JPH07106367B2 - Rolling mill train of H-section steel and rolling method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rolling mill train of H-section steel used in fields such as construction and civil engineering, and a rolling method of H-section steel using the same. .

(Prior Art) Conventionally, as a rolling method of H-section steel, rolling of H-section steel is carried out by rolling a crude billet in a universal rough mill group consisting of a rough universal mill and an edger mill, and then finish rolling in the universal mill. There is a way.

As shown in FIG. 1, this conventional H-section steel 1 is rolled by a group of universal rough mills, and a universal mill 20 composed of horizontal rolls and vertical rolls in FIG. 1 (a) and 2 in FIG. 1 (b) are used. It is carried out by an edger mill 22 composed of a double-staged edger roll. Universal mill
20 reduces the wall thickness of the H-section steel web and flange, and the edger mill 22 has the function of reducing the flange width of the H-section steel.

By the way, when the flange width is reduced in the edger mill, the flange thickness decreases with each pass due to the rolling by the universal mill 20, so that the roll hole type of the edger mill 22 has an inner surface and a tip surface of the flange (Fig. 1 (b)).
The surface is in contact with only the A surface and the B surface).

In order to improve the dimensional accuracy of the H-shaped steel product, for example, even if the shape of the edger roll is set to the shape such as the beam blank shaping hole die shown in FIG.
The shape must match the flange thickness at the end of the pass. Therefore, after the third pass, the outer surface of the flange has no choice but to be in a free state without coming into contact with the roll.

3 (a) to 3 (c) are schematic sectional views showing examples of the sectional shape of such a conventional edger roll. FIG. 3 (a) shows an example of using an edger mill roll pair having a drum-shaped drum peripheral surface together with a web guide, and FIG. 3 (b) shows a small-diameter roll having thick taper on both ends of a large-diameter roll cylinder. The third example using a body
FIG. 3C shows an example in which a sleeve-shaped split roll having a shape in which a body roll is split into two parts is used, which is fitted in a roll arbor in a reciprocating manner.

However, even if edging rolling is performed with such a conventional edger mill, the effect of controlling the flange width is extremely small. This is because as shown in Fig. 4, even if the flange width of H-section steel is reduced with a conventional edger mill, the flange outer surface is free and only the flange tip indicated by the arrow in the figure deforms outward, The central part does not deform. That is, only the tip of the flange is upset. When the material to be rolled in such a form is rolled by the universal mill in the next step, the upset portion widens and the flange width increases, so the reduction effect of the flange width becomes extremely small. is there. This is schematically shown in FIG.

In the state shown in FIG. 4, when the flange thickness is thin, the flange undergoes buckling deformation as shown in FIG. 6 as the flange is pressed down by the edger mill, resulting in a large center deviation of the product. Cause

As a means for preventing the above drawbacks, as shown in FIG. 7, a universal mill 70 is used as an edger mill, a horizontal roll 72 is shaped like a conventional edger roll, and a vertical roll 74 is rolled. There is a method in which the flange width is made smaller than that of the material, and the outer surface of the flange is supported by the vertical rolls 74 at each pass of rolling, while simultaneously reducing the flange width by the horizontal roll hole type. (WALZWERKSWESE
N, see page 304, 1934, DUSSELDORF VELRLAG STAHLEI
SEN MBM) Also, as a technology having a flange width control function,
There is a method disclosed in Japanese Patent Laid-Open No. 63-72413. This technology
As shown in FIGS. 8 (a) and 8 (b), it comprises two pairs of rolls 80, 80, and one roll of each pair of rolls.
80 is an arbor 84 and a collar 86, and has a working surface for guiding and supporting the inner surface of the flange of the material 1 to be rolled, and the other has a working surface 88 which serves to form the end of the flange of the material 1 to be rolled. It is an edger mill for H-section steel rolling having.

(Problems to be Solved by the Invention) However, a problem in using the universal edger mill 70 shown in FIG. 7 is that the material pressed down easily escapes in the direction perpendicular to the rolling direction, and therefore the flange tip is also left. There is a point that it is not possible to completely prevent the upset of. Further, since a universal mill composed of the horizontal roll 72 and the vertical roll 74 is used, the equipment cost is higher than that of the two-stage (double type) edger mill, which is also a drawback.

Further, in the edger roll 80 proposed by Japanese Patent Laid-Open No. 63-72413, that is, the assembly roll 80 in which one of them is the arbor 84 and the collar 86 which is movable in the axial direction thereof, the flange portion of the H-section steel 1 is It is not possible to restrain, the deviation of the web center of the product due to the buckling of the flange part in the edger mill cannot be prevented, and upsetting of the flange tip is likely to occur, and the effect of reducing the flange width is small.

As described above, in the conventional rolling of H-section steel using the edger mill, the flange width cannot be sufficiently controlled under the present circumstances.

However, the demands on the shape of H-section steel from users are becoming more and more stringent at present, and in order to counter the built-up H-section steel by welding, it is extremely important to prevent flange width variation and web center deviation. It has become to.

In view of the above points, the present invention prevents the upset of the flange tip and the buckling of the flange from occurring during the reduction of the flange width of the H-section steel, and moreover, the flange is efficiently formed without causing the web center deviation. An object of the present invention is to provide a rolling mill train of H-section steel capable of reducing the width and an effective rolling method using the rolling mill train.

(Means for Solving the Problems) In order to achieve the above object, the present inventor has conducted various studies, and as a result, found that the above problems can be solved by performing flange reduction as described below. ,
The present invention has been completed.

That is, the present invention is, from one aspect, an H including a universal rough mill group consisting of a rough universal mill and an edger mill, and a finishing universal mill following the group.
A rolling mill row of shaped steel, wherein the edger mill is provided with an arbor having a convex portion having a cross-sectional shape that constrains a desired flange inner surface of a material to be rolled, and positionally adjustable in the rotation axis direction of the arbor, A rolling mill train for H-section steel, comprising a two-stage roll having a sleeve capable of restraining the outer surface of the flange of the material to be rolled and simultaneously pressing down the tip of the flange.

From another aspect, the present invention is a method for rolling an H-section steel, comprising rolling a rough billet in a universal rough mill group consisting of a rough universal mill and an edger mill, and then finish rolling in the universal mill. The edger mill consisting of the above two-stage rolls is used as the above, and the convex portion of the sleeve or / and the arbor is moved in the direction of the rotation axis for each pass or every few passes of the group of universal rough mills. In the H-section steel rolling method, the inner surface of the flange is restrained by the convex portion and the outer surface of the flange of the material to be rolled by the sleeve, and at the same time, edging rolling is performed to reduce the tip of the flange.

Preferably, an angle θ ₁ formed by a surface that constrains the inner surface of the flange of the arbor with respect to a surface orthogonal to the rotation axis of the arbor, and an angle θ ₂ formed by a surface of the sleeve that restricts the outer surface of the flange of the arbor with a surface orthogonal to the rotation axis of the arbor. , And the angle θ ₃ formed by the surface of the sleeve pressing the flange tip with the rotation axis of the arbor, and the gap S between the surface and the convex portion of the arbor satisfy the following conditions.

0 ° <θ ₁ ≦ 5 °, 0 ° ≦ θ ₂ ≦ 10 °, 0 ° ≦ θ ₃ ≦ 5
° S = tf (flange thickness of rolled material) x 0 to 10% In the present invention, the rough universal mill and finish universal mill are not limited to those having a specific structure,
For example, it is sufficient to use a conventional one.

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

The edger mill consisting of two-stage rolls used in the present invention is, as shown in FIG. 9, an arbor 92 having a convex portion 90 in its center and a movable arbor 92 in the direction of the rotation axis of the arbor 92 and its position being adjustable. , A cylindrical sleeve 94 provided in a pair on the left and right of the convex portion 90.

As shown in FIG. 10, in the edging rolling of H-section steel using the edger mill according to the present invention, the rolled material 1
The inner surface of the flange is constrained by the convex portion of the arbor 92, and the outer surface of the flange is constrained by the sleeve 94 which is movable in the rotation axis direction of the arbor 92, and at the same time, the sleeve 94 compresses the tip of the flange. By doing so, since the front end of the flange is constrained by the hole shape formed by the arbor 92 and the sleeve 94, the wall thickness does not increase at the front end of the flange but increases at the lower part of the flange. Furthermore, in the next process of universal rolling, even if the flange portion is pressed down in the thickness direction, the thickness increase portion is close to the center of the flange, so the thickness increase portion does not flow in the flange width direction Most will flow in the (extending direction). Therefore, the influence of the increased thickness of the flange portion is extremely small. Therefore, the outer peripheral sleeve is moved in the direction of the rotation axis of the arbor for each pass, and the groove width of the hole-shaped flange portion and the flange thickness of the material are always matched to prevent the increase of the flange width in universal rolling. Therefore, the effect of reducing the width of the flange is significantly larger than the current situation.

In addition, a means for moving and fixing the sleeve in the rotation axis direction,
That is, the position adjusting means can be easily realized by screws and hydraulic pressure. This is because the rolling load in the edger mill is extremely small because only the tip of the flange is rolled down. For example, it is possible to exemplify means for fixing a sleeve to the arbor by providing a bolt hole reaching the center of the arbor on the circumference of the sleeve and engaging the bolt with the bolt hole.

As is clear from FIGS. 9 and 10, in the present invention, an arbor 92 having a convex portion 90 having a cross-sectional shape that restrains the inner surface of the flange of the material 1 to be rolled is used. The convex portion 90 may be a single body with the arbor body or may be separable, and is not particularly limited.

However, since the convex portion 90 restrains the inner surface of the H-shaped steel 1 which is the material to be rolled at the time of rolling, it is necessary to have a cross-sectional shape that matches the desired inner surface shape of the flange of the material to be rolled 1.

That is, when the angle formed by the surface that constrains the inner surface of the flange of the arbor 92 and the surface perpendicular to the rotation axis of the arbor 92 is θ ₁ ,
Generally, in rough universal rolling of H-section steel and subsequent edger rolling, the flange of the material to be rolled has a maximum inclination of about 5 ° with respect to the vertical plane, so 0 ° <
It is preferable that θ ₁ ≦ 5 °.

Two sleeves 94, which are movable / fixable in the direction of the rotation axis of the arbor 92 and can restrain the outer surface of the flange of the material to be rolled, are attached to the left and right of the convex portion 90. The sleeve 94 is a cylindrical member having an inner hole for being inserted into a general portion (a portion other than the convex portion) of the arbor 92. The outer diameter may be larger than the convex portion of the arbor 92 and is not particularly limited, but in the present invention, the roll shown in FIG. Needless to say, it is necessary to prevent the sleeves 94, 94 from interfering with each other.

First, in the present invention, the roll hole type of the edger mill formed by the arbor 92 and the sleeve 94 is, as shown in FIG. 10, provided with two arbors 92 having a hole type which is a convex portion for supporting the center of the web. The sleeves 94, 94 are formed by being fitted with each other by screws or hydraulic pressure or their combined means. For example, in the case of screwing, the screw corresponding parts are located at positions left and right displaced from the hole-shaped position.

Of the outer surface of the sleeve 94, to restrain the outer surface of the flange is a plane at right angles to a plane and theta ₂ of the angle to the axis of rotation of the arbor 92, as shown in FIG. 10, the angle theta ₂ is 0 ° ≦ θ
_It is desirable to set in the range of ₂ ≤ 10 °. Because θ
_{When 2} <0, it becomes difficult to engage the flange portion of the rolled material with the hole shape of the edger roll, and θ
_{This is because if 2} > 10 °, the effect of restraining the outer surface of the flange is weakened.

The position for pressing down the flange tip is, as shown in Fig. 10,
The outer surface of the sleeve forms an angle θ ₃ with the rotation axis of the arbor 92, and the angle θ ₃ forms an angle θ ₁ with a surface that constrains the inner surface of the flange of the arbor 92 and a surface perpendicular to the rotation axis of the arbor 92.
It is important to keep the squareness of the flange tip equal to. Therefore, it is preferable that θ ₃ be 0 ° <θ ₃ ≦ 5 °.

Further, as shown in FIGS. 11A and 11B for the initial pass and the final pass, respectively, the gap between the surface of the outer surface of the sleeve for pressing down the flange tip and the convex portion of the arbor 92 is S. Then, S is large in the initial pass of the edger rolling and becomes small as it approaches the final pass. The smaller S is in all the passes of rolling, the more effective it is in preventing the flange tip from biting out, but it is generally desirable that it is within 10% of the flange thickness of the material to be rolled 1.

From this point of view, it is preferable that the pressure lower surface of the flange tip is provided on the sleeve side as in the present invention, and if FIGS. 12 (a) and 12 (b) similarly show the cases of the initial pass and the final pass, respectively. When attempting to press down the flange tip with a part of the outer surface of the arbor 92, the gap S of the sleeve 94 of the arbor 92 becomes larger as it approaches the final pass of the edger rolling, and as shown in FIG. 12 (b). There is a risk that the tip end of the flange will be bitten into the roll gap, leaving a flaw on the product.

As described above, in the edger mill, by constraining substantially the entire surface of the H-shaped steel as the material to be rolled by the hole type formed by the arbor and the sleeve, local deformation of the flange tip under the flange pressure is not generated, Further, the buckling of the flange portion can be prevented, and the H-section steel can be uniformly stretched in the longitudinal direction over the entire cross section.

According to the present invention, as shown in FIG. 13, the convex portion 90 of the arbor 92 shown in FIG. 10 is divided into two, and a sleeve structure that can be moved / fixed in the rotation axis direction online or offline is obtained. By adjusting the distance between the inner sleeves 130, 130, it is possible to perform edging rolling with the same edger roll for manufacturing H-section steels having different web height internal methods, and the number of edger rolls held can be reduced. Needless to say, the movement / fixing of the inner sleeve 130 in the direction of the rotation axis can be easily realized by using a screw, hydraulic pressure, or a compounding means thereof, similarly to the outer sleeve 132.

Further, by appropriately moving the sleeve or / and the convex portion of the arbor so that the flange thickness of the material to be rolled and the flange thickness of the edger hole type are matched for each pass, the flange inner surface of the material to be rolled is It is desirable that the convex portion further restricts the outer surface of the flange of the material to be rolled by the sleeve, and at the same time, edging rolling is performed to reduce the tip of the flange of the material to be rolled by the sleeve. But,
If the sleeve is moved too often, it may take a long time and the temperature of the material to be rolled may decrease and the rolling efficiency may decrease. Therefore, during actual operation, the sleeve may be moved in the three stages of the initial rolling, middle rolling and final rolling. The method of dividing the flange width may be used, and the effect of controlling the flange width is greater than that of the conventional method.

The present invention will be described in detail with reference to examples, but this is merely an example of the present invention, and the present invention is not unduly limited thereto.

(Example) As a material to be rolled, H600 × 200 (mm) H-section steel was subjected to edging rolling by the apparatus and method according to the present invention.

First, the dimensions of the beam blank rolled by the breakdown mill were, as shown in FIG. 14, a web thickness of 60 mm and a flange thickness of 90 mm. This was rolled with a universal coarse mill group consisting of a universal mill and a two-stage edger mill in 9 passes to a web thickness of 11.3 mm and a flange thickness of 17.5 mm. At this time, the hole shape of the edger roll is θ
₁ = 5 °, θ ₂ = 10 °, and θ ₃ = 5 °. Further, S was within 10% of the flange thickness for each pass.

The web thickness and flange thickness reduction scale at this time
Shown in the table.

Table 2 shows the results of measuring the flange width and the web center deviation of the product obtained by performing the edging rolling by the apparatus and the method according to the present invention and then shaping-rolling with the universal finishing mill over the entire length.

For comparison, the table also shows the results of edging rolling using a conventional edger roll.

As can be seen from Table 2, when the conventional edger roll is used for rolling, the fluctuation of the flange width and the deviation of the web center are large, whereas in the case of the present invention, the shape is always symmetrical in the vertical and horizontal directions. Can be held through each pass of the universal rough mill group, so the deviation of the center of the product and the fluctuation of the flange width are extremely small.

In addition, the moving amount of the sleeve due to the reduction of the flange thickness in each rolling pass is about 20 mm at the maximum, and the width change time of the sleeve required for it is around 10 seconds. Little impact was seen.
In addition, no flaw was observed due to biting of the flange tip into the roll gap.

(Effects of the Invention) Since the present invention is configured as described above, a state in which the flange thickness of the edger roll hole type is made to match the flange thickness of the rolled material by moving it every pass or every few passes You can edging with. Therefore, it is possible to roll an H-section steel having a small variation in flange width and a small deviation in the center of the web while using the conventional edging stand as it is, which is extremely useful industrially.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 (a) and 1 (b) are schematic explanatory diagrams showing rolling conditions of H-section steel performed by a conventional universal mill group including a universal mill and an edger mill; FIG. 3 is a schematic sectional view showing an outline of a conventional hole-type edger mill; FIGS. 3 (a), (b), and (c) are schematic sectional views showing a sectional shape of a conventional edger roll; Fig. 5 is an explanatory diagram showing the outline of upset by edging; Fig. 5 is an explanatory diagram of the return of the upset part; Fig. 6 is a schematic diagram showing the buckling situation due to edging; 8A and 8B are schematic sectional views showing an outline of a jar mill; FIG. 8A and FIG. 8B are schematic sectional views showing an edger mill for H-section steel rolling proposed by JP-A-63-72413; , H-section steel rolling mill according to the present invention FIG. 10 is a schematic cross-sectional view showing the edger mill forming the arbor and the sleeve in an assembled state; FIG. 10 is a schematic cross-sectional view showing the edger mill forming the H-shaped steel rolling mill row according to the present invention; ), (B) are partial schematic sectional views showing the edger rolling condition of the H-section steel according to the present invention; FIG. 12 is a partial schematic sectional view showing the biting-out condition of the flange tip in the edger rolling of the H-section steel. FIG. 13 is a schematic sectional view showing a modified example of an edger mill used in a rolling mill train of H-section steel according to the present invention in a state where an arbor and a sleeve are assembled; and FIG. 14 is an embodiment of the present invention. It is a schematic sectional drawing which shows the shape of the beam blank used. 90: convex part 92: arbor 94: sleeve 130: inner sleeve 132: outer sleeve

Claims (3)

[Claims] 1. A rolling mill train of H-section steels comprising a group of universal roughing mills consisting of a rough universal mill and an edger mill, and a finishing universal mill followed by the edger mills for forming a desired flange inner surface of a material to be rolled. An arbor having a convex portion having a cross-sectional shape to be constrained, and a sleeve that is provided so as to be positionally adjustable in the rotation axis direction of the arbor and that constrains the flange outer surface of the material to be rolled and at the same time can press down the flange tip. A rolling mill train for H-section steel, which comprises two stages of rolls provided. 2. The edger mill comprising a two-stage roll according to claim 1, wherein the convex portion of the arbor is divided into two, and has a sleeve structure which can be moved in a rotation axis direction online or offline. Shaped steel rolling machine. 3. A method for rolling H-section steel, comprising rolling a rough steel slab in a universal rough mill group consisting of a rough universal mill and an edger mill, and then finishing rolling in the universal mill, which is an edger mill.
Using an edger mill consisting of two rolls described in
By moving the convex portion of the sleeve and / or the arbor in the rotation axis direction for each pass or every few passes of the universal rough mill group, the flange inner surface of the material to be rolled is covered by the convex portion and further by the sleeve. A method for rolling H-section steel, which comprises performing edging rolling in which the outer surface of the flange of the rolled material is restrained and, at the same time, the tip of the flange is rolled down.