JPH07178406A - Production of shape steel for steel-made continuous wall - Google Patents

Abstract

PURPOSE:To economically produce a shape steel for steel-made continuous wall having excellent roll shape and asymmetric circular joints by using an H-beam rolling installation in common and arranging a guide device in a rolling process. CONSTITUTION:This processing process is composed of a first rougher rolling process for rolling a continuously cast slab in the width direction through a break-down mill BD, a second rough rolling process for forming a rough rolled stock 21 having a horizontally asymmetric dog bone shape by turning the rolled preform, an intermediate rolling process for forming the rough rolled stock to approximately wide flange shape steel having a horizontally asymmetrical shape through universal mills U1, U2 and edger mills E1, E2 as the same way as the production of the H-beam and a circular bending process for bending the flange parts as arc through a finishing mill F. Further, this producing process is composed of a finishing process for forming the flange parts to the circular joints as the product shape and the guide devices 31 for guiding the rough rolled stock to the rolling rolls at the rolling mill side in each process except the first rough rolling process. By this method, the rolling is smoothly executed and the shape steel for continuous wall is economically produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a steel wall section steel used as a member for a deep-sea retaining wall or the like, and particularly to a steel wall section steel having a left-right asymmetric circular joint. The present invention relates to a manufacturing method by rolling.

[0002]

2. Description of the Related Art A steel connecting wall is a steel underground connecting member made in a factory and built into the ground to form an underground connecting wall, which is thinner than the conventional reinforced concrete underground wall.・ It is possible to reduce the construction site space and save labor. Also, normal H
It has excellent features such as good installation accuracy and water resistance compared to the installation of shaped steel. As the steel section wall for connecting walls, a straight section steel having joints at both ends is generally used. A so-called caliber rolling method shown in FIG. 8 is generally widely used as a method for manufacturing a straight-section steel having such a joint.

In FIG. 8, the rough shaped steel pieces that have passed through the hole type B in the roughing process are sequentially passed through the first pass Kal. 10th-10th pass Ka
l. It becomes a product through each step of 1. In such a rolling method, the depth of the roll die is large, and especially in the closed die, the amount of roll refurbishment is large due to the wear of the die, the roll unit is high, and the roll cooling water and Rolling oil is hard to spread to each part, so roll surface roughening, heat cracks, hole type local wear, cracks in mating joints on both edges of the product, etc. easily occur, making the product shape unstable and mass production impossible Further, there is a problem that it is relatively difficult to form the double-edged joint portion of the straight shaped steel. In addition, the above method requires a large number of holes, so even if an attempt is made to roll a large shaped steel, there is a problem that a sufficient number of holes cannot be prepared due to restrictions of the roll cylinder length and the number of mills. It was

As a solution to the problem of forming the joint portion in the above-described caliber rolling method using a hole type, a rolling method for steel sheet pile by universal rolling is disclosed in Japanese Patent Publication No. 47-4.
No. 7784. A typical example of this universal rolling is shown in FIG. In this method, a universal rolling method is introduced into the intermediate rolling process to directly apply reduction to the material forming the joint. However, even in this method, the cross-sectional shape of the steel sheet pile to be rolled is vertically asymmetrical with respect to the longitudinal axis of the steel sheet pile. It uses molds and could not completely solve the above problems.

Therefore, as a method for producing a linear steel sheet pile by making the product shape suitable for the universal rolling method and reducing the hole depth in the universal rolling, Japanese Patent Laid-Open No. 55-1913 shown in FIG. There is a technique disclosed in the publication. However, according to the publication, since the shape of the universal rolling roll is an arc shape, the thickness of the web and the joint is limited to a narrow range. In addition, since it is necessary to prepare dedicated rolls in all steps after the rough rolling step, it is not possible to sufficiently improve the roll unit.

[0006] On the other hand, as a conventional technique for making the H-shaped steel manufacturing universal rolling and sharing the roll, there is a method disclosed in, for example, Japanese Patent Application Laid-Open No. 2-200302. In this method, as shown in FIG. 11, a roll similar to a horizontal roll used for rolling H-shaped steel is used in a universal mill in an intermediate rolling process, and the roll unit is improved by sharing the roll. However, the hard roll uses a flat roll without a taper, and complete sharing with the H-section steel rolling roll has not been achieved. Further, as a method of bending the flange outward, a skew roll mill, which is not commonly used as a shape rolling mill, is used, so it is necessary to introduce new equipment, resulting in an increase in manufacturing cost.

Therefore, as an example of using a preforming mill or the like instead of the skew roll mill, for example, Japanese Patent Laid-Open No. 4-757.
There is a series of methods for manufacturing a straight-section steel typified by Japanese Patent Publication No. The one disclosed in the same publication does not require a large capital investment as in the case of using the skew roll mill, but as shown in FIG. It is the same as that of the -200302 gazette, and the complete sharing with the H-section steel rolling roll is not achieved. The method disclosed in Japanese Patent Laid-Open No. 4-75702 is a technique for rolling a shaped steel having a specific shape that is vertically and horizontally symmetrical, as can be seen from FIG.

As a method of rolling asymmetrical straight steel bars, for example, there is a technique disclosed in Japanese Patent Laid-Open No. 4-330113. As shown in FIG. 13, the rolling method disclosed in this publication is one in which one end side of a shaped steel is formed in a female shape and the other end side is formed in a male shape, and the fitting mode of the joint is limited to one type. Therefore, there is a drawback that the degree of freedom in construction is limited when the steel connecting wall is constructed.

As a solution to the above-mentioned various problems, there is a method for manufacturing an asymmetric linear steel sheet pile disclosed in Japanese Patent Publication No. 55-11921 filed by the present applicant. The method disclosed in the publication includes primary and secondary intermediate rolling steps by means of upper and lower horizontal rolls of a universal mill and a pair of vertical rolls and upper and lower rolls of an edger mill in a rolling step, respectively. In the above, the formation of the web is performed by the upper and lower horizontal rolls of each universal mill, and the formation of both fitting portions is performed by directly applying the reduction by the vertical roll of each universal mill. In order to form the female fitting portion, in the primary intermediate rolling step, the angle of the vertical roll on the female fitting portion side of the universal mill is set to 5 to 2 outward from the vertical direction in the rolling profile.
It is tilted 0 degrees, and in the secondary intermediate rolling process, it is 20 to 4 similarly.
It is tilted at 0 °, and in the subsequent finishing rolling step, the female fitting portion is finish-formed by the upper and lower two-stage horizontal roll stands.

According to the method disclosed in the above Japanese Patent Publication No. 55-11921, the method shown in FIG.
It is possible to manufacture a steel wall section steel having a left-right asymmetric circular joint shown in FIG. And this shaped steel is shown in FIG.
As shown in FIG. 2, the plate is welded to two webs of shaped steel to be used as box-shaped steel sheet piles 50 and 51 having an H-shaped cross section. In the shaped steel having the asymmetrical circular joint, the joint on the small diameter side is commonly used for both male and female members, and therefore various connecting modes are possible as shown in FIG. In the connection mode 52, joints having different left and right diameters are directly fitted, and in the connection modes 53 and 54, the joint portions are connected via H-section steel. in this way,
The steel section wall steel having asymmetrical circular joints shown in FIG. 14 can facilitate fine adjustment of the wall length in the construction of a continuous wall by combining it with H-section steel. There is an advantage that the flexibility of construction is also high.

[0011]

As described above, FIG.
Although the steel wall section steel with asymmetrical circular joints shown in Figure 1 has excellent advantages, the above-mentioned conventional methods for producing steel wall section steels are mainly symmetrical and have an asymmetric joint with a male joint on one side. There are few documents that clearly disclose a method for manufacturing a steel wall-shaped steel section having the above-mentioned left-right asymmetric circular joint for a shaped steel section. Further, even in the method for producing a steel wall section steel having a left-right asymmetric circular joint, the method disclosed in Japanese Unexamined Patent Publication No. 2-200302 can achieve complete sharing with H-section rolling rolls. In addition, as a method of bending the flange outward, an oblique roll mill, which is not generally used as a shape rolling mill, is used, which causes a problem of high manufacturing cost.

Further, according to the method of Japanese Patent Publication No. 55-11921, the left-right asymmetric straight-section steel can be rolled by the same roll as the conventional H-section steel until the first intermediate universal rolling. In the secondary intermediate universal rolling, the angles of the horizontal rolls, vertical rolls and edger rolls are tilted outwardly from the vertical direction by 20 to 40 degrees in the rolling profile, so a dedicated roll is required and the cost increases. Further, a major problem in manufacturing left-right asymmetric shaped steel by rolling is due to a difference in posture of the rolled material during transportation and during rolling. That is, since the left and right flanges of the rolled material are asymmetrical, the flange width dimension is different between the left and right, and the rolled material is in a posture inclined with respect to the horizontal transport table 57 during transportation as shown in FIG. At the time of rolling with the universal mill, as shown in FIG. 18, the web portion is bitten by the horizontal rolls 59 and 60 to be horizontal, and the deviation from the posture during transportation is large. Therefore, biting into the mill is not smoothly performed, and normal rolling cannot be performed.

Further, in the finish forming step, since the diameters and plate thicknesses of the left and right joints are different, an imbalance occurs in the load applied to the left and right joints, and the rolled material moves toward the large joint during rolling, As a result, there is also a problem that the base end side of the joint portion on the small diameter side is caught in the horizontal portion of the finish forming roll, and that portion is rolled and stretched, so that the rolled material is bent toward the large diameter joint side. Furthermore, since there is one pair of finish forming cavities, when forming a large-diameter, thin-walled joint, there is a high possibility that molding defects such as waviness will occur at the joint, and the size of the joint that can be formed is limited. There was also a problem.

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a method for inexpensively manufacturing a steel wall section steel having a rolled shape and a right-left asymmetric circular joint having good quality. Has an aim.

[0015]

Means and Actions for Solving the Problems A method for manufacturing a steel continuous wall shaped steel according to the present invention is directed to a continuous cast steel piece such as a slab which comprises a pair of upper and lower horizontal rolls having vertically asymmetric hole shapes. A first rough rolling step of rolling in the width direction of the continuous cast steel with a break down mill that has, and rolling into a vertically asymmetric rough shaped material;
The rough shaped material rolled in the process is turned around, and the rough shaped material is rolled into a left-right asymmetric dogbone-shaped rough shaped material with a breakdown mill having a pair of upper and lower horizontal rolls having a left-right asymmetrical hole shape. The second rough rolling step and a plurality of reverses are performed by a universal mill similar to the one using the dogbone-shaped rough shaped material rolled in the step and H-shaped steel manufacturing, and an edger in which the rolling setting of the flange toes is asymmetrical. An intermediate rolling step of forming a left-right asymmetrical substantially H-shaped steel having a predetermined shape by rolling, and a pair of upper and lower horizontal rolls having a left-right asymmetrical hole shape for the flange portion of the substantially H-shaped steel rolled in the step. It has a circular bending process in which it is bent into an arc shape by a finishing mill having a circular shape, and a hole shape of a shape that is almost the same as the target product shape of the flange part that is bent in the arc shape in this process. A finish forming step of forming a circular joint having a product shape by a finishing mill having a pair of upper and lower horizontal rolls, and in each of the second rough rolling step, intermediate rolling step, circular bending step and finish forming step. A guide device for guiding the rolled material to the rolling rolls is provided on the entrance side of the rolling mill.

Further, a stopper is provided on the entrance side of the finishing mill to restrict the rolling material from moving toward the large diameter flange.

[0017]

FIG. 1 is an explanatory view of an embodiment of the present invention, and FIG. 2 is an explanatory view for explaining the arrangement of rolling mills when the method shown in FIG. 1 is carried out. 1 and 2, B
D is a breakdown mill used in a rough rolling process for forming a thin rolled slab into a rough rolled material, and R1 and R2 are rough rolled materials formed in the rough rolling step and are formed into asymmetrical H-shaped steel. It is a group of rough rolling mills used in the intermediate rolling process. The rough rolling mill groups R1 and R2 are respectively composed of a rough universal mill U1 and an edger E1, and a rough universal mill U2 and an edger E2. F is a forming mill used in a forming step of forming the flange portion into a circular joint shape. First, the apparatus used in each step will be described with reference to FIGS.

The break mill BD used in the rough rolling process has a plurality of upper and lower asymmetric hole molds B1 in which the material is stood and edged to form an asymmetric dogbone shape.
~ B3 and at least one left / right asymmetrical hole type Kal. Which rolls a dogbone-shaped material by edging to a rough rolled material for universal rolling. Consists of 0. Here, a vertically asymmetrical hole type B1 for edging
B3 to B3 are hole types of lower horizontal rolls B1 L to B3 L (rolls arranged on the lower side are denoted by L, rolls disposed on the upper side are denoted by U). The same shall apply hereinafter.) Is larger than the width of the hole dies B1 U to B3 U of the upper horizontal roll. This is because when asymmetric edging is performed, the extension of the end of the rolled material rolled by the narrower die is larger than the extension of the end of the rolled material rolled by the wider die. , The rolled material warps, but as described above, the vertical asymmetrical hole type B1 ~
By arranging B3, the warp of the rolled material is directed downward, and the warp is corrected by pressing the rolled material against the conveying table, so that rolling can be performed without any trouble.

The rolling mills used in the intermediate rolling process are coarse universal mills U1 and U2 and edgers E1 and E2, respectively. It is arranged as shown in. Here, the horizontal roll 13H of the rough universal mill U1 has a flat surface for rolling the web of the rolled material, the side surface of the roll for rolling the inner surface of the flange is inclined outward at an inclination angle θ, and the outer circumference of the roll is longer. Use a shape with a short length. The same applies to the horizontal roll 14H of the coarse universal mill U2. Further, the hard roll 13V of the rough universal mill U1 for rolling the outer surface of the rolled material flange portion projects from the central portion of the outer peripheral surface and inclines from the central portion to the upper and lower ends of the roll. A shape having the same θ as the side surface inclination angle θ is used.

The inclination angle θ of these rolls is 3 to 10 degrees as in the case of a normal H-section steel rolling roll, and rolling is performed so that the thickness of the flange portion becomes constant in the width direction. This allows
The universal rolling roll can be shared with a normal H-shaped steel rolling roll, so that the roll cost can be greatly reduced and the number of rolls held can be reduced. Further, the horizontal rolls incorporated in the edgers E1 and E2 have a hole shape in which the reduction setting of the flange toes is left-right asymmetric so that the target flange width of the left-right asymmetric intermediate rolled material can be obtained.

The forming mill F used in the forming step has a hole having a flat portion having a width substantially equal to the inner width of the web of the intermediate rolled material, and arc-shaped joint forming portions having different diameters on the left and right sides at both ends of the flat portion. Use a mold. In this hole die, the radius of the joint forming portion of the final finish forming hole die 17 is made substantially equal to the target product shape, and the radius of the joint forming portion of the circular bending work hole die 16 of the flange portion preceding this is Use a larger one. With this, the amount of bending work per hole die when forming the flange of the intermediate rolled material into the joint with the hole die is adjusted,
Molding defects such as wavy joints can be prevented.

Next, a guide device for preventing defective biting of the rolled material into the mill due to a difference in posture of the rolled material during conveyance and rolling will be described. FIG. 3 is an explanatory view for explaining the shape of such a guide device, and a front view and a right side view are drawn. The guide 31 is composed of two parts, an upper guide piece 32 and a lower guide piece 33, as shown in FIG. The lower surface of the upper guide piece 32 is provided with an inclined portion 32a extending from the front side to the rear side of the paper surface.
The inclination angle α of the guide upper piece 32 is set to be substantially the same as the inclination angle of the web portion at the time of conveying the rolled material at the front end portion 32b, and gradually decreases toward the rear end portion 32c. It is set to 0 before 32c. On the other hand, the upper guide piece 32 is provided on the upper surface of the lower guide piece 33.
An inclined portion 33a parallel to the lower surface of the. 4 is an explanatory view for explaining the installation state of the guide 31, FIG. 5 is a sectional view taken along the line AA of FIG. 4, and FIG. 6 is a sectional view taken along the line BB of FIG. As shown in FIG. 4, the guide 31 is installed such that the lower surface of the upper guide piece 32 and the upper surface of the lower guide piece 33 face each other and are separated by a predetermined distance. As a result, the guide groove 37 is formed in the facing portion between the upper guide piece 32 and the lower guide piece 33.

As shown in FIG. 5, the rolled material conveyed in the inclined posture has its web portion inserted into the guide groove 37, and is gradually raised so that the web portion becomes horizontal as it approaches the roll. At the rear end of the guide 31, the web portion is in a horizontal posture as shown in FIG. This prevents defective biting of the rolled material into the rolling roll,
Smooth rolling becomes possible. The guides 31 are installed on the front and rear surfaces of Kal.0 of the breakdown mill BD and each rolling mill thereafter. It is incorporated in the front and rear surfaces of each rolling mill because each rolling mill performs reverse rolling, so that both front and rear surfaces may be on the inlet side of the rolled material.

FIG. 7 is a sectional view of a stopper guide for preventing the rolled material from moving in the forming process. The stopper guide 39 is installed on the large diameter joint side or both sides of the inlet side of the forming mill F, and regulates the movement of the rolled material by contacting the outer surface of the flange on the web extension line. The reason why the stopper guide 39 is not of a penetrating type that consistently contacts the rolled material from the roll entrance side to the roll exit side is as follows.
First, when the through type is used, the contact length with the rolled material becomes too large, so that large flaws occur in the contact portion of the rolled material with the stopper guide, and multiple pairs of hole types are formed on the same roll. In this case, if the stopper guide 39 is movable so as to be movable in the roll width direction, it can be used as a stopper guide of each hole type, and versatility can be enhanced. With the stopper guide having the above structure, it is possible to prevent the rolled material from being flawed by using an appropriate lubricant on the mill entrance side.

Next, a method for manufacturing a steel section wall steel having a left and right asymmetric circular joint using the above apparatus will be described. First, in the rough rolling process, using a continuously cast steel slab such as a slab as a rolling material, a left and right asymmetric dogbone-shaped rough shaped material is manufactured with a break down mill BD having a pair of upper and lower horizontal rolls having an asymmetric hole shape. To do. That is, as shown in FIG. 1, the hole B1 forms an interrupt, the hole B2 enlarges the interrupt, and the hole B3 smoothes the interrupted portion. In this step, as described above, the warp of the rolled material is downward, and the warp is corrected by hitting the transport table, so that rolling can be performed without any trouble.

When smoothing of the interrupted portion is completed, the material is removed to 90
The left and right asymmetrical hole type Kal. 0. Then, it is rolled to a rough rolled material 21 which is a material for universal rolling. The left-right asymmetric hole type Kal. When performing reverse rolling at 0, by installing the guide 31 on the inlet side of the rolling mill, the rolled material can be smoothly caught in the roll.
The guides 31 are provided on the entrance and exit sides of the rolling mill thereafter, as described above.

Next, in the intermediate rolling step, the rough rolled material 21 is alternately reverse-rolled by the rough universal mill U1 and the edger E1, and further reversely rolled by the rough universal mill U2 and the edger E2. The tip of the flange is pressed down by the hole die of the edger arranged so as to be paired with the universal mill, and molded into a predetermined flange width,
A left-right asymmetric H-shaped steel is formed. At this time, by adjusting the reduction amount of the left and right hard rolls of the rough universal mills U1 and U2 as necessary, it is possible to manufacture a left-right asymmetric H-shaped rolled material having different flange thicknesses.

When a substantially H-shaped steel having a predetermined thickness and shape is formed by the intermediate rolling step, the forming step is started. In the forming process, first, the flange portion is bent into an arc shape having a diameter larger than the target product shape by the circular bending hole die 16, and finally, the target product shape is formed by the finish forming hole die 17. . Since the movement of the rolled material is regulated by the stopper guide 39 on the entry side of the forming mill F, the rolled material does not move during the forming process, and the rolled material can be smoothly formed without bending. .

Through the above steps, the steel sectional wall steel shown in FIG. 14 can be smoothly manufactured. The web thickness tw of this shaped steel
The size of the joint is adjusted by adjusting the reduction of the horizontal roll of the universal mill, and the thickness tf of the joint is adjusted by adjusting the reduction of the hard roll of the universal mill. Thus, according to the method of the present invention,
By taking advantage of the characteristics of the universal mill, it is possible to manufacture products with various plate thicknesses without changing the rolls.

In the present embodiment, an example in which two sets of intermediate rolling mills are arranged with one set of a rough universal mill and one set of edger as the intermediate rolling mills, but one set or three sets are shown. Even in the rolling line where the above mills are installed, the intermediate rolled material can be manufactured by the same method.

Further, the example in which the forming mold has two pairs of holes for circular bending and finish forming has been shown. However, if a larger number of holes are used as necessary, a joint having a thinner wall and a larger diameter can be obtained. Can be molded, and the range of product plate thickness that can be manufactured can be expanded. In addition to the finishing mill, if there is a mill having upper and lower horizontal rolls that can be used, the hole die may be divided into two or more mills. Further, if a plurality of pairs of hole dies are formed on one horizontal roll in parallel or superposed, it is possible to increase the number of hole dies with respect to the number of mills.

[0032]

As described above, in the present invention, since the same universal mill as in the H-section steel production is used in the intermediate rolling step, it becomes possible to utilize the H-section rolling process and the universal mill. The roll used in the mill can also be used in common with the conventional H-section steel, and the section steel for steel wall having asymmetrical circular joints can be manufactured at low cost.

Further, since the forming process for forming the joint portion into a circle is divided into the circular bending process and the finish forming process, the amount of bending can be adjusted, and the forming defects such as waviness of the joint can be prevented. It is possible to manufacture a steel wall section steel having a rolled shape and a right-left asymmetric circular joint having good quality.

Further, since a guide device for guiding the rolled material to the rolling rolls is provided on the inlet side and the outlet side of the rolling mill in each rolling process, defective biting of the rolled material into the rolling rolls is prevented,
Smooth rolling becomes possible.

Further, since the stopper guides for restricting the movement of the rolled material toward the large-diameter flange side are provided on the inlet and outlet sides of the finishing mill, the movement of the rolled material is regulated on the inlet and outlet sides of the finishing mill, and during the forming process. The rolled material does not move, and the rolled material can be smoothly formed without bending.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the invention.

FIG. 2 is an explanatory diagram illustrating the arrangement of rolling mills when the method shown in FIG. 1 is performed.

FIG. 3 is an explanatory diagram illustrating a shape of a guide device used in this embodiment.

FIG. 4 is an explanatory diagram illustrating an installation state of a guide device used in this embodiment.

5 is a cross-sectional view taken along the line AA of FIG.

6 is a cross-sectional view taken along the line BB of FIG.

FIG. 7 is a cross-sectional view of a stopper guide used in this example.

FIG. 8 is an explanatory view illustrating a method for manufacturing a shaped steel having a joint by a conventional caliber rolling method.

FIG. 9 is a rolling process diagram of a conventional technique in which a universal rolling method is introduced in an intermediate rolling process.

FIG. 10 is a rolling process diagram of a straight section steel by conventional universal rolling.

FIG. 11 is a rolling process diagram of a conventional rolling method in which the H-shaped steel is subjected to universal rolling and roll sharing.

FIG. 12 is a rolling process diagram of a conventional method of rolling straight and vertically symmetric linear shaped steel.

FIG. 13 is a rolling process diagram of a conventional method for rolling asymmetrical straight-section steel.

FIG. 14 is an outline view of a steel sectional wall steel having a left-right asymmetric circular joint manufactured as an embodiment of the present invention.

FIG. 15 is an explanatory view illustrating an example of a box-shaped steel sheet pile manufactured by assembling the steel wall-formed steel for steel wall manufactured by the present invention.

16 is an explanatory diagram illustrating an example in which the box-shaped steel sheet piles of FIG. 10 are connected to form a continuous wall.

FIG. 17 is an explanatory diagram illustrating a conventional rolled material transportation state.

FIG. 18 is an explanatory diagram illustrating a state during rolling on a universal mill.

[Explanation of symbols]

BD Breakdown mill R1 Rough 1st rolling mill group R2 Rough 2nd rolling mill group U1, U2 Rough universal mill E1, E2 Edger F Forming mill B1-B3 Edging hole type of breakdown mill Kal. 0-Kal. 10 Hole type 12U, 12L Horizontal roll of edger E1 13HU, 13HL Horizontal roll of universal mill U1 13VU, 13VL Hard roll of universal mill U1 14HU, 14HL Horizontal roll of universal mill U2 14VU, 14VL Hard roll of universal mill U2 15U, 15L Edger E2 horizontal roll 16U, 16L Circular bending hole die 17U, 17L Finish forming hole die 21 Rough rolled material 22, 23, 24, 25 Intermediate rolled material 26 Circular bent rolled material 27 Final product 31 Guide 39 Stopper guide

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Etsuo Higashi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (2)

[Claims] 1. A continuous casting steel piece such as a slab is rolled in the widthwise direction of the continuous casting steel with a breakdown mill having a pair of upper and lower horizontal rolls having a vertically asymmetrical hole shape to obtain a vertically asymmetric rough shaped material. And a first rough rolling step in which the rough shaped material rolled in the step is turned around, and the crude shaped material is left-right asymmetric with a breakdown mill having a pair of upper and lower horizontal rolls having a left-right asymmetric hole shape. The second rough rolling step of rolling into a rough shaped material and the same universal mill and flange foot reduction setting as those used for manufacturing the H-shaped steel using the dog bone-shaped rough shaped material rolled in the step An intermediate rolling step of forming a left-right asymmetric H-shaped steel having a predetermined shape by performing a plurality of reverse rollings by a left-right asymmetrical edger, and a flange portion of the H-shaped steel rolled in the step is left-right unpaired. A circular bending process in which a finishing mill having a pair of upper and lower horizontal rolls having a well-known hole shape bends into an arc shape, and a flange portion bent into an arc shape in the process has a shape almost equal to a target product shape. A finish forming step of forming a circular joint which is a product shape by a finish mill having a pair of upper and lower horizontal rolls having the above hole shape, the second rough rolling step, intermediate rolling step, circular bending step and finish forming A method for producing a steel wall section steel having a left-right asymmetric circular joint, characterized in that a guide device for guiding a rolled material to a rolling roll is provided on the entrance side of the rolling mill in each step of the steps. 2. The method for producing a steel wall for steel wall according to claim 1, wherein a stopper guide for restricting movement of the rolled material to the large-diameter flange side is provided on the entrance and exit sides of the finishing mill.