WO2007026906A1

WO2007026906A1 - Cooling facility and cooling method of steel plate

Info

Publication number: WO2007026906A1
Application number: PCT/JP2006/317395
Authority: WO
Inventors: Naoki Nakata; Takashi Kuroki; Akio Fujibayashi; Shogo Tomita; Masayuki Horie; Shunichi Nishida; Naoto Hirata; Michio Sato; Kyohei Ishida
Original assignee: Jfe Steel Corporation
Priority date: 2005-08-30
Filing date: 2006-08-29
Publication date: 2007-03-08
Also published as: EP1935522A4; KR100973691B1; CN101253009A; KR20080034965A; EP1935522B1; CN101253009B; EP1935522A1

Abstract

Cooling facility and method of a steel plate for cooling the steel plate properly on a hot rolling line by a compact structure when controlled rolling of the steel plate is performed. The cooling facility of a steel plate, which is a cooling facility for supplying cooling water to the upper and lower surfaces of the steel plate (10) while passing the steel plate (10) when it is hot rolled, has nozzles (22a, 22b) for supplying cooling water obliquely toward the upper surface of the steel plate (10) from above, wherein the nozzles (22a, 22b) are arranged such that ejections of cooling water on the steel plate (10) oppose each other in the carrying direction of the steel plate (10). More concretely, it is a passing type cooling facility (20) having a large water volume density of 4 m3/m2min or above.

Description

Specification

Steel sheet cooling equipment and method

The present invention relates to a steel plate cooling equipment and a cooling method. Background art

In recent years, in the hot rolling of steel sheets, the production of steel sheets with excellent strength and toughness has been demanded. As an example, by applying controlled rolling (CR) to the rolled material, an excellent material can be obtained. A steel plate is built in. That is, a slab heated to 100 ° C or higher is rolled to a predetermined plate thickness, and then the non-recrystallization temperature range) and temperature The rolling is performed to the finished plate thickness in a temperature range close to the range. For example, a slab with a thickness of 200-300 mm is heated to about 1100-120 ° C, then rolled to about 1.5-2 times the finished plate thickness, and then the temperature When the temperature of the non-recrystallized zone falls below 8500 ° C, controlled rolling is started and rolled to a finished sheet thickness (for example, 15 mm).

At that time, if the controlled rolling temperature (controlled rolling start temperature) is low and the thickness of the controlled rolling (controlled rolling start thickness) is thick, rolling Since it takes a considerable time for the material to reach the controlled rolling start temperature, the rolled material is allowed to cool until it reaches the controlled rolling start temperature on the rolling line near the rolling mill (reversing rolling mill). I was waiting. As a result, the waiting time for cooling caused a waiting time in the rolling mill, resulting in a problem that rolling productivity was lowered.

In order to eliminate the reduction of rolling efficiency due to idle time in the rolling mill due to such a waiting for cooling, a waiting position in which a steel plate that needs to wait for cooling is provided outside the rolling line. To the other steel plate while cooling A technique has been proposed in which when a steel sheet that has been cooled at the standby position reaches a predetermined controlled rolling start temperature, it is returned to the rolling line from the standby position and controlled rolling is performed (for example, JP-A-5). 3-1 4 6 20 8 publication, Japanese Patent Laid-Open No. 60 0-1860 0 4 publication).

However, in the techniques described in Japanese Patent Application Laid-Open Nos. 53-1440 6208 and Japanese Patent Application Laid-Open No. 6-0-18006, a space for providing a standby position outside the rolling line, Therefore, a means for moving the steel sheet between the rolling line and the standby position is required, which makes a large facility.

Further, in order to eliminate the reduction of rolling efficiency due to the idle time in the rolling mill due to such waiting for cooling, for example, Japanese Patent Application Laid-Open No. Sho 5 5-1 0 6 6 15 A controlled rolling method is shown in which a set of cooling devices is installed in front of and behind the rolling mill, and the rolling material is rolled in a reversible rolling mill while cooling with a cooling device in each rolling pass.

In addition, in Japanese Patent Laid-Open No. 2 0 0 5 0 0 9 7 9, a temperature adjustment cooling equipment for cooling the rolled material to a predetermined controlled rolling start temperature is installed, and reversible rolling is performed. The rolled material rolled to the specified plate thickness with the mill is cooled to the specified controlled rolling start temperature with the temperature adjustment cooling equipment (temperature adjustment 'cooling), and then rolled again to the finished plate thickness with the reversible rolling mill. The technology is described. This temperature-controlled cooling facility is installed at a position about 20 m away from the reversible rolling mill in order to avoid interference with the following material.

However, in the technique described in Japanese Patent Application Laid-Open No. Sho 5 5-1 0 6 6 15, the steel plate is cooled by a shower-type cooling device, but the cooling water drainage (damming of remaining water) Because it is not taken into account, the predetermined temperature drop

When a large amount of cooling water is supplied to the upper surface of the steel sheet to obtain (temperature drop), the cooling water staying on the upper surface of the steel sheet moves freely on the upper surface of the steel sheet, and the cooling region of the steel sheet fluctuates and cooling is not possible. There is a problem that it becomes uniform and adversely affects the material and shape of the product.

For draining the cooling water accumulated on the upper surface of the steel sheet, there is a method using a draining roll. However, it may cause a transport trouble such as the transported steel sheet colliding with the draining roll. There is concern about life. In addition, there is a method of draining with air, but it is not effective for a large amount of cooling water.

In the technique described in Japanese Patent Application Laid-Open No. 2005-000979, temperature-controlled cooling is performed up to a predetermined controlled rolling start temperature with a temperature-controlled cooling facility installed at a position about 20 m away from the rolling mill. However, there is a problem that it takes time to cool down including the time for transporting the steel sheet, and the reduction in rolling efficiency cannot be solved sufficiently.

Also, in the process of manufacturing steel sheets by hot rolling, it is common to supply cooling water or air cooling to control the rolling temperature. Development of technology to refine the weaving and increase the strength of the steel plate is thriving. For example, as a technique for cooling a steel sheet by supplying cooling water, there is a technique described in JP-A-62-260022. This is to raise and lower a slit nozzle unit that injects cooling water in the direction of steel sheet conveyance, and can be used with a separate laminar nozzle or spray nozzle to ensure a wide range of cooling rates. Has been.

Further, as a technique for cooling the steel sheet by supplying cooling water, there is a technique described in Japanese Patent Application Laid-Open No. ffgS 9-14513. This is because a film-shaped cooling water is jetted by inclining a header having a slit-like nozzle and a partition plate is provided to fill the space between the steel plate and the partition plate to obtain a high cooling rate. It is supposed to be done. As another technique for cooling the steel sheet by supplying cooling water, there is a technique described in Japanese Patent Laid-Open No. 2001-286925. This is done by installing slit-like nozzles or flat spray nozzles on the upstream and downstream sides of the steel sheet conveying direction, respectively, on the upper side of the steel sheet, and the spray angle of these nozzles (based on the normal line of the steel sheet). It is said that the cooling water on the steel sheet can be made a uniform flow and cooling unevenness can be prevented by discharging the cooling water so that the angle) ′ is more than 20 ° and less than 60 °.

However, the techniques described in JP-A-62-260022 and JP-A-59-144513 have significant problems in ensuring cooling uniformity and equipment costs.

That is, in the technique described in Japanese Patent Application Laid-Open No. Sho 62-260022, the slit nozzle must be brought close to the steel sheet, and the steel sheet with the warped tip and tail ends is cooled. In this case, the steel plate may collide with the slit nozzle unit, damaging the slit nozzle unit, or the steel plate may not move, resulting in production line stoppage and yield reduction. Therefore, it is conceivable that when the tip and tail ends pass, the lifting mechanism is operated to retract the slit nozzle unit upward, but in that case the leading and trailing ends are not sufficiently cooled, and the target material is It can no longer be obtained. In addition, there is a problem that the equipment cost for installing the lifting mechanism is high.

Further, in the technique described in Japanese Patent Application Laid-Open No. 59-144513, the cooling water is not filled between the steel plate and the partition plate unless the nozzle is brought close to the steel plate. When the nozzle is brought close to the steel plate, inconvenience occurs when the steel plate with the tip or tail end warped is cooled, as in the technique described in JP-A-6-260022.

Furthermore, in the techniques described in Japanese Patent Application Laid-Open No. 62-260022, Japanese Patent Application Laid-Open No. 59-144513, and Japanese Patent Application Laid-Open No. 200-286 925, Although it is assumed that a nozzle is used, the cooling water does not form a film unless the spout is maintained in a clean state. For example, as shown in FIG. 15, when the foreign matter 60 adheres to the throat outlet of the slit nozzle 52 and clogging occurs, the water film or water curtain 53 is broken. In addition, in order to keep cooling water in the spray area (in the cooling area), it must be injected at a high pressure, but when film-like cooling water 5 3 is sprayed at a high pressure, the jet pressure There was a problem that the cooling water film 53 was easily broken when the balance was poor. In addition, when film-like cooling water is sprayed obliquely, the water film near the steel sheet becomes thinner and becomes more easily spilled as the distance from the steel sheet to the nozzle increases. Furthermore, the slit shape disclosed in JP-A-62-2260022, JP-A-59-144413 and JP-A-2001-2869225. These nozzles are arranged in only one row upstream and downstream in the steel sheet conveyance direction. For this reason, if the cooling water film 53 is not formed well, the cooling water leaks in the upstream or downstream direction of the spraying region, and it stays on the steel plate 10 and partially causes the steel plate 10 to partially move. There is a problem of cooling and uneven temperature. There is also a technology to remove the cooling water staying on the upper surface of the steel plate 10 by side spraying, but when the amount of cooling water is large, it cannot be completely eliminated, and there is still a problem of uneven temperature. The present invention has been made in view of the circumstances as described above, and in the case of performing controlled rolling of a steel sheet, the steel sheet can be appropriately cooled on a hot rolling line with a compact structure (compact size). Can steel plate cooling equipment and? The purpose is to provide a rejection method.

Further, the present invention provides a steel sheet that can be cooled uniformly during the controlled rolling of the steel sheet to obtain a good product quality and also prevent a reduction in rolling efficiency due to waiting for cooling or the like. The purpose is to provide equipment and a hot rolling method.

In addition, the present invention provides a steel plate cooling facility and a cooling method capable of cooling a steel plate uniformly and stably at a high cooling rate when cooling water is supplied to the upper surface of the steel plate. It is for the purpose. Disclosure disclosure

In order to solve the above problems, the present invention has the following features.

1. A cooling facility that supplies cooling water to the upper and lower surfaces of a steel sheet while passing the steel sheet while hot rolling the steel sheet, and supplies cooling water obliquely from above the steel sheet toward the upper surface of the steel sheet. A steel sheet cooling facility comprising: a plurality of nozzles each arranged so that cooling water is opposed to each other in a conveying direction of the steel sheet on the steel sheet.

Here, supplying the cooling water during hot rolling of the steel sheet refers to rolling at least once after cooling, or further supplying cooling water at least once thereafter for cooling.

2. In 1 above, while passing the steel plate before and / or after rolling at a position close to the reversible rolling mill on the entry side and / or exit side of the reversible rolling mill for hot rolling the steel plate. Steel sheet cooling equipment with cooling equipment that supplies cooling water with a water density of 4 m ³ / m ² min or more on the upper and lower surfaces of each steel sheet.

3. In the above 1 or 2, the nozzle cools the steel plate spraying rod-shaped cooling water. 4. In 3 above, a header connected to the nozzle for spraying the rod-shaped cooling water is provided above the steel plate, and a tilt angle between the rod-shaped cooling water and the steel plate is 30. A steel plate cooling facility in which the nozzles are arranged so as to be up to 60 °.

5. The steel plate according to 4 above, wherein the nozzles are arranged in 3 rows or more, more preferably 5 rows or more in the conveying direction of the steel plate and in the direction opposite to the conveying direction, respectively, and the rod-shaped cooling water is injected at a speed of 8 mZ s or more. Cooling equipment.

6. In any of the above 3 to 5, in the jet direction of the rod-shaped cooling water, 0 to 35% of the component of the jet speed of the rod-shaped cooling water is directed outward in the width direction of the steel sheet perpendicular to the conveying direction. Is a steel plate cooling facility. · ·

7. In 6 above, the components of the injection speed of 40 to 60% of the total number of nozzles for injecting the rod-shaped cooling water are in two directions toward the outside in the width direction of the steel sheet perpendicular to the conveying direction. Among them, a steel sheet cooling facility for setting the spraying direction of the rod-shaped cooling water so as to have a component directed in one direction.

8. In 6 above, the number of rod-shaped cooling water having a component toward one direction and the number of rod-shaped cooling water having a component toward the other of the two directions toward the outside in the width direction of the steel sheet perpendicular to the conveying direction is equal. A steel sheet cooling facility for setting the injection direction of the rod-shaped cooling water.

9. In 6 above, each nozzle is placed in such a way that the component of the jet speed of the rod-shaped cooling water increases toward the outside in the steel plate width direction as the nozzle installation position goes from the center in the steel plate width direction to the outside. Installed steel sheet cooling equipment.

1 0. In 6 above, each nozzle is set so that the component of the jetting speed of the rod-shaped cooling water toward the outside in the steel plate width direction is constant, and the positions where the rod-shaped cooling water collides with the steel plate are equally spaced in the steel plate width direction. Installed steel sheet cooling equipment.

1 1. The steel sheet cooling equipment according to any one of the above 3 to 8, wherein a plate-like or curtain-like shield is provided above the rod-like cooling water and / or the stagnant cooling water in the most side row to be opposedly jetted.

1 2. In the above 1 1, the lowermost end of the shielding object provided above the innermost row of rod-shaped cooling water jetting oppositely is positioned 30 to 500 mm above the upper surface of the hot steel plate. Is steel sheet cooling equipment. 13. In 2 above, the cooling area of the cooling facility is a position of the steel sheet that is close to the reversible rolling mill except the position of the side guide portion arranged on the entry side and / or the exit side from the reversible rolling mill. Cooling equipment.

14. In the above item 13, the cooling area of the cooling facility is located on the upstream side of the side guide disposed on the entry side of the reversible rolling mill and in the vicinity of the reversible rolling mill and / or the reversible rolling mill. A steel plate cooling facility located in the vicinity of the reversible rolling mill on the downstream side of the side guide placed on the exit side.

15. A cooling method in which cooling water is supplied to the upper and lower surfaces of the steel sheet while passing the steel plate while hot rolling the steel plate so that the cooling water faces each other in the direction of conveyance of the steel plate on the steel plate. A method for cooling a steel sheet, in which cooling water is supplied obliquely from above the steel sheet toward the upper surface of the steel sheet by means of nozzles arranged in the above.

16. In the above 15, a cooling facility is disposed at a position close to the reversible rolling mill on the entry side and / or the exit side of the reversible rolling mill that hot-rolls the steel sheet, and rolling is performed from the cooling facility. A method of cooling a steel sheet, in which cooling water having a water density of 4 ia. ³ m ² min or more is applied to the upper and lower surfaces of the steel sheet while passing the steel sheet before and / or after rolling.

1 7. In the above 1 5 or 16, the nozzle is a method of cooling a steel plate that sprays rod-shaped cooling water.

18. In 17 above, a header connected to the nozzle for spraying the rod-shaped cooling water is provided above the steel plate, so that an inclination angle between the rod-shaped cooling water and the hot steel plate is 30 ° to 60 °. The cooling method of the steel plate which cools by arrange | positioning the said nozzle.

19. In 18 above, the nozzles are arranged in 3 or more rows, preferably 5 or more rows in the direction opposite to the conveying direction and the conveying direction of the hot steel plate, and more preferably 5 or more rows, and the steel plate injecting the rod-shaped cooling water at a speed of 8 mZs or more. Cooling method.

20. In any of 15 to 19 above, 0 to 0 of the injection speed component of the rod-shaped cooling water

A steel plate cooling method in which the injection direction of the bar-shaped cooling water is set so that 35% is directed outward in the steel plate width direction perpendicular to the conveying direction.

21. In the above 20, the injection speed component of 40-60% of the total number of nozzles spraying the rod-shaped cooling water is directed outward in the steel plate width direction perpendicular to the conveying direction. The steel plate cooling method in which the injection direction of the rod-shaped cooling water is set so as to have a component that goes in one direction out of the two directions.

2 2. In 20 above, the number of rod-shaped cooling water having a component directed in one direction and the number of rod-shaped cooling water having a component directed in the other of the two directions toward the outside in the width direction of the steel sheet perpendicular to the conveying direction. However, the steel sheet cooling method is to set the injection direction of the rod-shaped cooling water so as to be equal. '

2 3. In 20 above, each component is set so that the component toward the outside in the steel plate width direction of the jet speed of the rod-shaped cooling water gradually increases as the nozzle installation position goes from the center in the steel plate width direction to the outside. A method of cooling the steel plate where the nozzle is installed.

2 4. In 20 above, each component is set so that the component of the jetting speed of the rod-shaped cooling water toward the outside in the steel plate width direction is constant, and the positions where the rod-shaped cooling water collides with the steel plate are equally spaced in the steel plate width direction. Cooling method of installing the nozzle.

2 5. In any one of 15 to 19 above, the cooling of the steel plate provided above the rod-shaped cooling water and / or the stagnant cooling water in the innermost row in which the plate-like or curtain-like shields are opposedly jetted Method.

2 6. In the above 25, the lowermost end of the shield provided above the rod-shaped cooling water in the innermost row that projects oppositely is positioned 30 to 50 O mm above the upper surface of the steel plate. Steel plate cooling method.

2 7. In the above 16, the cooling area of the cooling facility is a position close to the reversible rolling mill excluding the length of the side guide portion arranged on the entry side and / or the exit side from the reversible rolling mill. A method of hot rolling a steel sheet.

28. In the above 27, the cooling area of the cooling facility is located on the upstream side of the side guide disposed on the entry side of the reversible rolling mill and in the vicinity of the reversible rolling mill, and / or the reversible rolling mill. A hot-rolling method for a steel sheet, which is a position close to a reversible rolling mill on the downstream side of a side guide disposed on the exit side of the steel sheet.

29. On the steel plate while passing the unrolled and / or rolled steel plate at a position close to the reversible rolling machine on the entry side and / or exit side of the reversible rolling mill for hot rolling the steel plate. Cooling equipment that supplies cooling water with a water density of 4 m ³ / m ² min or more is arranged on the bottom surface. The cooling equipment on the top surface supplies cooling water obliquely from above the steel plate toward the steel plate. A steel sheet hot rolling facility, comprising: a nozzle for feeding, wherein the nozzles are arranged so that cooling water faces each other in a conveying direction of the steel plate on the steel plate.

30. The hot rolling mill for steel sheets according to 29 above, wherein the nozzle sprays rod-shaped cooling water.

31. The steel sheet according to 29 or 30 above, wherein the cooling area of the cooling facility is located between the reversible rolling mill and the side guides arranged on the entry side and / or exit side thereof. Hot rolling equipment.

3 2. A cooling facility is arranged at a position close to the reversible rolling machine on the inlet side and / or the outlet side of the reversible rolling mill for hot rolling the steel sheet, and before the rolling and / or rolling from the cooling facility. Cooling water with a water density of 4 m ³ Zin ² min or more is supplied to the upper and lower surfaces of the steel plate while passing the later steel plate. At that time, the cooling water is applied to the upper surface of the steel plate on the steel plate. A method of hot rolling a steel sheet, characterized in that cooling water is supplied obliquely from above the steel sheet toward the steel sheet by nozzles arranged so as to face each other in the conveying direction.

3 3. The hot rolling method for steel plates according to 3 2 above, wherein the nozzle sprays bar-shaped cooling water.

34. The cooling area of the cooling facility is located between the reversible rolling mill and the side guides arranged on the entry side and / or exit side thereof, according to the above 3 2 or 3 -3. Hot rolling method for steel sheet.

3 5. A bar-shaped cooling water with a water density of 4 m ³ / m ² min or more is sprayed above the hot steel plate. The steel plate cooling equipment is characterized in that the nozzles are arranged so as to face each other in the conveying direction of the hot steel plate at ˜60 °.

36. The steel sheet cooling equipment according to 35, wherein five or more rows of the nozzles are arranged in the conveying direction of the hot steel sheet, and the rod-shaped cooling water is injected at a speed of 8 mZ s or more.

3 7. The steel sheet cooling equipment according to 3 5 or 3 6 above, wherein a plate-like or curtain-like shield is provided on the upper side of the rod-like cooling water in the innermost row that is jetted oppositely. . 38. The steel sheet cooling equipment according to 37, wherein the lowermost end of the shield is at a position 30 to 500 mm above the upper surface of the hot steel sheet. 3 9. Above the hot steel plate, provide a header with a nozzle that sprays rod-shaped cooling water with a water density of 4 m ³ / m ² min or more, and the tilt angle between the rod-shaped cooling water and the hot steel plate is A cooling method for a steel sheet, wherein the nozzle is arranged to cool at 3 ° to 60 ° so as to face each other in the conveying direction of the hot steel sheet.

40. The steel sheet cooling method according to 39, wherein the nozzles are arranged in five or more rows in the conveying direction of the hot steel sheet, and the rod-shaped cooling water is injected at a speed of 8 m / s or more. 4 1. The method for cooling a steel plate according to 39 or 40, wherein a plate-like or curtain-like shield is provided on the uppermost row of rod-like cooling water that jets oppositely. 42. The method for cooling a steel sheet according to 41, wherein the lowermost end of the shield is positioned 30 to 500 mm above the upper surface of the hot steel sheet.

In this effort, the cooling water is supplied to the upper and lower surfaces of the steel sheet while passing through the steel sheet, so that the equipment length can be shortened and the cooling water can be opposed to each other in the conveying direction on the steel sheet. Since the nozzles are arranged, the supplied cooling water itself dams up the stagnant cooling water on the steel plate and drains the water, so that the drainage can be performed appropriately even without an auxiliary device such as a draining roll. As a result, the steel sheet can be appropriately cooled with a compact structure on the hot rolling line when the steel sheet is subjected to controlled rolling.

Further, in the present invention, since a passing type cooling facility having a large water density of 4 m ³ Zm ² min or more is disposed at a position close to the reversible rolling mill, the steel sheet is cooled while being rolled. Thus, a predetermined controlled rolling start temperature can be obtained efficiently, and a reduction in rolling efficiency due to waiting for cooling or the like can be avoided. The nozzles are arranged on the steel plate so that the cooling waters face each other in the transport direction, and cooling water having a large water density of 4 m ³ / m ² min or more is supplied, so the supplied cooling water itself However, the stagnation cooling water on the steel plate is blocked and drained appropriately, and a stable cooling region can be obtained.

As a result, when performing the controlled rolling of the steel sheet, the steel sheet is uniformly cooled to obtain a good product quality, and it is also possible to prevent a reduction in rolling efficiency due to waiting for cooling. Further, by using the present invention, the steel sheet can be uniformly cooled to the target temperature at a high cooling rate. As a result, high quality steel sheets can be manufactured. Brief Description of Drawings

FIG. 1 is a layout diagram of hot-rolling equipment for steel sheets in one embodiment of the present invention. FIG. 2 is an explanatory diagram of the cooling facility according to the first embodiment of the present invention.

FIG. 3 is a detailed view of a cooling facility in one embodiment of the present invention.

Fig. 4 is a diagram showing an example of the nozzle arrangement of the upper header in one embodiment of the present efforts.

Fig. 5 is an explanatory diagram of another cooling facility according to the first embodiment of the present efforts.

FIG. 6 is an explanatory diagram of a steel sheet cooling facility according to the second embodiment of the present invention. FIG. 7 is an explanatory diagram of another steel plate cooling facility according to the second embodiment of the present invention. FIG. 8 is an explanatory diagram of the shooting direction in the second embodiment of this effort.

FIG. 9 is an explanatory diagram of the cooling facility according to the third embodiment of the present invention.

FIG. 10 is a view taken along arrows A—A in FIG.

FIG. 11: is an explanatory diagram of another cooling facility according to the third embodiment of the present invention. Fig. 12: A diagram for explaining scattered cooling water.

Fig. 13: Comparison of rolling time in examples of the present invention.

Figure 14: Explanatory drawing of the hot rolling line and transport pattern for thick steel plates in the example of this effort.

囡 15: A diagram showing the problems of the prior art.

FIG. 16 is a detailed view of a cooling facility in another embodiment of the present invention.

Fig. 17: An explanatory diagram of another cooling facility according to the third embodiment of the present invention.

(Explanation of symbols)

1 0: Steel plate, 1 3: Table roller, 2 1: Upper header unit, 2 1 a: First upper header, 2 1 b: Second upper header, 2 2 a: First upper nozzle, 2 2 b: First 2 Upper nozzle, 23 a: Rod cooling water, 23 b: Rod cooling water, 24: Stagnant cooling water, 31: Lower header, 3 2: Lower nozzle, 33: Rod cooling water, 25: Spatter cooling Water, 26a: Shield plate, 26b: Shield plate, 27a: Cylinder, 2 7 b: Cylinder, 2 8 a: Shielding curtain, 2 8 b: Shielding curtain, 2 9: Shielding plate, 40: Cooling unit, 51: Cooling header, 52: Slit nozzle, 53: Cooling water film, 60: Adhering material 61: Side guide 20: Cooling equipment (Cooling unit) BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to the drawings.

(First embodiment)

FIG. 1 is a layout diagram of a steel sheet hot rolling facility according to an embodiment of the present invention. As shown in FIG. 1, in this embodiment, the heating furnace 1 1, the reversible rolling mill 1 2, and the entry side (upstream side) and the exit side (downstream side) of the reversible rolling mill 1 2 are close to each other. Cooling equipment 20 is placed at the position. Cooling equipment (also referred to as a cooling unit) 20 is a passage-type cooling equipment, and as shown in FIG. 2, an upper header unit 2 1 for supplying cooling water toward the upper surface of the steel plate 10, A lower header 31 for supplying cooling water toward the lower surface of the steel plate 10 is provided. Figure:! In Fig. 2, 1 3 is a table roller.

3 and 16 are detailed views of the cooling facility 20. In FIG. 3, the cooling facility 20 is disposed between the reversible rolling mill 12 and the side guide 14, and in FIG. 16, the cooling facility 20 is located upstream of the side guide 14 (heating ^ Side> at a position close to the reversible rolling mill 12 2. In any case, the cooling facility 20 includes the upper header unit 21 and the lower header 31 as described above.

The upper header unit 2 1 is composed of a pair of upper headers 2 1 a and 2 1 b. Here, the upper header on the side close to the reversible rolling mill 1 2 is referred to as the first upper header 2 1 a. The upper header far from the reversible rolling mill 1 2 will be called the second upper header 2 1.

The circular tube nozzles 2 2 a, 2 2 b (this is arranged in the width direction of the steel plate in each of the first upper header 2 1 a and the second upper header 2 1 b and provided in a plurality of rows in the conveying direction) In Fig. 6, 6 rows in the conveying direction of the steel plate 10 are installed, and the circular nozzles of the first upper header 2 1 a (first upper nozzle) 2 2 a and the second upper header 2 1 b (No. 2 upper nozzles) 2 2 b are arranged so that the rod-shaped cooling water supplied from each of them faces each other in the carrying direction of the steel plate 10. That is, the first upper nozzle 2 2 a injects the rod-like cooling water 2 3 a from the reversible rolling mill 1 2 side at a tilt angle (injection angle) of 01, and the second upper nozzle 2 2 b is reversible rolling. The rod-shaped cooling water 2 3 b is sprayed toward the machine 1 2 side with an inclination angle (injection angle) of Θ2.

Incidentally, the rod-shaped cooling water (also referred to as columnar side cooling water) of the present invention refers to cooling water sprayed from a circular (including elliptical or polygonal) nozzle soot outlet. In addition, the rod-shaped cooling water of the present invention is not a spray-like jet, but the cross-section of the water flow is maintained in a substantially circular shape until it collides with the steel plate from the outlet of the nozzle soot, thereby cooling the continuous and straight water flow. Say water.

Therefore, the region sandwiched between the positions where the rod-shaped cooling water from the circular tube nozzles in the row farthest from each other's upper header (outermost row) collides with the steel plate 10 is called the cooling region.

At that time, if the injection line of the rod-like cooling water 2 3 a from the first upper nozzle 2 2 a and the injection line of the rod-like cooling water 2 3 b from the second upper nozzle 2 2 b do not intersect, As shown in Fig. 3 and Fig. 16, the water film of stagnant cooling water 24 is stably formed. As a result, the rod-shaped cooling water from the circular tube nozzles in the row closest to the upper header of each other (innermost row) is sprayed toward the water film of the accumulated cooling water 24. It is preferable because the other rod-shaped cooling water does not spill on each other. And if the interval between the positions where the rod-shaped cooling water from the circular tube nozzles in the innermost row collides with the steel plate 10 is called the staying zone length, the staying zone length should be 1.5 m or less. The ratio of cooling water 2 4 that cools the steel sheet 10 is relatively small, so that the cooling method changes greatly when the leading edge of the steel sheet 10 passes in an unsteady state. Can be prevented.

4A and 4B show examples of the arrangement of the circular tube nozzles 2 2 a and 2 2 b attached to the upper headers 2 1 a and 2 1 b. As described above, the circular tube nozzles 2 2 a and 2 2 b are arranged in six rows in the conveying direction of the steel plate 10. The reason for arranging a plurality of rows in the transport direction is that a single row of nozzles weakens the ability to dam the stagnant cooling water between the cooling water and the cooling water that collide with the steel sheet. Therefore, it is preferable to arrange three or more rows in the transport direction. More preferably, 5 or more rows are arranged. Ma In addition, in the width direction, it is installed so that cooling water can be supplied to the entire width of the passing steel sheet 10. In addition, although two upper headers are provided here, it is also possible to provide one header in which these are integrated, and to arrange the circular tube nozzles 22a and 22b. .

On the other hand, for the lower header 3 1, here, two lower headers 3 1 are arranged, each having a circular nozzle 3 2 attached, and a rod-shaped cooling water 3 from the gap between the table rollers 1 3. 3 is sprayed to supply cooling water to the entire width of the passing steel plate 10.

The cooling facility 20 supplies cooling water from the upper headers 2 1 a and 2 1 b so that the water density of the steel plate surface is 4 m ³ / m ² min or more toward the upper surface of the steel plate 10, The cooling water is supplied from the lower header 3 1 toward the lower surface of the steel plate 10 so that the water density on the steel plate surface is 4 m ³ Zm ² min or more.

Here, the reason why the water density is set to 4 m ³ Zm ² min or more will be described. The staying cooling water 24 shown in FIG. 3 and FIG. 16 is formed by damming with the rod-like cooling water 2 3 a and 2 3 b to be supplied. At this time, if the water density is small, the dam can not be dammed, and if the water density is larger than a certain amount, the amount of stagnant cooling water 24 that can be dammed increases, and the cooling discharged from the edge of the plate Stagnant cooling water 24 is kept constant by balancing the amount of water and the amount of cooling water supplied. In the case of thick steel plates, the typical plate width is 2 to 5 m. If cooling is performed with a water density of 4 m ^{3 2} in i ti or more, the stagnant cooling water can be kept constant at these plate widths and rolled. A desired temperature drop can be obtained while passing the steel plate 10 inside.

The higher the water density is 4 m ³ Zm ² min or more, the more control rolled material that eliminates the waiting time for cooling. For example, if the water density is small, the waiting time for cooling can be solved only with a rolled material with a thin plate thickness, but if the water content density is increased, the waiting time for cooling can be eliminated even with a rolled material with a somewhat thick plate thickness. However, the effect of shortening the cooling waiting time for increasing the water volume gradually decreases as the water density increases, so the water density takes into account the effect of shortening the cooling waiting time and the equipment cost. Therefore, it is preferable to determine. A more preferable water density is 4 to 10 m ³ / ni ² mi ri. In addition, in order to make the cooling equipment 20 compact and to cool the steel plate at a position close to the reversible rolling mill 12, the residence area length is 1.5 m or less and the cooling area is reduced. Cooling equipment 20 is placed so that it is located within 3 m and is located close to the reversible rolling mill 1 2 excluding the position of the side guides placed on the entry side and / or exit side of the reversible rolling mill 1 2 To do. In general, this position is within a range of 20 m from the center of the workpiece hole 1 2 a of the reversible rolling mill 12. If the cooling area is provided at a position excluding the side guide so as not to cover the side guide, the cooling water staying on the upper surface of the steel plate 10 is not disturbed by the side guide 14 and from the width of the steel plate 10 It is discharged smoothly. '·'

At that time, as shown in Fig. 3, the cooling zone is a reversible rolling mill 1 2 Work roll center 1 2

2 It is preferable to arrange the cooling equipment 20 so as to be positioned between the a and the side guide (about 2 to 4 m from the work roll center 12 to 2 m) because the rolling efficiency can be improved efficiently.

On the other hand, the cooling area of the cooling facility 20 is moved to the position close to the reversible rolling mill 1 2 by the upstream inversion of the side guide 14 arranged on the entry side of the reversible rolling mill 12 as shown in FIG. Installed force \ Or, the side guide 14 located on the exit side of the reversible rolling mill 1 3 is installed on the downstream side of the side guide 14 near the reversible rolling mill 1 2 It is good because a cooling area can be secured.

In addition, a cooling region may be provided both between the work center G 1 of the reversible roll extender 12 and the side guide 14 and upstream of the side guide 14 shown in FIG. Needless to say, it is good.

In this cooling equipment 20, the rod-like cooling water 2 3 a sprayed from the first upper nozzle 2 2 a and the rod-like cooling water 23 b injected from the second upper nozzle 2 2 b Since they are opposed to each other in the carrying direction, the stagnant cooling water 2 4 on the upper surface of the steel plate 10 is about to move in the conveying direction of the steel plate 10.

3 b stops itself. As a result, even if cooling water is supplied with a large water density of 4 m ³ Zm ² min or more, a stable cooling region can be obtained and uniform cooling can be performed. Note that the cooling water sprayed from the upper nozzles 2 2 a and 2 2 b is, for example, a rod-shaped cooling water rather than a film-shaped cooling water using a slit nozzle, so that the rod-shaped cooling water forms a more stable water flow. This is because the power to block the accumulated cooling water is great.

In addition, when the film-like cooling water is sprayed obliquely, the water film near the steel sheet becomes thinner and more prone to spilling as the distance from the steel sheet to the nozzle increases.

At this time, the injection angle θ 1 of the first upper nozzle 22 2 a and the injection angle 0 2 of the second upper nozzle 22 b are preferably 30 ° to 60 °. If the injection angles Θ1 and Θ2 are smaller than 30 °, the first upper nozzle 2 2a and the second upper nozzle 2 2b must be separated from each other. Cooling water 2 3 a, 2 3 b in the vertical direction. Because the direction component becomes smaller, the collision with the steel plate 10 becomes weaker and the cooling capacity is reduced. The incident angles Θ 1 and Θ 2 are This is because if it is larger than 60 °, the speed component in the conveying direction of the rod-shaped cooling water 2 3 a and 2 3 b becomes small, and the force to dam the stagnant cooling water 24 becomes weak. Note that the spray angle 0 1 and the injection angle Θ 2 are not necessarily equal. More preferable injection angles 0 1 and Θ 2 are 40 ° to 50 °.

In addition, in order to obtain the desired cooling capacity and drainage capacity, the upper nozzle / le 22a and 2 2b should be arranged in 5 rows or more in the direction of conveyance of the steel sheet and in the direction opposite to the conveyance direction. It is preferable that the injection speed of the rod-shaped cooling waters 2 3 a and 2 3 b from a and 2 2 b is 8 mZ s or more.

In order to achieve complete draining, the number of nozzles that spray cooling water in the direction opposite to the direction of conveyance and the direction of conveyance is preferably multiple, at least 3 or more, respectively. More preferably, there are at least 5 rows. The upper limit of the number of rows may be appropriately determined depending on the size of the steel sheet to be cooled, the conveyance speed, the target temperature drop amount, and the like.

Also, if the injection speed exceeds 3 O m / s, the pressure loss increases, and the problem of increased wear on the nozzle inner surface arises. In addition, the capacity of the pump and the outer diameter of the piping also increase, resulting in excessive equipment costs. For this reason, the injection speed is preferably 3 O mZ s or less. In order to prevent the nozzle from clogging and to ensure the spraying speed of the cooling water, the inner diameter of the nozzle only needs to be in the range of 3 to 8 mm. Further, in order to prevent the cooling water from flowing out from the gap between the rod-shaped cooling waters, the interval between adjacent nozzles on the imaginary line drawn in the plate width direction should be within 10 times the nozzle inner diameter. Figure 4A shows an array with six rows in the transport direction with an adjacent nozzle spacing of 40 mm, and Figure 4B shows four rows in the transport direction with an adjacent nozzle spacing of 4 Oram. An example of an arrangement is shown in which two rows are provided in the transport direction in which the interval between adjacent nozzles is 20 mm.

Furthermore, in order to prevent the upper nozzles 2 2 a and 2 2 b from being damaged by warpage of the steel plate 10, the positions of the tips of the upper nozzles 2 2 a and 2 2 b should be separated from the pass line. However, since the cooling water is dispersed when separated too much, it is preferable that the distance between the tip of the upper nozzles 2 2 a and 2 2 b and the pass line is set to 500 mm to 1.800 mm. In the case where controlled rolling is performed using the steel sheet hot rolling equipment configured as described above, a predetermined control rolling start plate thickness (for example, 1.5 to 2 times the finished plate thickness) is used. The steel sheet that passes through the cooling zone of the cooling equipment 20 before and / or during and / or after the rolling is controlled so that the controlled rolling start temperature (for example, 85 ° C. or lower) is reached. Roll with a reversible rolling mill 1 2 while cooling. Then, when the predetermined control rolling start plate thickness reaches the predetermined control rolling start temperature, after that, the cooling equipment 20 is not cooled and the rolling is performed to the finished plate thickness (for example, 15 mm).

Note that it is not necessary to cool by the inlet and outlet side cooling facilities 20 in all rolling passes until the controlled rolling start temperature is reached, and the predetermined controlled rolling start temperature is set at the predetermined controlled rolling start plate thickness. Cooling equipment (also called cooling unit) 20

In the above embodiment, one or more cooling facilities (cooling units) 20 having a pair of upper headers 2 1 a and 2 1 b as shown in FIG. 2 are provided. If you want to obtain a larger cooling capacity by combining the units to some extent, you can install an intermediate header 2 1 c between the pair of upper headers 2 1 a and 2 1 b as shown in Figure 5. There can be any number.

Here, the cooling equipment 20 is arranged on the entry side and the exit side of the reversible rolling mill 12, but the cooling equipment 20 may be arranged on either one of them.

Thus, in this embodiment, since the cooling water is supplied to the upper and lower surfaces of the steel plate 10 while passing the steel plate 10, the equipment length can be shortened. And the upper nozzles 2 2 a, 2 2 b so that the cooling water faces each other in the transport direction on the steel plate 10 Since the supplied rod-like cooling water 2 3 a _N 23 b itself dams up the stagnant cooling water 24 on the steel plate 10 and drains it, an auxiliary device such as a draining roll is installed. Even if it does not drain properly. As a result, the steel sheet can be appropriately cooled with a compact structure on the hot rolling line when the steel sheet is controlled and rolled.

Further, in this embodiment, since the passing type cooling equipment 20 having a large water density of 4 m ³ / m ² min or more is arranged at a position close to the reversible rolling mill 12, the steel plate 10 is By cooling while rolling, a predetermined control temperature can be efficiently obtained, and a reduction in rolling efficiency due to waiting for cooling is avoided. Then, the circular nozzles 2 2 a and 22 b are arranged on the steel plate 10 so that the cooling water faces each other in the transport direction, and cooling water having a large water density of 4 m ³ / m ² min or more is supplied. Therefore, the injected rod-shaped cooling waters 23a and 23b themselves dam the staying cooling water 24 on the steel plate 10 and appropriately drain the water, and a stable cooling region is obtained.

As a result, when performing the controlled rolling of the steel sheet, the steel sheet is uniformly cooled to obtain a good product quality, and it is also possible to prevent a reduction in rolling efficiency due to waiting for cooling or the like.

In the above embodiment, the rod-shaped cooling water is supplied to the lower surface of the steel sheet so that the water density on the steel sheet surface is 4 m ³ / m ² min or more. However, the present invention is not limited thereto. If it is possible to supply cooling water with a water density of 4m ³ Zm ² min or more on the steel plate surface, the film cooling water from other slit nozzles can be sprayed cooling water from the spray nozzle, etc. Any form of cooling water may be used.

In this embodiment, upper headers 2 1 a, 2 1 b connected to upper nozzles 22 a, 22 b for spraying rod-shaped cooling water having a water density of 4 m ³ Zm ² min or more above steel plate 10 The upper nozzle 2 2 so that the slant angles 0 1 and 0 2 formed by the rod-shaped cooling water 23 a and 23 b and the steel plate 10 are 30 ° to 60 ° and face each other in the conveying direction of the steel plate 10. Since a and 22b are arranged so that cooling water is supplied to the upper surface of the steel plate 10 while passing the steel plate 10, it must be installed in the hot rolling line for thick steel plates and thin steel plates. Thus, the steel sheet can be cooled uniformly and stably at a high cooling rate to the target temperature. As a result, high quality steel sheets can be manufactured.

(Second embodiment)

In the second embodiment of the present work, the steel sheet cooling equipment in the first embodiment shown in FIG. 2 is 0 to 35% of the velocity component in the injection direction of the rod-like cooling water 2 3 a and 2 3 b. The injection direction of the rod-shaped cooling waters 2 3 a and 2 3 is set so that becomes a component toward the outside in the steel plate width direction.

As shown in Fig. 6 and Fig. 7, as shown in Fig. 6 and Fig. 7, 0 to 35% of the velocity component in the spray direction of rod-shaped cooling water 2 3 a and .2 '3 b As shown, when the injection direction of the rod-shaped cooling water 2 3 a and 2 3 b is set, the cooling water injected from the upper nozzles 2 2 a and 2 2 b onto the steel plate 10 is As shown by the arrow A in the middle, it joins and falls quickly from the 10-width end of the steel plate. Therefore, it is preferable in terms of energy cost reduction because it is possible to drain the retained cooling water 24 with a small amount of water compared to the case where there is no velocity component toward the outside in the width direction of the steel plate. A more preferable range is 10 to 35%. By the way, if it exceeds 35%, it costs equipment costs to prevent the scattering of cooling water, and the vertical component of the rod-shaped cooling water becomes smaller, resulting in lower cooling capacity.

In addition, the component of the injection speed of 40 to 60% of the total number of nozzles for injecting the rod-shaped cooling water has a ratio of one of the two directions toward the outside in the steel plate width direction perpendicular to the transport direction. It is preferable that the injection direction of the rod-shaped cooling water is set so as to have a component toward the direction. Specifically, if the number of nozzles facing one side is 60% or more of the total, and if the cooling water discharge from the end of the plate is biased, the rod-like cooling will occur when the thickness of the stagnant cooling water increases. This is because the water can no longer block the accumulated cooling water and temperature unevenness in the width direction may occur. Moreover, if the amount of splashed water on one side becomes extremely large, the equipment cost for preventing this will increase.

By the way, as shown in Fig. 6, even if nozzles that radiate without facing outward in the width direction are installed in the central part of the plate width, the number of nozzles should be within 20% of the whole, and the remaining nozzles should face both outer sides. If the number of nozzles is almost equal, the accumulated cooling water can be discharged smoothly. It is most suitable to drain water by blocking the stagnant cooling water.

Here, the setting of the injection direction of the rod-shaped cooling water will be specifically described with reference to FIG.

In other words, Fig. 8 shows the injection direction of the rod-shaped cooling water. The angle between the jet line of the rod-shaped cooling water and the steel plate (actual dip angle) is .β, the dip angle with respect to the transport direction is θ, and the steel plate width. The angle toward the outside of the direction (outward angle) is shown as ひ. And, the spraying speed of rod-shaped cooling water is set to 0 to 35% as a component toward the outside in the steel plate width direction. That is, the ratio L of the steel plate width direction component L w to the cooling water injection length L wZ L

This means that the (width direction velocity component ratio) is 0 to 35%. Table 1 shows the calculation results when the nozzle height h is 90 mm and the dip angle Θ with respect to the transport direction is 45 ° and 50 °. The ratio of velocity component in the width direction is 0 to 35%. When the tilt angle Θ is 45 ° with respect to the transport direction, the outward angle a is 0 to 25 °, and the tilt angle Θ force with respect to the transport direction is 50 °. Then the outward angle α is 0 ~ 30. This is the case. Note that a preferable spray rate component in the width direction of the steel sheet is 10 to 25%.

FIG. 6 described above is a plan view showing an example when the upper nozzles 2 2 a and 2 2 b are installed based on the above. Here, the rod-shaped cooling water from the central nozzle in the steel sheet width direction has an outward angle _α of 0 °, and the outward angle _α gradually increases as the nozzle installation position goes outward in the steel sheet width direction. ing. In addition, each nozzle is installed so that the positions where the rod-shaped cooling water collides with the steel plate are equally spaced in the steel plate width direction (for example, 60 mm pitch).

Further, FIG. 7 described above is a plan view showing another example when the upper nozzles 2 2 a and 2 2 b are installed based on the above. Here, the outward angle ct of the cooling water spray is constant (for example, 20 °), and the positions where the rod-shaped cooling water collides with the steel plate are equally spaced in the steel plate width direction.

Each nozzle was installed so as to be (for example, 60 mm pitch). At that time, in the vicinity of the center in the width direction of the steel sheet, nozzles that spray toward both the left and right sides must be installed. Nozzle row that injects toward the outside in the direction (for example, a nozzle row that has an injection component in the upward direction in Fig. 7) and nozzle row that injects toward the outside in the other steel plate width direction (for example, " "Nozzle rows with a spray component in the F direction) are alternately shifted in the transport direction by a predetermined distance (for example, 20 mm), and within the two directions toward the outside of the steel sheet width direction perpendicular to the transport direction, Make sure that the number of rod-shaped cooling water with a component toward one direction is equal to the number of rod-shaped cooling water with a component toward the other. Specifically, the number of nozzles that spray rod-shaped cooling water having a component facing outward in one of the steel sheet width directions perpendicular to the conveying direction component of the steel plate and the rod-shaped cooling water having a component facing outward in the other side The number of nozzles to be shot is made equal.

If the outward angle α is increased, draining with a smaller amount of water becomes possible, but as shown in Figs. 6 and 7, the range in which the nozzle density increases near the center in the width direction of the steel sheet increases. The outward angle α should be determined so as to obtain a uniform flow distribution in the width direction of the steel sheet, and considering the capacity of the pump that supplies water to the header and the thickness of the piping.

And it is preferable to provide a wall, a drain outlet, etc. in the both outer sides of the above cooling facilities. This is because it is effective to prevent the cooling water from leaking outside the facility or being scattered inside the facility to become new accumulated water. However, when the outward angle _α exceeds 30 °, it is not preferable because it increases the equipment cost for preventing the cooling water from scattering and the vertical component of the rod-shaped cooling water becomes small, resulting in a decrease in cooling capacity.

(Third embodiment)

In the first embodiment, when the velocity power of the rod-like cooling water 2 3 a and 2 3 b sprayed from the opposing upper nozzles 2 2 a ′ and 2 2 b is high, for example, 10 m / s or more In this case, the rod-shaped cooling water 2 3 a and 2 3 b collide with the steel plate 10, collide with each other, and scatter upward. There is no problem if the scattered cooling water falls onto the stagnant cooling water 24. However, as shown in Fig. 7, the scattered cooling water 25 is scattered obliquely upward, and the rod-shaped cooling water 2 3a, 2 3b If it falls to the surface, the scattered cooling water 25 may leak from the gap between the rod-shaped cooling waters 2 3 a and 2 3 b, preventing complete draining. In particular, this problem is likely to occur when the length of the retention zone is within 200 mm. Furthermore, when the spraying speed of the cooling water is high, the scattered cooling water 24 may jump over the upper headers 21a and 21b and fall on the steel plate 10.

On the other hand, the cooling facility according to the third embodiment replaces the cooling unit 20 in FIG. 1 used in the first embodiment with a side view in FIG. 9 and an A in FIG. — As shown in the arrow A view, a cooling unit 40 is used in which shielding plates 2 6 a and 2 6 b are added above the rod-shaped cooling water in the outermost row.

As a result, even if the scattered cooling water 25 is scattered obliquely upward, the falling scattered cooling water 25 is blocked by the shielding plates 2 6 a and 2 6 b, and the rod-shaped cooling water 2 3 a and 2 3 Without falling down, it will drop onto the stagnant cooling water 24. Therefore, it becomes possible to drain water accurately.

The shielding plates 2 6 a and 2 6 b can be moved up and down by the cylinders 2 7 a and 2 7 b, and are used only when manufacturing products that require the shielding plates 2 6 a and 2 6 b. At other times, it can be pulled up to the retracted position.

By the way, when using the shielding plates 2 6 a and 2 6 b, the bottom end of the shielding plates 2 6 a and 2 6 b should be positioned 30 to 500 mm above the upper surface of the steel plate 10. Is preferable. That is, it should be positioned 30 O mm or more above the upper surface of the steel plate 10 By doing so, even if a steel plate with a warp at the tip or tail ends, it will not collide. However, if the height is higher than 50 O mm from the upper surface of the steel plate 10, the scattered cooling water 25 cannot be sufficiently shielded.

Also, instead of the shielding plates 26a and 26b in Fig. 9, it is also possible to use lighter and smoother shielding screens 28a and 28b as shown in Fig. 11. ,. Shielding curtains ² 8 a and 2 8 b normally stand by in a suspended state, and when the injection of rod-shaped cooling water 2 3 a and 2 3 b is started, it follows the rod-shaped cooling water in the innermost row. Lift up. At that time, the rod-shaped cooling water 2 3 a and 2 3 b are jetted vigorously, so that the flow is not disturbed.

Furthermore, as described above, when the cooling water injection speed is high and the scattered cooling water is about to jump over the upper headers 2 la and 2 1 b and drop onto the steel plate 10, it is shown in Fig. 17 Such a shielding plate 29 that straddles the upper header 21a and the upper header 21b and is located above the stagnant cooling water 24 may be used. If that using such a shielding plate ² 9, it is possible to accurately shield the splashing cooling water and you'll fall jumping over the upper header 2 1 a, 2 1 b on the steel plate 1 0. In addition, the scattered cooling water hitting the shielding plate 29 is effective because when it falls, it engulfes the scattered cooling water to be scattered in the horizontal direction and falls onto the stagnant cooling water 24 together. Example 1

Example 1 of the present invention will be described below.

FIG. 14 is a diagram showing a hot-rolling line for thick steel plates used in Example 1 of the present invention and a transport pattern there.

This thick steel plate hot rolling line is equipped with a heating unit 11.1, a reversible rolling mill 12, a first cooling unit 14, a hot leveler 15 and a second cooling unit 16.

Conveyance pattern A is for accelerated cooling after finish rolling. The slab extracted from heating furnace 1 1 is roughly rolled and finish-rolled by reversible rolling mill 1 2 to a thickness of 25 mm. After that, the hot cooling leveler 15 is passed through and the second cooling device 16 performs accelerated cooling with a temperature drop of 150 ° C. Conveyance pattern B is temperature-controlled cooling before controlled rolling. The slab extracted from the heating furnace 1 1 is roughly rolled in a reversible rolling mill 1 2 to a thickness of 6 O mm. Thereafter, the first cooling device 14 performs adjusted cooling with a temperature drop of 80 ° C., and then performs low-temperature finish rolling, that is, controlled rolling.

Based on the above, as the first example of the present invention, the cooling unit 20 shown in FIG. 2 is installed in the first cooling equipment 1 4 as a unit of the first cooling equipment 1 6 according to the first embodiment. In addition, 6 patterns were installed to transfer transfer pattern A and transfer pattern B. At that time, the upper nozzles 2 2 a and 2 2 b have a nozzle tip height of 1.2 m from the table roller, the arrangement shown in Fig. 4A, the nozzle inner diameter is 6 mm, and the water density is 6 m ³ / m ² min, rod-shaped cooling water spray angle θ 1 0 2 was set to 45 °, and spray speed was set to 8 m Z s.

Also, as Example 2 of the present invention, the nozzle tip height position, nozzle inner diameter, water density, spray angle Θ1, Θ2, and spray speed are the same as Example 1 of the nozzle arrangement shown in FIG. The cooling unit with a rod-shaped cooling water outward angle α of 20 ° is fixed to 1 unit in the 1st cooling facility 14 and 6 units in the 2nd cooling facility 16 and the transfer pattern よび and Transport pattern B was transported.

In Examples 1 and 2, the position where the rod-shaped cooling water collides with the steel sheet was set at a pitch of 60 mm in the width direction of the steel sheet.

On the other hand, as Comparative Example 1, the first cooling equipment 14 and the second cooling equipment 16 are used as conventional general cooling equipment, and the transportation pattern A and transportation pattern B are transported. Went.

Further, as Comparative Example 2, the first cooling equipment 14 and the second cooling equipment 16 are used as the cooling device described in Patent Document 2 in which the film-like cooling water is jetted to oppose the transfer pattern A. In addition, the conveyance pattern B was conveyed.

In each case, after cooling (after sufficient recuperation), the temperature in the width direction of the steel sheet was continuously measured using a radiation thermometer to examine the temperature distribution on the upper surface of the steel sheet. The variation in temperature '(difference between the highest temperature and the lowest temperature) in the stationary part excluding the leading edge, tail edge, and width direction plate edge was defined as temperature unevenness and compared. The temperature unevenness is bow I It almost responded to variations in the mechanical properties of products such as tensile strength. Production efficiency and yield were compared based on Comparative Example 1.

The results are shown in Table 2. Table 2

First, Comparative Example 1 is shower cooling. Due to the effect of the cooling water staying on the steel plate, temperature unevenness is 80 ° C in transport pattern A (accelerated cooling after finish rolling), and transport pattern B (before controlled rolling). Temperature control cooling) was 40 ° C, and the product strength variation was large.

Next, in Comparative Example 2, since the nozzle had to be brought close to the steel plate, the equipment was sometimes damaged when the steel plate warped. Since the steel plate that collided with the equipment did not become a product, the product yield decreased compared to Comparative Example 1. Also, since it took a considerable amount of time to repair the damaged equipment, the production efficiency also declined. Also, the membranous cooling water Since it was supplied, foreign matter adhered to the nozzle outlet and film-like cooling water was not formed, and cooling water could not be blocked in the injection area (cooling area). Therefore, due to the influence of the cooling water staying on the steel plate, the temperature unevenness is 80 ° C for transport pattern A (accelerated cooling after finish rolling), and 4 for transport pattern; B (temperature-controlled cooling before controlled rolling). It was 0 ° C, and the strength variation of the product was large.

In contrast, in Example 1 of the present invention, the height of the nozzle tip was increased to 1.2 m, so that the equipment was not damaged even if the steel plate warped, and the yield was not reduced by trouble. Production efficiency has improved. In addition, since the rod-shaped cooling water was jetted at high speed, the cooling water could be completely blocked in the cooling region, and the temperature unevenness could be kept at a very low value of 8 to 15 ° C.

did it.

Further, in Invention Example 2, the cooling water jetted from the upper nozzles 2 2 a, 2 2 b onto the upper surface of the steel plate 10 merges and quickly moves as shown in the arrow A in FIG. Compared to the case where it falls from the end and does not have an outward angle α, the accumulated cooling water 24 can be dammed up and drained with a small amount of water, and the temperature unevenness is kept at a very low value of 6 to 12 ° C. It was possible to cool uniformly. In addition, because the cooling water could be stopped even if the flow rate and pressure were slightly reduced, the equipment would not require so much pressure or a large amount of water, and an economical equipment design could be performed. It was.

From the above results, the effectiveness of the present invention was confirmed. Example 2

Example 2 of the present invention will be described below.

Here, the rolling time of the present invention example was compared with that of the conventional example when a steel plate having a thickness of 18.5 mm, a width of 256 Omm, and a length of 35 m was manufactured by controlled rolling. . The example of the present invention uses the hot rolling facility according to the above-described embodiment to replace the cooling unit 20 shown in FIG. 2 with 1 unit for the first cooling facility 14 and 6 units for the second cooling facility 16. Installed and went. At that time, the upper nozzles 2 2 a and 2 2 b have a nozzle tip height of 1.2 m from the table roller, the arrangement shown in Fig. 4A, the nozzle inner diameter is 6 mm, and the water density is 6 m ³ / m ² min, Bar coolant injection angle 0 1, Θ 2 4 The injection speed was 5 m / s at 5 °. Further, the steel sheet is rolled while being cooled by the cooling device 20 so that the predetermined controlled rolling start temperature (820 ° C) is obtained at a predetermined controlled rolling start plate thickness (34 mm), and then the cooling equipment 20 This is when cooling is stopped and the finished sheet is rolled to a thickness of 18.5 mm.

In the conventional example, as in the technique described in Japanese Patent Laid-Open No. 2005-000979, after rolling to a predetermined controlled rolling start plate thickness (34 mm), the rolling is stopped and a predetermined temperature is controlled by a temperature adjusting cooling device. This is the case where temperature-controlled cooling is performed to the controlled rolling start temperature (820 ° C), and then the finished sheet thickness is rolled to 18.5 mm.

The results are shown in Figure 13. The circles and marks in the figure represent the respective rolling passes. In this way, the time from extraction of the heating furnace to the end of rolling was 205 seconds in the conventional example, while it was shortened to 165 seconds and 40 seconds in the present invention example. The product quality of this example is not inferior to that of the conventional example.

This confirmed the effectiveness of the present invention. Example 3

As an example of the present invention, based on the second embodiment described above, the cooling unit 20 shown in FIG. 2 is installed in the first cooling equipment 14 in a unit and the second cooling equipment 16 in a unit. went. At that time, the upper nozzles 22a and 22b have a nozzle tip height of 1.2 m from the table roller, the arrangement shown in Fig. 4A, the nozzle inner diameter is 6 mm, and the water density is 6 m ³ / m ² min In addition, the steel sheet was cooled using the cooling equipment shown in Fig. 6 or Fig. 7. At that time, the dip angle Θ with respect to the conveying direction of the rod-shaped cooling water was 45 °, and the injection speed was 8 m / s.

Then, as the present invention example 1, using the cooling equipment shown in FIG. 6, the outward angle _α of the rod-shaped cooling water at the center in the width direction of the steel sheet is 0 °, and the outward angle a of the outermost rod-shaped cooling water is 25 °. In addition, the position where the rod-shaped cooling water collides with the steel sheet was set to 60 mm pitch in the steel sheet width direction.

In addition, as Example 2 of the present invention, the cooling equipment shown in FIG. 7 was used, and the outward angle _α of the rod-shaped cooling water was set to 20 ° -constant, and the position where the rod-shaped cooling water collided with the steel plate was in the width direction of the steel plate. 6 O.mni pitch. As a result, in both inventive examples 1 and 2, the cooling water injected from the upper nozzles 2 2 a and 2 2 b onto the steel plate 10 0. As shown by the arrow A in FIGS. The steel plate 10 was quickly dropped from the 10-width edge and drained by damming up the stagnant cooling water 24 with a smaller amount of water than when there was no outward angle α. Example 4

In the hot rolling line of thick steel plate shown in FIG. 14, the cooling unit 40 shown in FIG. 9 or FIG. 11 is replaced with the first cooling equipment 14 based on the second embodiment described above. 1 unit, 2nd cooling facility 16 6 units were installed in 16 to cool the steel plate. At that time, the injection angle of the rod-shaped cooling water Θ1, Θ2 is 45. The injection speed was set to 12 m / s. The residence zone length L was O mm.

Inventive Example 2 is a case where the cooling unit 40 provided with the shielding plates 26 a and 26 b shown in FIG. 9 is used. At that time, the shielding plates 2'6a and 26b were set so as to be positioned 50 mm above the rod-shaped cooling water in the innermost row. Then, the distance in the transport direction (δ in FIG. 9) between the lowermost position of the shielding plates 2 6 a and 26 b and the point where the rod-shaped cooling water in the outermost row collides with the steel plate 10 is 30 O It was set to mm. 'In addition, Example 3 shows the case where the cooling unit 40 provided with the shielding screens 28a and 28 shown in Fig. 11 is used. At that time, the distance in the transport direction between the lowermost position of the shielding screens 2 8 a and 2 8 that are lifted by the spray of the rod-shaped coolant and the point where the rod-shaped coolant in the outermost row collides with the steel plate 10 (Fig. 1). The δ) in 1 was set to 300 mm.

As a result, in both of the present invention examples 2 and 3, the splashed cooling water 25 that collided with the steel plate 10 and splashed upward was prevented accurately from falling onto the rod-shaped cooling water 2 3 a and 2 3 b. I was able to. As a result, the uniformity of cooling could be maintained. Industrial applicability

In the present invention, since the cooling water is supplied to the upper and lower surfaces of the steel sheet while passing the steel sheet, the equipment length can be shortened and the nozzles can be arranged so that the cooling water faces the conveying direction on the steel sheet. Therefore, the supplied cooling water itself dams up the stagnant cooling water on the steel plate and drains it. Even if there is no place, draining is performed appropriately. As a result, the steel sheet can be appropriately cooled with a compact structure on the hot rolling line when the steel sheet is controlled and rolled.

Further, in the present invention, since a passing-type cooling facility having a large water density of 4 m ³ / m ² min or more is disposed at a position close to the reversible rolling mill, the steel sheet is cooled while being rolled. As a result, a predetermined controlled rolling start temperature can be efficiently obtained, and a reduction in rolling efficiency due to waiting for cooling or the like is avoided. The nozzles are arranged on the steel plate so that the cooling waters face each other in the transport direction, and cooling water having a large water density of 4 m ³ Zm ² min or more is supplied. Residual cooling water on the steel plate will be blocked and drained appropriately, resulting in a stable cooling area.

As a result, when performing the controlled rolling of the steel sheet, the steel sheet is uniformly cooled to obtain a good product quality, and it is possible to prevent a reduction in rolling efficiency due to waiting for cooling or the like.

Further, by using the present invention, the steel sheet can be uniformly cooled to the target temperature at a high cooling rate. As a result, high quality steel sheets can be manufactured.

Claims

The scope of the claims

1. Cooling equipment that supplies cooling water to the upper and lower surfaces of the steel sheet while passing the steel plate while hot rolling the steel sheet, and supplies the cooling water obliquely from above the steel plate to the upper surface of the steel plate. A steel sheet cooling facility comprising: a plurality of nozzles each arranged so that cooling water is opposed to each other in a conveying direction of the steel sheet on the steel sheet.

2. In claim 1, the steel sheet before and / or after rolling is passed through a position adjacent to the reversible rolling mill on the entry side and / or the exit side of the reversible rolling mill for hot rolling the steel sheet. However, the steel sheet cooling equipment is equipped with cooling equipment that supplies water with a water density density of 4 m ³ / m ² min or more on the upper and lower surfaces of the steel sheet.

3. The cooling equipment for steel sheets according to claim 1 or 2, wherein the nozzle sprays rod-shaped cooling water.

4. The header according to claim 3, wherein a header connected to the nozzle for injecting the rod-shaped cooling water is provided above the steel plate, and a tilt angle between the rod-shaped cooling water and the steel plate is 30 ° to 60 °. A steel sheet cooling facility in which the nozzles are arranged.

5. The steel plate according to claim 4, wherein the nozzles are arranged in three or more rows in the conveying direction and in the direction opposite to the conveying direction of the steel plate, and spray the rod-shaped cooling water at a speed of '8 m / s or more. Cooling equipment.

6. In any one of claims 3 to 5, the rod-shaped cooling water of the rod-shaped cooling water is arranged so that 0 to 35% of the component of the jet speed of the rod-shaped cooling water is directed outward in the width direction of the steel sheet perpendicular to the conveying direction. Steel sheet cooling equipment for which the spray direction is set. .

7. In claim 6, the component of the injection speed of the rod-shaped cooling water of 40 to 60% of the total number of nozzles that injects the rod-shaped cooling water is directed outward in the steel plate width direction perpendicular to the conveying direction. The steel sheet cooling equipment that sets the spraying direction of the rod-shaped cooling water so as to have a component that goes in one direction out of the two directions.

8. In claim 6, the number of rod-shaped cooling water having a component toward the direction and the number of rod-shaped cooling water having a component toward the other of the two directions toward the outside in the width direction of the steel sheet perpendicular to the conveying direction is: A steel plate cooling facility for setting the injection direction of the rod-shaped cooling water to be equal. .

9. In claim 6, each nozzle is installed so that the component toward the outside in the steel plate width direction of the spray speed of the rod-shaped cooling water gradually increases as the nozzle installation position goes from the center in the steel plate width direction to the outside. Steel plate cooling equipment. '

1 0. In claim 6, each of the components of the jetting speed of the rod-shaped cooling water toward the outside in the steel plate width direction is constant, and the positions where the rod-shaped cooling water collides with the steel plate are equally spaced in the steel plate width direction. Steel sheet cooling equipment with a nozzle.

1 1. In any one of claims 3 to 8, a plate-like or curtain-like shield is provided above the innermost row of rod-like cooling water and / or stagnant cooling water that jets oppositely. Cooling equipment.

1 2. In Claim 11, the lowermost end of the shield provided above the innermost row of rod-shaped cooling water that jets oppositely is positioned 30 to 500 mm above the upper surface of the steel plate, Is steel sheet cooling equipment.

1 3. The cooling area of the cooling facility according to claim 2, wherein the cooling area of the cooling facility is a position close to the reversible rolling mill excluding the position of the side guide portion arranged on the entry side and / or the exit side from the reversible rolling mill. Steel sheet cooling equipment.

14. The cooling area of the cooling facility according to claim 13, wherein the cooling area is located on the upstream side of a side guide disposed on the inlet side of the reversible rolling mill and / or close to the reversible rolling mill. A steel plate cooling facility located in the vicinity of the reversible rolling mill on the downstream side of the side guide placed on the exit side of the mill.

1 5. A cooling method in which cooling water is supplied to the upper and lower surfaces of a steel sheet while passing the steel plate while hot rolling the steel plate, and arranged so that the cooling water faces each other in the conveying direction of the steel plate on the steel plate. A method for cooling a steel sheet, in which cooling water is supplied obliquely from above the steel sheet toward the upper surface of the steel sheet by the nozzle formed.

16. The cooling device according to claim 15, wherein a cooling facility is disposed at a position adjacent to the reversible rolling mill on the entry side and / or the exit side of the reversible rolling mill for hot rolling the steel sheet, and rolling from the cooling facility. A method of cooling a steel sheet in which cooling water having a water density of 4 m ³ / m ² min or more is supplied to the upper and lower surfaces of the steel sheet while passing the steel sheet before and / or after rolling.

17. The method for cooling a steel plate according to claim 15 or 16, wherein the nozzle sprays a rod-like cooling permanent.

18. The header according to claim 17, wherein a header connected to the nozzle for spraying the rod-shaped cooling water is provided above the steel plate, and an inclination angle between the rod-shaped cooling water and the steel plate is 30 ° to 60 °. The cooling method of the steel plate which cools by arrange | positioning the said nozzle so that it may become.

19. The method for cooling a steel sheet according to claim 18, wherein the nozzles are arranged in three or more rows in the conveying direction of the steel sheet and in a direction opposite to the conveying direction, and the bar-shaped cooling water is injected at a speed of 8 mZ s or more.

2... In any one of claims 15 to 19, the rod is arranged such that 0 to 35% of the component of the jet speed of the rod-shaped cooling water is directed to the outside in the steel plate width direction perpendicular to the conveying direction. Steel plate cooling method for setting the direction of injection of water-like cooling water.

21. In claim 20, the component of the jet speed of the rod-shaped cooling water of 40 to 60% of the total number of nozzles spraying the rod-shaped cooling water is an outer side in the steel plate width direction perpendicular to the conveying direction. A steel plate cooling method in which the P noble direction of the rod-shaped cooling water is set so as to have a component that goes in one direction out of two directions.

2 2. The number of rod-shaped cooling water having a component directed in one direction and the number of rod-shaped cooling water having a component directed in the other of the two directions toward the outside in the width direction of the steel sheet perpendicular to the conveying direction. The method for cooling a steel sheet, in which the injection direction of the rod-shaped cooling water is set so that they are equal.

2 3. In claim 20, as the nozzle installation position moves from the center in the steel plate width direction to the outside, the component of the bar-shaped cold water injection speed toward the outside in the steel plate width direction increases in order. The cooling method of the steel plate which installs each nozzle.

2 4. In claim 20, the component of the spraying speed of the rod-shaped cooling water toward the outside in the steel plate width direction is set to 1 /, and the positions where the rod-shaped cooling water collides with the steel plate are equally spaced in the steel plate width direction. The cooling method of the steel plate which installs each nozzle.

25. Claim 15. In any one of claims 15 to 19, a plate-like or curtain-like shield is provided above the innermost row of rod-like cooling water and / or stagnant cooling water that is jetted oppositely. A method for cooling steel sheets.

26. In Claim 25, the lowermost end of the shield provided above the innermost row of rod-shaped cooling water facing the opposite side is positioned 30 to 50 O mm above the upper surface of the steel plate. The cooling method of the steel sheet.

27. The cooling area of the cooling facility according to claim 16, wherein the cooling area of the cooling facility is located close to the reversible rolling mill excluding the length of the side guide portion arranged on the entry side and / or the exit side from the reversible rolling mill. A method for hot rolling steel sheets.

28. The cooling area according to claim 27, wherein the cooling area of the cooling facility is located near the reversible rolling mill on the upstream side of the side guide disposed on the entry side of the reversible rolling mill and / or the reversible rolling mill. A hot rolling method for a steel sheet, which is a position close to the reversible rolling mill on the downstream side of the side guide disposed on the outlet side of the steel sheet.

29. On the steel plate while passing the unrolled and / or rolled steel plate at a position close to the reversible rolling machine on the entry side and / or exit side of the reversible rolling mill for hot rolling the steel plate. Cooling equipment that supplies cooling water with a water density of 4 m ³ / m ² ni in or more is arranged on the bottom surface, and the cooling equipment on the top surface supplies cooling water obliquely from above the steel plate toward the steel plate. A hot rolling facility for a steel sheet, comprising a nozzle, wherein the nozzles are arranged so that cooling water faces each other in a conveying direction of the steel sheet on the steel sheet.

30. The hot-rolling equipment for steel sheets according to claim 29, wherein the nozzle sprays rod-shaped cooling water.

31. The cooling area of the cooling equipment according to claim 29 or 30, characterized in that the cooling region of the cooling equipment is located between the reversible rolling mill and the side guides arranged on the entry side and / or exit side thereof. Steel sheet hot rolling equipment.

3 2. A cooling facility is arranged at a position close to the reversible rolling machine on the inlet side and / or the outlet side of the reversible rolling mill for hot rolling the steel sheet, and before the rolling and / or rolling from the cooling facility. Cooling water with a water density of 4 Hi ³ Zm ² min or more is supplied to the upper and lower surfaces of the steel plate while passing the subsequent steel plate. At that time, the cooling water is applied to the upper surface of the steel plate on the steel plate. By nozzles arranged to face each other in the conveying direction of the steel A method of hot rolling a steel sheet, wherein cooling water is supplied obliquely from above the plate toward the steel sheet.

3. The method of hot rolling a steel sheet according to claim 32, wherein the nozzle sprays rod-shaped cooling water.

34. The steel sheet according to claim 32, characterized in that the cooling area of the cooling facility is located between the reversible rolling mill and the side guides arranged on the entry side and / or exit side thereof. Hot rolling method.

3 5. Above the hot steel plate, 4111 ³ 01 ² 111 i A rod-shaped cooling water with a water density of more than i ϋ is injected. A heading connected to the nozzle is installed, and the yield force between the rod-like cooling water and the hot steel plate 0. The steel plate cooling equipment is characterized in that the nozzles are arranged so as to face each other in the conveying direction of the hot steel plate at ˜60 °.

36. The steel sheet cooling equipment according to claim 35, wherein five or more rows of the nozzles are arranged in the conveying direction of the hot steel sheet, and the rod-shaped cooling water is injected at a speed of 8 m / s or more.

3 7. The steel sheet cooling according to claim 35 or 36, characterized in that a plate-like or curtain-like shield is provided above the rod-like cooling water in the innermost row facing oppositely. .Facility.

38. The steel sheet cooling equipment according to claim 37, wherein the lowermost end of the shield is a position 300 to 500 mm above the upper surface of the hot steel sheet.

3 9. A bar-shaped cooling water with a water density of 4m ³ / m ² ni in or more is sprayed above the hot steel plate, and a header connected to the nozzle is installed, and the angle between the bar-shaped cooling water and the hot steel plate is 30 ° A cooling method for a steel sheet, comprising cooling at 60 ° by arranging the nozzles so as to face each other in the conveying direction of the hot steel sheet.

40. The method for cooling a steel sheet according to claim 39, wherein five or more rows of the nozzles are arranged in the conveying direction of the hot steel sheet, and the rod-shaped cooling water is sprayed at a speed of 8 mZ s or more.

41. The method for cooling a steel sheet according to claim 39 or 40, wherein a plate-like or curtain-like shield is provided above the rod-like cooling water in the innermost row that is jetted oppositely.

4 2. The method for cooling a steel sheet according to claim 41, wherein the lowermost end of the shield is positioned 30 to 500 mm above the upper surface of the hot steel sheet.