JP2000280001A - High-precision rolling method of h-shaped steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to reduce web height while preventing occurrence of web center deviation and accurately roll H-shaped steel of various sizes by using rolls mutually different in a sectional form as horizontal rolls of a universal edger mill. SOLUTION: An upper horizontal roll 11a and a lower horizontal roll 11b of a universal edger mill are provided at the width center portion of a web contact portion 16 with a concave portion 13 and a convex portion 14, Even under such a rolling condition that the gap between the upper and lower horizontal rolls 11a and 11b becomes wider than the web thickness, the end portion of the web contact portion 16 of the upper horizontal roll 11a and the end portion of the web top are brought into contact with each other. At the same time, the center portion of the web contact portion 16 of the lower horizontal roll 11b and the center portion of the web bottom are brought into contact with each other, and a material 15 to be rolled is pulled in by the upper and lower horizontal rolls 11a and 11b. It is preferable to use a universal edger mill equipped with horizontal rolls variable in width and reduce the web height through the last pass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rolling an H-beam with high dimensional accuracy used in the fields of construction and civil engineering.
More particularly, the present invention relates to a method of rolling a multi-size H-section steel with dimensional accuracy comparable to that of a welded H-section steel by hot rolling using a universal mill.

[0002]

2. Description of the Related Art FIG. 1 is a diagram showing a sectional shape of an H-section steel and dimensions of each part. H is the web height, B is the flange width, t
1 is the thickness of the web, t2 is the thickness of the flange, and b1 and b2 are the distances from the web to the tip of the flange (also referred to as "inner depth").
It is.

The name of the H-section steel is, for example, H500 × B2
Displayed as 00 × 10/15, H500 has a web height of 500 mm, B200 has a flange width of 200 m
m, 10/15 means that the web thickness is 10 mm and the flange thickness is 15 mm.

[0004] Conventionally, in the rolling of H-section steel, a slab is mixed with a dockbone-shaped coarse material (hereinafter, referred to as a beam blank) using a double-hole type roll roughing mill (hereinafter, referred to as a "breakdown mill"). After that, a universal rough mill and a double roll edger mill (hereinafter referred to as “2Hi edger mill”)
And a universal finishing mill. That is, the mill group performs intermediate rolling by reciprocating rolling, and then finishes to an H-section steel by one-pass rolling in a universal finishing mill.

FIG. 2 is a front view of a roll and a cross-sectional view showing a shape of a rolled material and an H-section steel for explaining a method of rolling an H-section steel using a conventional 2Hi edger mill.
FIG. 4 is a diagram showing a rough rolling state by a universal roughing mill, FIG. 4B is a diagram showing a rough rolling state by a 2Hi edger mill, and FIG. 4C is a diagram showing a finishing rolling state by a universal finishing mill.

In the rough rolling by the universal rough mill shown in FIG. 2A, a rough shape of an H-section steel is formed using horizontal rolls 1 and 1 and vertical rolls 2 and 2. Reference numeral 3 denotes a rolled material.

In the rough rolling by the 2Hi edger mill shown in FIG. 2B, the horizontal rolls 4 and 4 ensure the accuracy of the dimensions of each part such as the flange width and the center of the web (the center where the web is located at the center of the flange). That is, the width of the flange of the rolled material 3 is reduced by the horizontal rolls 4 and 4 to correct the web center deviation of the rolled material. At this time, in order to enhance the correcting effect, the inner surface of the flange of the rolled material is restrained by the side surface of the horizontal roll so that the rolled material does not shift in the left-right direction.

In the finish rolling by the universal finishing mill shown in FIG. 2C, one-pass rolling is performed using the horizontal rolls 5, 5 and the vertical rolls 6, 6, and an H-shaped steel 7 having a product size is obtained. Can be

Incidentally, various types of H-shaped steel are used for steel frames of high-rise buildings and the like. Therefore, various types of H-section steels having different nominal dimensions are manufactured. However, even with one nominal size, there are actually different web heights and flange widths.

[0010] In order to manufacture various types of H-section steels having different nominal dimensions, an edger mill or a universal mill corresponding to each web height is required. Many proposals have been made for rolling methods for reducing the number of these rolls.

For example, the present inventors have disclosed in Japanese Patent Laid-Open No. 2-842.
No. 03 and Japanese Patent Application Laid-Open No. 4-258301 have proposed methods for reducing the web height. Also, JP-A-63-30
No. 102 discloses a method for increasing the web height.

However, the method disclosed in the above publication includes:
In any case, there is a problem that the web center deviation becomes large.

As a measure against the web center deviation, the present inventor disclosed in WO 095/17269 an H-shape in which the outer surface of the flange is restrained by a vertical roll of a 4-roll universal edger mill, and the flange is reduced in width by a horizontal roll. A method for producing steel was proposed.

[0014]

However, the above W
In the method disclosed in O095 / 17269, reduction of the web height of the universal edger mill is restricted particularly in rolling of a web having a small web thickness, and rolling of a multi-size H-section steel by reducing the web height is performed. There is a problem of difficulty.

That is, in the universal edger mill, the thickness of the web and the width of the flange are reduced by a driven horizontal roll, and the height of the web is reduced by a non-driven vertical roll. By the way, for example, an H-section steel with a constant inner dimension (a series of H-sections with the same spacing between the flange inner surfaces and different web height, flange width, flange thickness, and web thickness) and an H-section steel with a constant outer dimension ( In the case of manufacturing H-shaped steel series having the same web height and flange width and different web thickness and flange thickness) at the same rolling chance, the inner depth of each product (b1, b2 in FIG. 1) is reduced. Because of the differences, the horizontal roll depth of the universal edger mill must be adjusted to the size of the product with the smallest inner depth. However, when rolling a deep inner roll with a horizontal roll with a shallow horizontal roll depth, it is impossible to reduce the web by the horizontal roll and the material cannot be pulled in.As a result, it is difficult to reduce the height of the web. Condition occurs.

An object of the present invention is to solve the above-mentioned conventional problems and to reduce the height of the web while preventing the center deviation of the web, thereby enabling high-precision rolling of H-shaped steels of various sizes. An object of the present invention is to provide a high-precision rolling method for H-section steel.

[0017]

Means for Solving the Problems The inventor of the present invention has conducted research on reducing the web height by a universal edger mill, and has obtained the following findings.

(A) As horizontal rolls of the universal edger mill, rolls having different cross-sectional shapes from each other, for example, rolls having a convex central portion of one horizontal roll and a concave central portion of the other horizontal roll, are used. Even under rolling conditions in which the gap between the upper and lower horizontal rolls is larger than the web thickness, the vertical roll can reduce the web height.
That is, since the horizontal roll contacts the web of the rolled material before the flange of the rolled material contacts the vertical roll due to the presence of the uneven portion, the rolled material can be drawn by the horizontal roll.

(B) By making the horizontal roll of the universal edger mill a variable width roll, the height of the web can be reduced while restraining the inner surface of the flange, and the dimensional accuracy of the flange is improved.

(C) By reducing the web height in the final pass of the universal edger mill, H-beams having different web heights (multi-size H-beams) can be manufactured with the same universal edger mill. The present invention has been completed based on the above findings, and the gist thereof is as follows.

(1) Rolling of H-section steel using a rough universal mill group composed of a universal rough mill and a universal edger mill each having a pair of vertical rolls and a pair of horizontal rolls in the intermediate rolling step In the method,
A high-precision rolling method for H-section steel, wherein rolls having different cross-sectional shapes are used as horizontal rolls of the universal edger mill.

(2) The universal edger mill is characterized in that one horizontal roll has a convex portion at the web contact portion and the other horizontal roll has a concave portion corresponding to the convex portion at the web contact portion. (1) A high-precision rolling method for an H-section steel according to the item (1).

(3) The high-precision rolling of the H-section steel according to the above (1) or (2), wherein a universal edger mill provided with a horizontal roll having a variable width is used as the universal edger mill. Method.

(4) The height of the H-section steel according to any one of the above items (1) to (3), wherein the web height is reduced in the final pass of the universal edger mill in the intermediate rolling step. Precision rolling method. Here, the web contact portion refers to a portion of the rolled material facing the web.

[0025]

FIG. 3 is a schematic view showing one example of a production line for H-section steel by the method of the present invention.

As shown in FIG. 3, the rolling of the H-section steel according to the method of the present invention is performed by a breakdown mill (hereinafter referred to as “BD mill”).
), The cast slab is made into a rough material of a dock bone type, and then a coarse universal mill group composed of a universal rough mill (hereinafter, referred to as a “UR mill”) and a universal edger mill (hereinafter, referred to as a “UE mill”) (Hereinafter simply referred to as “mill group”) and a universal finishing mill (hereinafter “UF group”).
Mill ”). That is, intermediate rolling by reciprocating rolling is performed in the mill group,
It is finished to an H-beam by one-pass rolling in an F mill.

The present invention relates to a horizontal roll of a UE mill,
It is characterized in that rolls having different cross-sectional shapes are used. Here, the meaning of “different cross-sectional shapes” means that the web of the rolled material is subjected to bending deformation in the longitudinal direction and the width direction, and the web is drawn in by a horizontal roll, and at least one of the horizontal rolls is used. A convex portion may be provided at the web contact portion, but usually, the cross-sectional shapes of the upper and lower horizontal rolls are inverted shapes of each other, and have shapes complementary to each other. The cross-sectional shape of the upper and lower horizontal rolls is preferably symmetrical with respect to the center in the width direction of the horizontal rolls from the viewpoint of stability of web biting.

Hereinafter, the present invention will be described by taking a horizontal roll in which the central portion of the web contact portion of the upper horizontal roll is concave and the central portion of the web contact portion of the lower horizontal roll is convex.

FIG. 4 is a front view of a roll schematically showing the shape of each roll and the rolled material of the universal edger mill used in the present invention, and a longitudinal sectional view of the rolled material. 11a is an upper horizontal roll, 11b is a lower horizontal roll, 12 is a vertical roll,
13 is a concave portion, 14 is a convex portion, 15 is a rolled material, and 16 is a web contact portion.

As shown in FIG. 4, the upper horizontal roll 11a and the lower horizontal roll 11b have a concave portion 13 and a convex portion 14 at the center of the width of each web contact portion 16. For that reason,
Even under the rolling condition in which the gap between the upper and lower horizontal rolls is wider than the web thickness, the end of the web contact portion of the upper horizontal roll and the end of the upper surface of the web and the center of the web contact portion of the lower horizontal roll and the lower surface of the web Since the center portion is in contact, the rolled material 15 can be pulled in by the horizontal roll. Therefore, even in the case of H-section steels with different inward depths,
In the final pass of the UE mill, the web height is reduced so that multiple sizes of H-beams having different web heights can be obtained in the same UE mill.

For example, a case where the UE mill shown in FIG. 4 is arranged on the UE mill on the line shown in FIG. 3 will be described.

In FIG. 3, a slab heated to about 1250 ° C. is rolled by a BD mill to obtain a beam blank. Next, rolling is performed to predetermined dimensions by reciprocating rolling (intermediate rolling) of 7 to 15 passes in a mill group composed of a UR mill and a UE mill, and finally, finish rolling of one pass is performed by a UF mill to form an H-shape of a target size. Finish to steel.

For example, a case where an H-section steel of H600 × 200 is rolled will be described. H on horizontal roll of UR mill
A roll having a roll width of 576 mm for 600 × 200 is used, and the horizontal roll of the UE mill has a roll width of 544 mm and a depth (Da) of the concave portion of the upper roll of the basic shape shown in FIG.
mm, the height of the convex portion of the lower roll (Db) is 10 mm, and the height of the web is reduced in the final pass of the UE mill, so that H600 × 200 × 11/17, H6
06 × 201 × 12/20, H612 × 202 × 13 /
23 inner constant H-section steel and H600 × 200 × 9/1
6, H600 × 200 × 12/16 H-shape steel with constant outer diameter can be rolled.

The web that has been bent and deformed by the UE mill is flattened by the subsequent finish rolling using a UF mill having a variable width horizontal roll. In addition, UF
Since the width variable horizontal roll of the mill has a space corresponding to the seam of the roll at the center in the width direction, the roll and the web do not come into contact with that space, but the cross-sectional shape of the horizontal roll of the UE must be optimized. As a result, a product free from problems of dimensional accuracy and surface quality can be obtained.

FIG. 5 is a cross-sectional view schematically showing an example of the shape of the horizontal roll of the UE mill according to the present invention. FIG. 5 (A) shows a protrusion at the center of the width of the web contact portion of one of the horizontal rolls. In the case where a concave portion is provided at the center of the width of the web contact portion of the other horizontal roll, a convex portion is provided at the end of the web contact portion of one horizontal roll. In the case where a concave portion is provided at the end of the web abutting portion, FIG. 4C shows that a convex portion and a concave portion are provided at the center and at the end of the width of the web abutting portion of one horizontal roll, and the other horizontal roll is provided. In this case, a concave portion and a convex portion are provided at the center and the end of the width of the web contact portion. 4 are denoted by the same reference numerals.

In the present invention, a horizontal roll having a roll shape shown in FIGS. 5A, 5B, and 5C can be used as a horizontal roll of the UE mill. From the viewpoint of accuracy and rolling stability, FIG.
(A) is preferred. However, the horizontal roll of the UE mill according to the present invention is not limited to FIGS. 5A, 5B, and 5C.

A preferred embodiment of the present invention is characterized in that a variable width roll is used as a horizontal roll of the UE mill.

FIG. 6 is a schematic view showing a front view of a variable width horizontal roll and a vertical roll of a UE mill and a cross section of a rolled material. Reference numeral 17 denotes a variable width horizontal roll, and the same elements as those in FIG. 5 are represented by the same reference numerals.

As shown in FIG.
Can change the width online, so even when reducing the web height in the final pass of intermediate rolling, the inner surface of the flange can be restrained by the side of the variable width horizontal roll and the flange tip can be lowered, so dimensional accuracy Can be further improved. Further, the number of horizontal rolls held by the UE mill can be reduced.

In order to make the width of the horizontal roll variable as described above, for example, as shown in Japanese Utility Model Application Laid-Open No. 3-111404, a protrusion is provided on the outer peripheral surface of the movable sleeve roll and connected to the arbor by a slide key. Then, a male screw is formed at the base end of the sleeve, and a protrusion provided at an equal position of the nut screwed to this male screw is fitted into the protrusion gap of the movable sleeve roll. What is necessary is just to make it the structure fixed to.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The effect of the present invention was obtained by using H600 × 200 H
A series of section steels will be described based on Examples 1 and 2 and a conventional example. The standard size of the H-shaped steel with constant inner method in this series is H600 × 200 × 11/17, and the inner method depths (b1, b2) are 94.5 mm, which is the same as the thickness difference.
It is. On the other hand, the size of the outer constant H-section steel is H600 × 2
00 × 9/16 and H600 × 200 × 12/16, and each inner depth (b1, b2) is 95.5 mm.
And 94.0 mm.

Example 1 A breakdown mill (BD mill) and a universal coarse mill (UR mill) shown in FIG.
Group consisting of a steel and a universal edger mill (UE mill) and a universal finishing mill (UF mill)
A UE mill having a horizontal roll as shown in FIG. UR mill horizontal roll width is 57
6 mm. UE mill horizontal rolls have a roll width of 54
5A, the lower horizontal roll has a height (Db) of 10 mm and a width (W) at the center of the width of the web contact portion as shown in FIG.
b) It has a trapezoidal protrusion of 100 mm, and the upper horizontal roll has a trapezoidal recess of 10 mm in depth (Da) and 100 mm in width (Wa) at the center of the width of the web contact part. Using this apparatus, the slab was beam-blanked with a BD mill (web thickness 40 mm, flange thickness 70 mm, flange width 225 m).
m, web height 716 mm), then UR, U
H600 × 200 × 11/1 in each of E and UF mills
7, H600 × 200 × 9/16 and H600 × 20
Three types of H-beams of 0x12 / 16 were rolled.

First, when rolling H600 × 200 × 11/17, tandem reversal rolling of 7 passes is performed by two units of a UR mill and a UE mill. In the final pass of the UE mill, the web height is reduced by 10 mm and the flange is reduced. 199mm width
And finally pass H60 with one pass of UF mill.
Finished to 0 × 200 × 11/17. At this time, the inner projection depth was 94.5 mm for both the upper and lower sides, and there was no occurrence of center deviation, which was favorable.

Next, when rolling H600 × 200 × 9/16, the UR mill and the UE mill perform tandem reversal rolling of 7 passes by two units, and the final pass of the UE mill reduces the web height by 8 mm and Flange width is reduced to 199mm.
× 200 × 9/16. In the rolling of the UE mill, the interval between the upper and lower rolls at both ends of the horizontal roll is 12 mm.
The thickness of the web was 9 mm, and the lower roll and the web were in contact at the center, and the upper roll and the web were in contact at both ends, so that the rolling could be performed without any problem. The inner depth of the obtained H-section steel was 94.0 in each of the upper side and the lower side.
mm, 96.0 mm and a center deviation of 1 mm occurred, but there was no problem within the dimensional tolerance.

When rolling H600 × 200 × 12/16, the UR mill and the UE mill perform tandem reversal rolling of 7 passes by two units, and the final pass of the UE mill reduces the web height by 8 mm and reduces the flange height. The width is reduced to 199mm, and finally, the H600 is passed with one pass of the UF mill.
× 200 × 12/16. In the rolling of the UE mill, the interval between the upper and lower rolls at both ends of the horizontal roll is 12 mm.
In, the web thickness is 12 mm, the lower roll and the web contact at the center, the upper roll and the web contact at both ends,
Rolling could be performed without any problems. The inner depth of the obtained H-section steel is 94.
0 mm and 93.0 mm, and the center deviation was as small as about 0.5 mm, which was favorable.

The horizontal roll of the UF mill has a width of 2 mm in the width direction.
Although it was divided and had a space of 8 mm at the center, the web was rolled flat, the dimensional accuracy and shape were good, and no surface flaw was generated. As the horizontal roll of the UE mill, a roll having a fixed roll width was used.

(Conventional Example 1) Mill Line UE shown in FIG.
A conventional 2Hi edger mill was placed on the mill. The hole depth of the 2Hi edger mill was 93.5 mm. Using this device, H600 × 200 × 11/17, H600 ×
200 × 9/16 and H600 × 200 × 12/1
6 were rolled.

H600 × 200 × 11/17, H600
× 200 × 9/16 and H600 × 200 × 12/1
In the rolling of No. 6, tandem reversal rolling of 7 passes is performed by two units of the UR mill and 2Hi edger mill, the flange width is reduced to 199 mm in the final pass of the UE mill, and finally, the height of the web is increased by one pass of the UF mill. H-shaped steel of each size was finished by reducing the size. The web center deviation of the obtained H-section steel was H600 × 200 × 11/17, H600 ×
200 × 9/16 and H600 × 200 × 12/16
Were 3.2 mm, 4.0 mm, and 2.8 mm, respectively.

(Conventional Example 2) Mill line UE shown in FIG.
A conventional universal edger mill in which the horizontal roll was a flat roll was arranged on the mill. The horizontal roll widths of the UR mill and the UE mill were 576 mm and 544 mm, respectively. Using this device, H600 × 200 × 11/1
7, H600 × 200 × 9/16 and H600 × 2
Three types of H-beams of 00 × 12/16 were rolled.

In the rolling of H600 × 200 × 12/16, the UR mill and the UE mill perform tandem reversal rolling of 7 passes by two units, and the web height of 8 mm in the final pass of the UE mill.
At the same time, reduce the flange width to 199mm while reducing the size.
Finished to 12/16. The center deviation of the obtained product is 0.
It was as good as 5 mm.

H600 × 200 × 11/17 and H600
In the rolling of × 200 × 9/16, since the horizontal roll did not contact the web of the rolled material in the final pass of the UE mill, the rolling was impossible due to poor biting.

[0052]

According to the present invention, it is possible to reduce the height of the web while preventing the occurrence of the center deviation of the web, thereby enabling high-precision rolling of multi-size H-sections by the same universal edger mill.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross-sectional shape of an H-section steel and dimensions of each part.

FIG. 2 is a front view of a roll and a cross-sectional view showing a shape of a rolled material and an H-section steel for explaining a method of rolling an H-section steel using a conventional 2Hi edger mill, and FIG. FIG. 4B is a diagram showing a rough rolling state by a mill, FIG. 4B is a diagram showing a rough rolling state by an edger mill, and FIG. 4C is a view showing a finish rolling state by a universal finishing mill.

FIG. 3 is a schematic diagram showing an example of an H-section steel production line according to the method of the present invention.

FIG. 4 is a front view of a roll schematically showing the shape of each roll and the rolled material of the universal edger mill used in the present invention, and a longitudinal sectional view of the rolled material.

FIG. 5 is a cross-sectional view schematically showing an example of the shape of a horizontal roll of a UE mill according to the present invention. FIG. In the case where a concave portion is provided at the center of the width of the web abutment portion of the horizontal roll, a convex portion is provided at the end of the web abutment portion of one horizontal roll, and the web abutment of the other horizontal roll is shown in FIG. In the case where a concave portion is provided at an end of the horizontal roll, FIG. (C) shows that a convex portion and a concave portion are provided at the width center portion and the end portion of the web contact portion of one horizontal roll, and the web contact portion of the other horizontal roll is provided. This is a case where a concave portion and a convex portion are provided at the width center portion and the end portion of the contact portion, respectively.

FIG. 6 is a schematic view showing a front view of a variable width horizontal roll and a vertical roll of a UE mill and a cross section of a rolled material.

[Explanation of symbols]

 1, 4, 5: horizontal roll, 2, 6, 12: vertical roll, 3, 15: rolled material, 7: H-section steel, 11a: upper horizontal roll, 11b: lower horizontal roll, 13: concave portion, 14: convex Part, 16: web contact part, 17: variable width horizontal roll.

Claims (4)

[Claims] 1. A method of rolling an H-section steel using a group of coarse universal mills each comprising a universal rough mill and a universal edger mill having a pair of vertical rolls and a pair of horizontal rolls in an intermediate rolling step. Wherein the rolls having different cross-sectional shapes are used as horizontal rolls of the universal edger mill.
High precision rolling method for section steel. 2. The universal edger mill according to claim 1, wherein one of the horizontal rolls has a convex portion at the web contact portion and the other horizontal roll has a concave portion corresponding to the convex portion at the web contact portion. 2. The high precision rolling method for an H-section steel according to 1. 3. As the universal edger mill,
3. The H according to claim 1, wherein a universal edger mill having a horizontal roll having a variable width is used.
High precision rolling method for section steel. 4. The method according to claim 1, wherein the height of the web is reduced in the final pass of the universal edger mill in the intermediate rolling step.