JP2658676B2 - Rolling method for H-section steel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hot rolling of an H-section steel, and more particularly to a method of rolling a center of a web over an entire length of a rolling material in an intermediate rolling step of an H-section steel using a universal rolling mill and an edger rolling mill. The present invention relates to a method for rolling an H-section steel, which can reduce the H value.

[0002]

2. Description of the Related Art Generally, in hot rolling of a section steel represented by an H-section steel, for example, as shown in FIG. The operation is performed by a combination of a rolling mill 4, an edger rolling mill 5, and a finishing universal rolling mill 6. That is, after a rolled material such as a slab, a rectangular slab, or a steel slab for an H-section steel is roughly formed into a predetermined shape by a breakdown rolling machine 3 to obtain a rolled material, a rough universal rolling mill 4 and an edger rolling mill 5 are used. After intermediate-stage rolling in which reversible rolling is performed in a plurality of passes, finish rolling is performed in a single pass in the finishing universal rolling mill 6 to obtain a product section steel.

FIG. 6 (a) shows the rolling process at this time, taking an H-section steel as an example. In the figure, in a rough universal rolling mill (UR) 4, an H-section steel web 2c is rolled by a horizontal roll 7, and flanges 2a and 2b are vertically rolled.
It is supported with a taper. Next, in the edger mill (E) 5, the upper and lower ends of each flange 2a, 2b are pressed down by the edger roll 9, and in the finishing universal mill (UF) 6, the horizontal roll 10 and the vertical roll 11 cooperate. As a result, the flanges 2a and 2b are raised to have a predetermined shape.

Further, as a method for producing a highly efficient H-section steel,
As proposed by Japanese Patent Publication No. 50-21984,
An edger rolling mill is installed at the center of two coarse universal rolling mills arranged in series, and three rolling mills are arranged in a skewer shape close to each other so as to be able to bite simultaneously and break down. There is a method in which the rolled material after rolling is subjected to reversible multiple-pass rolling in a rolling mill group including the above three rolling mills, and sent to a finishing universal rolling mill group to obtain a finished product. The arrangement of each rolling mill in this method is shown in FIG. The rolling material roughly formed by the breakdown rolling mill 3 is reversibly rolled between a first rough universal rolling mill 4, an edger rolling mill 5, and a second rough universal rolling mill 12, and finally a finishing universal rolling mill 6 To the final shape. The rolling process of each rolling mill at this time is shown in detail in FIG. In the figure, in a first coarse universal rolling mill (UR1) 4, an H-section steel web 2c is rolled by a horizontal roll 13 and flanges 2a and 2b are tapered and supported by a vertical roll 14. Next, in the edger rolling mill (E) 5, the upper and lower ends of the flanges 2a and 2b are pressed down by the edger roll 15, and the second coarse universal rolling mill (UR)
2) In 12, the flanges 2 a and 2 b are raised by the cooperation of the horizontal roll 16 and the vertical roll 17, and the final shape is obtained by the horizontal roll 18 and the vertical roll 19 of the finishing universal rolling mill (UF) 6.

As described above, conventionally, FIG. 6 (a) and FIG.
The purpose of the edger rolling mill (E) 5 shown in FIG. 5B is to roll only the both ends of the flanges 2a and 2b so that the flange width can be restricted and the flange end can be shaped and forged. Therefore, the edger roll 9 or 15
In general, the large-diameter convex portion at the center was not brought into contact with the web 2c.

However, in the rolling process of such H-section steel, the cross-sectional areas of the four flanges of the rolled material at the upper, lower, left, and right are not uniform, or the relative positional relationship between the horizontal roll and the vertical roll is poor. As a result, a web center deviation occurs. As shown in FIG. 7, which is a schematic cross-sectional view of the H-section steel in which the web center deviation has occurred, the web center deviation is represented by (a−
b) / 2. Here, a and b are distances from both ends of the upper and lower flanges to the upper and lower web surfaces, respectively.

Conventionally, in order to prevent such a web center deviation, a horizontal roll pair of a coarse universal rolling mill is moved to the entrance side or the exit side of the rolling mill as proposed in Japanese Patent Publication No. 59-13921. In this case, the first and second coarse universal rolling mills as shown in FIG. 5 (c), as proposed in Japanese Patent Application Laid-Open No. Sho 62-263801, are proposed. In a rolling mill train including an intermediate rolling mill group consisting of 4, 12 and a breakdown rolling mill 3, and a finishing universal rolling mill 6,
A method has been proposed in which the entire surface of the web 2c and the flange end are simultaneously reduced by the horizontal rolls of the second coarse universal rolling mill while a part of the flange surface is reduced by the vertical rolls of the coarse universal rolling mill 12. I have. FIG. 8 shows a state of rolling by the first coarse universal rolling mill 4 and the second coarse universal rolling mill 12 at this time. In the figure, the web is rolled by a pair of horizontal rolls 20, 20 'and a pair of vertical rolls 21, 21', and the outer surface of the flange is reduced by the pair of vertical rolls 21, 21 '.

[0008] Further, as a technique for reducing the flange width without reducing the center of the web when the flange width of the H-section steel is reduced, the present applicant has disclosed a technique disclosed in Japanese Patent Application Laid-Open No. Hei 3-1749.
According to Japanese Patent Application Laid-Open No. 07-29980 or Japanese Patent Application No. 2-298051, there is provided an arbor for restraining an inner surface of a flange of a rolled material, and a sleeve roll movably provided in a rotation axis direction of the arbor to restrain an outer surface of the flange of the rolled material. A technique for rolling an H-section steel using the H-section steel edger rolling mill and using the edger rolling mill and the universal rough rolling mill has been proposed.

The rolling mill and rolling method according to these proposals are shown in FIGS. 9 (a), 9 (b) and 10. The contact situation with FIG 9 (a) the rolling stock 1 and the sleeve roll 22, 22 at the time of rolling ^'and arbor 23, ^23', the configuration of a roll used in FIG. 9 (b) the rolling mill, further 10 It is the schematic explanatory drawing which shows the outline | summary of the whole rolling mill typically, respectively. Fig. 9 (a)
Alternatively, as can be seen from FIG. 9B, the arbor 23 having a convex portion having a cross-sectional shape capable of restraining the inner surface of the flange of the rolling material 1 and the rolling member movably provided in the rotation axis direction of the arbor 23. By using an edger roll 24 composed of a double roll composed of sleeve rolls 22 and 22 capable of restraining the outer surface of the flange of the material 1, the sleeve roll 22 is rolled every rolling pass or every several passes. The arbor 23
The edging rolling is performed while restricting the flange portions 2a and 2b of the rolling material 1 by moving the rolling material 1 in the rotation axis direction. That is, in FIG. 10, arbor 23, 23 'having a convex portion 25 having a sectional shape for restraining the inner surface of the flange of the rolled material 1 is used. The arbor 23 and 23 'face to restrain the flange inner surface of the arbor 23, 23' and theta ₁ a plane perpendicular angles between the axis of rotation of, in general, followed by a rough universal rolling of H-shaped steel edger rolling, The flange of the rolled material has a maximum inclination of about 5 ° with respect to the vertical plane.
{≦ θ ₁ ≦ 5}. Sleeve rolls 22, 22 ^′ which are movable and fixed in the rotation axis direction of the arbor 23, 23 ′ and can restrain the outer surface of the flange of the rolled material 1.
Are inserted so as to be located on the left and right of the convex portion 25. The sleeve rolls 22, 22 ^'
3 'is a cylindrical member having an inner hole to be attached to a general portion (a portion other than the convex portion). The roll groove of the edger mill formed by the arbors 23 and 23 'and the sleeve rolls 22 and 22 ^' is provided with two arbors 23 and 23 'having a groove which is a convex portion for supporting a central portion of the web. The two sleeve rolls 22, 22 ^′ , 22, 22 ^′ are formed by being fitted together with screws or hydraulic pressure or a combination thereof.For example, in the case of screwing, the screw equivalent portion is left and right from the hole type position. It has shifted to. Sleeve roll 2
2,22 ^'of the outer surface of, for restraining the outer surface of the flange arbor 23, 23' a plane at right angles a plane and theta ₂ of the angle to the axis of rotation of, as shown in FIG. 10, the Angle θ ₂ is 0 ° ≦
It is desirable to set the range of θ ₂ ≦ 10 °. Because
When θ ₂ <0, it becomes difficult to cause the flange portion of the rolled material to bite into the hole shape of the edger roll, and when θ ₂ > 10 °, the effect of restraining the flange outer surface is weakened. Position for rolling the flange tips, as shown in FIG. 10, 'a sleeve roll outer surface forming an angle of the rotation axis and theta ₃ of the angle theta ₃ is the arbor 23, 23' the arbor 23, 23 The surface that restrains the inner surface of the flange is arbor 23,
23 equal to the perpendicular plane and the angle theta ₁ to the rotation axis of 'it is important to maintain the perpendicularity of the flange tip. Therefore, it is preferable that θ ₃ be 0 ° ≦ θ ₃ ≦ 5 °.

By the way, from the basic conditions of the edging rolling by the conventional edger rolling mill (E) 5 shown in FIG. 6A or FIG. The width of the flange piece of the H-section steel of the product is standardized as shown in Table 1, and in fact, it must be constant within each designation series.

[0011]

[Table 1]

This is because, if the width of the flange piece is to be greatly changed in each of the designation series, it is difficult to obtain the structure shown in FIG.
In (b), it is necessary to previously set a large gap between the large diameter portion of the central convex shape of the edger roll 5 and the web surface 2c of the rolled material 1, which deteriorates the center deviation of the product web as described later. It is because it causes. This is inconsistent with the fact that it is more convenient for the whole width of the flange to be constant within each name series in terms of application technology, and this has been a problem.

[0013] In order to solve such a problem that the flange piece width is constant, and to prevent the web center deviation from deteriorating, the flange full width is kept constant within each of the designation series, and the flange piece width is not adjusted online. Edging mills that can be performed in stages have been proposed.

For example, Japanese Patent Application Laid-Open No. Sho 62-77107 discloses FIG.
As shown in 11 (a) to 11 (c), the edging roll
An eccentric ring 27 is fitted on an outer peripheral surface of the eccentric ring 27 via a bearing 29 on an outer peripheral surface which is axially close to the operating surface of the eccentric ring 26, and is further concentrically mounted on the outer peripheral surface of the eccentric ring 27 via a bearing 29 '. An eccentric ring type edging rolling device in which a restraining ring 28 is fitted has been proposed. 11 (a) and 11 (c) are horizontal sectional views, and FIG. 11 (b) is a vertical sectional view. In this edging rolling device, a pair of edging rolls (split-type horizontal rolls) 26 for rolling and rolling and shaping the front end of a flange of a rolled material are provided for each of the upper and lower sides, and are driven in a corrective manner via a drive shaft. An eccentric ring 27 is mounted on the outer periphery of the edging roll 26 via a bearing 29. Further, a web restraining ring 28 for guiding the rolling material 1 to an appropriate rolling position and restraining the web is provided with a concentric outer circumference of the eccentric ring 27. It is rotatably mounted via a bearing 29 in the shape of a circle. The eccentric ring 27 is controlled by the eccentric ring position setting device 30.
After rotating to an appropriate position according to the rolling conditions, it is fixed. Thus, since the relative distance between the restraining surface of the web and the edging surface at the tip of the flange can be changed steplessly, the entire width of the flange of the product can be formed steplessly.

Japanese Patent Application Laid-Open No. Sho 62-77101 discloses FIG.
(a) or as shown in FIG.
And a horizontal roll 33 having a shaft portion 32, a pair of backup rolls 34 that rollably contact the outer peripheral surface of the shaft portion 32, and an operating roll 35 for rolling down a rolled material flange supported by the backup roll 34. Means for displacing the backup roll 34 in a direction intersecting a straight line connecting the axes of the horizontal roll 33 and the rolled material flange lowering operation roll 35 are provided. ing. In this edging rolling device, the split type horizontal rolls 33 abut the outer peripheral surface of the web of the rolling material 1 so as to roll freely, and hold and restrain the web of the rolling material in the rolling process. Further, it has a web restraining collar 31 and a tapered shaft portion 32, which is rotated by a drive shaft. The backup rolls 34 rotatably support a pair of rolls 35 for rolling the rolled material flange. The pair of backup rolls 34
It is displaced (opened and closed) in a direction intersecting a straight line connecting the axis of each of the split type horizontal roll 33 and the rolled material flange lowering operation roll 35, that is, the directions of arrows K and K 'in the illustrated example. Due to the displacement of the backup roll 34 in the directions of arrows K and K ', the roll 35 for rolling the rolled material flange is displaced in the direction of arrow A. The backup roll 34 is displaced in the directions indicated by the arrows K and K 'by using a roll position adjusting mechanism (press-down mechanism) using a conventional screw, hydraulic mechanism, or the like, which is known per se. In addition, the rolled material flange lowering operation roll 35 is pre-driven by being pressed against the shaft portion 32 of the drive roll via the backup roll 34 with a preload,
It guarantees smooth passing. Further, one roll end face of the rolled material rolling operation roll 35 is configured so as to be in close contact with the side wall of the horizontal roll 33 as shown in the drawing, so that there is no inconvenience in rolling down and forming of the flange tip. I have.

[0016]

First, in the method of manufacturing an H-beam as shown in FIG. 5 (a) or 5 (b), the rolling process shown in FIG. 6 (a) or FIG. As shown, only the both ends of the flange are rolled by the edger rolling mill 5, and the large convex portion at the center of the edger roll 9 or 15 is web 2c.
In general, a gap of about 1 to 3 mm is secured without contacting the surface. Accordingly, the flange portions 2a and 2b of the H-section steel during the edger rolling have the upper and lower end faces on the edger roll 9 or 15 respectively.
The web portion 2c is not restrained by the edger roll 9 or 15, and is free to move up and down, compared to the flange portions 2a and 2b being positioned almost vertically symmetrically with respect to the pass center of the rolling mill. , Leaving a possibility of causing a web center deviation.

Therefore, when the rolling material 1 (beam blank) having irregularities in the flange cross-sectional areas at four locations in the upper, lower, left and right directions in the upstream breakdown rolling is formed,
In the process of repeating rolling in a plurality of passes in the intermediate rolling mill group including the edger rolling mill 5, the web 2c is easily replaced vertically and asymmetrically with respect to the pass center of the rolling mill, and the web center deviation as shown in FIG. May occur.

On the other hand, according to the technique disclosed in Japanese Patent Publication No. 59-13921, the horizontal roll of the universal rolling mill is moved by several hundred mm to the entrance side or the exit side of the rolling mill online at each rolling pass or during rolling. This is not easy in terms of equipment. In addition, when the vertical roll is a spindle type as seen in a general coarse universal rolling mill, the vertical roll and the side face of the horizontal roll are moved as the horizontal roll moves to the entrance or exit of the rolling mill. The gap changes and the flange thickness of the material after rolling changes.
For this reason, it is necessary to change the opening degree of the vertical roll in response to the change in the horizontal roll position, and the control method becomes complicated.

Further, Japanese Patent Application Laid-Open No. 62-26 described with reference to FIG.
According to the method disclosed in Japanese Patent No. 3801, although the center deviation of the web is somewhat improved, it is still not sufficient, and furthermore, it is not a practical means because of the following problems.

FIGS. 13 (a) and 13 (b) show the roll arrangement shown in FIG. 8 in an enlarged manner by dividing the roll arrangement into an initial pass and a final pass, respectively. The gap with 21 is highlighted. Therefore, when the rolling material rolled by the breakdown rolling mill is rolled by a universal rolling mill having a structure as shown in FIGS. 8, 13 (a) and 13 (b), FIG. 13 (b), the width of each of the vertical rolls 21 and 21 'is the same as the width of the vertical rolls 20 and 20' when the minimum gap is set between them.
Because of the smaller vertical distance between 20, 20 ', the reduction of the flange by the vertical rolls 21, 21' is limited only to the parts of the rolls in contact. Therefore, the above vertical roll
The part which is not subjected to reduction without contact with 21, 21 'always exists as an unrolled part 36 with a certain degree of difference in all passes from the start to the end of rolling, and a predetermined flange thickness cannot be obtained. The boundary between the rolled portions is left as a linear flaw in the rolling direction.

Further, when the universal rolling mill having the structure shown in FIG. 8 is realized, each time the product flange width is changed, in addition to the horizontal roll pair 20, 20 ', the shape and dimensions of the horizontal rolls 20, 20' (The minimum gap between the upper and lower horizontal rolls 20, 20 ') needs to be replaced with a vertical roll pair 21, 21' corresponding to the minimum gap. For this reason, a new problem that leads to an increase in the number of rolls held and an increase in the time required for the roll replacement work arises.

On the other hand, the width of the flange piece of the product can be freely adjusted without deteriorating the center deviation of the web proposed in JP-A-62-77101 described with reference to FIGS. 12 (a) and 12 (b). In order to reduce the flange width, the working roll 35 for rolling down the flange of the rolled material must be smaller in diameter than the roll of the current edger rolling mill. Is limited, and since the split type horizontal roll 33 and the rolled material flange lowering operating roll 35 have completely different rotational movements, the rolls cannot be brought into contact with each other. Need to be kept. For this reason, there is a problem that the rolled material 1 may bite into the gap and cause a trouble when the front end of the flange is lowered, and the present technology cannot be said to be practical.

Similarly, the edging for adjusting the width of the flange piece while preventing the center deviation of the web proposed in Japanese Patent Application Laid-Open No. 62-77107 described with reference to FIGS. 11 (a) to 11 (c). Since the rolling device has an eccentric mechanism, the entire device is extremely complicated, and bearings are interposed between the horizontal roll 26 and the eccentric ring 27, and between the eccentric ring 27 and the web restraining ring 28. Therefore, there is a problem that the durability may be extremely deteriorated due to a problem in a method of lubricating the bearing and a method of sealing from surrounding water or scale, and the present technology is not practical.

Finally, regarding the edger rolling mill and the edger rolling method previously filed by the present applicant, FIG. 14 shows an example of a shape defect of an H-beam by a conventional edger rolling mill.
As shown in Fig. 14 (a) or Fig. 14 (b), it has the effect of preventing dog bone deformation at the flange tip and buckling of the flange and suppressing the occurrence of web center deviation during edging rolling. The point that the gap between the roll body (large diameter part) and the web part of the rolled material has to be secured by about several mm is the same as the conventional edger roll. , That is, there is a limit in reducing the deviation of the web center. Furthermore, when trying to freely adjust the flange width with an edger roll of the same size, even if the edger rolling machine and the edger rolling method are used, it is undeniable that the center deviation of the web becomes worse.

Here, an object of the present invention is to reduce the center deviation of the web over the entire length of the rolled material in the intermediate rolling stage of the H-section steel using a universal rolling mill and an edger rolling mill. An object of the present invention is to provide a method for rolling a section steel.

[0026]

The inventor of the present invention has conducted various studies to solve the above-mentioned problems, and as a result, FIG. 15 (a) and FIG. As shown in (b), when the universal rolling was performed on a rolled material having different flange tip thicknesses in the upper and lower directions, the change in the web center deviation was investigated, and the following findings were obtained.

That is, in FIGS. 15 (a) and 15 (b), the upper and lower flange pieces have the same width, there is no apparent deviation of the web center, ((a−b) / 2 ≒ 0), and the flange tip thickness is As shown in the same figure, as a result of rolling the rolled material of the H-section steel (tfu> tfd or tfu <tfd), which is different at the top and bottom, using a universal rolling mill to reduce the thickness of the flange and web thickness, When the thickness is tfu> tfd, a negative web center deviation ((a−b) / 2 <0) occurs in the rolled material. Conversely, when the flange tip thickness of the material is tfu <tfd, On the other hand, a positive web center deviation ((a−b) / 2> 0) was observed in the rolled material.

The inventor of the present invention has found that the cause of this problem is that, in the case of universal rolling, the flange portion having the larger flange tip thickness precedes the flange portion having the smaller flange thickness, so that the horizontal roll side surface and the vertical roll of the universal rolling mill are separated. Since the larger the flange thickness of the material flange is, the greater the flange reduction rate is, the difference in the extension (elongation in the rolling direction) of the upper and lower flanges occurs, and the web moves vertically ( (Replacement) occurs.

Based on the above premise, the present inventor has conducted further studies. As a result, when the H-section steel in which the web center deviation exists in advance is subjected to edging rolling, the above-described FIG. 9 (a) or FIG. FIG. 1 (a) or FIG. 1 (b) is obtained by utilizing vertically asymmetrical rolling by an edger rolling mill using rolls shown in FIG. 9 (b).
As shown in (b), when the center deviation of the web is positive in the rolled material of the H-section steel, the center deviation of the web is reversed so that the tip thickness of the upper flange of the rolled material is larger than the tip thickness of the lower flange. In the negative case, the upper and lower end thickness of the flange (dog bone shape) is adjusted by adjusting the flange constraint degree by the edger rolling mill so that the lower flange end thickness of the rolled material is larger than the upper flange end thickness. We found that universal rolling is effective.

That is, as described above, the present invention solves the conventional problems that the center deviation of the web and the width of the flange piece in the conventional hot rolling of the H-section steel cannot be freely adjusted. The gist is that an arbor having a convex portion having a cross-sectional shape that restrains the inner surface of the flange of the rolled material, and a sleeve roll that is provided so as to be movable in the rotation axis direction of the arbor and restrains the outer surface of the flange of the rolled material. An H-shaped steel rolling method for performing reversible rolling using an edger rolling mill for rolling H-beams constituted by double rolls comprising: and a universal rolling mill, comprising: By moving the sleeve roll in the rotation axis direction for each pass, the flange inner surface of the rolled material is formed by the convex portion, and the flange outer surface of the rolled material is formed by the sleeve roll. While Risorezore restraint when performing edging, entry side or the input and the edger rolling mill
On the exit side, the center deviation value of the web: (ab) / 2 (where a and b indicate the width of the upper and lower flange pieces), and when the center deviation value of the web is positive, the flange of the rolled material is measured. When the web center deviation value is negative, the doubleness is set so that the degree of constraint at the upper part of the flange of the rolled material is greater than the degree of constraint at the lower part of the flange so that the degree of restriction at the lower part is greater than the degree of restriction at the upper part of the flange. A method of rolling an H-section steel, wherein a gap in a rotation axis direction between the convex portion of the roll of the formula and the sleeve roll is adjusted vertically.

[0031]

The structure and operation of the present invention will be described more specifically with reference to the accompanying drawings. In the example of the arrangement of the rough universal rolling mill-edger rolling mill (UR-E arrangement) as a basic configuration of the H-section steel rolling line to which the present invention is applied, FIG.
FIG. 6 (a) shows the state of processing of the H-section steel in the case of the rolling line in the cross-sectional shape.

The arrangement of the first coarse universal rolling mill, the edger rolling mill, and the second coarse universal rolling mill (UR1−
Another example of the arrangement of the rolling line when the present invention is applied in the example of (E-UR2 arrangement) is as shown in FIG. 5 (b).
FIG. 6 (b) shows a change in the cross-sectional shape of the H-section steel when using the rolling line. The state due to the reduction applied to the rolled material in each step is the same as the conventional state.

First, according to the rolling method of the present invention,
Breakdown rolling may be performed in the same manner as in the conventional method, whereby the rolled material is rolled into a beam blank (coarse billet). The rolling stock is then finished to the final dimensions of the flange width, flange thickness and web thickness in an intermediate rolling step using a UR-E or UR1-E-UR2 configuration coarse universal mill and edger mill.

Therefore, an edger rolling mill for rolling H-beams composed of double rolls as shown in FIG. 9 (a) and FIG. 9 (b) or FIG. Introduced, while reducing the web thickness and flange thickness in the universal rolling mill, in each pass of the reversible rolling to reduce the flange width to a predetermined value in the edger rolling mill, the upper and lower rolls of the edger rolling mill By performing reversible rolling of desirably 10 to 15 passes while adjusting the degree of groove shape restraint, occurrence of web center deviation is largely suppressed.

Next, the H-section steel according to the present invention using an edger rolling machine for rolling an H-section steel, which is constituted by double rolls as shown in FIG. 9 (a), FIG. 9 (b) or FIG. The rolling method will be described. As shown in FIG. 1 (a), in the case of rolling a rolled material 1 having a positive web center deviation, in edger rolling, the flange thickness of the upper flange is set to be larger by a predetermined amount than the thickness of the lower flange. Shape when the width is reduced. This causes a difference in elongation between the upper and lower flanges during the subsequent universal rolling, the web is replaced, and the web center deviation of the H-section steel (= (a′−b ′) /
2) can be made almost zero.

Further, as shown in FIG. 1 (b), in the case of rolling of a rolled material 1 ^' having a negative web center deviation (= (ab) / 2 <0), the lower portion of the roll is subjected to edger rolling. It is shaped when the flange width is reduced so that the flange tip thickness is larger by a predetermined amount than the upper flange tip thickness. Thereby, similarly, the web center deviation (= (a'-b ') / 2) of the H-section steel after the universal rolling can be reduced to almost zero. FIG. 3 (a) or FIG. 3 (b)
FIG. 4 is a schematic explanatory view for collectively explaining the principle of control of web center deviation by edger rolling and subsequently performed universal rolling.

In the present invention, as shown in FIG. 2, in the edger rolling, the interval between the convex portion of the arbor and the sleeve roll is changed for the upper and lower double rolls, so that the degree of restraint of each flange by the hole shape is changed. FIG. 3 shows the deviation of the center of the web after edging rolling using different edger rolls.
As shown in (a), S ₀ (= a ₀ −b ₀ ) / 2), and the web center deviation after universal rolling by a universal rolling mill including a horizontal roll 37 and a vertical roll 38 is S ₁ (= (a
₁₋ b ₁ ) / 2). In FIG. 3 (a), assuming that the tip thicknesses of the upper and lower flanges after edging rolling are tfu and tfd, respectively, and that tfu> tfd, in the next universal rolling mill, the projected contact length between the outer surface of the flange and the vertical roll of the universal rolling mill will be described. Is different between the upper and lower sides, resulting in asymmetric rolling. Here, assuming that the maximum projected contact lengths of the upper and lower flange outer surfaces and the vertical roll are (1df) u and (1df) d respectively, naturally (1d
f) u> (1df) d. Further, assuming that the difference between these maximum projection contact lengths is Δldf, it is represented by Δ1df = (1df) u− (1df) d ≒ [2 · Rv · (tfu−tfd)] ^1/2 . Here, Rv is the vertical roll radius.

FIG. 3 (b) shows Δ1df and H obtained before and after universal rolling obtained from the experimental results of the present inventor.
The relationship between the difference between the web center bias of shape steel ΔS (= S ₁ -S ₂₎ is a graph schematically showing. From the figure, when Δ1df is positive, that is, the upper flange tip thickness of the H-section steel before universal rolling is made larger than the lower flange tip thickness, and the contact between the upper part of the flange outer surface and the vertical roll in universal rolling is made to the lower part. It can be seen that, by leading ahead, the flange center can be moved downward to make ΔS negative. Conversely, when Δ1df is negative, ΔS can be made positive by the same principle, and a linear relationship is established between the two. However, since the amount of change of ΔS with respect to Δ1df, that is, the gradient of the straight line in FIG. 3 (b) changes depending on the universal rolling conditions, various rolling conditions (rolling material shape / material,
It is desirable in the practice of the present invention that the gradient is determined experimentally or theoretically with respect to the reduction ratio of the flange and the web, the rolling temperature, and the like, and used appropriately as appropriate.

As described above, in order to control the center deviation of the web in the present invention, based on the measurement result of the center deviation of the web of the H-section steel before the edger rolling, the following relationship is established based on the relationship between ΔS and Δ1df. The Δ1df required for correcting the center deviation of the web in the universal rolling is calculated, and then the hole-type constraint of the upper and lower rolls in the edger rolling is calculated. Thereafter, the positions of the upper and lower movable sleeves in the direction of the rotation axis are adjusted so as to have a predetermined hole-shaped constraint. Of course, at this time, if the web center deviation of the H-section steel is different between the left and right (the driving side and the operating side of the rolling mill), the left and right hole type constraint Needless to say, if the above is also changed, the effect of correcting the center deviation of the web in the universal rolling mill further increases.

FIGS. 4 (a) and 4 (b) illustrate a web center deviation control flow in the H-section steel rolling method according to the present invention. First, FIG. 4 (a) shows that a web center deviation measuring device 38 is connected to a universal rolling mill 39 and an edger rolling mill.
40, that is, on the entrance side of the edger rolling mill 40, and controls the upper and lower roll hole type restraint of the edger rolling mill 40 based on the web center deviation data of the rolled material 1 after the universal rolling. That is, in the control shown in the figure, the main processing unit 41 determines the optimum rolling schedule for each rolling pass based on predetermined rolling schedule information, rolling temperature information, rolling load information, and a measured value of the web center deviation of the rolled material. The difference in thickness at the tip of the flange is determined, and a command to drive and control the motor for adjusting the position of the sleeve roll (setting the opening) of the upper and lower edger rolls is output so as to obtain the difference in flange thickness. In addition, the reason why the rolling temperature and the rolling load information are taken in the calculation of the flange tip thickness difference is to perform more reliable control.

On the other hand, FIG. 4 (b) shows that the web center deviation measuring devices 38 and 38 ^' are installed on the entrance side and the exit side of the edger rolling mill, and the web center deviation of the rolled material 1 after the universal rolling and the edging rolling. The method for controlling the degree of restriction of the upper and lower holes of the edger rolling mill based on the data is shown. That is, the main arithmetic unit determines the optimum flange tip thickness difference for each rolling pass based on the predetermined rolling schedule information and the measured value of the web center deviation of the rolled material, and moves up and down so that the flange thickness difference can be obtained. Outputs commands to drive and control the motor for adjusting the position of the sleeve roll (setting the opening) of the edger roll and the motor for adjusting the position of the guide roller. In calculating the flange tip thickness difference, more reliable control should be performed by incorporating the web center deviation values before and after universal rolling and edging rolling, rolling temperatures of both rolling mills, and rolling load information. Can be.

It should be noted that the above-mentioned web center deviation measuring device does not need to be limited at all, and for example, Japanese Patent Application Laid-Open No. 58-179515.
It is sufficient to use a measuring device disclosed in Japanese Patent Application Laid-Open Publication No. H11-157, 1988. Furthermore, the present invention will be described with reference to examples, but these are merely examples of the present invention, and the present invention is not limited thereto.

[0043]

EXAMPLES The present invention will be described in detail with reference to examples. (Example 1) In the rolling line shown in FIG. 5 (a), the method for rolling an H-section steel according to the present invention shown in FIG. 1 was introduced to manufacture a JIS size H-section steel H800 × 300 series.

First, after the continuous cast slab was heated, it was subjected to reversible rolling by a breakdown rolling mill having a roller die to form a beam blank. In addition, coarse universal rolling mill
(UR) and reversible rolling with an edger rolling mill (E) to obtain a product with a thickness close to the flange thickness, web thickness and flange width,
Rolled to dimensions.

The specifications of the edger rolling mill used in the embodiment are as shown in FIG. 10. A hole-type edger roll composed of a double roll composed of a sleeve roll and an arbor slidable in the direction of the rotation axis. The shape of the convex portion of the arbor shown in the figure was set to θ ₁ = 5 °, and the shape of the sleeve roll was set to θ ₂ = 0 ° and θ ₃ = 5 °. The hole shape formed by the convex portion of the arbor and the sleeve roll can adjust the hole shape constraint degree by appropriately moving the sleeve roll for each rolling pass by an electric motor, a speed reducer, and a position adjustment mechanism (not shown). And In addition, a web center offset meter (not shown) is installed between the UR-E, and feed-forward control of the position of the sleeve roll of the double-type edger rolling mill is performed in each pass based on the measured web center offset after the coarse universal rolling. I went every time.

Next, the rolled material after the intermediate rolling is slightly reduced in the thickness of the web and the flange, flattened on the outer surfaces of the flange, and further flattened by a single pass rolling in a finishing universal rolling mill (UF). The product was finished to have a right angle opening.

Table 2 shows the measurement results of the center deviation of the web of the product manufactured according to the present invention for three sizes of the H800 × 300 series. In addition, the same table also shows the results of measuring the center deviation of the web of a product when a conventional edger rolling mill without the movable sleeve roll shown in FIG. 10 is applied to the same rolling line as a conventional example.

[0048]

[Table 2]

From this table, it can be seen that, using the H-beam rolling method according to the present invention, the web center deviation of the product is remarkably reduced over the entire length of any size H-beam, and a product having excellent dimensional accuracy can be obtained. It can be seen that it was obtained.

Example 2 In the rolling line shown in FIG. 5 (b), the method of rolling an H-section steel according to the present invention shown in FIG. ×
Production of 3 size H-section steels of the 200 series was performed.

Also in the case of this embodiment, after the continuous casting bloom was heated, reversible rolling was performed with a breakdown rolling mill, and the same process as in the previous embodiment 1 was performed until a beam blank was formed. Next, two coarse universal rolling mills (UR1,
UR2) and an edger rolling mill (E) located in the middle of the reversible rolling, and rolled to a shape and dimensions close to the product flange thickness, web thickness and flange width.

The specifications of the edger rolling mill used in the present embodiment are the same as those in the first embodiment, and include a sleeve roll and an arbor slidable in the direction of the rotation axis as shown in FIG. A hole-type edger roll was adopted, and the shape of the convex portion of the arbor shown was set to θ ₁ = 5 °, and the shape of the sleeve roll was set to θ ₂ = 0 ° and θ ₃ = 5 °. . With respect to the hole shape formed by the protrusions of the arbor and the sleeve roll, the sleeve roll was moved for each rolling pass by an electric motor, a speed reducer, and a position adjustment mechanism (not shown) to adjust the hole shape constraint. In addition, the web center deviation meter (not shown) is used for UR1-E and E-UR2
The feeder and feedback control of the position of the sleeve roll of the edger mill were performed for each pass based on the measured value of the web center deviation after UR1 or UR2 rolling.

Next, the rolled material after the intermediate rolling is slightly reduced in the thickness of the web and the flange, flattened on the outer surfaces of the flange, and further flattened by a single pass rolling in a finishing universal rolling mill (UF). The product was finished to have a right angle opening. Table 3 shows H500 × 200
The measurement result of the web center deviation of the product manufactured by this invention about three sizes of a series is shown. Similar to the first embodiment, a conventional example will be described.

[0054]

[Table 3]

In the rolling according to the conventional example, when the entire width of the flange of the product is constant, the width of the flange piece increases as the web thickness (tw) of the product decreases, so that the body (large diameter portion) of the edger rolling mill is used. ) And the web surface of the rolled material must be increased. For this reason, the possibility that the center of the web is replaced up and down increases, and the center of the web of the product becomes worse.

On the other hand, by introducing the method for rolling an H-section steel according to the present invention, the hole-shaped restraint of the upper and lower edger rolls can be performed online in response to a change in the product flange piece width and a change in the web center deviation. It can be seen that by controlling the degree, the deviation of the web center of the product over the entire length of the rolled material was significantly improved as compared with the conventional method.

[0057]

According to the present invention, as described above, the present invention can significantly reduce the center deviation of the web in the universal rolling of H-section steel, and has various sizes such as H-section steel having a constant outer dimension. H-section steel can be manufactured with high dimensional accuracy, which is extremely useful in industry.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are schematic explanatory views schematically showing a rolling process of a method for rolling an H-section steel according to the present invention.

FIG. 2 is a schematic sectional view illustrating an example of rolling an H-section steel by an edger rolling mill in the present invention.

FIG. 3 (a) is a schematic explanatory view showing the principle of correcting the center deviation of the web in the universal rolling mill according to the present invention, and FIG. 3 (b) shows the maximum projection length of the outer surfaces of the upper and lower flanges and the vertical roll. It is a graph which shows the relationship between the difference (DELTA) ldf and the difference (DELTA) S of the web center deviation before and after universal rolling.

FIGS. 4 (a) and 4 (b) are explanatory diagrams of a flow of a control example in the present invention.

5 (a) to 5 (c) are configuration diagrams of a conventional H-section steel rolling line.

6 (a) and FIG. 6 (b) correspond to FIG. 5 (a), respectively.
FIG. 6 is an explanatory diagram showing in detail a process of hot rolling of the conventional H-section steel shown in FIG. 5 (b).

FIG. 7 is an explanatory diagram of a web center deviation.

FIG. 8 is a front view of a universal rolling mill in implementing a conventional method for preventing a web center deviation of an H-section steel.

FIG. 9 (a) and FIG. 9 (b) show H according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS It is an explanatory view which shows an example of the structure of the edger rolling machine for H-shaped steel rolling comprised by the double type roll used for implementing the rolling method of a shape steel.

FIG. 10 is an explanatory diagram showing a rolling state by the edger rolling mill shown in FIGS. 9 (a) and 9 (b).

FIGS. 11 (a) to 11 (c) are explanatory views showing the structure of an edger rolling mill in a conventional web center deviation preventing method.

FIGS. 12 (a) and 12 (b) are a schematic longitudinal sectional view and a side view showing the structure of an edger rolling mill in a conventional web center deviation preventing method.

FIG. 13 (a) or FIG. 13 (b) is a schematic explanatory view showing a universal rolling process in an initial pass and a final pass in a conventional web center deviation preventing method, respectively.

FIGS. 14 (a) and 14 (b) are explanatory diagrams showing the problems of the conventional edger rolling.

FIG. 15 (a) and FIG. 15 (b) are explanatory diagrams for explaining the state of occurrence of web center deviation due to asymmetric rolling in a universal rolling mill.

[Explanation of symbols]

1,1 ': Rolled material 2a, 2b: Flange 2c: Web 3: Breakdown rolling mill 4: First coarse universal rolling mill 5: Edger rolling mill 6: Finishing universal rolling mill 7: Horizontal roll 8: Vertical roll 9: Edger roll 10: Horizontal roll 11: Vertical roll 12: Second coarse universal rolling mill 13: Horizontal roll 14: Vertical roll 15: Edger roll 16: Horizontal roll 17: Vertical roll 18: Horizontal roll 19: Vertical roll 20, 20 ': Horizontal roll 21, 21': Vertical roll 22, 22 ': Sleeve 23, 23': Arbor 24: Edger roll 25: Convex part 26: Edging roll 27: Eccentric ring 28: Web restraining ring 29, 29 ' : Bearing 30: Eccentric ring position setting device 31: Web restraining collar 32: Shaft 33: Horizontal roll 34: Backup roll 35: Roll for rolling down the flange of rolled material 36: Unrolled part 37: Horizontal roll 38: Web Bias measurement device 39: Universal rolling mill 40: edger rolling mill 41: main processing unit

Claims (1)

(57) [Claims] An arbor having a convex portion having a cross-sectional shape for restraining an inner surface of a flange of a rolled material, and a sleeve roll movably provided in a rotation axis direction of the arbor and restraining an outer surface of the flange of the rolled material. A method for rolling an H-section steel, which performs reversible rolling using an edger rolling mill for rolling an H-section steel constituted by double rolls and a universal rolling mill, comprising: By moving the sleeve roll in the rotation axis direction every time, when performing edging while restraining the flange inner surface of the rolled material by the convex portion and the flange outer surface of the rolled material by the sleeve roll, the edger rolling is performed. On the entry side or entry / exit side of the machine, the web center deviation value: (ab) / 2 (however, a and b indicate the upper and lower flange piece widths, respectively) When the center deviation of the web is negative, the constraint of the upper part of the flange of the rolled material is negative when the value of the center deviation of the web is negative so that the degree of constraint at the lower part of the flange of the rolled material is greater than the degree of constraint at the upper part of the flange. An H-shape wherein the gap in the rotation axis direction between the convex portion of the double roll and the sleeve roll is adjusted for each of the upper and lower rolls so that the degree is larger than the restraint degree of the lower portion of the flange. Steel rolling method.