JP3228144B2 - H-section flange width control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an H-section steel, and more particularly to a method for controlling a flange width of an H-section steel in a group of rough universal rolling mills for H-sections provided with at least one edger rolling mill.

[0002]

2. Description of the Related Art H-section steels, such as blooms, slabs, and beam blanks, are first heated in a heating furnace, and then rough-rolled by a breakdown rolling machine incorporating rolls having a caliber shape. The rolled material is rolled by performing a plurality of pass rollings in a rough rolling mill group including a rough universal rolling mill U shown in FIG. 12A and an edger rolling mill E shown in FIG. 12B. Coarse universal rolling mill U converts the material to be rolled into horizontal rolls 4, 4 'and vertical rolls 5,
5 'to reduce the flange thickness and the web thickness of the material to be rolled so as to approach the specified product thickness. The edger rolling machine E uses the horizontal rolls 6 and 6' to roll the flange of the material to be rolled. The tip is pressed down to finish to the specified flange width.

In the above-mentioned method for producing an H-section steel, as a method for changing the roll opening degree of an edger rolling mill E during rolling to improve the dimensional accuracy of the flange width, Japanese Patent Laid-Open No. 59-1 is disclosed.
There is one disclosed in Japanese Patent No. 1611. As shown in FIGS. 13A and 13B, the flange width of the material to be rolled is measured directly or indirectly, and the main arithmetic unit 30 calculates the flange width expansion formula to calculate the flange width expansion. The roll opening of the edger rolling mill is continuously adjusted so that the flange width after the next pass universal rolling becomes the target width.

[0004] In the hot rolling of a sheet material, when products having various sheet widths are separately produced by reducing the width of a material such as a slab using a roll, generally, the sheet width is reduced by a vertical roll and then horizontally. When rolling in the thickness direction with a roll, the width expansion behavior at the end of the material differs from the steady part,
There is a problem that the plate width is not uniform. To solve such a problem, as shown in FIG. 14, the difference between the width of the steady portion and the width of the end in the horizontal rolling is predicted to reduce the width reduction by the vertical rolls 41 and 41 'at the end of the rolled material. A technique has been developed in which the width is reduced by reducing the amount, followed by rolling in the thickness direction by the horizontal roll 42, and then equalizing the width over the entire length.

[0005]

SUMMARY OF THE INVENTION The above-mentioned JP-A-59-1
The flange width control method disclosed in Japanese Patent No. 1611 is to set a roll opening of an edger rolling mill from a result of calculating a flange width after universal rolling for a stationary portion, and to set an unsteady portion at a leading end and a trailing end of a material to be rolled. Did not have a function to control the flange width. For this reason, the flange width of the front and rear end unsteady portions cannot be rolled as intended, and the flange width deviated from the target dimensions as shown in FIGS. 15A and 15B. This is because the unsteady deformation of the front and rear ends of the material to be rolled was not considered,
For example, as shown in FIG.
₁ even though a constant to the end portion, the flange width B ₂ after universal rolling subsequent if edging amount constant is often a narrow size as the end. This difference is due to the fact that the metal at the end due to the reduction in edging rolling is more likely to flow in the longitudinal direction than the steady part, and the dog bone at the end is smaller than the steady part, and the width in the universal rolling is reduced. This is caused by the spread being reduced at the end.

As a method for eliminating such width fluctuations at the end, in hot rolling of a sheet material, as described above, a technique for adjusting the roll opening at the end is used. But H
The section steel has two flanges on the left and right sides, and as shown in FIG. 12B, the edger rolling mill E rolls these simultaneously using a pair of grooved rolls. Therefore, when the width variation of the end of the rolled material differs between the left and right flanges, both must be corrected simultaneously. However, such a control cannot be performed by the conventional mechanism, and the technique of adjusting the width of the end of the rolled material in sheet rolling cannot be directly applied to the H-section steel.

[0007] The above-described defective flange width at the end portion reduces the yield due to troublesome maintenance in a later step and cutting and discarding of the defective portion, resulting in reduced productivity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and the left and right flanges at the front and rear ends are also rolled to target widths, and have excellent dimensional accuracy and yield. An object of the present invention is to provide a method for controlling a flange width of a section steel.

[0009]

In order to achieve the above object, the present inventors have made various studies and found that at least one rough universal rolling mill and at least one edger rolling mill are arranged adjacent to each other. In the group of coarse universal rolling mills,
When rolling the unsteady portion at the leading and trailing end of the material to be rolled, the roll opening of the edger rolling mill is increased or decreased independently and continuously with respect to the set value of the steady portion, and the subsequent universal rolling is performed. It has been found that the width of the front and rear end flanges can be made equal to the width of the stationary portion, and the present invention has been accomplished. That is, at the leading and trailing end of the material to be rolled, the dog bone forming behavior by the edger rolling and the width spreading behavior by the universal rolling are measured or predicted to be different from the steady part, thereby continuously adjusting the roll opening degree of the edger rolling mill at the end. We have developed a method to adjust to this. In the present invention, the mechanism for continuously increasing or decreasing the roll opening of the edger rolling mill at the front and rear ends of the material to be rolled can independently adjust the roll opening of the hole-shaped portion that lowers the left and right flange tips. If it is a thing, no limitation is required. Examples of such a mechanism include a roll opening adjustment mechanism using hydraulic pressure, a mechanism combining a screw down screw and an electric motor, or a mechanism combining these.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an arrangement diagram showing an example of an H-section steel rolling equipment arrangement to which the present invention is applied. After being heated, the rolled material is rough-rolled by a breakdown rolling mill BD, and subsequently is roll-rolled in a plurality of passes by a group R of rough rolling mills. Here, FIG. 1 shows a universal rolling mill U1 as a rough rolling mill group.
Although the example in which the base and the flange rolling mill E1 are arranged adjacent to each other is shown, the number and arrangement of the rolling mills are not limited to this example, and one or more rolling mills are arranged adjacent to each other. Any format is acceptable, and the order can be arbitrarily determined.
In addition, although the rolling equipment arrangement with one rough rolling mill group R is illustrated, these may be two or more. The material to be rolled after passing through the rough rolling mill group R is finally finished to the universal rolling mill F.
Is finished to the target dimensions.

Although these arrangements are the same as those of the prior art, in the present invention, the roll opening of the edger rolling mill of the rough rolling mill group is determined by rolling the unsteady part at the front and rear ends of the material to be rolled. A mechanism for rolling while increasing or decreasing independently and continuously to the set value is adopted. First, focusing on one flange, a method of making the flange width uniform to the end will be described.

When the tip of the flange is lowered by the edger rolling mill E, the dog bone 7, as shown in FIG.
7 'is formed. Of course, the shape of this dog bone varies in size depending on the amount of reduction at the tip of the flange,
Since the metal flow in the rolling direction tends to increase at the front and rear end portions of the material to be rolled, the dog bone becomes smaller than the steady portion even when the same amount of reduction is applied. If the subsequent rolling is performed by the universal rolling mill U, the flange width at the end of the material to be rolled tends to be smaller than that in the steady portion where the dog bone is formed large. In view of the above, the present invention has developed a method of adjusting the roll opening of an edger rolling mill so that the flange width after universal rolling becomes equal to the steady portion in the unsteady portion at the front and rear ends of the material to be rolled.

FIG. 3 is a schematic view showing an edger rolling method according to the present invention. The horizontal line in the figure indicates the position of the upper end of the flange when the flange is viewed from the side. Rolling stock flange width B ₁ of the front edging is constant to the tip. When rolling this with edger mill E, the tip larger than the set value of the constant region of the roll opening, continuously rolls opens between L _T to reach a steady portion after biting the strip The degree is reduced, and as shown by _BE in the figure, the width of the flange is wide at the front end, the width is gradually reduced as approaching the steady portion, and the width is gradually reduced after the steady portion. Although not shown in the drawing, the roll opening of the edger rolling mill is also adjusted at the rear end so that the flange width becomes wider toward the end. When this is rolled with an adjacent coarse universal rolling mill, the front and rear end portions where the dog bone is hard to be formed and the width expansion is small are widened in advance,
Consequently, the flange width spread dogbone large becomes as wide as the large stationary portion, the flange width B ₂ after universal rolling is the material to be rolled which became constant to the end is obtained.

FIG. 4 is a schematic diagram showing a flange width control method according to the present invention when the flange width is narrow at the front and rear ends of the material to be rolled before edging. By increasing the roll opening of the edger rolling mill at the end than in the case of FIG. 3 and narrowing the roll opening as approaching the steady portion, the end width drop of the material to be rolled is corrected and continued. The flange width after universal rolling can be constant.
Depending on the rolling conditions of the rough rolling and the universal rolling, the end of the material to be rolled may be wider than the steady portion, but in this case, as shown in FIG. The degree may be narrower than that of the steady portion, and the roll opening may be increased as approaching the steady portion.

The adjustment of the roll opening of the edger rolling mill in the unsteady region of the end portion of the material to be rolled is not limited to the increase or only the decrease, but how the end of the material to be rolled is determined by a combination of the two. It is possible to cope with a large flange width.

Next, a method and mechanism for independently controlling the roll opening of the edger rolling mill on the left and right sides will be described. FIG. 6 is a diagram showing a mechanism of an edger rolling mill that performs independent left and right opening control. The edger rolling rolls 6, 6 'are supported by left and right roll chocks 53, 53', 54, 54 '. The roll chocks can be hydraulically operated, a screw down and an electric motor, or a roll opening adjusting device 51 which combines these. The height is controlled by 51 ', 52, 52'. Here, in order to adjust the right and left flange reduction amounts independently, the right and left roll chock heights are adjusted to positions where a required reduction amount can be obtained, and the flange ends are rolled while the rolls are inclined. In the mechanism shown in FIG. 6, both the upper and lower edger rolling rolls 6, 6 'are inclined to adjust the amount of reduction in the width of the left and right flanges, but a mechanism for inclining only one of the upper and lower rolls. Even if it does, the right and left flange width reduction amounts can be adjusted independently.

In this way, by independently controlling the roll opening adjustment amount in the lower portion of the left and right flange tips, even if the left and right flange widths of the rolled material are different at the end portions, a suitable amount of reduction is provided. In the universal rolling U following the edger rolling mill E, the flange width can be effectively made uniform.

FIG. 7 is a block diagram showing a control device for actually measuring the flange width before the edger rolling and implementing the flange width control method of the present invention and related equipment. The right and left flange widths are measured over the entire length by the flange width meter 8, and the flange width information 9 is input to the main processing unit 10. At this time, by simultaneously detecting the in-material flange width measurement position by the pulse transmitters 12 and 13 signals installed on the driving motor 14 of the universal rolling mill U and the driving motor 15 of the edger rolling mill E, the front and rear ends and the stationary part are detected. Calculate the unsteady part length together with the flange width difference. The roll opening information 11 of the edger rolling mill is obtained using this result, and the roll opening of the edger rolling mill is adjusted at the time of reverse rolling in the next pass. Here, in order to easily and surely control the roll opening of the edger rolling mill E, the roll opening adjustment is linearly changed as shown in FIG.
Guides the tightening amount ΔB _ET in the following manner.

After the edger rolling, the width expansion when the stationary portion is rolled by a universal rolling mill is expressed by the following equation.

[0020]

(Equation 1)

B ₁ : flange width before edger rolling B _E : flange width after edger rolling B ₂ : flange width after universal rolling t _F1 : flange thickness before edger rolling t _FE : flange thickness after edger rolling t _F2 : flange after universal rolling Thickness t _W1 : Web thickness before edger rolling t _WE : Web thickness after edger rolling t _W2 : Web thickness after universal rolling A _W : Web cross-sectional area A _F : Flange cross-sectional area I _dE : Projected contact arc length of edger rolling ξ: Coefficient

The width expansion of the tip is expressed by the following equation.

[0023]

(Equation 2)

B _ET : Flange tip width after edger rolling B _2T : Flange tip width after universal rolling c: Coefficient R _V : Vertical roll radius of universal rolling mill

The conditions for preventing the tip from dropping in width after universal rolling are shown in the following equation.

B ₂ = B _2T (3) From the equations (1) and (2), the edger tightening amount ΔB _ET is as follows.

[0026]

(Equation 4)

The length L _T of the opening adjustment from the end was the same as the unsteady length measured after universal rolling. From this .DELTA.B _ET and L _T, tightening control speed V _r of the roll opening of edger rolling mill is calculated by the following equation.

[Number 5] _{V r = (2 · π ·} R E · N RE · ΔB ET) / (60 · L T) ... (5) R E: Ejjaroru radius N _RE: Ejjaroru rotational speed

[0028]

[Embodiment] FIG. 9 is a graph for calculating ΔB _ET suitable for the left and right flanges using the equation (4) derived above.
(5) seeking tightening control speed V _r of the roll opening of edger rolling mill using equation is a diagram showing the longitudinal distributions of the products flange width in the case of performing flange width control according to the present invention . Even in the unsteady part at the front and rear ends of the rolled material, the left side D
The flange widths of r and the right side Fr are dimensions close to the target value. On the other hand, FIG. 10 is a diagram showing the product flange width when the method of the present invention is not used. The width of the flange at the end is smaller than that of the stationary part, and the difference in width between the end and the stationary part is different between the left side Dr and the right side Fr. In addition, the flange width of the steady portion is set to be larger than the target value of 300 mm so that the flange width drop portion at the tip falls within the dimensional tolerance. For this reason, the steady part cross-sectional area becomes unnecessarily large, and the yield is reduced.

The present invention can also provide a sufficient effect by estimating the roll opening adjustment amount and the adjustment length of the edger rolling mill from the flange width of the unsteady part of the product without measuring the flange width. FIG. 11 shows the product flange width when the present invention is applied by a method of back-calculating the roll opening adjustment amount of the edger rolling mill in the unsteady part along the pass schedule from the unsteady part flange width and the unsteady part length of the product. FIG. It can be seen that also in this method, the dimensional accuracy of the left and right flange widths is improved. As shown in the above embodiment, the flange width control method of the present invention can roll the left and right flanges to the target width even in the unsteady region at the end of the material to be rolled. It is needless to say that the use of the conventional technique in combination with the flange width control method in the steady portion improves the flange width dimensional accuracy over the entire length of the material to be rolled.

[0030]

As described above, according to the present invention, the roll opening degree of the edger rolling mill with respect to the unsteady portion of the material to be rolled is adjusted in consideration of the deformation of the unsteady portion at the front and rear ends of the material to be rolled. Since the rolling is performed while increasing or decreasing independently and continuously with respect to the set value, the material to be rolled having the target flange width up to the front and rear ends can be obtained. This eliminates the need for maintenance in the post-process, and also allows the portion where the flange width was defective to be used as a product, thereby improving the yield.

[Brief description of the drawings]

FIG. 1 shows the arrangement of rolling equipment for H-section steel to which the present invention is applied.
It is a layout drawing showing an example.

FIG. 2 is an explanatory diagram of a state of occurrence of a dog bone during edger rolling.

FIG. 3 is a schematic diagram showing a flange width control method according to the present invention when the rolled material flange width is constant over the entire length.

FIG. 4 is a schematic view showing a flange width control method according to the present invention when a flange width at an end of a material to be rolled is narrower than a steady portion.

FIG. 5 is a schematic diagram showing a flange width control method according to the present invention when a flange width at an end of a material to be rolled is wider than a steady portion.

FIG. 6 is an explanatory view showing a mechanism of an edger rolling mill used for carrying out the present invention.

FIG. 7 is a block diagram showing a control device for implementing the flange width control method of the present invention and related equipment.

FIG. 8 is a schematic diagram showing a method of lowering the flange tip in the embodiment of the present invention.

FIG. 9 is a diagram showing an example of a longitudinal distribution of a product flange width when the flange width control according to the present invention is performed.

FIG. 10 is a diagram showing a flange width distribution of a product according to a conventional method.

FIG. 11 is a diagram showing another example of the longitudinal distribution of the product flange width when the flange width control according to the present invention is performed.

FIG. 12 is a view showing a mechanism of a rough universal rolling mill and an edger rolling mill.

FIG. 13 is a block diagram of a control system to which a conventional flange width control method is applied.

FIG. 14 is an explanatory diagram of an end plate width control method in plate rolling.

FIG. 15 is a diagram showing an example of a flange width shape at an end of a material to be rolled.

FIG. 16 is a schematic view showing a change in a flange width at a non-stationary portion of a material to be rolled by a conventional method.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 37/00-37/78 B21B 13/10

Claims (2)

(57) [Claims] 1. A method of controlling a flange width of an H-beam in a group of rough universal rolling mills for rolling an H-beam provided with one or more edger mills, comprising the steps of: Rolling is performed by increasing or decreasing the roll opening independently and continuously with respect to the set value of the stationary part, and in the subsequent universal rolling mill, the flanges at the leading and trailing ends of the material to be rolled have the same width as the stationary part. A flange width control method for an H-section steel, characterized by: 2. A flange width difference between a leading end or a rear end of the material to be rolled and a steady portion and a length of an unsteady portion, respectively, and an edger is determined based on the flange width difference and the length of the unsteady portion. 2. The method for controlling the flange width of an H-section steel according to claim 1, wherein the right and left roll openings and the tightening speed of the rolling mill are obtained and the left and right roll openings are respectively controlled.