JPH10291001A - Method and device for rolling of rough steel slab for shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a high quality steel shape without biting-in defect, falling down and biting out of a flange part, etc., of a material to be worked by arranging two horizontal rolling mills at a proximate position and at least a pair of calibers different in a web height or a flange width to rolls and continuously rolling a material to be worked. SOLUTION: A beam blank 6 of a material to be worked is subjected to three pass reciprocation rolling with a caliber 31 of a roll 30 and, at a third pass rolling, continuous rolling with a caliber 31 as well as a caliber 41 of a roll 40 to increase a web height. At this time, a material to be worked is firstly rolled with the caliber 31 when biting in a caliber 41 of the roll 40, push-in rolling is made possible by a horizontal rolling mill having the roll 30 so as to completely eliminate slip. Further, for example, a large rough shape steel slab having a web height higher by 50 mm is finished by one pass rolling with continuous rolling of a caliber 42 and a caliber 32, a large rough shape steel slab having a web height higher by 100 mm with a caliber 33, further a large rough shape steel slab having a web height higher by 150 mm is finished by one pass continuous rolling with a caliber 33 and a caliber 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for rolling a rough shaped steel slab for shaping steel bars of various sizes having different web heights and flange widths with good efficiency and good dimensional accuracy. About.

[0002]

2. Description of the Related Art FIG. 13 schematically shows a conventional hot rolling process for a section steel such as an H-section steel. A raw material such as a slab or a bloom or a beam blank heated to a predetermined temperature in the heating furnace 1 is rolled into a coarse steel slab by a molding and rolling mill 2,
Thereafter, the rolls are rolled to the product shape and dimensions by the coarse universal rolling mill group consisting of the universal rolling mills 3 and 3 'and the edger rolling mills 4 and 4' or the horizontal rolling mill group having a die for forming steel and the finishing rolling mill 5. .

[0003] In the forming and rolling mill 2, for example, when rolling a crude steel slab for an H-beam using a beam blank 6 as shown in FIG. The desired coarse shaped slab is rolled by gradually changing the thickness and the flange thickness, the flange width and the web height. At this time, since the body length of the roll 10 of the molding and rolling mill 2 is fixed, the number of cavities that can be given to the roll is restricted, and the same roll from the same size beam blank is used for the same roll to handle a plurality of product sizes. It is very difficult to roll shaped slabs, and usually only one series of H-shaped steels (several types of H-shaped steels having the same web height and flange width but different thicknesses) is the same roll that is incorporated into a molding mill. It was shaped by. Therefore, it is necessary to have dedicated modeling rolls for each series, the number of which is enormous, and it is necessary to change the rolls every time the series to be rolled changes, which is a factor that hinders the operation rate I was

As shown in FIG. 15, when a slab 11 is used as a raw material to roll a crude steel slab for an H-beam, a plurality of edging rolling box hole dies 12, 13, 14 for forming a flange portion are usually used. Then, the thickness of the portion corresponding to the web is reduced, and a desired coarse shaped steel slab is rolled by a hole die 15 which is rolled and formed into a substantially H shape. In the edging rolling in the step of forming a flange portion from a slab, buckling (falling) as shown in FIG. 16 is likely to occur. It becomes remarkable when you do.
This falling not only degrades the shape and dimensional accuracy of the crude billet, but also has a great adverse effect on the dimensional accuracy of the final product. The falling of the material to be rolled at the time of edging can be suppressed by filling the material to be rolled on the side wall 16 of the box hole shape. However, since the number of box hole shapes that can be given is limited due to the restriction of the roll body length, a large number of It was impossible to perform a flange rolling step in which all the edging passes were filled by using a box hole die, and it was difficult to stably prevent the falling. Further, in the case of molding a rough steel slab for large H-section steel, in order to impart a large finished hole die 15 to the roll, it is necessary to form the flange portion with a smaller box hole die due to restrictions on the roll body length. However, it has been a serious problem in terms of dimensional accuracy. Also, it is extremely difficult to support multiple product series with the same roll even in the form rolling from slabs, and reducing the number of rolls and the frequency of changing rolls was a major issue as in the case of forming roll from a beam blank. . Furthermore, in shaping and rolling from a slab, compared to shaping and rolling from a beam blank that already has a flange portion, an edging pass in the forming process of the flange portion is required, so that the rolling efficiency and the temperature of the material to be rolled are reduced. Causes a decline. Excessive temperature drop increases the rolling load in the subsequent universal rolling, the required material characteristics deviate, and furthermore, in the size where the ratio of web thickness to flange thickness is small, buckling of the web due to thermal stress in the cooling process after rolling, so-called web Since a serious problem such as generation of a wave is caused, efficient rolling has been strongly desired especially in shaping and rolling from a slab.

As a technique for efficiently forming a coarse shaped steel slab, there is Japanese Patent Application Laid-Open No. 1-224101. This is an arrangement in which an edger rolling mill composed of a pair of non-driven vertical rolls is disposed between two horizontal rolling mills, and enables biting from a die without rolling the material to be rolled by 90 °. This is a technology that enables efficient shaping and rolling. However, it is possible to suppress biting from the mold by designing the appropriate mold, and it is not necessary to perform edging with the flat box provided to the vertical roll for each pass. Hole type is 1
Since the width of the flange portion of the material to be rolled changes during the rolling process, it is impossible to always fill the material to be rolled on the side wall of the flat box hole type. The vertical roll is not always necessary because the falling of the material cannot be completely prevented by shaping the piece. Furthermore, it is not possible to improve the efficiency through the rolling process by simply improving the rolling efficiency of only the shaping and rolling process. It is enough if the efficiency of the process can be realized. Also, in this technique, when rolling different H-section series, it is necessary to rearrange the rolls of two horizontal rolling mills and an edger rolling mill or more continuous rolling mills disposed therebetween. Therefore, there is a drawback that the operation rate cannot be improved, and that a large number of rolls must be possessed corresponding to each series.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a method for forming and rolling an H-section steel and a similar section steel, which is efficient and supports a series of a plurality of section steel products by the same roll without changing the roll. Provided is a rolling method and apparatus capable of forming a coarse shaped billet, thereby enabling the number of rolls to be reduced compared to the conventional method, and forming a rough shaped billet with good shape and dimensional accuracy by stable rolling. It is intended to be.

[0007]

According to the present invention, there is provided a method of rolling a crude steel slab for a shaped steel according to the present invention. A horizontal rolling mill is arranged at a position where continuous rolling of the material to be rolled is possible, and at least one pair of dies having different web heights or flange widths is provided on the rolls of the two horizontal rolling mills. The material to be rolled is continuously rolled by using a die having the following shape.

[0008] In the present invention, a rolling device for a crude steel slab for shaped steel comprises two horizontal rolling mills arranged at close positions capable of continuously rolling a material to be rolled, and the two horizontal rolling mills. And at least one pair of dies having different web heights or flange widths arranged so that continuous rolling can be performed on the rolls. Since the shaped slab is shaped, the web height and / or
Alternatively, it is possible to form a crude steel slab corresponding to a plurality of series having different flange widths. Therefore, the number of rolls can be reduced as compared with the related art, and the frequency of changing rolls can be reduced.

Further, when the material to be rolled is continuously rolled by using a pair of groove dies, the material to be rolled is rolled while applying a tension or a compressive force, thereby making it possible to eliminate the biting which tends to occur on the side surface of the flange. Since the number of edging passes is reduced and the number of rolling passes is reduced and the operation of turning the material to be rolled by 90 ° becomes unnecessary, the rolling efficiency can be improved. When using a slab as a material to be rolled,
Since continuous rolling is performed while applying tension to the material to be rolled using a pair of box-shaped dies, it is possible to increase the edging amount per pass, and the flange ends are filled with the box-shaped dies without excess or shortage. Therefore, the rolled material does not fall.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, the rolling method of the present invention using a rolling device and a beam blank or a slab having a rectangular cross section, which constitute the present invention, will be described in detail in comparison with the conventional method.

FIG. 1 is a schematic diagram showing an example of an H-section steel rolling process to which the rolling apparatus of the present invention is applied. In FIG. 1, reference numerals 2 and 2 'denote two adjacent horizontal rolling mills, which constitute a rolling apparatus of the present invention. Other constructions are the same as those in FIG. 13 of the conventional example, a heating furnace 1 for heating the material to be rolled to a predetermined temperature, and a group of coarse universal rolling mills comprising universal rolling mills 3, 3 'and edger rolling mills 4, 4'. When,
The finishing universal rolling mill 5 constitutes an H-section steel rolling production line.

First, the present invention will be described in comparison with a conventional method when a beam blank is used as a material to be rolled.

FIG. 2A shows a conventional molding roll and a rolling pass. The roll 20 has three cavities 21, 2
2 and 23 are provided, and the die 21 has three passes and the die 2
In Nos. 2 and 23, the crude steel slab was rolled in a total of five passes, one pass each. In H-section steel, products of several sizes with different web thickness and flange thickness with almost the same web height and flange width are called 1 series, but with such a conventional method, a pair of rolls corresponds to only 1 series. Only the rough slab that could be formed could be shaped and rolled. In rolling in which the web height is increased from the die 21 to the die 22 in the conventional rolling,
At the start of rolling, the material to be rolled is poorly bitten and unstable, and sometimes slips occur, which causes a problem of impairing the rolling efficiency.

On the other hand, FIG. 2 (b) shows a roll hole arrangement and a rolling pass of the present invention capable of forming a coarse steel slab corresponding to four series having different web heights. The die 31 of the roll 30 has the same shape as the die 21 of the conventional method, and the die 41 of the roll 40 has the same shape as the die 22 of the conventional method. Further, the die 31 and the die 41 are arranged at positions where continuous rolling is possible, and the die 42 is a die corresponding to 23 of the conventional method.
The die 32 is a finished die of a series whose web height is 50 mm larger than the die 42, and the die 32 and the die 42 are also arranged at positions where rolling can be continuously performed. Finished hole type with a height of 100mm and hole type 4
Reference numeral 3 denotes a finished die having a web height 150 mm larger than the die 42, and the die 33 and the die 43 are also arranged at positions where they can be continuously rolled. Further, one roll 30 is incorporated in the upstream horizontal rolling mill 2 shown in FIG. 1, and the other roll 40 is incorporated in the downstream horizontal rolling mill 2 ′.

The beam blank 6 of the material to be rolled is subjected to the same three-pass reciprocating rolling as in the prior art using the die 31 of the roll 30, and the die 31 and the die 4 of the roll 40 are rolled in the third pass.
Continuous rolling at 1 increases the web height. At this time,
The material to be rolled is firstly rolled by a die 31, and when the material to be bitten into the die 41 of the roll 40, the horizontal rolling mill 2 having the roll 30
As a result, it is possible to eliminate slippage at the time of biting, which tends to occur in the conventional method, and this is one of the effects of the present invention.

Further, in order to obtain a rough slab of the series shown in the conventional method, the shaping process is completed by one pass rolling of the die 42, and the rough forming is performed in four passes, which is one pass less than the conventional five passes. Billets are finished. Also, if the web height is 50
The rough steel slab having a larger diameter of 1 mm was subjected to one-pass rolling by continuous rolling of the die 42 and the die 32, and the coarse slab having a web height of 100 mm was the die 33 and further having a web height of 150 m.
A m-shaped rough steel slab can be finished in one continuous rolling pass of the die 33 and the die 43, and can be finished in a total of five passes. In other words, in the present invention, it is possible to supply the rough shaped steel slab corresponding to the 4 series having different web heights without shaping the rolls by shaping the rolls four times in the conventional method without changing the rolls. The invention has the great advantage that what is needed is made possible by two pairs of rolls.

Further, for example, a method of forming a coarse billet corresponding to three series having the same web height and different flange widths according to the present invention will be described. FIG. 3 (a) shows the conventional method. In the case of shaping and rolling a crude steel slab corresponding to a series with a small flange width from the beam blank 6, it is necessary to reduce the flange more than in the case of a large flange width. If the flange is forcibly pressed down, a bite 6a is formed from the side surface of the groove during rolling as shown in FIG. Conventionally, the squeezing 6a has 9
It is indispensable to perform the edging pass by the 0 ° turning and the hole mold 52 called a flat box, and the rolling work and the edging pass increase, thereby impairing the rolling efficiency. In order to suppress this biting, it is necessary to gradually lower the flange portion by using a hole type that provides an appropriate flange pressure reduction, that is, by using many hole types. But,
In the conventional method, it was difficult to suppress the biting due to the limited number of hole types due to the restriction of the roll body length.

FIG. 3B shows a method according to the present invention. The hole mold 72 is a series having a large flange width, for example, 3
It is a finishing hole type corresponding to 00 mm, a hole type 62 or a hole type 63 is a finishing hole type with a flange width of 250 mm of an intermediate size, a hole type 73 is a finishing hole type with a small flange width of 200 mm, and a flange width of 300 mm. In this case, similarly to the above-described present invention, finishing is performed in two passes with the die 61, one pass by continuous rolling of the die 61 and the die 71, and one pass of the die 72. In the case of a flange width of 250 mm, finishing is performed with the die 62. In the continuous rolling of the die 61 and the die 71, tension is applied to the material to be rolled. Similarly, in the continuous rolling of the die 72 and the die 62, the tension is similarly increased. By acting, the material to be rolled is preferentially stretched in the longitudinal direction, so that the flange portion can be prevented from biting. Further, in the case of a flange width of 200 mm, finishing is performed with the die 73. In the continuous rolling of the die 63 and the die 73, the engagement of the flange can be suppressed by applying a tension.

The effect of suppressing the engagement of the flange portion by the action of the tension and the conventional structure in which the flange portion is forcibly reduced by the three hole shapes 51, 53, and 54 are doubled to the six hole shapes in the related art. By gradually lowering the flange portion at 61, 62, 63, 71, 72, 73, biting can be completely prevented and a rough shaped steel slab having a good shape can be formed. Conventionally, 3
In the present invention, a series of rough slabs with different flange widths were formed by changing the rolls a number of times. However, in the present invention, the number of passes was increased up to 5 in a single roll change without increasing the conventional method. It is possible. Further, in the present invention, by combining the above-described shaping method of a plurality of coarse shaped steel slabs which differ only in the web height dimension and the shaping method which only differs in the flange width, the shaping and rolling in consideration of the demands in the operation, the ability of the post-process, etc. In other words, it is possible to flexibly meet the needs of the operation, and to manufacture a rough shaped steel slab corresponding to a plurality of series of different sizes having good quality while significantly reducing the frequency of roll changeover.

Next, FIG. 5 shows an example of a method of forming a relatively large H-shaped steel slab using a conventional slab as a material to be rolled.
(A). According to this conventional method, first, a rough steel slab is formed by three box hole dies 81, 82, 83 for forming a flange portion by edging the slab 11 by 90 °, and a hole die 84 for finishing to almost H shape. Is a way to
For the material to be rolled, a flange portion is formed by a plurality of reciprocating passes in each box hole die, and furthermore, rolling is performed about 10 passes mainly using a finishing hole die for reducing the thickness of the web, thereby forming a coarse billet. Requires more rolling passes than passes.

In the method of the present invention shown in FIG.
The nine molds 91, 92, 93, 101, 102 and 103 are molds for forming a flange portion by edging.
Reference numerals 4 and 104 denote finishing holes of a coarse billet. The mold 91 and the mold 101, the mold 102 and the mold 92, the mold 93 and the mold 1
03 and the die 104 and the die 94 are arranged so as to enable continuous rolling, and the die 94 is a rough type corresponding to a series 50 mm larger than the web height of a product manufactured from the rough billet finished by the die 104. This is a finished hole type of shaped steel slab.

As described above, when a relatively large H-shaped steel slab is formed from the slab 11, the width of the raw material slab becomes large, and the material to be rolled is formed in a box hole die which is set up and edged. It is easy to fall down, and an effective technique for suppressing this is to contact the material to be rolled with the hole-shaped side wall as much as possible and to restrain it. However, in the conventional method, only three box hole types can be arranged due to the limitation of the roll body length, and it is necessary to increase the swelling of the end of the material to be rolled in the flange width direction by edging in each box hole type. Therefore, many edging passes are required, and the rolled material does not contact the side wall of the box-shaped die, that is, the edging is likely to occur in most of the edging passes until the die is filled with the die. In the present invention, six edging box holes can be arranged twice as much as the conventional method, so that the edging path in which the end of the material to be rolled does not fill the hole can be reduced, and the material to be rolled can fall. Can be suppressed.

In the process of making the invention, the present inventor has found a new finding that the falling of the material to be rolled during edging rolling can be greatly suppressed by applying tension to the material to be rolled. In the present invention, at the end of the edging rolling pass of a certain box hole type capable of continuous rolling is the initial pass and continuous rolling of the next box hole type edging rolling,
At this time, by applying tension to the material to be rolled, it is possible to suppress the occurrence of falling of the material to be rolled. In other words, the present invention has a great advantage that the rolled material can be almost prevented from falling during edging rolling by the synergistic effect of the above-described falling suppressing effect and the falling suppressing effect due to the tension action during continuous rolling. In addition, since the falling of the material to be rolled can be largely suppressed, the edging amount per pass can be made larger than in the past, so that the number of edging rolling passes can be reduced.

The material to be rolled after edging rolling is 90
゜ It is turned and finished into a coarse steel slab by reciprocating rolling in the finishing die 104. Further, the coarse billet having a large web height is finished by one-pass rolling of the die 94.

In the above, there has been described an example in which a relatively large H-section steel is formed while significantly suppressing the falling of the slab and the number of passes is reduced to form two types of coarse steel slabs. FIG. 6 shows an example of the present invention in which efficiency can be prioritized.

As shown in FIG. 6, four edging box dies 111, 121, 112, and 113 and a finishing dies 11 of substantially the same shape arranged at positions where continuous rolling is possible.
By arranging the finishing dies 122 corresponding to the coarse steel slabs whose web height is 50 mm larger than that of the finishing dies 104 and 123, in the continuous rolling using the finishing dies 114 and 123,
Since the number of reciprocating rolling passes can be reduced to half of the conventional one, and it is possible to finish with the die 122, it is possible to form two types of coarse shaped steel slabs without changing the rolls.

As described above, even when a slab is used as a material to be rolled, the frequency of roll changing of a plurality of high quality coarse steel slabs having different sizes, which can flexibly meet operating needs, is greatly reduced. It can be manufactured.

[0028]

【Example】

Embodiment 1 FIG. From the beam blank having dimensions of 480 mm in web height, 400 mm in flange width, and 120 mm in web thickness shown in FIG. 7, coarse steel slabs corresponding to three series having a product web height of 450 mm and flange widths of 300 mm, 250 mm, and 200 mm. (A), (b), and (c) of FIG. 8 respectively show conventional methods of forming. However, in the conventional method, rolling is performed with a pair of rolls corresponding to each series.
Rolling different series requires roll changing work and time, and in this case, it must have three pairs of rolls. In addition, as shown in FIG. 8C, in the forming and rolling of a series having a small flange width of 200 mm, a large reduction from the beam blank needs to be applied to the flange portion to reduce the surface area. In order to flatten the side surface of the flange by rolling the extruded portion, it is necessary to roll the material to be rolled by 90 ° and roll it using a flat box hole die.

FIG. 3B shows an example in which the present invention is applied to the shaping and rolling of a crude steel slab corresponding to the above three series of products. The roll 60 in FIG. 3B is connected to the shaping mill 2 in FIG.
The roll 70 is incorporated in the shaping mill 2 ′, and the die 72 is a finished die corresponding to a flange width of 300 mm, the die 62 is a finished die corresponding to a flange width of 250 mm, and the die 73 is a finished die corresponding to a flange width of 200 mm. is there.

A web height of 450 mm and a flange width of 300
The rough shaped steel slab corresponding to the mm series is rolled continuously with the die 61 and the die 71 after two-pass rolling with the die 61, and the rolling speed of the molding and rolling mill 2 is reduced to the rolling speed of the molding and rolling mill 2 ′. As long as it is set to be equal to or larger than 2 to 3%, that is, if a compressive force is slightly applied to the material to be rolled, the biting failure in the die 71 can be eliminated.

When forming and rolling a crude steel slab corresponding to a series having a flange width of 250 mm, the effect of preventing the flange portion from biting out by applying tension to the material to be rolled, which is a feature of the present invention, is described by using a die 72. And a continuous rolling pass of the die 62. Here, tension was applied to the material to be rolled by giving a difference between the rolling speeds of the two rolling mills. Since it is difficult to directly measure the magnitude of the applied tension, the speed imbalance A of the two rolling mills was defined as follows, and the effect of the applied tension was evaluated. A = (V1−V2) / V2 × 100 (%) V1: Rolling speed of forward rolling mill during continuous rolling V2: Rolling speed of backward rolling mill during continuous rolling It is shown in FIG. When the speed imbalance A is 0, that is, when the tension is hardly applied, the biting amount is 7 mm.
However, as the speed imbalance A is increased (the tension acting on the material to be rolled is increased), the biting is reduced. By setting A to about 10%, the biting amount becomes 6%.
mm, and it was possible to substantially prevent biting. Further, in the forming rolling corresponding to the series having a flange width of 200 mm, rolling is performed by setting the speed imbalance A to 10% by continuous rolling of the die 72 and the die 72, and then the die 63 and the die 7 are formed.
Even in the continuous rolling of No. 3, by setting the speed unbalance to 8% and rolling, it was possible to form a good coarse shaped steel slab without biting. Table 1 summarizes the comparison between the present invention and the conventional method in this example.

[0032]

[Table 1]

According to the present invention, compared with the conventional method, the roll exchange frequency (required time) is reduced to 1/3, the number of rolls held is reduced to 2/3, and the rolling efficiency of a series having a flange width of 200 mm is reduced to 30.
%.

Embodiment 2 FIG. 1400 mm width shown in FIG.
From a slab with a thickness of 250 mm, the product flange width is 300 mm and the web height is 800 mm and 850 mm
FIGS. 11 (a) and 11 (b) show a conventional method of forming a coarse shaped steel slab corresponding to the above two series. When a product having a large web height is formed from a slab, the slab is turned by 90 °, and the process of edging is apt to fall. Due to the fall, the dimensional accuracy of the product is reduced, particularly the uneven thickness of the flange and the flange 4. The difference in the leg length of the part (center deviation) is worsened.

FIG. 5B shows an example in which the present invention is applied to the shaping and rolling of a crude steel slab corresponding to the above two series of products. The roll 90 in FIG. 5B is connected to the shaping mill 2 in FIG.
The roll 100 is incorporated in the shaping mill 2 ′,
Is a finished hole type for a coarse steel slab corresponding to a web height of 800 mm, and a hole type 94 is a finished hole type for a coarse steel slab corresponding to a web height of 850 mm.

In the conventional method, as described above, only three edging box holes for forming the flange portion can be provided due to the restriction of the roll body length. Since it is difficult to restrain the material on the side surface, the material to be rolled tends to fall if an excessive reduction is taken during edging. Therefore, the edging amount is set to 30 per pass.
Rolling needs to be suppressed to about 40 mm, and it is difficult to reduce the number of passes.

In the present invention, since six box hole dies can be provided twice as much as the conventional method for forming the flange portion, it is possible to obtain a larger edging amount than the conventional method. In addition, the effect of suppressing the falling of the material to be rolled due to edging by applying tension to the material to be rolled, which is a feature of the present invention, was investigated by continuous rolling of the die 102 and the die 92. FIG. 12 shows the relationship between the speed imbalance A and the rate of occurrence of falling of the material to be rolled.

In the conventional method, edging of about 40 mm per pass is performed, but in the present invention, edging of 60 mm is performed with the hole mold 92. When the single rolling was performed with the die 92, as shown in FIG.
When the speed imbalance A was set to 3% in the continuous rolling with the die 102, the fall was reduced to about 3%, and when A was set to 8%, no fall occurred. The speed imbalance A is set to 8% in all passes that can be continuously rolled in the present invention, and the web height is 800 mm and the flange width is 3
Table 2 shows the product dimensional accuracy when a rough steel slab corresponding to 00 mm was formed by finishing with a die 104 in comparison with the conventional method.

[0039]

[Table 2]

By applying the present invention to shaping and rolling,
It was confirmed that the dimensional variation of the flange thickness deviation and the center deviation of the product can be significantly reduced. Web height 8
A rough shaped steel slab corresponding to 50 mm and a flange width of 300 mm is formed by continuous rolling of the die 104 and the die 94.
In the conventional method, both the crude steel slab and the coarse steel slab having a web height of 800 mm require 23 passes as shown in FIG. 14, but in the present invention, as shown in FIG. Thus, it was confirmed that a significant improvement in the rolling efficiency in the shape rolling from the slab can be achieved.

[0041]

As described above, according to the present invention,
Two horizontal rolling mills are arranged at close positions where the material to be rolled can be continuously rolled, and at least one pair of cavities having different web heights or flange widths is arranged on the rolls of the horizontal rolling mill. Since the material to be rolled is continuously rolled in the groove shape, it is possible to efficiently roll the rough shaped steel slab corresponding to a plurality of product series having different web heights and / or flange widths with the same roll. In addition, the frequency of changing rolls can be significantly reduced, and the number of rolling passes and the number of rolls held can be reduced. Furthermore, when continuous rolling is performed with a pair of dies, rolling is performed while applying tension or compressive force to the material to be rolled, thereby eliminating poor biting of the material to be rolled, biting out of the flange portion, and falling down of the material to be rolled. Therefore, there is an effect that a high-quality shaped steel can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a rolling process of a crude steel slab of an H-section steel to which a rolling apparatus of the present invention is applied.

FIGS. 2A and 2B are diagrams showing a conventional method corresponding to a series having different web heights and a groove arrangement and a rolling path of a forming roll according to the present invention, wherein FIG. 2A shows the conventional method and FIG. is there.

FIGS. 3A and 3B are diagrams showing a conventional method corresponding to a series having different flange widths and a groove arrangement and a rolling path of a molding roll according to the present invention, wherein FIG. 3A shows the conventional method and FIG. 3B shows the case of the present invention. .

FIG. 4 is a view showing the occurrence of a bulging portion of a flange portion and edging rolling thereof.

FIGS. 5A and 5B are diagrams showing a conventional method for forming and rolling from a slab and a groove arrangement and a rolling path of a forming roll according to the present invention, wherein FIG. 5A shows the conventional method and FIG. 5B shows the case of the present invention.

FIG. 6 is a diagram showing a groove arrangement and a rolling path of another shaping roll according to the present invention.

FIG. 7 shows dimensions and dimensions of a beam blank used in the embodiment.
FIG.

FIG. 8 is a view showing a conventional roll hole type and a rolling pass in the case of rolling coarse shaped steel slabs having the same web height and three flange widths from the beam blank.

FIG. 9 is a graph showing the relationship between the speed imbalance and the amount of decrease in the bite.

FIG. 10 is a dimensional and shape diagram of a slab used in an example.

FIG. 11 is a view showing a conventional roll hole type and a rolling pass in the case of rolling two types of rough steel slabs having the same flange width and two web heights from the slab.

FIG. 12 is a graph showing a relationship between a speed imbalance and a falling incidence rate.

FIG. 13 is a schematic diagram showing a conventional rolling process of a crude steel slab of an H-section steel.

FIG. 14 is a diagram showing a conventional roll hole die when forming and rolling from a beam blank.

FIG. 15 is a diagram showing a conventional roll hole die when forming and rolling from a slab.

FIG. 16 is a diagram showing the falling of a material to be rolled during edging rolling.

[Explanation of symbols]

1: heating furnace 2, 2 ': horizontal rolling mill 3, 3': universal rolling mill 4, 4 ': edger rolling mill 5: finishing rolling mill 6: beam blank 11: slab 30, 40, 60, 70, 90, 100, 110, 12
0: Rolls 31 to 33, 41 to 43, 61 to 63, 71 to 73, 9
1-94, 101-104, 111-114, 121-
123: Hole type

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yukio Takashima 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) Inventor Motohisa Yoshida 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (5)

[Claims] 1. A method of rolling a crude steel slab using a beam blank or a slab having a rectangular cross section as a material to be rolled, comprising: disposing two horizontal rolling mills at close positions where continuous rolling of the material to be rolled is possible; At least one pair of dies having different web heights or flange widths are provided on the rolls of the two horizontal rolling mills, and the material to be rolled is continuously rolled by the pair of dies. Rolling method for coarse shaped billets. 2. A method of rolling a crude steel slab using a beam blank or a slab having a rectangular cross section as a material to be rolled, comprising: placing two horizontal rolling mills at close positions where continuous rolling of the material to be rolled is possible; When continuously rolling the material to be rolled by the pair of dies arranged on the rolls of the two horizontal rolling mills, the section steel is rolled while applying tension or compression to the material to be rolled. Method for rolling raw slabs. 3. An apparatus for rolling a crude steel slab using a beam blank or a slab having a rectangular cross section as a material to be rolled, comprising: two horizontal rolling mills arranged at close positions where continuous rolling of the material to be rolled is possible. At least one pair of molds having different web heights or flange widths arranged so that continuous rolling can be performed on the rolls of the two horizontal rolling mills. Rolling equipment for shaped slabs. 4. The apparatus according to claim 3, wherein each of the pair of dies is a finished dies. 5. The rough shaped steel slab according to claim 3, wherein one of the rolls of the horizontal rolling mill is further provided with a finishing hole die having a different web height or a different flange width. Rolling equipment.