JPH105846A - Method and equipment for cooling hot finish rolled metal strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling method and a cooling equipment capable of eliminating the super-cooling of a width end part of a hot-finish rolled metal strip when the cooling is started, and unifying the cooling completion temperature in the width direction. SOLUTION: The temperature distribution in the width direction in the metal strip 1 which is finish-rolled and travels on a hot run table is measured, water is sprayed toward a center part in the width direction of the metal strip on the farther side from an upper part on each side of the hot run table while the water spraying direction 8A is adjusted based on the result of the measurement, and air is sprayed toward the width end part of a part to which water is sprayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for cooling a hot-finished rolled metal strip.

[0002]

2. Description of the Related Art In order to impart a desired metallurgical property to a metal strip after hot finish rolling, a hot run cooling device is generally provided on a hot run table for transporting the metal strip from a hot finish rolling mill to a winding facility. When passing through the metal strip, the metal strip is wound on a winding facility such as a downcoiler while being controlled and cooled to a predetermined temperature.

FIG. 4 is a conceptual side view of a conventional hot run cooling facility. In FIG. 4, 1 is a metal strip,
2 is a table roller of a hot run table, 3 is a finish rolling mill, 4 is a temperature sensor (width direction thermometer), 5 is a water injection header, and 6 and 8 are arrows indicating the direction of passing material and the direction of water injection, respectively. As a water injection method, a laminar, a spray or the like is employed. The metal strip 1 is often water-cooled by spraying or the like at the same time as the upper surface is cooled.
Here, the lower cooling device is not shown.

Using such equipment, the cooling end temperature can be set as a target by adjusting the water injection amount, the number of water injection banks, etc. according to the sheet thickness, the sheet passing speed, the cooling start temperature (actually measured by the temperature sensor 4), and the like. Control cooling is performed to match the temperature. At this time, the water injection amount is generally distributed in a uniform pattern in the width direction. However, as shown in the temperature distribution diagram in the width direction of the metal strip after finish rolling in FIG. 5, the temperature at the end of the width of the metal strip of about 100 mm is higher than the temperature at the center of the width.
The so-called width edge subcooling, which drops by about 30 to 70 ° C., often occurs. If a metal strip having such a temperature distribution in the width direction is cooled by a conventional hot-run cooling facility before cooling, supercooling of the width end is promoted, and a predetermined metallurgical quality cannot be secured at the width end. Yields are reduced because parts must be truncated.

The following method is known as a measure for preventing such excessive cooling of the width end portion. The width side edge of the metal strip is cooled from the cooling jet to prevent temperature drop at the width end (for example,
No. 62-49125). Edge heater (for example, see JP-A-63-133484)
By using a flame burner (see, for example, Japanese Utility Model Application Laid-Open No. 61-152312), the width end of the metal strip is heated on the entrance side of the finishing mill, and the supercooling on the exit side is controlled. Slit laminar The drift water on the upper surface of the plate to be cooled is flow-restricted with high-pressure water and is allowed to flow out from the end of the width to achieve a uniform temperature distribution in the width direction after cooling (for example, Japanese Patent Application Laid-Open No. 3-230809).
Reference).

[0006]

However, according to the above-mentioned method, even if direct water injection from the water injection header can be cut off,
Since the width end is a place where the drifting water from the width center gathers and flows down, as shown in the width distribution diagram of the water density on the plate in FIG. 6, the water density is larger than the width center, and However, the fact that the width end is supercooled does not change. In the above method, the width end should be 30-70 before finish rolling.
Since heating must be performed at a high temperature, a large amount of energy is required, resulting in an increase in fuel consumption rate and an increase in equipment costs. With the above method, it is not possible to eliminate the width end subcooling that has already occurred on the cooling equipment entrance side.

Therefore, the present invention solves these problems, eliminates the excessive cooling at the width end at the start of cooling of the hot finish-rolled metal strip in the cooling equipment, and makes the cooling end temperature uniform in the width direction. It is an object of the present invention to provide a cooling method and a cooling facility that can be made into a single unit.

[0008]

SUMMARY OF THE INVENTION The present invention measures the temperature distribution in the width direction of a finish-rolled metal strip running on a hot run table, and adjusts the direction of water injection based on the measured results to adjust the temperature of both sides of the hot run table. A method for cooling a hot-finished rolled metal strip, characterized by pouring water from the upper side to the center of the width of the metal strip on the far side.

Further, according to the present invention, the temperature distribution in the width direction of the metal strip which is finished and rolled and travels on the hot run table is measured. A method of cooling a hot-finished rolled metal strip, characterized by injecting water toward a width center portion of a side metal strip and blowing air toward a width end of a portion where water is injected.

The above-mentioned method of the present invention is a cooling system for a hot-finish-rolled metal strip, comprising: a temperature sensor for measuring a temperature distribution in a width direction of the metal strip before the start of cooling; A cooling zone in which a water spray header and an air header having a nozzle that can change the nozzle angle are arranged on both sides of the hot run table,
An electromagnetic valve provided on an air supply path to the air header and opened and closed by a command from a temperature sensor can be smoothly implemented by a cooling facility.

[0011]

FIG. 1 is a schematic view of a water injection pattern on the upper surface of a metal strip. FIGS. 1 (a) and 1 (b) show a method according to the present invention in which only water injection and water injection / air blowing are used, respectively. c) shows the result obtained by the conventional method. In FIG. 1, 1 is a metal strip (hereinafter also referred to as a “plate”), 6
Is the arrow indicating the direction of the timber, 7 is the water injection pattern, 8, 8A
Heretofore, conventionally, arrows indicating the direction of water injection according to the present invention, 9 indicates an air blowing portion, and 10 indicates an arrow indicating the direction of air blowing.

As shown in FIG. 1 (c), all the conventional cooling methods adopt a form in which water is injected vertically downward from above as indicated by an arrow 8. In such a water injection mode, the water injected into the central portion of the plate width is forced to flow down from the end portion of the plate width, so that the end portion of the plate width is supercooled in the cooling zone. On the other hand, in the method of the present invention, as shown by an arrow 8A in FIG. 1A, a mode is adopted in which water is injected from the upper side of both sides of the hot run table to the center of the plate width of the metal strip 1 on the far side, The direction of water injection was adjusted according to the measurement result of the temperature distribution in the sheet width direction after the finish rolling. As a result, as shown in the water density distribution diagram in the width direction on the plate at the time of carrying out the present invention in FIG. In order to reduce the width, overcooling of the width end portion in the cooling zone is alleviated.

Further, in the method of the present invention, water is injected as described above into the metal strip 1 in which the temperature distribution in the width direction on the cooling zone entrance side is in the supercooled state at the width end as shown in FIG. In addition to this, air was blown toward the end of the plate width as shown by the arrow 10. As a result, an air blowing portion 9 is formed at the end of the plate width, which serves as a resistance to the flow of water on the plate, so that escape of the water on the plate from the end of the plate width is further suppressed, and the cooling rate at the end of the plate width is minimized. As a result, it is possible to perform controlled cooling such that the temperature difference between the central portion of the plate width and the end portion of the plate width on the entrance side of the cooling zone is eliminated on the exit side of the cooling zone.

In addition, according to the method of the present invention, since the water injection mode follows the direction in which the plate is fed, the water injection resistance is small, and the state-of-the-art head break, which has conventionally occurred with a relatively thin metal strip, does not occur. Also has the effect. A cooling facility that can smoothly carry out the above-described method of the present invention will be described with reference to examples.

[0015]

FIG. 3 shows an embodiment of the cooling equipment of the present invention.
(A) is a conceptual side view, (b) is a control system diagram in plan view. In FIG. 3, 11 is a water spray header, 12 is an air header, 13 is a water pipe, 14 is an air pipe, 15 is a water nozzle, 16
Is an air nozzle, 17 is a nozzle angle adjuster, 18 is a solenoid valve, 19
Is a command, and the same members as those in FIGS. 4 and 1 are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 3, the cooling system of the present invention has a temperature sensor 4 for measuring the temperature distribution in the width direction of the metal strip 1 before the start of cooling at the entrance side (outside of the hot finishing mill 3). The point of provision is the same as the conventional one, but the cooling zone is composed of a plurality of water spray headers 11 and air headers 12 arranged on both sides of the hot run table, and the water and air headers (11, 12) have a nozzle angle. It comprises a variable water nozzle / air nozzle (15, 16) and, for example, an electric nozzle angle adjuster 17, and receives a command 19 from the temperature sensor 4 by the nozzle angle adjuster 17, and according to the command 19, each nozzle It is designed to change the nozzle angle of (15, 16). further,
The air pipe 14 to the air header 12 is provided with a solenoid valve 18 that opens and closes in response to a command 19 from the temperature sensor 4.

The nozzle angles of the water / air nozzles (15, 16) are set such that the deflection angle from the vertical direction to the passing direction 6 is in the range of 0 ° to 60 °, and the angle can be freely adjusted in the width direction. It was set to be able to. The description of the control system of the water injection amount and the air blowing amount which is not a requirement of the present invention is omitted, but a known control system can be used as it is. In this embodiment, the water injection rate is 2000 to 5000 l / min per bank, and the pressure is 10 to 15 kg.
/ cm ² or so, air blowing amount, at 100 to 300 nm ³ / min, the pressure is 0.5 ～1.5Kg / cm ² approximately.

The operation of the cooling equipment is as follows.
When the temperature sensor 4 detects the tendency of the width end subcooling as shown in FIG.
A command 19 is issued to the nozzle angle adjuster 17 of the above, the nozzle angles of the respective nozzles (15, 16) are set to the form as shown in FIG. 1 (b), and a command 19 is issued to the solenoid valve 18. To open. Thereby, the water density on the plate has a distribution as shown in FIG. 2, and the cooling speed at the width end is minimized, and the temperature distribution in the plate width direction on the outlet side of the cooling equipment becomes uniform. .

If the degree of subcooling at the width end is small, the temperature sensor 4 sends a command 19 to the nozzle angle adjuster 17 of the water spray header 11, and as shown in FIG. The water nozzle angle is changed so that the water injection pattern is slightly shifted toward the width end, and a command 19 for closing the solenoid valve 18 is issued to stop blowing air to the width end. As described above, since the water nozzle 15 is directed toward the center of the plate width, the amount of water flowing out from the width end of the plate water is significantly suppressed even when the air blowing is stopped, compared to the conventional cooling. As a result, the cooling history substantially equal to the width end portion and the width central portion of the metal strip 1 can be traced, and the temperature distribution in the plate width direction on the cooling equipment outlet side becomes uniform.

As described above, by using the cooling equipment of the present invention,
The cooling method of the present invention can be performed smoothly.

[0021]

According to the present invention, the super-cooling of the width end portion of the hot-finished rolled metal strip at the start of cooling can be eliminated in the cooling equipment, and the cooling end temperature can be made uniform in the width direction. The yield is improved, and a remarkable effect is achieved that the cutting edge of the state of the art, which has been occasionally generated with a relatively thin metal strip, does not occur.

[Brief description of the drawings]

FIGS. 1A and 1B are schematic diagrams of a water injection pattern on the upper surface of a metal strip, wherein FIGS. 1A and 1B respectively show water injection only, and water injection and air spraying according to the method of the present invention, and FIG. Is shown.

FIG. 2 is a diagram illustrating a water density distribution in a width direction on a plate when the present invention is implemented.

3 shows an embodiment of the cooling equipment of the present invention, (a) is a conceptual side view, and (b) is a control system diagram in plan view.

FIG. 4 is a conceptual side view of a conventional hot run cooling facility.

FIG. 5 is a temperature distribution diagram in the width direction of the metal strip after finish rolling.

FIG. 6 is a widthwise distribution diagram of a water density on a plate in conventional hot run cooling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal strip (plate) 2 Table roller 3 Finish rolling mill 4 Temperature sensor (widthwise thermometer) 5 Water injection header 6 Arrow indicating the direction of passing material 7 Water injection pattern 8 Arrow indicating the direction of conventional water injection 8A Water injection of the present invention Arrow indicating the direction of air 9 Air blowing section 10 Arrow indicating the direction of air blowing 11 Water spray header 12 Air header 13 Water piping 14 Air piping 15 Water nozzle 16 Air nozzle 17 Nozzle angle adjuster 18 Solenoid valve 19 Command

Claims (3)

[Claims] 1. A method of measuring a temperature distribution in a width direction of a metal strip which is finished and rolled and travels on a hot run table. A method for cooling a hot-finished rolled metal strip, characterized by pouring water toward a center of the width of the strip. 2. A metal strip, which is finished and rolled and travels on a hot run table, is measured in a width direction, and the direction of water injection is adjusted on the basis of the measurement result. A method for cooling a hot-finish-rolled metal strip, characterized by injecting water toward a center of the width of the strip and blowing air toward an end of the width of the area where water is injected. 3. A cooling system for hot-finished rolled metal strip, comprising: a temperature sensor for measuring a temperature distribution in a width direction of the metal strip before the start of cooling; and a nozzle angle changing in accordance with a command from the temperature sensor. A cooling zone in which a water spray header having a nozzle to be obtained and an air header are arranged on both sides of the hot run table, and a solenoid valve provided on an air supply path to the air header and opened / closed by a temperature sensor command. Cooling equipment for hot finished rolled metal strip.