JPH10235407A - Manufacture of t-steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a T-steel whose bends and deformation are minimized and which is excellent in the stability of manufacture by cooling the outside of flange while transporting T-steels on a roller table overlapping the webs vertically after obtaining two T-steels by executing finish rolling of a wide- flange shape steel or an I-steel with a universal mill and simultaneously cutting its web in the longitudinal direction. SOLUTION: After the wide flange shape is cut into T-steels 4a, 4b with a hot saw which is provided on the downstream side of the universal mill group, immediately those T-steels are transported on the roller table 5 while making the position of the H-shaped hold by supporting them in a state where the webs 22 are vertically overlapped with a jig 6 on the roller table 5. During transporting, cooling water is jetted from spray nozzles 7 on the outsides of the flanges 21. In such a case, by adjustion the flow rate of each spray nozzle 7 and intermittently thinning, flange cooling is controlled.

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 a T-section by cutting a web thereof from a hot-rolled H-section or an I-section by a universal mill.

[0002]

2. Description of the Related Art As a method for producing a T-section steel, for example, JP-A-58-135704 and JP-A-64-1
No. 5,203,503 discloses a method of finishing and rolling an H-beam or an I-beam by a universal mill while simultaneously cutting the H-beam or the I-beam in a longitudinal direction. It is intended to obtain a two-section T-shaped steel and aims to improve productivity.

However, in this manufacturing method, the hot T
When cooling the section steel, the web thickness of the T section steel is very thin compared to the flange thickness, so when cooling after cutting the web, the web buckles and bends, and A permanent deformation called a web wave occurred. As a method of preventing this, a method of water-cooling the outer surface of the flange has conventionally been used in the production of an H-section steel, particularly in the production of an H-section steel having a small web thickness. Therefore, as a method of manufacturing a T-beam without distortion, a method of cutting the web in the longitudinal direction after cooling the flange with the H-beam can be considered. However, the stress generated when the H-beam is cooled remains. Since it remains as a stress, when the H-section steel is cut cold after cooling, there is a problem that the web is cracked or deformed. On the other hand, in the method of hot-cutting the H-section steel into two strips immediately after rolling and cooling the outer surface of the flange, the flange restrains the deformation of the web in the state of the H-section steel. Since the restraining force of the flange is reduced by half, even if the flange in the middle of cooling is strongly cooled, the flange around the web is likely to be warped or twisted, and the production stability is very poor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method for producing a T-section steel having a small bending and deformation and excellent production stability. Is an issue.

[0005]

SUMMARY OF THE INVENTION A method of manufacturing a T-section steel according to the present invention is to finish-roll an H-section steel or an I-section steel by a universal mill and cut the web in the longitudinal direction at the same time. After the steel is obtained, the outer surfaces of the flanges are cooled while the webs are stacked one on top of the other and conveyed on a roller table.

[0006] In the present invention, H
First, the amount of heat radiation from the web is reduced by transporting the T-section steel, which has been cut into two sections from the shape steel, on a roller table with the webs stacked one on top of the other. Further, by bringing the high-temperature flange closer, heat radiation from the web is suppressed and reduced by radiant heat transfer from the high-temperature flange. These effects reduce the temperature drop of the web. In addition, by cooling the flange from the outside, the temperature difference between the flange and the web can be further reduced. Due to the above effects, the temperature difference between the web and the flange during cooling is not widened, and the occurrence of bending and web waves is small without generating large stress.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view showing a method for manufacturing a T-section steel according to the present invention. In FIG. 1, reference numeral 1 denotes a finishing universal mill group for finish-rolling an H-section steel 2 or an I-section steel, and includes a universal mill 11 and an edger mill 12. Reference numeral 3 denotes a hot saw provided downstream of the finishing universal mill group 1, which cuts the web 22 in the longitudinal direction at the same time as finishing rolling of the H-beam or I-beam. By this cutting, 2
The strip T-shaped steel members 4a and 4b are obtained.

FIG. 2 is a front view of a transport device for the cut T-section steel and a cooling device for cooling the flange thereof, and FIG. 3 is a side view thereof. 2 and 3, reference numeral 5 denotes a roller table, and reference numeral 6 denotes a jig for horizontally supporting the webs 22 of the T-section steels 4a and 4b in a state of being vertically overlapped. The jig 6 has two vertical plates 62 erected on a horizontal plate 61 as shown in FIG. 4. The jig 6 is placed on the roller table 5, and at the upper end of the vertical plate 62 of the jig 6, Horizontal T-section steel 4
The web 22 superimposed on the top and bottom of a and 4b is horizontally supported. Reference numeral 7 denotes a spray nozzle which sprays cooling water from the lateral direction onto the outer surface of the flanges 21 of the T-shaped steel members 4a and 4b to cool the nozzles, and is arranged at a predetermined pitch in the line direction.

Immediately after being cut into the T-shaped steel members 4a and 4b as described above, the T-shaped steel members are transferred to the web 22 by the jig 6 mounted on the roller table 5 as shown in FIGS.
Are transported on the roller table 5 while maintaining the H-shape posture by supporting them in a state where they are vertically overlapped.
During this conveyance, the spray nozzle 7 moves the flange 2
The cooling water is sprayed onto the outer surface of 1 to cool it. In this case, the flow rate of each spray nozzle 7 is adjusted, and if necessary, the spray nozzles 7 are intermittently thinned to control flange cooling. Thus, the T-section steels 4a, 4b
The cooling water is sprayed from the spray nozzle 7 on the outer surface of the flange 21 to cool the web while the roller 22 is conveyed on the roller table 5 with the webs 22 stacked one above the other.

FIG. 5 is a front view showing another method of supporting a T-section steel web, in which a web supporting roll is provided in place of the jig 6 described above. This web support roll 8
Is provided between the rollers of the roller table 5 so that the height can be adjusted. Web 2 of each T-section steel 4a, 4b
Although the space between the two surfaces is slightly open as shown in FIG. 5, the effect of reducing the amount of heat radiation from the web 22 is the same as in the example of FIG.

[0011]

Embodiments of the present invention will be described below. First, using the apparatus shown in FIG.
The H-section steel 2 was rolled while performing reverse rolling. The dimensions of each part of the rolled H-beam 2 at the end of rolling have a width of 800
mm, height 200 mm, flange thickness 22 mm, web thickness 13 mm, and pressure extension 50 m. This H-beam 2
The center of the web 22 was immediately cut in the longitudinal direction by the hot saw 3.

The T-section steel 4 thus cut into two sections
Immediately after the cutting, the webs 22 are transported on the roller table 5 while supporting the webs 22 in a state of being vertically stacked using the jig 6 as shown in FIGS. Was cooled by spraying cooling water from the spray nozzle 7 on the outer surface of the sample. This cooling device is a water cooling device having a length of 60 m, in which commercially available spray nozzles are continuously arranged. Spray nozzles 7 are arranged at a pitch of 200 mm, and the flow rate of each nozzle is adjusted and the nozzles are thinned out intermittently. This makes it possible to control the cooling. And
In this embodiment, the cooling condition of the outer surface of the flange is 400 mm.
30 liters / each from spray nozzle 7 of pitch
The outer surface of the flange was cooled by injecting cooling water for min. After passing through the cooling device, the T-shaped steel was further conveyed to a cooling floor, allowed to cool naturally on the cooling floor, and cooled at room temperature. As a result, no significant deformation, bending, or twisting occurred in the web and flange of the T-section steel. As described above, in the present invention, the outer surface of the flange is cooled after laminating the web of the T-section steel, so that the outer surface of the flange is cooled while suppressing heat radiation from the web. The difference can be reduced, and the deformation, bending, and the like can be suppressed to a very small value without generating a large stress.

(Comparative Example) In the comparative example, the H-shaped steel 2 was rolled while performing reverse rolling by the finishing universal mill group 1 using the same manufacturing apparatus as in FIG. The dimensions of each part of the H-section steel at the end of rolling are the same as those of the embodiment, and the width is 800
mm, height 200 mm, flange thickness 22 mm, web thickness 13 mm, and pressure extension 50 m. This H-shaped steel was immediately cut in the longitudinal direction at the center of the web with a hot saw 3. After cutting, the two T-bars were allowed to cool naturally by allowing them to stand apart from each other with the web facing down and the flange up. As a result, in this comparative example, a bend of 50 mm per 10 m occurred in the flange with the web side being convex. The reason for such a large bending is that the web cools faster because the web thickness is very thin compared to the flange thickness, and the flange cools later, resulting in a large temperature difference and thus a stress difference between the web and the flange. Is caused. For this reason, shape correction had to be performed later by a straightening machine.

[0014]

As is clear from the above description, according to the present invention, the following effects can be obtained. (1) After the H-section steel or I-section steel is finish-rolled and the web is cut in the longitudinal direction to form a T-section steel, the T-section steel webs are immediately superimposed on each other and transported on a roller table. While cooling the flange outer surface, there is no generation of web waves or bending after cooling, and since there is no need for a refining process such as straightening, it is possible to produce a T-shaped steel with high yield and high efficiency. . (2) A T-section steel can be efficiently manufactured using the current H-section steel production line as it is.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a production line for a T-section steel according to the present invention.

FIG. 2 is a front view of a T-shaped steel conveying device and a flange cooling device.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a perspective view of a jig for supporting a T-section steel web.

FIG. 5 is a front view showing another method of supporting the web of the T-section steel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Finish universal mill group 2 H section steel 3 Hot saw 4a, 4b T section steel 5 Roller table 6 Jig 7 Spray nozzle 8 Web support roll 11 Universal mill 12 Edger mill 21 Flange 22 Web

Claims (1)

[Claims] An H-shaped steel or an I-shaped steel is finish-rolled by a universal mill, and at the same time, the web is cut in the longitudinal direction to obtain two T-shaped steels. A method for manufacturing a T-section steel, wherein the outer surface of a flange is cooled while being transported on a table.