JPH0211201A - Method for rolling h-shape steel - Google Patents

Abstract

PURPOSE:To improve the product quality and to reduce the equipment cost by forge pressing a web height of a shaped bloom to be small by use of press anvils and then performing finish rolling of an H-shape steel by a pair of vertical rolls and a pair of horizontal rolls whose roll width is changeable. CONSTITUTION:A pair of upper and lower press anvils 2 are installed for a shaped bloom 1 after rough universal rolling and intermittent forging is performed to the shaped bloom 1 with pinch rolls 7 transferring the shaped bloom 1. In that time, the web height over the total length of or only the top and rear end parts of the shaped bloom 1 are reduced by use of buckling preventing tool 3 for a web part 1a. Then, by use of a universal rolling mill consisting of vertical rolls 5 and horizontal rolls 4 whose width is changeable, finish rolling of an H-shape steel is performed by adjusting a flange thickness and a web height. The number of universal mills are reduced because finish rolling is performed after the anvils 2 previously forge and reduce the shaped bloom 1. Therefore, the product quality is improved and the equipment cost is reduced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for rolling H-section steel, and in particular to a method for rolling an H-section steel that has excellent dimensional accuracy in web height and that can roll the H-section steel without changing the rolls. This is an attempt to freely adjust the

(Prior Art) In general, H-beam steel is produced by a breakdown rolling mill 8, a roughing universal rolling mill 9, an edger rolling mill 4110, and a finishing universal rolling mill 11, as shown in FIGS. 5(a) and 5(b). In the combined process, Fig. 6(a)
, each material 12 shown in (b) and (c) 13.1
4 by hot rolling.

That is, each of the materials shown in FIGS. 6(a), (b), and (c) (that is, numeral 12 is a slab, numeral 13 is a rectangular steel billet, and numeral 14 is a steel billet for section 11) is first broken down rolled. A rough mold is formed into a predetermined shape using machine 8. As this rolling mill 8, a double breakdown rolling mill having upper and lower rolls having open hole shapes 15 or closed hole shapes 16 shown in FIGS. 7(a) and 7(b) is used. In short, this breakdown rolling mill 8 uses multiple flower shapes,
By sequentially rolling each of the plurality of buses, the material is processed into a shape suitable for subsequent intermediate rolling. The roughly shaped material is shown in Figure 8 (
By one or more rough universal rolling mills 9 having a roll shape as shown in a) and one or more edger rolling mills 10 having a roll shape as shown in FIG. After that, it is rolled into an H-shaped steel product in one bath in a finishing universal rolling mill 11 having a roll shape as shown in FIG. 8(c).

Therefore, once the product dimensions are determined, the roll dimensions of the finishing universal rolling mill 11 and the roll dimensions of the previous rolling mills are determined. That is, the dimensions (a) in FIG. 7(a), dimensions (b) in FIG. 8(a), and dimensions (d) in FIG. 8(c) are designed to be approximately equal.

In this way, the change in shape especially after breakdown rolling is limited. That is, for a particular series (e.g.
Horizontal rolls with a specific width are used for rolling H600X300. For this reason, since the inner web width of the rolled 11-section steel is constant, the web height dimension changes by an amount corresponding to the flange thickness. Even in one series, 11 sections of various sizes are manufactured by rolling with different spacing between horizontal rolls and vertical rolls, but the difference between the maximum and minimum flange thickness of the product is around 16 mm. Therefore, the web height changes by about twice that amount, that is, about 32 mm. Changes in web height within the same series are unavoidable in conventional rolling methods, and this poses a major problem when used for construction purposes, for example. In other words, when a beam is made by joining several sizes of H-section steel in the same series, when the outer surfaces of one flange are aligned, there will be a large deviation (twice the difference in flange thickness) from the other.
This poses a problem during construction.

Furthermore, when designing the structure of a building, dimensions are normally determined sequentially from the outside to the inside. On the other hand, with rolled H-beams, the inner web width is constant, but the outer width (web height) changes by the flange thickness, so exact dimensions are required at the construction site. If this happens, it becomes a serious problem.

Furthermore, rolled H-beam steel also has the problem of dimensional accuracy.

That is, in the rolling of I4 section steel, as shown in FIG.
There is a tendency for the inner width dimension to decrease. In addition, horizontal roll 1
Although the vertical roll 19 also wears out along with the roll 7, in this case, the opening degree of the vertical roll 19 can be adjusted by the amount of wear, and no problem occurs with the horizontal roll.

Therefore, with respect to the wear of the horizontal roll, as shown in FIG. 10, if the flange thickness (E) is kept constant, the web height (E) will be lowered by the amount of wear on the side surface 11 of the horizontal roll 10. Normally, the flange thickness (E) is increased to the extent that dimensional tolerances allow to ensure the web height (E).
There were the following problems.

In other words, the tolerance of the web height of the product is web height 40
13.0 mm for less than 0 mm, h6 for 400 mm or more
JIS G 3192 stipulates that the tolerance is ±4.0 mm for less than 00 mm, and ±5.0 mm for 600 mm or more. Since the web height of the material is affected by the width of the horizontal roll 17, the width of the action roll to be used is usually limited within the dimensional tolerance of the web height.

Therefore, the flange thickness varies depending on the width of the horizontal roll 17 used, and the flange thickness of the product becomes particularly thick when rolling is performed using the horizontal roll 17 whose width has been reduced due to wear. Of course,
The thickness of the flange portion changes due to variations in product dimensions from one rolling chance to another due to changes in the width of the rolls used for each rolling chance, or even within the same rolling chance due to wear of the horizontal roll side surface 18. Unfavorable in terms of dimensional accuracy.

Because rolled H-section steel has the above problems, H-section steel manufactured by welding plates is used, especially for construction purposes, so that the web height remains constant even if the flange thickness changes. However, in this case, of course, there was a disadvantage that the manufacturing cost was higher than that of rolled H-section steel.

Rolling 1 (In an attempt to solve the above-mentioned problems in section steel, for example, Japanese Patent Laid-Open No. 59-133902 discloses split rolls whose axial positions can be changed. - A rolling method that is incorporated into a rolling mill IO and a finishing universal rolling mill, thereby performing partial rolling of the web and rolling of the flange end, thereby making it possible to roll different web height sizes with the same roll, has also been disclosed Publication No. 82201 discloses divided rolls whose axial positions can be changed, as shown in FIG. Figure 5 (b) shows a rolling method that allows rolling of different web height sizes and flange width sizes by incorporating into the same roll, or a split roll that can change the axial position.
) is incorporated in the primary phase universal rolling mill a9a, the secondary roughing universal rolling mill 9b, and the finishing universal rolling mill 11 to enable rolling of different web height sizes with the same roll, as disclosed in Japanese Patent Application Laid-open No. 61-2624
Publication No. 04 discloses that when the material after breakdown rolling is rough rolled and then hot rolled into a TR section steel through processes such as finish rolling, protrusions are formed at both ends of the web during rough rolling. Each of these methods discloses a method in which rough rolling is performed as shown in FIG. There is.

(Problems to be Solved by the Invention) In all of these prior arts, the web height of the H-beam steel can be changed over a wide range, and several series can be rolled in succession, so the roll replacement frequency is lower than in conventional rolling. It has many effects such as reducing However, in order to make the web height constant for all sizes in the same series, even though the adjustment amount of the split roll interval is only about 30 mm, all of the coarse universal mill, Ensher mill, and finishing universal mill Since two split rolls movable in the axial direction are used as horizontal rolls, the equipment cost is very high.In particular, the technology disclosed in JP-A No. 61-262404 is not suitable for materials that are thin and have a low temperature. Because the web protrusions are partially rolled in the finish rolling process, there was a significant increase in the roll surface pressure, causing problems such as overloading the split rolls.

H-beam steel, which solves the above-mentioned conventional problems and has a nearly constant web height even when materials with different flange thicknesses are used in the same series, is not suitable for rolling mills, resulting in increased manufacturing costs or equipment costs. It is an object of the present invention to propose a rolling method that can be efficiently manufactured without applying an excessive load to the rolling stock.

(Means for Solving the Problem) This invention provides continuous rolling in the web height direction of a rough-shaped steel billet for 11-shaped steel that has undergone a rough universal rolling stage with a pair of press anvils arranged oppositely across a pass line. A vertical roll pair and a horizontal roll pair whose roll width can be changed are subjected to a forging process, first reducing the web height to a predetermined height over its entire length, and then adjusting the roll spacing to achieve the desired inner web width. Finish rolling is carried out in a universal rolling mill having a universal rolling mill, and final adjustments are made to the flange thickness and web height of the steel billet.

Here, in this invention, in order to prevent the temperature drop of the steel billet, the forging of the rough shaped steel billet using the press anvil is performed only in the region near the tip and the region near the rear end, and the steel billet is directly transferred to the universal rolling mill. to perform finish rolling, or
Alternatively, after forging only the area near the tip and the area near the rear end of the steel billet, the unprocessed area of the billet is rolled down in the web height direction with a pair of rolls, and then finish rolled with the above-mentioned universal rolling machine. It is more effective to do this.

(for production) The present invention will be described in detail below with reference to the drawings.

In this invention, first, as shown in FIG. 1, a rough-shaped steel billet 1 that has undergone a rough rolling process is conveyed by pinch rolls 7, and the steel billet 1 is placed facing each other across the 11 feeding pass line. For example, a pair of trapezoidal press anvils 2 are used to perform intermittent forging in the web height direction to reduce the web height of the steel billet 1 to a predetermined height over its entire length. .

At this time, it is preferable to use a buckling prevention tool 3 so that the web portion 1a of the steel piece 1 does not buckle.

Next, the rough shaped steel slab 1 after forging is finish rolled in a finishing universal rolling machine to eliminate dimensional irregularities caused by intermittent reduction during forging and to a desired size. In particular, the dimension (W) of the horizontal roll 4, which has a structure in which the roll width can be changed as shown in FIG. , each time the rough-shaped steel billet 1 is fed to the mill and subjected to finish rolling, the flange thickness and web height of the steel billet 1 are reduced by the rolling by the vertical rolls 5 of the rolling mill, with an increase in the load on the rolling mill. It will be adjusted to the desired size without any problems.

If the rough slab 1 that has gone through the rough rolling process is subjected to forging over its entire length, there is no need to use a universal rolling mill equipped with horizontal rolls whose roll width can be changed at this point, which has the advantage of reducing equipment costs. On the other hand, since the machining time becomes longer, there is the advantage that the temperature of the rough shaped steel piece 1 decreases. Therefore, in the present invention, for example, as shown in FIG. 3, only the region T near the tip and the region B near the rear end of the rough shaped steel slab 1 are forged and then finished using the above-mentioned finishing universal rolling mill. After rolling or forging only the vicinity of the front and rear end regions of the rough-shaped steel piece 1, the steel piece 1 is rolled with a reduction roll 6 such as a vertical roll as shown in FIG.
If the unprocessed area of the steel sheet is rolled down in the web height direction and then finish rolling is performed using the above-mentioned rolling mill, the processing speed can be increased compared to the pressing method, which is advantageous in preventing the temperature drop of the steel billet as much as possible. .

In addition, in the above-mentioned rolling method, the reason for forging only the area near the front and rear ends of the rough-shaped steel slab 1 is that the rough-shaped steel slab 1 is
This is because the web portion 1a of the shaped steel piece 1 is likely to buckle if rolled down by rolling J across the entire length of the longitudinal direction.
If this region is previously subjected to forging processing to obtain a predetermined inner width, there will be no buckling of the web portion even if the other regions are rolled down.

(Example) The web thickness and flange thickness of the I” section steel are respectively (81Tb (11mm x 22+n
m) and (14m+nX28mm).
Rolling was performed according to the conditions of 1. The results of measuring the web height of each H-section steel obtained are shown in Table N.

Web thickness and flange thickness are (14mm x 28mm)
mm) and (11 mm x 22+ nm) were manufactured by applying this invention, and in both cases, the web height was approximately 450 mm and they were manufactured using the conventional method (8 mm x] 4 mm). The web height could be made almost the same as the web height of the H-shaped invention.

In addition, (9 mm x 16 m + n), (10 mm x 19
A similar rolling method according to the present invention was attempted for an H-beam steel having a diameter of 2 mm), and it was confirmed that this could also be manufactured without any problems.

(Effects of the Invention) According to the present invention, I-I section steel having a constant web height and having different flange thicknesses within the same series can be efficiently manufactured without requiring frequent change of rolls. In addition, according to the present invention, finish rolling is performed after forging the rough-rolled steel section, so there is no need to prepare multiple expensive universal rolling mills, especially horizontal rolls whose width can be changed. In addition, since the processing allowance is small, a large load is not placed on the rolling mill, so the structure is relatively simple and equipment costs can be easily reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a rolling procedure according to the present invention, FIG. 2 is a schematic diagram of a horizontal roll whose roll width can be changed, FIGS. 3 and 4 are explanatory diagrams of other rolling procedures according to the present invention, and FIG. Figures (a) and (b) are explanatory diagrams of the rolling procedure for H-section steel according to the conventional method. Figures 6 (a), (b), and (C) are cross-sectional shapes of the H-section steel material after each rolling stage. Figures 7(a) and (b) are diagrams showing the caliber shape of the rolling rolls during breakdown. Figures 8(a), (b), and (C) are diagrams showing the caliber shape of the rolling rolls at each rolling stage of H-beam steel. Figure 9 is a diagram showing the cross-sectional shape, Figure 9 is a diagram showing the wear status of the horizontal roll, Figure 10 is H
It is a figure showing the main dimensions of a section steel. ■... Rough shaped steel piece for H-shaped steel 1a... Web height 2.
...Press anvil 3...Buckling prevention tool 4...
Horizontal roll 5...Vertical roll 6...Reducing roll 7...Pinch roll 8...Breakdown rolling mill 9...Kan universal rolling mill 10...ESOGAR rolling i II...Universal rolling mill 12...Slab 13...Rectangular steel piece 14...° Steel piece for H-beam steel 15...Open hole type 16...Closed hole type @3 Figure 4 Patent/producer applicant Kawasaki Steel Corporation Co., Ltd. Figure 5 Figure 6 Figure 7 1986

Claims (1)

[Scope of Claims] 1. The web height of the H-section steel slab that has undergone the rough universal rolling stage is reduced to its entire length using a pair of press anvils placed oppositely across the pass line. The flange thickness of the shaped steel piece is subjected to a forging process to reduce the thickness, and then finish rolled using a universal rolling mill that has a pair of vertical rolls and a pair of horizontal rolls whose roll width can be changed, and which has been adjusted to a desired roll spacing in advance. and a method for rolling an H-beam steel, comprising the steps of: final adjustment of the web height; 2. Claim 1, wherein the forging process of the rough-shaped steel piece by the press anvil is performed only in the area near the tip and the area near the rear end of the rough-shaped steel piece.
Method described. 3. The web height of the H-shaped steel slab that has gone through the rough universal rolling stage is measured by a pair of press anvils placed opposite each other across the pass line to measure the web height of the H-shaped steel slab in the vicinity of its tip and at its rear end. After applying a forging process to reduce the size only in the vicinity of the section, the unprocessed area of the section is passed through a pair of rolls with a roll spacing comparable to the forging width, and then rolled down to a desired roll spacing in advance. The final adjustment of the flange thickness and web height of the shaped steel piece is carried out by finishing rolling using a universal rolling mill having a vertical roll pair and a horizontal roll pair whose roll width can be changed.
Method of rolling section steel.