Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
  • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
  • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
  • B21B45/0203—Cooling
  • B21B45/0209—Cooling devices, e.g. using gaseous coolants
  • B21B45/0215—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes
  • B21B45/0218—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes for strips, sheets, or plates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
  • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
  • B21B37/44—Control of flatness or profile during rolling of strip, sheets or plates using heating, lubricating or water-spray cooling of the product

Definitions

• the present invention relates to a steel plate cooling equipment and a cooling method.
• 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.
• 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).
• controlled rolling start temperature controlled rolling start temperature
• controlled rolling start thickness the thickness of the controlled rolling
• 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.
• 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.
• 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.
• 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.
• a temperature-controlled cooling facility installed at a position about 20 m away from the rolling mill.
• JP-A-62-260022 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.
• JP-A-62-260022 and JP-A-59-144513 have significant problems in ensuring cooling uniformity and equipment costs.
• the slit nozzle must be brought close to the steel sheet, and the steel sheet with the warped tip and tail ends is cooled.
• 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.
• the equipment cost for installing the lifting mechanism is high.
• 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.
• 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.
• 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
• the present invention has the following features.
• 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.
• 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.
• the nozzle cools the steel plate spraying rod-shaped cooling water. 4.
• 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.
• 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.
• 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 is equal.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• the nozzle is a method of cooling a steel plate that sprays rod-shaped cooling water.
• 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
• 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.
• 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.
• 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 sheet cooling method is to set the injection direction of the rod-shaped cooling water so as to be equal.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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 °.
• 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.
• 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.
• the steel sheet is cooled while being rolled.
• 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.
• the steel sheet 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.
• 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.
• ⁇ 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.
• FIG. 1 is a layout diagram of a steel sheet hot rolling facility according to an embodiment of the present invention.
• 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.
• FIG. 3 and 16 are detailed views of the cooling facility 20.
• 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.
• 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.
• 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)
• 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.
• 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 ⁇ 2.
• 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.
• 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.
• the cooling region 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.
• 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.
• FIGS. 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.
• 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 the width direction it is installed so that cooling water can be supplied to the entire width of the passing steel sheet 10.
• 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. .
• the lower header 3 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.
• 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 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.
• the cooling zone is a reversible rolling mill 1 2 Work roll center 1 2
• cooling equipment 20 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.
• 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.
• 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.
• 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.
• the injection angle ⁇ 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 ⁇ 1 and ⁇ 2 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 ⁇ 1 and ⁇ 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.
• the spray angle 0 1 and the injection angle ⁇ 2 are not necessarily equal. More preferable injection angles 0 1 and ⁇ 2 are 40 ° to 50 °.
• 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.
• 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.
• the injection speed is preferably 3 O mZ s or less.
• the inner diameter of the nozzle only needs to be in the range of 3 to 8 mm.
• 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
• 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.
• the positions of the tips of the upper nozzles 2 2 a and 2 2 b should be separated from the pass line.
• 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.
• 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.
• Cooling equipment (also called cooling unit) 20 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
• 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.
• 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.
• the equipment length can be shortened.
• 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
• an auxiliary device such as a draining roll is installed. Even if it does not drain properly.
• the steel sheet can be appropriately cooled with a compact structure on the hot rolling line when the steel sheet is controlled and rolled.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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 is . ⁇
• the dip angle with respect to the transport direction is ⁇
• the steel plate width is shown as ⁇ .
• 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
• 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 ⁇ with respect to the transport direction is 45 ° and 50 °. The ratio of velocity component in the width direction is 0 to 35%.
• the tilt angle ⁇ is 45 ° with respect to the transport direction
• the outward angle a is 0 to 25 °
• the tilt angle ⁇ force with respect to the transport direction is 50 °.
• the outward angle ⁇ is 0 ⁇ 30. This is the case.
• 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.
• the rod-shaped cooling water from the central nozzle in the steel sheet width direction has an outward angle ⁇ of 0 °, and the outward angle ⁇ gradually increases as the nozzle installation position goes outward in the steel sheet width direction.
• 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).
• 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.
• 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.
• 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.
• 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 is made equal.
• the outward angle ⁇ 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.
• 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
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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 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.
• 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.
• 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.
• 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.
• 6 patterns were installed to transfer transfer pattern A and transfer pattern B.
• 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 ⁇ 1 0 2 was set to 45 °, and spray speed was set to 8 m Z s.
• Example 2 of the present invention the nozzle tip height position, nozzle inner diameter, water density, spray angle ⁇ 1, ⁇ 2, 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 ⁇ 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 ⁇ ⁇ and Transport pattern B was transported.
• 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.
• 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.
• the conveyance pattern B was conveyed.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• Example 2 of the present invention will be described below.
• 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.
• 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.
• the nozzle inner diameter is 6 mm
• the water density is 6 m 3 / m 2 min
• Bar coolant injection angle 0 1, ⁇ 2 4 The injection speed was 5 m / s at 5 °.
• 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.
• 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.
• 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
• the steel sheet was cooled using the cooling equipment shown in Fig. 6 or Fig. 7.
• the dip angle ⁇ with respect to the conveying direction of the rod-shaped cooling water was 45 °
• the injection speed was 8 m / s.
• the outward angle ⁇ of the rod-shaped cooling water at the center in the width direction of the steel sheet is 0 °
• the outward angle a of the outermost rod-shaped cooling water is 25 °
• 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.
• Example 2 of the present invention the cooling equipment shown in FIG. 7 was used, and the outward angle ⁇ 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.
• the cooling water injected from the upper nozzles 2 2 a and 2 2 b onto the steel plate 10 0.
• 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 ⁇ .
• Example 4 the cooling equipment shown in FIG. 7 was used, and the outward angle ⁇ 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.
• 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.
• the injection angle of the rod-shaped cooling water ⁇ 1, ⁇ 2 is 45.
• the injection speed was set to 12 m / s.
• the residence zone length L was O mm.
• 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 ( ⁇ 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.
• Example 3 shows the case where the cooling unit 40 provided with the shielding screens 28a and 28 shown in Fig. 11 is used.
• the ⁇ ) in 1 was set to 300 mm.
• 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.
• 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.
• 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.
• 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.
• 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.

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• Engineering & Computer Science (AREA)
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• Heat Treatments In General, Especially Conveying And Cooling (AREA)
• Heat Treatment Of Strip Materials And Filament Materials (AREA)

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• 2006
  • 2006-08-29 KR KR1020087004608A patent/KR100973691B1/ko active IP Right Grant
  • 2006-08-29 WO PCT/JP2006/317395 patent/WO2007026906A1/ja active Application Filing
  • 2006-08-29 EP EP06783167.7A patent/EP1935522B1/en active Active
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