KR20230030972A - Cooling system and method of steel - Google Patents

Abstract

The present invention relates to a system and a method for uniform cooling of steel, which can uniformly rapidly cool steel materials by controlling the passing speed of reheated steel materials through a quencher in an off-line thick plate process. The system for uniform cooling of steel may comprise: a variable speed feeder capable of transferring a steel material at variable speed; a quencher for quenching the steel material being transferred by the variable speed feeder by spraying a coolant on the steel material; and a feed rate control unit for applying a speed control signal to the variable speed feeder so as to control the speed at which the steel material passes through the quencher to prevent supercooling of the front end and the tail end of the steel material compared to the middle part of the steel material.

Description

Uniform cooling system and method of steel materials {Cooling system and method of steel}

The present invention relates to a system and method for uniform cooling of steel materials, and more particularly, to a system and method for uniform cooling of steel materials, which enables uniform rapid cooling of steel materials by controlling the passing speed of steel materials reheated in an off-line thick plate process through a quencher. it's about

Recently, cooling control technology is required to improve weldability and low-temperature toughness through low carbon equivalent due to the thickening of steel materials, and flatness securing technology through uniform cooling control is required due to the market demand for high-strength ultra-thin heat-treated steel. there is.

Conventional general cooling facilities for steel products that simply cool steel products that are usually formed long in the longitudinal direction, for example, spray a lot of cooling water to the front and tail portions of a steel product that is transported at constant speed, and spray a small amount of cooling water to the middle portion. A method of controlling the flow rate of cooling water, such as by performing a cooling process, or a method of controlling masking, such as masking a specific part, was used.

However, since the quencher facility is a facility for rapidly cooling by supplying a large amount of cooling water at room temperature to obtain a high-strength, high-toughness structure, it is difficult to rapidly reduce the cooling rate with the conventional cooling water flow rate control method or masking method. There was a limit to the uniform cooling of the steel, and due to this, there were problems in that the front and tail ends of the steel after quenching were not uniformly cooled, such as relatively overcooling or the middle of the steel.

Korean Patent Application No. 10-2003-0026260

The present invention is to solve various problems, including the above problems, by controlling the speed of passing the quencher of the reheated steel material in the offline thick plate process, the steel material can be rapidly cooled uniformly, and thereby the steel material has a uniform tissue distribution It is possible to prevent overcooling of the front and tail ends and overheating of the middle part of the steel while guaranteeing the cooling rate so that it can be stored. , Additional equipment cost and time can be saved, and the temperature curve of the steel can be flattened even under various cooling conditions by precisely compensating the transfer speed according to the position of the steel, and the temperature flatness for high-strength ultra-thin materials can be achieved. It is an object to provide a system and method for uniform cooling of steel materials that can significantly improve product quality. However, these tasks are illustrative, and the scope of the present invention is not limited thereby.

A uniform cooling system for steel materials according to the spirit of the present invention for solving the above problems includes: a variable speed conveying device capable of speed-transferring steel materials; A quencher for quenching by spraying a coolant on the steel material transported by the variable speed feeder; and a feed rate control unit for applying a speed control signal to the variable speed feed device so as to control the speed at which the steel material passes through the quencher to prevent supercooling of the front end and the tail end of the steel material compared to the middle part of the steel material. can

In addition, according to the present invention, the feed rate controller applies a first high-speed movement control signal to the variable speed feed device so that the tip of the steel material is moved at a high speed at a first speed to reduce the time to pass through the quencher a primary high-speed movement controller; a tertiary low-speed movement controller for applying a tertiary low-speed movement control signal to the variable-speed feeder so that the middle portion of the steel material is moved at a second speed lower than the first speed to increase a time passing through the quencher; and a 5th high-speed movement control unit for applying a 5th high-speed movement control signal to the variable speed feeder so that the tail end of the steel material is moved at a third speed faster than the second speed to reduce the time required to pass through the quencher. can include

In addition, according to the present invention, the feed rate control unit, a secondary deceleration control unit for applying a secondary deceleration control signal to the variable speed feed device so that the steel material can be decelerated from the first speed to the second speed; and a fourth acceleration control unit for applying a fourth acceleration control signal to the variable speed feeder so that the steel material can be accelerated from the second speed to the third speed.

In addition, according to the present invention, the steel material detection sensor for detecting the position or conveying speed of the front end or the tail end of the steel material, and applying the sensed detection signal to the conveying speed control unit; may further include.

In addition, according to the present invention, the speed change conveying device, a plurality of conveying rollers; and a roller driving device that entirely or individually rotates the conveying rollers using a variable-speed drive motor or a variable-speed power transmission device.

In addition, according to the present invention, the quencher may include a water box nozzle installed above and below the variable speed feeder and spraying cooling water vertically or inclined toward the steel member.

In addition, according to the present invention, a constant speed feed device installed in front of the variable speed feed device and capable of conveying the steel material transported off-line after rolling at a constant speed to the variable speed feed device or stopping and waiting; and a reheating furnace for reheating the steel material transported by the constant speed feed device so as to reheat the steel material before quenching the steel material.

In addition, according to the present invention, the standby control unit for applying a standby signal to the constant speed feeder so that the steel material can be waited before transferring the steel material to the variable speed feeder; may further include.

On the other hand, the uniform cooling method of the steel material according to the spirit of the present invention for solving the above problems, (a) transferring the steel material so that the tip of the steel material is moved at a high speed at a first speed to reduce the time to pass through the quencher Applying a first high-speed movement control signal to the variable speed feeder; (c) applying a third low-speed movement control signal to the variable-speed feeder so that the middle portion of the steel material is moved at a second speed lower than the first speed to increase a time for passing the quencher; and (e) applying a fifth high-speed movement control signal to the variable speed feeder so that the tail end of the steel is moved at a third speed faster than the second speed to reduce the time required to pass through the quencher. can include

In addition, according to the present invention, after the step (a), (b) applying a secondary deceleration control signal to the variable speed feeder so that the steel material can be decelerated from the first speed to the second speed; And after the step (c), (d) applying a fourth acceleration control signal to the variable speed feeder so that the steel material can be accelerated from the second speed to the third speed; may further include .

According to some embodiments of the present invention made as described above, by controlling the speed of passing the quencher of the reheated steel material in the off-line thick plate process, the steel material can be rapidly cooled uniformly, thereby enabling the steel material to have a uniform tissue distribution While guaranteeing the cooling speed, it is possible to prevent overcooling of the front and tail ends of the steel and overheating of the middle part, and it is possible to simplify the equipment because it can be applied by simply changing the transfer device to a speed change method in the existing equipment, and at the same time, additional equipment Cost and time can be reduced, and the temperature curve of the steel can be flattened even under various cooling conditions by precisely compensating the transfer speed according to the position of the steel, and the temperature flatness for high-strength ultra-thin materials can be achieved to achieve product quality. has the effect of greatly improving Of course, the scope of the present invention is not limited by these effects.

1 is a conceptual diagram showing a uniform cooling system for steel materials according to some embodiments of the present invention.
2 is a graph showing the temperature before cooling of steel materials of the uniform cooling system for steel materials of FIG.
Figure 3 is a block diagram showing a feed rate control unit of the uniform cooling system for steel materials of Figure 1;
Figure 4 is a graph showing the process of controlling the feed rate of the uniform cooling system for steel of Figure 1 over time.
5 is a graph showing the temperature after cooling of the steel material of the uniform cooling system for steel materials of FIG.
6 is a flowchart illustrating a method for uniformly cooling steel materials according to some embodiments of the present invention.
7 is a flowchart illustrating a method for uniformly cooling steel materials according to some other embodiments of the present invention.

Hereinafter, several preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the invention to those skilled in the art. In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity of explanation.

Hereinafter, embodiments of the present invention will be described with reference to drawings schematically showing ideal embodiments of the present invention. In the drawings, variations of the depicted shape may be expected, depending on, for example, manufacturing techniques and/or tolerances. Therefore, embodiments of the inventive concept should not be construed as being limited to the specific shape of the region shown in this specification, but should include, for example, a change in shape caused by manufacturing.

1 is a conceptual diagram showing a uniform cooling system 100 for steel according to some embodiments of the present invention.

First, as shown in FIG. 1, the uniform cooling system 100 for steel materials according to some embodiments of the present invention largely includes a variable speed feeder 10, a quencher 20, and a feed rate controller 30. can include

For example, as shown in FIG. 1, the speed change feed device 10 is a device capable of speed-changeably transferring the steel material 1 at a high speed or a low speed, and the speed change feed device 10 , A plurality of conveying rollers 11 respectively installed below and above the steel material 1 so that the lower and upper surfaces of the steel material 1 are supported along the conveying path of the steel material 1, respectively, and a drive motor capable of speed change Alternatively, a roller driving device 12 that rotates the conveying rollers 11 as a whole or individually using various power transmission devices such as a variable speed gear combination, a chain and sprocket wheel combination, a belt and pulley combination, and a pulley and wire combination, etc. can include

Here, the variable speed conveying device 10 is not necessarily limited to the drawing, and is, for example, installed only below the steel material 1, installed on the side of the steel material 1, or other conveyors that are not necessarily roller-type. Variety of shiftable conveying devices, such as a method, can all be applied.

In addition, for example, as shown in FIG. 1, the quencher 20 is a device for quenching by spraying a coolant C to the steel 1 transported by the variable speed feed device 10, and more specifically For example, the quencher 20 is installed above and below the variable speed feed device 10 for rapid cooling of the steel material 1, respectively, and directs the cooling water vertically or inclined toward the steel material 1 A spraying water box nozzle 21 may be applied.

Here, it is preferable that the spray amount of the cooling water sprayed from the water box nozzle 21 is installed such that a constant spray flow rate can be maintained while the steel material 1 passes through the quencher 20 .

However, the water box nozzle 21 is not necessarily limited thereto, and it may be applied that the spray flow rate of the cooling water is adjusted. For example, in the front end 1a and the tail end 1c of the steel member 1, It is also possible to reduce the spraying flow rate to prevent overcooling or to increase the spraying flow rate to prevent overheating in the middle portion 1b of the steel material 1.

FIG. 2 is a graph showing the temperature before cooling of steel materials of the uniform steel cooling system 100 of FIG. 1 .

Therefore, as shown in FIG. 2, the steel material 1 of the steel uniform cooling system 100 of the present invention has the front end part 1a, the middle part 1b and the tail end part 1c in the longitudinal direction. ) is formed, and the state before passing through the quencher 20, that is, the state before cooling of the steel material, as shown in the temperature distribution graph, the temperature of the middle portion 1b of the steel material 1 is relatively uniform However, it can be confirmed that the front end 1a and the middle part 1b of the steel 1 are easily cooled even if they are reheated due to the characteristics of the ends, and the temperature is lowered.

Figure 3 is a block diagram showing the transfer rate control unit 30 of the uniform cooling system 100 for steel materials of Figure 1, Figure 4 is a transfer rate control process of the uniform cooling system 100 for steel materials of Figure 1 over time It is a graph that represents

On the other hand, for example, as shown in FIGS. 1 and 3, the feed rate control unit 30 controls the speed at which the steel material 1 passes through the quencher 20 so that the intermediate portion of the steel material 1 (1b) A microprocessor capable of applying a speed control signal to the variable speed feeder 10 to prevent supercooling of the front end 1a and the tail end 1c of the steel material 1, a semiconductor integrated circuit, Semiconductor chip, arithmetic unit, central processing unit, control circuit, control panel, control panel, electronic control parts, computer, laptop computer, laptop computer, server computer, communication device, mobile phone, smart phone, smart pad, smart device, stored program Various control devices such as a storage device may be applied.

More specifically, for example, as shown in FIGS. 1 to 4, the feed rate control unit 30 moves the front end 1a of the steel material 1 at a high speed at a first speed V1 so that the quencher A primary high-speed movement control unit 31 for applying a primary high-speed movement control signal to the variable speed feeder 10 so as to reduce the time passing through (20), and the steel material 1 has the first speed ( A secondary deceleration control unit 32 for applying a secondary deceleration control signal to the variable speed feed device 10 so that it can be decelerated from V1) to the second speed V2, and the intermediate portion 1b of the steel member 1 ) is moved at a low speed at a second speed V2 that is slower than the first speed V1 to increase the time to pass through the quencher 20. The tertiary low-speed movement controller 33 and the 4th acceleration control to the variable speed feeder 10 so that the steel material 1 can be accelerated from the 2nd speed V2 to the 3rd speed V3 The 4th acceleration controller 34 for applying a signal and the tail end 1c of the steel 1 are moved at a high speed at a third speed V3 faster than the second speed V2 to pass through the quencher 20 A 5th high-speed movement control unit 35 for applying a 5th high-speed movement control signal to the variable speed feeder 10 may be included to reduce the time required to perform the movement.

Therefore, as shown in FIG. 4, by using the feed rate control unit 30, the front end 1a of the steel material 1 is moved at a high speed at a first speed V1, and the steel material 1 is moved at the first speed V1. It is decelerated from the first speed (V1) to the second speed (V2), and the middle part (1b) of the steel material (1) is moved at a low speed at a second speed (V2) slower than the first speed (V1), The steel material 1 is accelerated from the second speed V2 to the third speed V3, and the tail end 1c of the steel material 1 is faster than the second speed V2 at a third speed ( A series of processes moving at high speed to V3) can be performed.

On the other hand, as shown in FIG. 1, the uniform cooling system 100 of the steel material of the present invention detects the position or conveying speed of the tip part 1a or the tail end part 1c of the steel material 1, and , It may further include a steel detection sensor 40 for applying the sensed detection signal to the transfer speed control unit 30.

Therefore, the conveying speed control unit 30 can accurately determine the position or conveying speed of the steel material 1 using the steel material detection sensor 40, and accordingly, the speed change conveying device 10 has an accurate time. By applying a compensation signal or an accurate distance compensation signal, etc., it is possible to control the conveying speed of the steel material 1 more precisely.

On the other hand, as shown in Figure 1, the uniform cooling system 100 of the steel material of the present invention is installed in front of the variable speed feed device 10, and the steel material 1 transported offline after rolling A constant speed feeder 50 capable of being transferred to the variable speed feeder 10 at a constant speed or stopped and standby may be further included.

More specifically, for example, the constant speed conveying device 50 uses a plurality of conveying rollers 51 and a drive motor capable of constant speed driving or a power transmission device capable of constant speed driving, etc. to move the conveying rollers 51 as a whole. Alternatively, it may include a roller driving device 52 that rotates individually.

In addition, for example, as shown in FIG. 1, the uniform cooling system 100 of the steel material of the present invention, the constant speed feed device to reheat the steel material 1 before quenching the steel material 1 The reheating furnace 60 for reheating the steel material 1 conveyed by the heating device 61 and the steel material 1 before transferring the steel material 1 to the variable speed conveying device 10 It may further include a standby control unit 70 for applying a standby signal to the constant speed transfer device 50 to standby.

Therefore, as shown in FIG. 1, before being rapidly cooled by the quencher 20, the steel material 1 is cooled off-line at a constant speed by the constant speed feeder 50 using the reheating furnace 60. As it can be reheated while being moved, the steel material 1 reheated in this way can be handed over to the variable speed conveying device 10 after waiting by the standby control unit 70 to control the conveying speed.

5 is a graph showing the temperature after cooling of the steel material of the uniform steel cooling system 100 of FIG.

Therefore, as shown in FIG. 5, the front end 1a and the tail end 1c of the steel material 1 quickly pass through the quencher 20 while the front end part 1a of the steel material 1 and the tail end 1c can prevent overcooling, and the middle part 1b of the steel material 1 passes through the quencher 20 slowly while the middle part 1b of the steel material 1 ) By preventing the overheating phenomenon, as shown in the temperature graph after cooling of the steel material 1 of FIG. 5, it is possible to uniformly cool the steel material 1 as a whole.

Therefore, in the off-line thick plate process, the steel material 1 can be rapidly cooled uniformly by controlling the quencher passing speed of the steel material 1 reheated by the reheating furnace 60, and thereby the steel material 1 It is possible to prevent overcooling of the front end (1a) and the tail end (1c) of the steel material (1) and overheating of the middle part (1b) while ensuring the cooling rate so as to have a uniform tissue distribution, and the transfer device in the existing facility Since it can be applied by simply changing it to a variable speed method, it is possible to simplify the facility, save additional equipment costs and time, and accurately compensate for the conveying speed according to the position of the steel (1) for various cooling conditions. Also, the temperature curve of the steel material 1 can be flattened, and the quality of the product can be greatly improved by achieving temperature flatness for the high-strength ultra-thin material.

6 is a flowchart illustrating a method for uniformly cooling steel materials according to some embodiments of the present invention.

As shown in FIGS. 1 to 6, a method for uniformly cooling a steel material according to some embodiments of the present invention, (a) the front end 1a of the steel material 1 is moved at a high speed at a first speed V1 Applying a first high-speed movement control signal to the variable speed feeder 10 that transfers the steel material 1 to reduce the time to pass through the quencher 20, (b) the steel material 1 Applying a secondary deceleration control signal to the speed change feed device 10 so that it can be decelerated from the first speed V1 to the second speed V2, (c) the middle portion of the steel member 1 ( 1b) is moved at a low speed at a second speed (V2) slower than the first speed (V1) to increase the time to pass through the quencher (20) A third low-speed movement control signal to the variable speed feeder (10) and (d) applying a fourth acceleration control signal to the variable speed feeder 10 so that the steel material 1 can be accelerated from the second speed V2 to the third speed V3. and (e) the tail end 1c of the steel 1 is moved at a high speed at a third speed V3 faster than the second speed V2 to reduce the time to pass through the quencher 20 and applying a fifth high-speed movement control signal to the variable speed feeder 10 so as to be

7 is a flowchart illustrating a method for uniformly cooling steel materials according to some other embodiments of the present invention.

As shown in FIGS. 1 to 7, a method for uniformly cooling steel materials according to some other embodiments of the present invention first receives quenching recipe information such as the amount of water or plate speed for each header (S1), and the reheating ( 60), that is, at least about 2 minutes before the steel material 1 (or plate) is extracted from the heat treatment furnace, the water supply of the quencher 20 may be started (S2).

Then, by using the steel material detection sensor 40, etc., it is determined whether it is the pouring start time of the tip part 1a of the steel material 1 (S3), if it is the pouring start time of the tip part 1a, the The feed speed of the steel material 1 can be reduced in consideration of the compensation distance of the tip portion 1a, that is, the plate speed when pouring water of the tip portion 1a (S5). Otherwise, the tip portion 1a The steel material 1 may be fed at a constant speed at a feed rate before pouring until the pouring start point is reached (S4).

Then, while maintaining the reduced plate speed during pouring in the middle part 1b of the steel material 1 (S6), if the tail end part 1c of the steel material 1 ends at the end of pouring, the tail end ( When the compensation distance of 1c) is subtracted, that is, when the tail end 1a starts (S7), the compensation distance of the tail end 1c, that is, the plate speed at the time of injection of the tail end 1c is considered By doing so, it is possible to accelerate the conveying speed of the steel material 1 (S8). Then, it is possible to maintain the plate speed after pouring for the next steel material (1) (S9).

Therefore, rapid cooling is possible for uniform tissue distribution during quenching, and at the same time, the front end (1a), the middle part (1b), and the tail end ( While transferring 1c) at a differential speed, the steel material 1 can be uniformly cooled as a whole.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

1: Steel
1a: distal end
1b: middle part
1c: Tail end
10: variable speed feeder
11: conveying roller
12: roller driving device
C: coolant
20: Quencher
21: water box nozzle
30: feed rate control
V1: first speed
V2: 2nd speed
V3: 3rd speed
31: primary high-speed movement control unit
32: 2nd deceleration control unit
33: 3rd low speed movement control unit
34: 4th acceleration control unit
35: 5th high-speed movement controller
40: steel detection sensor
50: constant speed feeder
51: conveying roller
52: roller driving device
60: reheat furnace
61: heating device
70: atmospheric control
100: uniform cooling system for steel

Claims (10)

A variable speed transfer device capable of speed-transferring steel materials;
A quencher for quenching by spraying a coolant on the steel material transported by the variable speed feeder; and
a feed rate controller for controlling a speed at which the steel material passes through the quencher and applying a speed control signal to the variable speed feed device to prevent supercooling of the front end and the tail end of the steel material compared to the middle part of the steel material;
Including, a uniform cooling system for steel. According to claim 1,
The feed rate control unit,
a first high-speed movement control unit for applying a first high-speed movement control signal to the variable speed feed device so that the tip of the steel material is moved at a first speed and the time required to pass through the quencher is reduced;
a tertiary low-speed movement controller for applying a tertiary low-speed movement control signal to the variable-speed feeder so that the middle portion of the steel material is moved at a second speed lower than the first speed to increase a time passing through the quencher; and
a 5th high-speed movement control unit for applying a 5th high-speed movement control signal to the variable speed feeder so that the tail end of the steel member is moved at a third speed faster than the second velocity to reduce the time required to pass through the quencher;
Including, a uniform cooling system for steel. According to claim 2,
The feed rate control unit,
a secondary deceleration controller for applying a secondary deceleration control signal to the speed change feed device so that the steel material can be decelerated from the first speed to the second speed; and
a fourth acceleration controller for applying a fourth acceleration control signal to the variable speed feeder so that the steel can be accelerated from the second speed to the third speed;
Including, a uniform cooling system for steel. According to claim 1,
a steel material detection sensor for detecting the position or conveying speed of the front end or the tail end of the steel, and applying the sensed detection signal to the conveying speed control unit;
Further comprising a uniform cooling system for steel. According to claim 1,
The variable speed feeder,
a plurality of conveying rollers; and
a roller driving device that rotates the conveying rollers as a whole or individually using a variable-speed drive motor or a variable-speed power transmission device;
Including, a uniform cooling system for steel. According to claim 1,
The quencher,
water box nozzles installed above and below the variable speed feeder, respectively, and spraying cooling water vertically or inclined toward the steel member;
Including, a uniform cooling system for steel. According to claim 1,
a constant speed feeder installed in front of the variable speed feeder and capable of transporting the steel material transported off-line after rolling to the variable speed feeder at a constant speed or stopping and waiting; and
a reheating furnace for reheating the steel material transported by the constant speed feed device so as to reheat the steel material before quenching the steel material;
Including, a uniform cooling system for steel. According to claim 7,
a standby control unit for applying a standby signal to the constant speed feeder so that the steel material can be standby before transferring the steel material to the variable speed feeder;
Further comprising a uniform cooling system for steel. (a) applying a first high-speed movement control signal to a variable speed feeder that transfers the steel material so that the front end of the steel material is moved at a first speed and the time required to pass through the quencher is reduced;
(c) applying a third low-speed movement control signal to the variable-speed feeder so that the middle portion of the steel material is moved at a second speed lower than the first speed to increase a time for passing the quencher; and
(e) applying a fifth high-speed movement control signal to the variable speed feeder so that the tail end of the steel member is moved at a third speed faster than the second speed to reduce the time required to pass through the quencher;
Including, uniform cooling method of steel. According to claim 9,
After step (a),
(b) applying a secondary deceleration control signal to the variable speed feeder so that the steel material can be decelerated from the first speed to the second speed; and
After step (c),
(d) applying a fourth acceleration control signal to the variable speed feeder so that the steel can be accelerated from the second speed to the third speed;
Including, uniform cooling method of steel.

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