JPH05115901A - Size-free rolling method for height of web of shape steel - Google Patents

Abstract

PURPOSE:To remarkably increase the kinds of shape steel which can be rolled at the same roll chance by expansion of common range by extending or reducing the inside width of web of a base stock by combining at least two finishing mills. CONSTITUTION:At the time of finish rolling of a roughly shaped billet with a web and flange, at least two finishing universal mills 4 are arranged in tandem and the inside width of web of the roughly shaped billet is extended or reduced by properly changing the roll width of the rolling mill 4a in the prestage. And that billet is pushed into the rolling mill 4b in the poststage, the inside width of web is extended or reduced with the rolling mill 4b in the poststage too and also each mill is allowed to share each function so that the final finish rolling serving for raising up the angle of flange as well can be executed. Then, the kinds of shape steel which can be rolled at the same roll chance can be remarkably increased by expansion of common range without accompanying clogging of material in the rolling mill and deterioration of dimensional accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the rolling of an H-section steel or a section steel similar thereto by changing the inner width of the web of the rolled material (the height of the web minus the flange thickness). It is intended to propose a rolling method suitable for rolling shaped steels having different heights with the same roll chance.

[0002]

2. Description of the Related Art Since H-section steels and shaped steels similar thereto have a wide variety of sizes and sectional shapes, when rolling on the same line, the rolls are recombined every time the size is changed. It is necessary to reduce the production efficiency. Regarding the technology that tried to solve such a problem, a method of expanding the web of the material in the width direction with a special roll (see JP-A-59-202101 and JP-A-60-206502) or the stage of finish rolling Japanese Patent Laid-Open No. 2-80102 discloses a method of positively reducing the inner width of the web of the material.

[0003]

By the way, the above-described method for widening the inner width of the web requires a special rolling mill and has a disadvantage that the equipment cost is unavoidably increased because the size of the apparatus itself is inevitable. there were. In this respect, the method of reducing the inner width of the web can be handled only by changing the finishing rolling mill, so there is no increase in equipment costs, but if the amount of reduction of the inner width of the web is large, There is an increase in the web thickness and it is difficult to put the web thickness within the allowable range, and it is difficult to bit the material into the rolling mill.
There is a limit to the amount of reduction in the width of the web, and in each case there are advantages and disadvantages.

In the case of rolling different shaped steels of different sizes on the same rolling line, a new rolling method with a wide communal range is proposed, which does not require the complicated work of frequently replacing the rolling rolls and other incidental equipment. That is the object of the present invention.

[0005]

According to the present invention, at the time of finish rolling a rough steel billet having a web and a flange, at least two finish universal rolling mills are arranged in tandem, and the front stage of the finish universal rolling mill is arranged. A web height of a shaped steel characterized by performing rolling to expand or reduce the inner width of the web on the above-mentioned rough shaped steel slab with a rolling mill, and then performing final finishing rolling also as a flange raising at the subsequent stage. A size-free rolling method, in which a finishing universal rolling machine that expands or contracts the inner width of the web of a rough steel slab, the inclination angle of the roll width end face is included in the rolling mill at the rough rolling stage, the inclination angle at the roll width end face of the horizontal roll. And smaller than the inclination angle at the roll width end face of the horizontal roll provided for the rolling mill in the final finishing rolling stage,
Further, it is advantageous that the corner portion from the roll cylinder end portion to the roll width end surface has a multiple radius by a plurality of radiuses.

FIG. 1 shows an example of rolling equipment suitable for carrying out the present invention. The number 1 in the drawing is a heating furnace.
2 is a breakdown rolling mill, 3 is a rough rolling mill group, and this rough rolling mill group 3 is composed of universal rolling mills 3a and 3b and an edger rolling mill 3c arranged between them. Further, 4 is a finishing rolling mill group, and this rolling mill group 4 comprises universal rolling mills 4a and 4b and an edger rolling mill 4c arranged between them.

[0007]

A finishing universal rolling mill, which is suitable for reducing the inner width of a web, as disclosed in Japanese Patent Application Laid-Open No. 2-80102, is capable of rolling shaped steels having various web heights. The roll width of the rolling roll can be arbitrarily changed. However, since the vertical rolls of such a rolling mill are not driven, if the allowance for the reduction of the inner width of the web increases, the biting property of the material into the rolling mill deteriorates, and this rolling mill is used to expand the common range of the rolling mill. Even if an attempt is made to carry out rolling to increase the web inner width of the material, the roll placed there is the final forming roll, so it is not possible to form a roll shape suitable for expanding the web inner width of the material. .. In particular, when a guide for restraining the flange portion is applied in order to avoid the deviation of the center of the web and to improve the dimensional accuracy, there is a disadvantage that the biting property is further deteriorated.

According to the present invention, at the time of finish rolling a rough-shaped steel slab having a web and a flange, at least two finishing universal rolling mills are arranged in tandem as shown in FIG. Increase or decrease the inner width of the crude steel slab by changing it appropriately. (The shape of the roll in the former rolling mill is limited to the finishing rolling mill in the latter stage. (The roll shape can be freely selected so that it can be applied) and the steel piece is pushed into the rolling mill 4b in the subsequent stage, and the rolling mill 4b in the subsequent stage also enlarges or reduces the inner width of the web and also serves to raise the angle of the flange. Since each function is assigned to each rolling mill so that final finishing rolling can be performed, the width of the web inside the shaped steel can be increased. It can be varied over a wide range in the case of reducing the cases.

Taking the case of rolling an H-section steel using a continuous casting slab or bloom as a material according to FIG. 1 above, first, the material h heated and soaked at 1200 to 1280 ° C. in the heating furnace 1 is broken. The down rolling mill 2 rolls to an H-shaped rough section, and then the rough universal rolling mill group 3 performs reciprocating rolling a plurality of times. Up to this point, the steps exactly the same as those of the usual H-section steel rolling are performed. Then, as shown in FIG. 2, in performing rolling such that the inner width of the web of the crude steel strip h ′ is reduced from W ₀ to W ₁ by finish rolling, in the rolling mill 4a in the preceding stage of finish rolling, Finishing rolling is performed by the rolling mill 4b in the subsequent stage so that the web of the crude steel piece h'is slightly reduced so that the inner width W ₀ of the web remains almost unchanged after rolling. In this case, the rolling mill 4a functions to push the crude steel piece h'into the rolling mill 4b in the subsequent stage, so that even if the vertical roll 4bV of the rolling mill is not driven, it can be bitten by the horizontal roll, and the web inner width Even if the reduction amount (W ₀ −W ₁ ) of the steel sheet is slightly large, smooth rolling can be performed. When rolling to reduce the inner width of the web as described above, for example, when the guide 5 for restraining the flange outer surface of the crude steel piece is provided as shown in FIG. It was difficult to bite h'into the rolling mill 4b in the subsequent stage, but there is no problem with this method, and the impact at the time of biting the crude steel piece into the rolling mill can also be bitten at a low speed. Since it can be made as small as possible, there is an advantage that the gap between the restraint guide and the billet can be set small.

FIG. 4 shows the state of contact between the roll and the crude steel billet in the rolling mill 4a in the preceding stage of finish rolling. We are rolling that delays the contact between the vertical roll 4bV and crude steel piece h'at the final finishing mill by slightly rolling the tip P ₁ of the flange of the crude steel piece h'at vertical roll 4aV at this stage You can also

FIG. 5 shows a rough steel piece h'which has been rough rolled.
The width W of the web₀To W ₂To expand to
In the case of performing simple rolling, the above is performed up to the stage of the rough rolling mill group 3.
Roll as usual and finish with the finishing mill 4a.
The width of the inside of one web is W₀To W ₂Expand to. like this
As shown in Fig. 6, the tip of the steel slab
The flange part of A bites into the horizontal roll of the rolling mill.
Need to be protected. The conditions in that case are
7, the leg length of the steel piece h'is L, and
Point P where the horizontal roll 4aH of the rolling machine 4a contacts the steel piece h '₂
If the position of L'is L'≤ 2/3 L
Is preferred. Widening width of the inner web (W₂-W₁) Is large
In order to make it
Inclination angle Θ₁And horizontal roll 4aH of finish rolling machine 4a
Of the roll width end face ₂Increase the difference
It is desirable that the horizontal roll of the finishing rolling mill 4a
The end face of the tool contacts the inner surface of the flange of the steel slab and rubs there
To increase the inner width of the web while lowering₁Is small
The other is Θ₁And Θ₂The smaller the difference, the better
Yes. In the present invention, the above Θ₁About 3 to 6 °, Θ
₂Rolling under the condition of L'≤ 3/4 L at about 2-4 °
And The end of the horizontal roll 4aH of the finishing rolling mill 4a is
In order to smoothly expand the width of the web,
Section to the end face of the roll width.
(Here R₁, R₂As an example,
Is preferably provided. Pre-rolling pressure of finish rolling
Inclination angle Θ of the horizontal roll 4aH in the rolling machine 4a₂And vertical
Inclination angle Θ on the roll surface of roll 4bV₃(On the drawing
Replenish! ) Have approximately the same angle, and
Make sure that the lunge thickness does not change and the width of the web
W₀To W₁Clearance Δb so that it can be easily expanded to
It may be selected so as to form. A web according to the invention
When rolling to expand the inner width, the flange tip of the billet
P₁Contacts the vertical roll faster than other areas,
There is an advantage of having a centering property. Front stage of finish rolling
The steel strip whose inner width has been expanded by the rolling mill 4a of
As it is, it is guided by the rolling mill 4b in the subsequent stage, and there is some reduction
Of the forming and rolling that also functions as a flange raiser with expansion
In practice, it is finished into shaped steel with a predetermined web height. Na
The horizontal roll of the former rolling mill 4a is a roll for reducing the inner width of the web.
Size and roll for expansion
The roll width may be changed when the roll width changes.
By placing a changeable role of
It is possible to reduce or expand it in combination. In addition,
Edger rolling between the rolling mill 4a and the subsequent rolling mill 4b
By disposing the machine 4c, the deviation of the center of the web can be prevented.
Always small and with extremely good dimensional accuracy of the flange width
Obtainable.

[0012]

EXAMPLE W ₀ = 490.0 mm, H = 72.0 mm after rough rolling,
Θ ₁ = 5 °, Θ ₂ = 3 °, web height t ₁ = 6 mm from crude steel slab, web height 500 mm, flange width 150 mm, web thickness 6
The maximum reduction amount and the maximum expansion amount of the inner width of the web were investigated, which did not adversely affect the product quality when rolling the H-section steel having a thickness of 12 mm and a flange thickness of 12 mm. As a result, the maximum reduction amount is W ₀ −W ₁ = due to the accuracy improvement by setting the flange outer edge restraint guide and the effect of indentation by the former rolling mill.
^{_{100 (t 1 2 / W 0}} ) ≒ 7.3 mm, while the maximum amount of expansion is W ₂ -W
_{Since 0} = 2 x h x tan Θ ₁ ≈ 9.4 mm, it is possible to change the inner width of the web by a total of 16.7 mm, and it is possible to obtain a change amount about twice that of the conventional reduction rolling method. I was confirmed.

[0013]

As described above, according to the present invention, the expansion and contraction of the inner width of the web of the material is performed by combining at least two finishing rolling mills, so that clogging of the material into the rolling mill and dimensional accuracy can be prevented. Without deterioration, it is possible to greatly increase the types of shaped steel that can be rolled with the same roll chance by expanding the common range.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a rolling facility suitable for carrying out the present invention.

FIG. 2 is a diagram showing a rolling situation in which the inner width of the web is reduced.

FIG. 3 is a diagram showing an arrangement of flange restraint guides.

FIG. 4 is a diagram showing a rolling situation in a preceding stage of finish rolling.

FIG. 5 is a diagram showing a rolling situation in which the inner width of the web is expanded.

FIG. 6 is a view showing a tip end portion of a crude billet for H-section steel before finish rolling.

FIG. 7 is an explanatory diagram of a rolling situation in finish rolling.

[Explanation of symbols]

 1 Heating furnace 2 Breakdown rolling mill 3 Coarse universal rolling mill group 4 Finishing universal rolling mill group 5 Flange restraint guide

Claims (2)

[Claims] 1. At the time of finish rolling a rough shaped steel slab having a web and a flange that have been rough rolled, at least two finish universal rolling mills are arranged in tandem, and the above-mentioned finishing universal rolling mill is provided in front of the finishing universal rolling mill. Rolling to increase or decrease the inner width of the web on the rough steel slab,
Then, the web height size-free rolling method for shaped steel is characterized in that the final finishing rolling that also functions as the raising of the flange is performed in the subsequent stage. 2. A finish universal rolling machine for expanding or contracting a web inner width of a rough-shaped steel slab is such that an inclination angle of a roll width end face is larger than an inclination angle of a horizontal roll provided in a rolling mill at a rough rolling stage. It shall be smaller and larger than the inclination angle at the roll width end face of the horizontal roll provided for the rolling mill in the final finishing rolling stage, and the corner part from the roll body end part to the roll width end face is a multiple radius with a plurality of radiuses having different radii of curvature. The method of claim 1, comprising a variable width horizontal roll having a.