JP2000071001A - Rolling method for section steel - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To surely suppress the center deviation of a web without providing a separate constraint guide or the like and without causing unevenness in product flange thickness for a shaped steel product having a flange. SOLUTION: In a method for hot-rolling and manufacturing a section steel having a flange 2 and a web 3 by a universal rolling mill 7 and an edging rolling mill 4, edging rolling is performed according to the form of the web center deviation of the material 1 to be rolled. The center position 10 of the roll gap of the mill 4 is adjusted in the vertical direction, and the relative positions of the upper and lower rolls 5 and 6 in the axial direction are adjusted to correct the web center deviation of the material 1 to be rolled.

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 a shaped steel having a flange and a web by using a universal rolling mill and an edging rolling mill.
The present invention relates to correction of web center deviation by operating an edging mill.

[0002]

2. Description of the Related Art When a shaped steel having a flange and a web, such as an H-section steel, is manufactured by hot rolling, an edging rolling machine is used to shape a flange end and to define a flange width dimension. Is usually performed. In particular, recent edging rolling mills have been developed which have a function of correcting the center deviation of the web in addition to the shaping of the flange. The center deviation of the web as referred to herein is a type of dimensional defect that occurs in a shaped steel product having a flange and a web. As shown in FIG. 3 is the displacement of the center position in the thickness direction.

As a technique for correcting the center deviation of the web at the time of edging rolling, the gap between the web guiding portion of the edging roll and the web of the material to be rolled is made very small, and the web of the material to be rolled is cut in the flange width direction. A rolling method (web touch rolling method) for correcting eccentricity of the web center by performing edging rolling while reliably guiding the center to the center is known.

In this web touch rolling method, the material to be rolled is guided to the center of the roll gap by a strong restraining force due to the contact between the web guiding portion of the edging roll and the web of the material to be rolled. The edging reduction amount is large, the edging reduction amount of the flange with a short leg length is reduced, and the effect of correcting the center deviation of the web by reducing the edging reduction amount. The shearing deformation is applied to the fillet portion, which is the joining portion of the flanges, and the replacement of the web has the effect of correcting the bias of the center of the web.

The web touch rolling method has an effect of effectively suppressing the center deviation of the web as described above. However, when the web touch rolling is performed, a large difference in roll peripheral speed generally occurs between the flange tip rolling portion and the web contact portion. Occurs. In order to avoid inconveniences such as the generation of surface eaves due to this, rolling must be performed by providing a gap between the web and the edging roll, and therefore the web touch rolling method has not been implemented at present. It is.

[0006] For this reason, in order to suppress the center deviation of the web of the product, it is necessary to rely on the universal rolling mill. By changing the setting of the restraining guide adjacent to the universal rolling mill, the biting posture of the material to be rolled can be reduced. A method of controlling or a method of realizing a web change rolling method by adjusting a center position of a horizontal roll gap to an upper side or a lower side with respect to a center position of a vertical roll of a universal rolling mill is adopted. However, in order to perform the above-described operation during universal rolling, a separate restraining guide must be provided in the vicinity of the universal rolling mill. And the flange thickness reduction rate of each material to be rolled is different, and there is a problem that the flange thickness of each product is not uniform. In addition, since the flange thickness reduction ratios of the respective flanges are different, the flange width expansion amounts are also uneven at the respective flanges, and the respective flange leg lengths are different. As a result, it has been difficult to effectively correct the web center deviation. .

[0007]

The center deviation of the web that occurs in a shaped steel product having a flange is corrected by adopting at least one of the web touch rolling method described above and the setting operation of a universal rolling mill. However, in addition to the fact that it was not always possible to effectively suppress the center deviation of the web, irregularities in the thickness of the product flange sometimes occurred. In the method using the constraint guide,
It was necessary to separately provide a constraint guide near the universal rolling mill.

The present invention has been made in view of such a situation, and has been developed for a shaped steel product having a flange without providing a separate restraining guide or the like and without causing irregularities in the product flange thickness. An object of the present invention is to provide a method for rolling a section steel that reliably suppresses center deviation.

[0009]

Means for Solving the Problems (1) In a method for rolling a section steel according to one embodiment of the present invention, a section steel having a flange and a web is hot-rolled by a universal rolling mill and an edging rolling mill. In the method of rolling section steel, the center position of the roll gap of the edging mill is adjusted in the vertical direction, and the axial relative position of the upper and lower rolls is adjusted according to the form of the web center deviation of the material to be rolled. It corrects the web center deviation of the material. (2) The method for rolling a section steel according to another aspect of the present invention is the rolling method according to the above (1), wherein the form of the web center deviation of the material to be rolled is changed to a line-symmetric component and a point-symmetric component. The center position of the roll gap of the edging mill is adjusted in the vertical direction based on the line-symmetric component, and the axial relative position of the upper and lower rolls of the edging mill is adjusted based on the point-symmetric component. Things.

Here, taking the H-section steel, which is a typical example of a section steel having a flange, as an example, the web center deviation is usually a point symmetrical shape as shown in FIG. Can be quantitatively decomposed into a type A composed of a and a type B composed of a line-symmetric form.

Here, a method of disassembling the type A and the type B will be described. As shown in FIG. 3, there are two types of center deviation of the material 1 to be rolled, that is, a D side and an F side. If this center deviation is Sd and Sf, respectively, it is expressed by the following equation. Sd = (ab) / 2 (1) Sf = (cd) / 2 (2) The center deviation A of the type A is obtained from the flange width dimensions A1 and A2 shown in FIG. −A2) / 2 (3) The center deviation B of the type B is also expressed as B = (B1−B2) / 2 (4) from the flange width dimensions B1 and B2 shown in FIG. Then, since 2a = A1 + B1 2b = A2 + B2 2c = A2 + B1 2d = A1 + B2, the above-mentioned center deviations A and B can be calculated as follows using the above-described equations (1) and (2).

[0012]

(Equation 1)

The offset amounts X and Y with respect to the center deviations A and B at this time are obtained as follows. The axial offset amount X of the type A is obtained by the following equation using the center deviation A and the correction coefficient α. X = α × A + adjustment items (9) Offset amount Y of the center position of the roll gap of type B
Is obtained by the following equation using the center deviation B and the correction coefficient β. Y = β x B + adjustment items ... (10)

With respect to the type A web center deviation obtained as described above, as shown in FIG.
The edging rolls 5 and 6 of the edging mill 4 are rolled while being offset in the roll axis direction by an offset amount X (the edging rolls 5 and 6 are moved to the shorter one of the flange leg lengths of the material 1 to be rolled), thereby forming a flange. The flange 2a having a longer leg length has a larger edging reduction amount,
A flange having a shorter flange leg length has a smaller edging reduction amount, and is subjected to edging rolling while correcting eccentricity of the web center. Further, the flange 2b having a shorter leg length is provided with a restraining force for maintaining a rolling posture by contact with the body of the edging rolls 5, 6, while the flange 2a having a longer leg length is provided on the body of the edging rolls 5, 6. Since there is no contact, no restraint force for maintaining the rolling posture is given, and as shown in FIG. 1 (A), the material 1 to be rolled tilts counterclockwise. Due to this inclination, the flange 2a having a longer flange leg length has a larger effect, and the flange 2b having a shorter flange leg length has an effect of promoting the effect of giving a smaller edging reduction amount, and the web center deviation is more effectively corrected. You.

In addition, as shown in FIG. 1 (B), for the type B weft center deviation, as shown in FIG. 1B, the rolled material 1 which is geometrically determined by the rolled material transport mechanism at the entrance and exit of the edging mill. When the upper flange leg length of the material to be rolled 1 is longer than the lower flange leg length with respect to the center position in the thickness direction of the web, the roll gap center position 10 is set to the lower side in accordance with the offset amount Y, so that the upper The web eccentricity is corrected by increasing the edging reduction amount of the flange. When the lower flange leg length of the material to be rolled 1 is longer than the upper flange leg length, the roll gap center position 10 is set to the upper side in accordance with the offset amount Y to perform rolling (see B2 in FIG. 2 described later). A larger edging reduction amount of the lower flange is used to correct the web center deviation. In this case, the rolled material 1 floats from the rolled material transport mechanism on the side of the edging rolling mill, and it is conceivable that a predetermined reduction amount cannot be obtained.
Considering the case where universal rolling continues immediately after edging rolling, as shown in FIG. 1C, the web of the rolled material 1 floating from the rolled material transport mechanism is transferred to the universal rolling mill 7 (the edge rolling mill 4). In this case, it is replaced on the lower side by the horizontal rolls 8 at the time of rolling by (disposed on the upstream side). At this time, since the setting of the universal rolling mill 7 does not need to be changed at all, it is possible to correct the deviation of the web center without causing uneven flange thickness and uneven flange width.

According to the present invention, the axial position of the edging roll and the center position of the roll gap are adjusted in accordance with the form of the web center deviation of the material to be rolled as described above. The form of the center deviation is measured as follows and reflected in the correction of the center deviation of the web of the material to be rolled. An online dimension measuring instrument is placed behind the line,
Of the center of the web of the product after the rolling is measured by measuring the flange dimensions a, b, c, and d. Then, this is reflected in the suppression of the deviation of the web center of the material to be rolled next. An on-line dimension measuring device is arranged at a position adjacent to the universal-edging mill group, and the web center deviation amount of the material to be rolled is measured in one or more rolling passes. Then, it is reflected in the edging rolling after the rolling pass in which the measurement is performed (that is, online control is performed).

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An H-section steel will be described as a typical example of a section steel, and a method of performing edging rolling while suppressing web center deviation according to the present invention will be described below. FIG. 2 is a schematic view of an example of an operation method of the edging mill according to the present invention. First, the center deviation of the web of the material to be rolled
And type B (A1, A1)
For the web center deviation in 2), the upper edging roll 5 and the lower edging roll 6 are offset in the roll axis direction. At that time, it is desirable to give the upper edging roll 5 and the lower edging roll 6 the same offset amount in the opposite directions so that the right and left pass lines do not shift. The type A1 in FIG. 2 is an example in which the upper right flange of the figure is longer than the lower one and the lower left flange is longer than the upper one. In this case, the upper edging roll 5 is placed on the left side. The lower edging rolls 6 are respectively offset to the right. Type A2 is an example in which the flange on the lower right side of the figure is longer than that on the upper side, and the flange on the upper left side is longer than that on the lower side. To the right and the lower edging roll 6 to the left. In each of the types A1 and A2, the offset amount X is obtained from the above equation (9).

The type B of the material to be rolled (B1, B2)
For the web center deviation, the roll gap center position 10 constituted by the upper edging roll 5 and the lower edging roll 6 is vertically offset. The type B1 in FIG. 2 is an example in which the upper flange is longer than the lower part. In this case, the upper edging roll 5 and the lower edging roll 6 are shifted downward, and the roll gap center position 10 is shifted downward. Offset to Type B2 of FIG. 2 is an example in which the lower flange is longer than the upper flange. In this case, the upper edging roll 5 and the lower edging roll 6 are shifted upward, and the roll gap center position 10 is shifted upward. Offset. This type B
The offset amount Y is obtained from the above equation (10) for both 1 and B2.

[0019]

EXAMPLE In this example, an H-section steel was selected as a section steel having a flange and a web, and the rolling method according to the present invention was applied to an H600 × 300 series H-section steel having a web thickness of 9 mm and a flange thickness of 19 mm. The applied multi-pass rolling was performed.

In the first embodiment of the present invention, an on-line dimension measuring device is arranged behind a rolling line, and the web center deviation of the product after rolling is measured using the on-line dimension measuring device. This is a rolling method in which the roll offset amount based on the amount is reflected in the setting of the edging mill for the next material to be rolled. The web center deviation of the product obtained by the online dimension measuring device is decomposed into type A and type B, and the center deviation of each type of web is calculated (formulas (7) and (8) above), and Offset amount X, Y for each type
Was calculated (Equations (9) and (10) above), and the next rolled material was rolled by giving a uniform offset amount to the axial direction of the edging roll and the center of the edging roll gap in all rolling passes.

In a second embodiment of the present invention, an on-line dimension measuring device is arranged at a position adjacent to a universal-edging rolling mill group, and the dimension measuring device is used to perform rolling on one or more rolling passes. This is a rolling method in which a web center deviation amount of a material is measured, and a roll offset amount based on the web center deviation amount is reflected in settings of an edging rolling mill after a rolling pass in which the measurement is performed. The offset amounts X and Y of the type A and the type B were calculated in the same manner as in the first embodiment, and the axial direction of the edging roll and the axial direction of the edging roll in all the rolling passes after the rolling pass after the web center deviation measurement was performed. Rolling was performed by giving a uniform offset amount to the center of the edging roll gap.

In the first embodiment, the center deviation of the web, which has occurred up to about 4 mm in the conventional rolling method, is 3.0 in the first embodiment.
mm or less in the second embodiment, and can be suppressed to 2.4 mm or less, confirming the effectiveness of the present invention.

[0023]

As described above, according to the present invention, the center position of the roll gap of the edging mill is adjusted in the vertical direction according to the form of the web center deviation of the material to be rolled, and the axial direction of the upper and lower rolls is adjusted. By adjusting the relative position to correct the center deviation of the web of the material to be rolled, it is not necessary to separately provide a constraint guide or the like for the shaped steel product having a flange, and the product flange thickness is not uniform. Therefore, it is possible to reliably suppress the web center deviation, to reduce the frequency of the web center deviation of the shaped steel without the occurrence of flange thickness deviation, and to improve the straightness ratio and the yield.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an edging rolling method according to the present invention, wherein (A) is for offsetting an edging roll in the roll axis direction, (B) is for offsetting an edging roll gap downward, and (C) is The case where the edging roll gap is offset upward is shown.

FIG. 2 is a schematic diagram of an example of setting of an edging mill according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a web center deviation.

FIG. 4 is a conceptual diagram in which a web center deviation is decomposed into an A type and a B type.

[Explanation of symbols]

 Reference Signs List 1 rolled material 2 flange of rolled material 3 web of rolled material 4 edging mill 5 upper edging roll 6 lower edging roll 7 universal rolling mill 8 horizontal roll of universal rolling mill

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yukio Takashima 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. 4E002 AC03 BA04 BB01 CA12

Claims (2)

[Claims] 1. A method for hot rolling a shaped steel having a flange and a web by a universal rolling mill and an edging rolling mill, wherein the edging rolling is performed according to the form of the web center deviation of the material to be rolled. A method of rolling a shaped steel, comprising adjusting a center position of a roll gap of a machine in a vertical direction and adjusting an axial relative position of upper and lower rolls to correct a web center deviation of a material to be rolled. 2. A web center deviation form of a material to be rolled is decomposed into a line symmetric component and a point symmetric component, and a roll gap center position of an edging rolling mill is determined based on the line symmetric component. 2. The method for rolling a section steel according to claim 1, wherein the relative position of the upper and lower rolls of the edging rolling mill in the axial direction is adjusted based on the components having the point symmetry.