JPH04237501A - Line of device for hot rolling channel steel - Google Patents

Abstract

PURPOSE:To offer a line of devices with which many sizes in small quantity production are made possible and further a channel steel is rolled efficiently by saving the handling time of roll change or the like, at the time of hot rolling of channel steel which a continuously cast slab is used for a base stock, by continuously and on-line executing the adjustment of web thickness and flange thickness while keeping the dimensions of the outside width of the same series constant. CONSTITUTION:The rolling device consists of two devices of a break down mill BD and universal mill FU. Box-shaped calibers G1, G2, a flat caliber G3 and half U-shaped caliber Ka 1.2 are engraved on the upper and lower horizontal rolls of the break down mill BD and the barrel width of the lower horizontal roll of the universal mill FU is variable and also collar parts Q with which the inner corner parts at the tips of flanges are restrained are provided. After a slab is made into a flat metal plate 10 with the break down mill BD, it is made into an intermediate stock 11 for channel using the half U-shaped caliber Ka 1.2, finished with the universal mill FU and the channel steel with a fixed outside width and different thickness of the same series is manufactured from the continuously cast slab.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a hot rolling equipment train for channel steel, and more specifically, channel steel having uniform web and flange thicknesses and various thicknesses and widths are rolled from continuous casting slabs. This invention relates to a hot rolling equipment for channel steel that produces different types of steel with efficiency.

0002

[Prior Art] Cold-formed square columns, which are widely used as construction steel columns, are known, for example, from the "JSSC Report No. 5 Standardization of Box Columns" published by the Japan Steel Construction Association in August 1988. It is manufactured by cold working by either the roll forming method shown in FIG. 5(a) or the press forming method shown in FIG. 5(b) described in . However, in these methods, the yield ratio (YR: yield point or yield strength/tensile strength) is slightly higher because the material is work hardened during forming (arrow region in the figure) compared to the as-hot-rolled material. On the other hand, it is said in some circles that a lower YR for members used in high-rise buildings and the like is desirable from the standpoint of seismic performance. One way to deal with this problem is to weld and assemble a box (square column) using hot-rolled channel steel as a material. This assembly method is compatible with the recent labor-saving trend at construction sites, as it is possible to incorporate the diaphragm before assembling it by welding. Here, the hot-rolled channel steel used as the material has a constant outer width (web height and flange width) in the same series, and a thickness free size (the web and flange thickness are the same, and the flange inner surface is parallel with no taper. It is required to have uniform plate thickness) and low production costs comparable to general shaped steel.

[0003] As a representative example of manufacturing conventional hot-rolled channel steel, Japanese Patent Application Laid-Open No. 2-133102, which was previously proposed by the present applicant,
A method using a reverse mill, which is described as a prior art in the publication, is shown in FIG. 6(a), and a method using a continuous mill is shown in FIG. 6(b). In these conventional methods, even within a product group with the same web height series, for example, the horizontal roll 40 of the finishing mill F uses rolls with a constant body width W0.
If the flange thickness t differs, the web height W will differ. In addition, since rough and intermediate forming is performed using the hole pattern of double rolls, it is extremely difficult to produce various thicknesses over a wide range by simply adjusting the gap between the same rolls. Therefore, in order to meet the product requirements for channel steel of constant outer width and various plate thickness sizes within the same series, it is necessary to prepare dedicated rolling rolls and their rolling accessories according to each size. This poses the problem of not only increasing the cost of rolling tools but also significantly reducing production efficiency, such as lowering the operating rate due to roll changes.

0004

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and it is an object of the present invention to roll out rolled channel steel from one series to another without replacing any roll tools using a minimum number of rolling equipment. An object of the present invention is to provide a rolling equipment array for hot-rolled channel steel, which allows stepless online adjustment of the thickness of the web and flange while keeping the width constant.

[0005]

[Means for Solving the Problems] The gist of the present invention is as follows. In other words, ① a box-hole type and a flat-hole type for rolling a hot slab material with a rectangular cross section into a flat plate material of a predetermined thickness and width, and one end for pre-bending the flat plate material into an intermediate material having a substantially U-shaped cross section A breakdown mill consisting of a pair of upper and lower horizontal rolls each having a half-split U-shaped hole with a stepped part; The universal mill is composed of upper and lower horizontal rolls each having a restraining flange and the other horizontal roll having a flat surface that presses the outer surface of the web, and a pair of left and right vertical rolls that press the outer surface of the flange. Features: A row of hot rolling equipment for channel steel that rolls channel steel of various thicknesses with constant web height and flange width; This is a hot rolling equipment row for channel steel in which fixed guides and movable guide rollers whose left and right positions can be adjusted are installed opposite each other.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings. FIG. 1 and FIG. 2 show an example of the rolling equipment row and rolling process for channel steel according to the present invention. In the figure, 1a, 1b
are the upper and lower horizontal rolls of breakdown mill BD, and each roll has box-hole type G1, G2, flat-hole type G3, and half-split U.
Shape type Kal. 2 have been excavated. The hole bottoms of the box hole types G1 and G2 are both flat bottoms, and the hole bottom widths W1 and W2 are different. The peripheral surface of the roll of the flat hole type G3 is formed flat in the left-right direction. Half-split U-shaped hole type Kal. One of the hole bottoms in No. 2 is formed into a curved surface, and the surface continuous with this curved surface is flat.
A stepped portion P is formed at the other end of the flat surface. This half-split U-shaped hole Kal. Since the cross-sectional shape of No. 2 resembles a shape obtained by dividing a U-shape into two around the axis, this hole shape is referred to as a half-split U-shaped hole shape in the present invention.

In this breakdown mill BD, a hot slab with a rectangular cross section made by the continuous casting method is used as a raw material. First, it is edged from the width direction with a box hole type G1 to form the end face and peel off the scale. Rotate once and reduce the thickness using the flat hole die G3. During thickness reduction over multiple passes, the steel material is appropriately turned 90 degrees and edged multiple times with either box-hole type G1 or G2 to form the end face and adjust the width dimension to obtain a flat plate material with the required width and thickness. Roll to 10. Note that the required number of box hole shapes and their dimensions are determined by the required board thickness and material thickness, and are not necessarily limited to the two hole shapes G1 and G2.

Next, the flat plate material 10 has a half-split U-shaped hole type Ka.
l. In step 2, the intermediate material 11 (hereinafter referred to as the groove-shaped intermediate material 11) having a required substantially U-shaped cross section is formed by U-bending. The positioning of the portion of the flat plate material 10 corresponding to the flange end surface is regulated by a stepped portion P formed on the right end surface of the hole. This half-split U-shaped hole type Kal
．． The number of passes in step 2 is determined by the amount of U-bending, and the larger the size, the more passes need to be made, but usually 3
~7 passes of reverse rolling. In addition, the half-split U-shaped hole type Kal. 2, the flange-corresponding portion of the flat plate material 10 is bent to the right so that the U-shaped bottom of the groove-shaped intermediate material 11 is located on the left side of the drawing. The flat plate 10 is divided in half to form a U-shaped hole so as to take this posture. 2 can be achieved by restricting the end surface of the groove-shaped intermediate member 11 with a hole-shaped stepped portion P and by restraining manipulators on the front and rear surfaces (not shown).

In order to more reliably guide the flat plate material 10 in the bending direction, as shown in FIG. 3(a), a fixed guide G and a movable guide roller RG whose horizontal position can be adjusted
and a half-split U-shaped hole Kal. Mutual guides may be provided opposite to each other on either the front or rear surfaces or the front and rear surfaces of the two in the rolling direction. Once the material has been pre-bent, it can be easily U-bended with a small load and power from the second pass onwards. Half-split U-shaped hole type Kal. In the intermediate rolling stage in step 2, the movable guide roller RG is moved to the left in accordance with the progress of the pass,
By positioning and restraining the central part of the material in the height direction, more reliable guidance becomes possible. 3(a) shows the first pass of U-bending, and FIG. 3(b) shows the middle pass of U-bending, Kal. 2 indicates the final pass.

[0010] Also, the flange tip width W of the groove-shaped intermediate member 11
D (corresponding to the web height of the product) is the finish forming hole type Kal. Kal so that it is approximately the same as the web height W of 1.
．． 2. Set the roll gap for the final pass. If WD is too large than W, Kal. 1 causes biting, poor threading, and poor shape, scratches, and bite of the flange tip; conversely, if it is too small, it causes poor flatness of the web surface and flange surface, and poor shape of the flange tip. The manipulators disposed on the front and rear surfaces of the breakdown mill BD have a structure capable of turning and holding flat or curved plates.

As described above, the flat plate material 10 of appropriate width and thickness is rolled using the box-shaped hole type and the flat-hole type, and is then halved into the U-shaped hole type Kal. By U-bending to a desired width by adjusting the gap between the two rolls, a groove-shaped intermediate material 11 having a desired width and thickness is formed using the same roll.

Next, the structure of the universal mill FU for finish forming the groove-shaped intermediate material 11 will be explained with reference to FIG. 1(b). This universal mill FU has upper and lower horizontal rolls 7a, 7.
It has the same structure as a conventional general universal mill for section steel in that it has a horizontal roll 8a, 8b, and left and right vertical rolls 8a, 8b. The lower horizontal roll 7b located at the bottom of the drawing is provided with a variable body width, and a flange Q is provided protruding from one end of the roll's outer peripheral surface.

By adjusting the body width of the lower horizontal roll 7b according to the thickness of the product, it is possible to finish the channel steel 12 in the same series with a constant outer width (web height W and flange width B) and a thickness free size. Can be molded. Further, the flange Q restrains the inner corner portion of the flange tip of the groove-shaped intermediate member 11, and prevents the left and right flange tips from escaping inward. The upper horizontal roll 7a presses the outer surface of the web, and the left and right vertical rolls 8a, 8
Of course, the outer surface of the flange is pressed at b. In addition, the line length ld of the groove-shaped intermediate material 11 is
is lengthened by 0.3 to 5% to increase Kal. By adding compression processing to the line length in step 1, the product shape and molding are stabilized, and the corner radius of the apex portion of the groove is reduced.

As mentioned above, the lower horizontal roll 7b adjusts the body width interval of the left and right divided rolls according to the thickness of each product, but the upper horizontal roll 7a has a constant body width within the same series, so If the roll is not intended to be shared, a conventional integral roll may be used instead of the variable body width roll as in this embodiment.

[0015] Note that Kal. In step 1, if the flange Q of the lower horizontal roll 7b is removed and the lower horizontal roll is made into a flat roll as shown in FIGS. 4(a) and 4(b), no roll adjustment is required even if the thickness differs within the same series. It is thought that it is possible to form a channel steel with a relatively large width dimension because it can be formed under certain conditions without any problems, and because the equipment is simple and the roll diameter of the lower horizontal roll 7b can be relatively small. However, as a result of experiments, we found that when a slight compression of line length l was added to stabilize the product shape and molding, Figures 4(a) and (
In both cases (b), inward escape and bulging occurred at the tip of the flange, and in (a), chewing occurred at the tip of the flange. Therefore, if the compression of the wire length l is reduced to almost zero, the corner radius of the top corner of the channel steel will increase, and the material will swing in the roll hole, making the left and right sides likely to be uneven. At that time, the supply situation became unstable.

When the roll configuration as shown in FIGS. 4(a) and 4(b) is used, the appropriate compression ratio of the wire length l varies depending on the thickness and width of the material, the rolling temperature and its distribution, and the material, and changes depending on changes in the forming conditions. Since delicate adjustments are required, in the end, Figure 4(a),
The roll construction method as shown in (b) lacks practicality, and
al. It has been found that it is practical to form the lower horizontal roll 7b into a stepped shape having a flange Q as shown in FIG.

By applying the above method to a section steel rolling mill, for example, from a continuously cast slab of width 1400 mm x thickness 200 mm, web height 700 mm x flange width 3.
50mm x thickness 22, 25, 28, 32, 36, 40,
Channel steel with constant outer width of 45, 50, 55, and 60 (mm) can be made using the same roll set.

[0018]

Effects of the Invention According to the device series of the present invention, the dimensions of the roll hole in the part where the thickness and width of the web and flange are created can be arbitrarily changed online using the minimum necessary device configuration. It is possible to hot-roll channel steel with a constant width and a free size thickness, and it is possible to handle small-lot production of multiple sizes.It also requires roll replacement work, which improves production efficiency and reduces roll tool costs. In addition, the corner radius of conventional roll-formed or press-formed products is as large as 2 to 3 times the thickness of the plate, which may cause inconvenience in use, whereas according to the present invention, the corner radius is relatively large. Since it can be made smaller, the utility value of the product is improved from this aspect as well.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a roll configuration of the present invention.

FIG. 2 is a process diagram showing the arrangement of the device of the present invention.

FIG. 3 is an explanatory diagram during intermediate molding of the present invention.

FIGS. 4(a) and 4(b) are explanatory diagrams showing the finish forming process of channel steel.

FIGS. 5(a) and 5(b) are explanatory diagrams showing the conventional forming method of column material and the work hardening position.

FIGS. 6(a) and 6(b) are explanatory diagrams showing a conventional hot rolling process of channel steel.

[Explanation of symbols]

BD Breakdown Mill FU
Universal mill 1a, 1b Upper and lower horizontal rolls 7a of breakdown mill Upper horizontal roll 7b of universal mill Lower horizontal rolls 8a, 8b with variable body width of universal mill Left and right vertical rolls RG of universal mill Moving guide roller G Fixed guide

Claims (2)

[Claims] Claim 1: A box-hole type and a flat-hole type for rolling a hot slab material with a rectangular cross section into a flat plate material of a predetermined thickness and width, and preliminary bending processing of the flat plate material into an intermediate material with a substantially U-shaped cross section. a breakdown mill consisting of a pair of upper and lower horizontal rolls each having a half-split U-shaped hole with a stepped portion formed at one end; the horizontal roll for finishing the flange end of the intermediate material has a body width changeable and an inner angle at the flange tip; The other horizontal roll is composed of upper and lower horizontal rolls each having a flat surface that presses the outer surface of the web, and a universal mill that has a pair of left and right vertical rolls that press the outer surface of the flange. A hot rolling equipment line for channel steel, which rolls channel steel having constant web height and flange width and varying thickness. 2. The hot-working channel steel according to claim 1, wherein a fixed guide and a movable guide roller whose left and right positions can be adjusted are provided oppositely on the front and rear surfaces or one side of the half-split U-shaped hole of the breakdown mill. Rolling equipment row.