined by the geometrical relationship. In the actual adjustment, a to f of FIG. 6 (a: adjustment of width opening of upper width variable horizontal roll, b: adjustment of axial position of upper horizontal roll,
D: Adjust the axial position of the lower horizontal roll, E: Adjust the opening of the left vertical roll, F: Adjust the opening of the right vertical roll. However, 4 after rough universal rolling
If the difference in the flange thickness of the legs is large, warping, bending, or twisting may occur if the difference in thickness between the legs is set to 0 in finish universal rolling. At this time, the adjustment amount of the roll clearance in finish universal rolling is reduced by an appropriate amount.

The plastic constant M ₁ used in the above equations (5) to (9)
~ M ₅ is obtained in advance from past rolling results and theoretical analysis. Further, the elastic coefficients K _{1 to} K _{8 of} the respective parts are also determined by the rigidity measurement experiment and theoretical analysis.

Regarding the elastic deformation amounts δ _{1 to} δ ₄ , (10) to
From the equation (13), for example, the equation (101) is expressed. Therefore, the inverse matrix on the left side may be obtained and the rolling loads P _{1 to} P ₄ may be substituted.

[Equation 1]

The elastic deformation amounts δ ₅ and δ ₆ are respectively
From formulas (14) and (15), the rolling load is substituted into formulas (102) and (103). δ ₅ = (P ₁ + P ₂ + P ₅ ) / K ₅ --- (102) δ ₆ = (P ₃ + P ₄ + P ₅ ) / K ₆ --- (103)

The clearances S _{1 to} S ₄ of the roll are defined by the following (104)
Vertical after rolling as a target the expression obtained by substituting the flange thickness t ₁ ~t ₄ and the elastic deformation amount δ ₁ ~δ ₆ of the left and right four positions.

[Equation 2]

Next, a case where the inner width of the web is expanded by ΔB _W ′ by finish universal rolling in the situation shown in FIG.

In this case, the rolling loads P _{1 to} P ₄ are obtained from the equations (5) to (8) in the same manner as described above. Also, (9) above
The relational expression of Eq. (15) is as follows.

(Equation 3)

The elastic deformation amounts δ _{1 to} δ ₄ are calculated by the equations (10) ′ to (1
3) ′ can be expressed as, for example, the expression (107), the inverse matrix of the left side is obtained, and the rolling loads P _{1 to} P ₄ and P ₅ ′ are substituted and obtained.

(Equation 4)

The elastic deformation amounts δ ₅ and δ ₆ are (1
It is calculated by substituting the rolling load into Eqs. 08) and (109). δ ₅ = (P ₁ + P ₂ ) / K ₅ --- (108) δ ₆ = (P ₃ + P ₄ ) / K ₆ --- (109)

The gaps S _{1 to} S ₄ of the rolls are obtained from the equation (104) in the same manner as described above. In the finish universal rolling, if the inner width of the web of the material to be rolled is not expanded or reduced, ΔB _W in the above formula (9) is set to 0 (rolling load P ₅ is 0) or (9 ) ′ ΔB _W ′ is 0
(Rolling load P ₅ ′ is 0), elastic deformation amounts δ _{1 to} δ ₆
Ask for.

By following the above-mentioned procedure, the target flange thicknesses (t, 4) of the upper, lower, left and right after rolling (t
₁ , t ₂ , t ₃ , t ₄ ), four flange thicknesses (T ₁ , T ₂ , T ₃ , T ₄ ) before and after rolling, height of web before rolling
(H ₁ ), the height of the web after rolling (H ₂ ), the elastic deformation amounts δ _{1 to} δ _{6 of} each part, and the gaps S ₁ , S _{2 between} the rolls at the four flange portions at the top, bottom, left and right before rolling. , S ₃ and S ₄ are required.

The equations (10) to (13) are formulated assuming that the left and right chocks of the variable width horizontal roll are both fixed to the housing. When not fixed, the elastic coefficient K on the non-fixed side is set to 0. Regarding the web height H ₁ before finish rolling, the roll width of the horizontal roll of the rough universal rolling mill is the width B of the web before finish rolling.
_Since it is almost equal to _W1 , it may be obtained from the following equation. _{H 1 = B W1 + (T} 1 + T 2) / 2 + (T 3 + T 4) / 2

Various mechanisms are conceivable for adjusting and fixing the axial position of the variable width horizontal roll, and as one example, the one shown in FIG. 9 can be applied. In FIG. 9, the variable width horizontal roll 10 is held by the roll chock 12 via the thrust bearing 11. A guide arm 13 is attached to the roll chock 12 and its tip is a clamp arm.
14 and wedge-shaped spacer 15. In such a structure, by moving the wedge type spacer 15 up and down, the clearance c can be adjusted and the positions of the roll chock 12 and the variable width horizontal roll 10 in the roll axial direction can be adjusted.

As for the mechanism of the variable width portion of the variable width horizontal roll, any mechanism may be used as long as its width can be arbitrarily adjusted, but as an example, Japanese Patent Laid-Open No. 1-317.
The one disclosed in Japanese Patent No. 607 can be applied.

Regarding the thickness of the four leg flanges of the rolled material after the rough universal rolling (since the flange leg lengths of the four legs are usually almost equal to the target dimensions), the actual roll clearance S of the final pass of the rough universal rolling is S. _r1 to S _r4 left and right vertical rolls rolling load P _oP, P _dr and vertical horizontal rolls thrust load P _U, may be calculated by the _{P l (17) ~ (20} ) equation.

T ₁ = S _r1 + P _oP / K _oP + P _U / K _U --- (17) T ₂ = S _r2 + P _oP / K _oP + P _l / K _l --- (18) T ₃ = S _r3 + P _dr / K _dr -P _U / K _U --- (19) T ₄ = S _r4 + P _dr / K _dr -P _l / K _l --- (20) where K _oP and K _dr are vertical Elastic moduli of rolls K _U and K _l are elastic moduli in the axial direction of the upper and lower horizontal rolls.

In many cases, however, the thrust load of the horizontal roll cannot be measured. At that time, the approximation is as follows.

(Equation 5)

Similarly, for the web thickness T _W after the rough universal rolling, the horizontal roll gap S _rh before the rolling (final pass of the universal rolling) and the horizontal roll rolling load actual values P _h and P _oP , P _{dr are similarly applied} . The plastic constants M _{1 to} M ₅ and M ₅ ′ at the time of finish rolling may be determined from the following equation.

(Equation 6)

Next, the procedure for setting the roll position of the universal rolling mill when S _{1 to} S ₄ are determined will be described.

(A) When using a rolling machine in which the roll width of the upper horizontal roll is variable and the roll axial position is variable, and the lower horizontal roll is variable in roll width and the position in the roll axial direction is fixed i) Roll of the lower horizontal roll The width interval W ₂ is set. W ₂ = H−t ₂ −t ₄ + δ ₂ + δ ₄ (= H−δ ₅ −δ ₆ −S ₂ −S ₄ ) --- (110) H: Target web height ii) Roll position of left and right vertical rolls Set. The left vertical roll is at the position S ₂ which is the clearance with the lower horizontal roll, and the right vertical roll is the position S is the clearance with the lower horizontal roll.
Set the position to ₄ . iii) Set the roll width interval W ₁ of the upper horizontal roll. W ₁ = H−t ₁ −t ₃ + δ ₁ + δ ₃ --- (111) iv) Set the roll axial position of the upper horizontal roll. Set the gap with the left vertical roll to the position of S ₁ or the gap with the right vertical roll to the position of S _3.
(The other gap is correct). (b) When a rolling mill with variable roll width and variable axial position is used for both the upper and lower horizontal rolls

There are numerous roll position setting patterns.
As an example, the case where the left and right vertical rolls are designed to have the same distance from the mill center is shown. i) Set the left-right vertical roll interval D. D is the value of Eq. (16) ii) The roll width W ₁ W ₂ of the upper and lower horizontal rolls is set. W ₁ is the value of the formula (111) W ₂ is the value of the formula (110) iii) The position of the vertical roll in the axial direction of the roll is set. Set so that the gap between the upper horizontal roll and the left vertical roll is S ₁ and the gap between the lower horizontal roll and the left vertical roll is S ₂ (the gap between the right vertical roll is S ₃ ,
The S ₄₎

[0048]

Example 1 A beam blank (steel type: SS400) having a web height of 460 mm, a flange width of 400 mm and a web thickness of 120 mm by applying the equipment shown in FIG. The width of 200 mm, the web thickness of 12 mm, and the flange thickness of 16 mm, 19 mm, and 22 mm, three sizes of H-section steel were hot-rolled, and the flange thickness and the web thickness of the product were investigated. For flanges with a thickness of 16 mm, the inner width of the web is expanded by 6 mm with a universal finish.
For the flange thickness of 22 mm, the inner width of the web was reduced by 6 mm by finish universal rolling, and for the flange thickness of 19 mm, it was manufactured by the finish universal rolling without reducing or expanding the inner width of the web. Further, the number of finish rolling passes was once. The setting of the roll clearance in the finish universal rolling was performed as follows.

First, four legs of the material after rough universal rolling
The flange thickness, flange leg length and web thickness of
It measured with the fixed device. Universal rolling with this dimension and finish
Target dimensions after finishing and materials for finish universal rolling
From the predicted temperature of the part, the plastic constant M ₁~ M_FiveTo calculate the formula (1)
From (16) and (101) (111) Roll clearance setting value S₁~
S_FourAnd the distance D between the vertical rolls on the left and right
Horizontal roll width W₁And the lower horizontal roll
Width interval W_TwoI asked. The finishing unit made in this example
In the Niversal rolling mill, only the upper horizontal roll is adjusted in axial position.
There is a leveling mechanism, and there is no such mechanism for the lower horizontal roll.
The axial position is fixed. Accordingly
Width of the lower horizontal roll W_TwoAnd set it to match
The left and right vertical rolls are rolled by rolling the lower flange.
The clearance is S_Two, S_FourIs determined to be the position, and is horizontal
The position of the roll can be adjusted in the axial direction,
Since the roll width can be adjusted, the left and right rolls of the upper horizontal roll
Each of these can be located at any position. This place
Place the upper flange on the left and right vertical rolls
Roll gap S₁S_ThreeThe position is determined so that

In order to roll an H-shaped steel having a product height of 600 mm, a flange width of 200 mm, a web thickness of 12 mm and a flange thickness of 19 mm, the cross-sectional shape of each of the three raw materials after rough rolling was measured, and it was found that before finish rolling. The cross section of the material in Figure 10
(a) (Flanges on four legs are almost the same thickness.) Fig. 10
(b) (The upper left and lower right flanges are thicker than others)
10 (c) (The upper flange thickness is thicker than the lower flange thickness). Here, in the present invention, the roll gap of the finish universal rolling mill is shown in FIG.
Changed as shown in Fig. 11 (a) to (c) to correspond to (c).
(There is no significant difference between the roll gaps in Figure 10 (a)).

As shown in Table 1, the actual values of the flange thickness, web height dimension and roll gap setting before and after finish rolling were confirmed to be very good in product dimension accuracy when finish rolling according to the present invention. .

[0052]

[Table 1]

Example 2 Next, in this example, the dimensions of the raw material after the rough universal rolling were not measured, and T _{1 to} T ₄ and T _W were calculated by the equations (21) to (25).
Finish universal rolling was performed in the same manner as in Example 1 except that For comparison, the four-leg flange thickness after rough universal rolling was measured, the average value was calculated, and assuming that each flange thickness was the average value, the roll gap was set and the finish rolling was performed. The plastic constant M was determined from past rolling results, and the elastic coefficient K of each part of the finishing universal rolling mill was determined in advance by experiments. In each case, 10 pieces were rolled considering the reproducibility of the experiment. The average value X of the flange thickness and the web height and the standard deviation σ of the deviation from the target dimension in the product stage of 10 pieces in each case are shown in Table 2. As shown in FIGS. 4 to 4, it is apparent that the present invention can manufacture an H-section steel having excellent thickness accuracy of four-leg flanges and web height accuracy.

[0054]

As described above, according to the present invention, the flange thickness accuracy and the web height accuracy of the H-section steel manufactured by hot rolling can be further improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of rolling equipment for H-section steel.

FIG. 2 is an explanatory diagram of rolling equipment for H-section steel.

3A to 3D are explanatory views of rolling conditions of H-section steel at respective stages.

FIG. 4 is a diagram showing a configuration of equipment suitable for implementing the present invention.

FIG. 5 is a diagram (reduction of inner width of web) showing a relationship between a rolling load and a change in roll clearance in finish rolling.

FIG. 6 is a diagram showing a procedure for adjusting a clearance of a finishing universal rolling mill.

FIG. 7 is a diagram showing a relationship between a rolling load and a change in roll clearance in finish rolling (enlargement of inner width of web).

FIG. 8 is a diagram showing a flow of a procedure for adjusting a roll clearance.

FIG. 9 is a view showing a mechanism for adjusting the axial position of a variable width horizontal roll of the finishing universal rolling mill.

10A to 10C are diagrams showing a coarse cross-sectional shape after a rough rolling step.

11A to 11C are diagrams showing a change situation of the clearance of the finishing universal rolling mill.

[Explanation of symbols]

 1 Breakdown rolling mill 2 Rough universal rolling mill 3 Edger rolling mill 4 Finishing universal rolling mill 5 Dimension measuring device 6 Computing device 7 Rolling down setting device 8 Variable width horizontal roll 9 Vertical roll 10 Horizontal roll 11 Thrust bearing 12 Roll chock 13 Guide arm 14 Clamp arm 15 Wedge spacer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Hayashi, 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama Prefecture (no address) Inside the Mizushima Works, Kawasaki Steel Co., Ltd. (72) Motoshiro Hirano, Mizushima-kawasaki-dori, Kurashiki-shi, Okayama Prefecture 1-chome (no address) Mizushima Steel Works, Kawasaki Steel Co., Ltd. (72) Inventor Kazuo Omori 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture (no address) Kawashima Steel Co., Ltd. Mizushima Steel Works

Claims (2)

[Claims] 1. Finish rolling of a material subjected to rough rolling by using a universal rolling machine provided with a pair of horizontal rolls at the top and bottom and a pair of vertical rolls at the left and right. As a rolling mill, the width of the roll can be changed in any of the upper and lower sides, and at least one of the upper and lower rolls uses a universal rolling mill equipped with a pair of horizontal rolls whose position can be adjusted along the roll axis. The roll width of the horizontal roll pair, the position of the roll axial direction, and the position of the vertical roll in consideration of the elastic deformation amount of each part at the time of rolling are determined by the flange thicknesses at the four positions of the top and bottom and the left and right of the material to be rolled after rough rolling A method for rolling H-section steel, which comprises adjusting based on a web height and a target size of a product, and then finish rolling. 2. The rolling method according to claim _1, wherein the elastic deformation amounts δ _{1 to} δ ₆ of the respective portions during rolling of the rolling mill are predicted in accordance with the following equation. Note A. When rolling with reduction of the inner width of the web P ₁ = K ₁ · δ ₁ + K ₇ (δ ₁ + δ ₃ ) P ₂ = K ₂ · δ ₂ + K ₈ (δ ₂ + δ ₄ ) P ₃ = K ₃ · δ ₃ + K ₇ (δ ₁ + δ ₃ ) P ₄ = K ₄ · δ ₄ + K ₈ (δ ₂ + δ ₄ ) δ ₅ · K ₅ = P ₁ + P ₂ + P ₅ δ ₆ · K ₆ = P ₃ + P ₄ + P ₅ Here, P _{1 to} P ₅ : Rolling load at each part of the roll P ₅ = M ₅ ΔB _W K ₁ : Elastic coefficient between upper horizontal roll left side chock and upper horizontal roll left side roll K ₂ : Upper horizontal roll left side chock Between the left and right rolls of the lower horizontal roll and the lower horizontal roll K ₃ : Elastic modulus between the right chock of the upper horizontal roll and the right roll of the upper horizontal roll K ₄ : Elastic modulus between the right chock of the lower horizontal roll and the right roll of the lower horizontal roll K ₅ , K ₆ : Elastic moduli of left and right vertical rolls K ₇ , K ₈ : Elastic moduli between left and right rolls of variable horizontal width B. When rolling with an increase in the inner width of the web P ₁ + P ₅ ′ / 2 = K ₁ δ ₁ + K ₇ (δ ₁ + δ ₃ ) P ₂ + P ₅ ′ / 2 = K ₂ δ ₂ + K ₈ (δ ₂ + δ ₄ ) P ₃ + P ₅ ′ / 2 = K ₃ δ ₃ + K ₇ (δ ₁ + δ ₃ ) P ₄ + P ₅ ′ / 2 = K ₄ δ ₄ + K ₈ ((δ ₂ + δ ₄ ) δ ₅ · K ₅ = P ₁ + P ₂ δ ₆ · K ₆ = P ₃ + P ₄ where P _{1 to} P ₅ ′: rolling load P ₅ ′ = M ₅ ′ ΔB _W ′ M ₅ ′: plastic constant K ₁ : upper left horizontal roll chock Elastic coefficient between left roll of upper horizontal roll K ₂ : Elastic coefficient between left chock of upper horizontal roll and left roll of lower horizontal roll K ₃ : Elastic modulus between right chock of upper horizontal roll and right roll of upper horizontal roll K ₄ : elastic modulus between right roll of the lower horizontal roll right chocks and lower horizontal roll K _5, K _6: elastic modulus of the left and right vertical rolls K _7, K _8: vertical width variable horizontal rolls Modulus .DELTA.B _W between the right and left rolls': oversize web within the width t ₁ ~t _4: Flange after rolling thickness H _2: reduction of the web height C. web in width after rolling, without expanding rolling When carrying out the rolling load P _{5 in} A above is 0 (reduction allowance ΔB _W is 0)
Or the rolling load P ₅ ′ in B above is 0.
(ΔB _W ′ is 0).