KR100362674B1 - Waterless tip end cooling device of hot rolled steel sheet - Google Patents

Abstract

The present invention is a water-free end of a hot rolled steel sheet to improve the error rate of the product by removing the material deviation with the other parts cooled by quenching the front end of the steel sheet passed through the pinch roll in a water-free state at the winding machine inlet side It relates to a cooling device, the cooling device is installed in the upper and lower portions of the table roll for transferring the steel sheet discharged from the rolling mill to the pinch roll, and the cold-free end portion cooling device of the hot rolled steel sheet provided in the pinch roll and the gunch installation The upper and lower nozzle assemblies and hot rolled steel sheets are provided in the upper and lower guide tables installed at the upper and lower sides of the pinch roll and the upper and lower sides of the winder to guide the steel sheet to the winder. When the tip portion passes the upper and lower nozzle assemblies, the cooling water is supplied to the upper and lower nozzle assemblies before the coil is wound. It depends as a control means for cooling the end.

Description

Waterless tip end cooling device of hot rolled steel sheet

The present invention relates to an apparatus for cooling the water-free front end of a thin plate traveling with a winder after hot rolling, and more specifically, to quench only the water-free portion at the inlet side of the winder to reduce material deviation from other parts. The present invention relates to a waterless tip end cooling device of a hot rolled steel sheet, which is capable of improving a real error rate.

In general, the hot rolled steel sheet is cooled to an appropriate temperature while passing through a cooling section, and then wound into a coil-shaped product by a winder.

FIG. 1 schematically shows that cooling of the steel sheet S takes place in a section L appropriately set between the final rolling mill 1 and the winding machine 2, and the steel sheet S is wound from the exit of the rolling mill 1. It travels at a high speed by the table roll 4 provided continuously to the pinch roll 3 entrance of the side of a blower 2 electric current at a fixed interval.

The nozzle installation configuration for spraying the coolant in the cooling section L is schematically illustrated in FIG. 2, which is an upper injection nozzle 5 and a lower partial nozzle (L) respectively positioned on the upper and lower sides of the steel sheet S. 6), and the upper and lower injection nozzles (5) and (6) form a slit-type injection hole continuous in the width direction of the steel plate (S) to form a laminar flow type (Laminar Flow Type) (7) (7 ') is sprayed on the upper and lower surfaces of the steel sheet S, respectively. Of course, the upper and lower injection nozzles 5 and 6 are installed in a plurality at regular intervals with respect to the steel sheet S traveling direction, and are supplied with cooling water through the cooling water supply pipe 52.

The problem that occurs in such a steel sheet cooling facility is that, when the steel sheet S traveling at high speed along the table roll 4 is a thin plate (for example, a steel plate having a thickness of 2.5 mm or less), the top and bottom spray nozzles ( 5) It receives a strong external force in a direction perpendicular to the driving direction while colliding with the high-pressure coolant (7) (7 ') injected from the (6), which acts as a resistance element in the plate of the tip. That is, in the case of a thin plate, the leading end thereof is bent and proceeds to be inserted between the table rolls 4 to stop the operation of the equipment, thereby lowering the operating efficiency of the equipment, or to enter the winding machine 2 in a bent state, resulting in poor winding. It becomes a factor.

In order to prevent this, in the case of thin plates, so-called muju does not cool the part by blocking the coolant injected from the upper and lower injection nozzles 5 and 6 when the proper length of the tip portion (for example, 50 m) passes. The sheet was wound in the form of a coil by the winder 2 via a pinch roll 3 by passing through a male state.

However, if the tip is not cooled in this way, material deviations from other cooled parts are severely generated, and therefore, parts that are wound in a water-free state cannot be manufactured as they are, which is not preferable in terms of error rate. It was not.

The present invention is to solve such a conventional problem, by removing the material deviation from other parts cooled by quenching the front end of the steel sheet passed through the pinch roll in the water-free state at the winder inlet side to reduce the error rate of the product It is an object of the present invention to provide a water free tip cooling device for hot rolled steel sheet to be improved.

1 is a schematic view showing a winding process of a hot rolled steel sheet.

2 is a schematic diagram schematically showing a state of coolant injection in the cooling section.

Figure 3 is a block diagram showing a water-free tip end cooling device of a hot rolled steel sheet according to the present invention.

Figure 4 is a schematic diagram showing the installation position of the upper and lower partial nozzle assembly for the rapid cooling of the front end portion of the present invention.

Figure 5 is an exemplary view showing a detailed configuration of the upper and lower injection nozzle assembly according to the present invention.

6 is a flowchart showing the operation of the central controller according to the present invention.

Figure 7 is a block diagram showing a part of the configuration of a program block controller for controlling the rapid cooling spray according to the present invention.

* Description of the symbols for the main parts of the drawings *

2: winding machine 3: pinch roll

8: Operator terminal 9: Central controller (SCC)

10: Programmable Logic Controller (PLC)

12: solenoid valve 100: material detector

122: on-off valve 120: cooling water supply piping

110: upper nozzle assembly 110 ': lower nozzle assembly

As a technical configuration for achieving the above object, the present invention is provided in the cooling device provided in the upper and lower portions of the table roll for transferring the steel sheet discharged from the rolling mill to the pinch roll, the pinch roll, the winding device comprising a winder In the cold-free tip end cooling device of hot rolled steel sheet,

Upper and lower nozzle assemblies installed at upper and lower portions of the pinch rolls and the upper and lower sides of the winder and guide the steel sheet to the winder so that the spraying direction is directed to the steel sheet;

The waterless tip of the hot rolled steel sheet is provided with control means for cooling the waterless tip of the hot rolled steel sheet before winding by supplying cooling water to the upper and lower nozzle assemblies when the upper and lower nozzle assemblies pass through the upper and lower nozzle assemblies.

Hereinafter, the present invention will be described in more detail.

Figure 3 is a schematic configuration diagram showing the whole water free tip cooling device of the hot rolled steel sheet according to the present invention, which is mounted on the upper and lower portions of the steel sheet (S) between the pinch roll (3) and the winder (2) An upper and lower nozzle assembly 110 for spraying cooling water, an opening / closing valve 122 installed in the cooling water supply pipe 120 of the upper and lower nozzle assemblies 110 to open and close the flow of cooling water, and the opening / closing valve ( 122 is installed at an arbitrary position between the solenoid valve 12 for controlling the opening / closing operation, and the upper spray nozzle 5 and the pinch roll 3, which are installed above the table roll 4 and spray coolant. Rolled while tracking the position of the material through data communication with the material detector (HMD: Hot Metal Detector) (100) for detecting the material, the operator terminal (8) that the rolling operation status is displayed, and the programmable logic controller (10). The tip of the material is completely absent depending on the material thickness and material temperature. The central controller 9 which outputs the determination result to the programmable logic controller 10 and the operator terminal 8 by judging whether the water is to be partially pumped or completely filled, and the detection signals of various detectors and sensors are output to the central controller. And a program block controller 10 which is applied to (9) and checks the output signal of the material detector 100 and drives the solenoid valve 12 in accordance with the result of judging whether water is supplied from the central controller 9.

Each of the upper and lower nozzle assemblies 110 is connected to the cooling water supply pipe 120 to receive a high pressure cooling water therefrom, and the cooling water supply pipe 120 flows the cooling water supplied to the upper and lower nozzle assemblies 110. Opening and closing valve 122 that can open and close (it is also possible to have a function to adjust the coolant flow rate) is provided. Of course, the manual shut-off valve 124 may be installed at the current side of the shut-off valve 122 for abnormal operation of the shut-off valve 122 or manual shutoff.

Figure 4 is a front view showing in detail the upper and lower nozzle assembly (110, 110 ') is installed, the upper and lower portions of the pinch roll (3) exit side and the winder (2) inlet side is provided with a steel sheet (S) The upper and lower nozzle assemblies 110 and 110 'may be mounted on each of the flat upper and lower guide tables 130 and 130' to guide the winder 2 more smoothly. see. Unexplained reference numeral 140 is provided with a plurality of tension reel outer surface portion of the winder (2) to guide the front end of the steel sheet introduced to the winder (2) side can be wound more smoothly on the tension reel This is a guide roll to help you.

5 is a view illustrating the upper and lower nozzle assemblies 110 and 110 'in more detail, and each of the upper and lower nozzle assemblies 110 and 110' is connected to a cooling water supply pipe 120 to supply cooling water. The injection nozzles 114 and 114 'having headers 112 and 112' which can be received, and the nozzles are formed in the headers 112 and 112 'to face the surface of the steel sheet S, It is shown that a plurality of pieces are mounted at regular intervals in the width direction. Of course, it is preferable that the area of the cooling water sprayed from the injection nozzles 114 and 114 ′ is diffused as it is farther from the injection hole, and the cooling water regions thus spreading overlap each other on the surface of the steel sheet S. It is desirable to ensure that there is at least a portion where no cooling water injection is made. In the present invention, the nozzle assemblies 110 and 110 ′ have been described with a configuration in which a plurality of nozzle assemblies 110 and 110 ′ are mounted at a predetermined interval with respect to the width direction of the steel sheet S, but are not limited thereto. This is because even if such a nozzle assembly is used, it is included in the scope of the technical idea of the present invention.

Fig. 6 is a flowchart showing the operation flow of the central controller 9 according to the present invention, wherein the central controller 9 is a production schedule from an upper business computer (not shown) which schedules a production schedule as received in marketing. When the rolling command data according to the transmission (601), the sensor or timer signal received from the programmable logic controller 10 to track the position of the current material (602), the material is located in the front of the mill Crop shear (CROP SHEAR: material When the device (not shown) for cutting the tip portion (not shown) is operated (603), the rolling command data received from the upper business computer (BC) is received (604) while the material passes through the rolling mill and passes through the rolling mill (604). It is checked whether the thickness t of the following material is 2.0 mm or less (605). If the material thickness t is 2.0 mm or less, the front end of the rolled material is set to be completely water free (606). If the thickness (t) of the material is not less than 2.0, it is checked whether it is thicker than 2.0 mm and less than 2.5 mm (607). In the above, when the material thickness t is more than 2.0 and 2.5 or less, it is checked whether or not the material temperature when discharged from the rolling mill is 600 ° C. or less (608). Here, if the material thickness is greater than 2.0mm and less than 2.5mm and the temperature is less than 600 ° C, the material is set to be partially filled with its tip (609), and the material thickness does not exceed 2.5mm or exceeds 2.5mm. When the temperature of the material exceeds 600 ℃ it is set to completely water the front end of the material (610). When the main water supply is determined as described above, by checking whether the finishing rolling rear temperature sensor (not shown) installed on the discharge side of the rolling mill is turned on, that is, whether the corresponding material is discharged from the rolling mill, and when the starting material is discharged from the rolling mill, Then, the programmable controller 612 outputs the judgment result of the main water supply.

As described above, whether or not the leading end of the material to be wound from the central controller (9) is determined, the programmable controller 10 receives the result is a phase between the pinch roll (3) and the winder (2), Cooling water injection operation by the lower nozzle assembly (110,110 ') is controlled, which is made in three forms as follows.

First, in the case of completely free of water, the tip of the material (within 50m from the top of the material) is blocked by the flow of cooling water while passing through the cooling section (L) and passes through the water free of water. After the tip portion passes, cooling water is supplied by supplying cooling water to the upper and lower partial nozzles 5 and 6 of the cooling section L. In this way, when the top portion of the material entering the no water is detected by the material detector 100, the programmable logic controller 10 checks the conveying distance of the material while the front end portion of the material passes between the upper and lower nozzle assembly (110,110 ') The solenoid valve 12 is driven and the on / off valve 122 is opened and closed, and cooling water is supplied to the upper and lower nozzle assemblies 110 and 110 ′. Therefore, the water-free end of the material (within 50m from the top) is quenched by the cooling water injected from the upper and lower nozzle assemblies 110 and 110 'past the pinch roll 3, and then wound up in the winder 2.

Since the thickness of the no water repellent material is thinner than about 2.0mm, the running performance is extremely poor when water is injected, and thus the water free material must enter the full water free form, and the coolant is placed just before the winder (2). Even near rapid cooling by spraying can achieve the desired target winding temperature.

Secondly, in the case of some main casting materials, since the thickness of this material is relatively thick, the target winding temperature cannot be obtained only by rapid cooling by the upper and lower partial nozzle assemblies 110 and 110 'in front of the winder 2. Therefore, by checking the PLG signal of the rolling roll driving motor installed on the final stand of the rolling mill, the central controller 9 is a part of the section within the cooling section L at a predetermined distance (for example, 12.2M) interval (e.g., For example, out of 15 banks, only # 1 and # 2 banks are operated to allow cooling water to be injected. And, if the top portion of the material entered into the number of weeks as described above is detected by the material detector 100 while the program block controller 10 is passed through the front end of the material (section 50m from the top) as in the case of the completely free material The solenoid valve 12 is controlled to open the on-off valve 122 so that rapid cooling is achieved through injection from the upper and lower partial nozzle assemblies 110 and 110 '.

As described above, the cooling operation in the case of partial water is described as an example, and the finishing rear temperature (FDT) of the material determined as the partial water is 850 ± 20 ° C., and the winding target temperature CT is 580 ± 20 ° C. When the target hardness TS is 55 ± 3Kg / mm2, as in the above example, if only # 1 and # 2 banks are driven out of 15 banks, 1 in the cooling section L on the table roll 4 The amount of cooling water per bank is 20 l / sec, which results in a temperature drop of about 45 ° C. And the cooling temperature by air cooling at the time of no water injection is about 130 degreeC, and the cooling temperature by the rapid cooling between the pinch roll 3 and the winder 2 is about 40 degreeC. Therefore, according to some of the number of cycles as described above, a total of 160 ℃ by 130 ℃ lowering by air cooling, 90 ℃ lowering by the cooling water spray of # 1, # 2 bank, 45 ℃ lowering by rapid cooling between the pinch roll and the winder Since the cooling is performed, some castings having a finishing rear surface temperature of about 850 ° C can reach the target winding temperature of about 580 ° C.

In general, the relationship between the coiling temperature and the hardness TS decreases the hardness TS by 0.3 Kg / mm 2 each time the coiling temperature rises by 10 ° C. Therefore, as in the prior art, the hardness is 0.3Kg / mm2 × 4 = 1.2Kg / mm2 and 0.3Kg / mm2 by the operation of the # 1, # 2 banks, compared with the case of winding up in a completely free of water. × 9 = 2.7 Kg / mm 2, rising to obtain a total synergistic effect of 3.9 Kg / mm 2.

In addition, the complete injection material having a thickness of 2.5 mm or more is not affected by the progression during pouring, and operates the entire bank installed in the cooling section of the table roll to spray the cooling water through the upper and lower partial nozzles (5.6). In other words, the whole section of the material is poured by water and cooled without any water free period. In the upper and lower partial nozzle assemblies 110 and 110 'between the pinch roll 3 and the winder 2, the on-off valve 122 is closed by driving the solenoid valve 12 which is controlled by the programmable controller 10. The cooling water supply is cut off, and there is no rapid cooling operation. Therefore, it winds up as it is in the winder 2 past the pinch roll 3.

The configuration of the part controlling the cooling water injection in the upper and lower partial injection nozzles 110 and 110 'between the pinch roll 3 and the take-up machine 2 in the programmable logic controller 10 will be represented as shown in FIG. Can be. That is, the material detector installed at the rear end of the cooling section by calculating the calculated value (TRACKING signal) of the material tip position expressed by the transport distance from the arbitrary reference position (for example, material discharge point from the rolling mill) in the tracking calculation unit 701. The correct position is calculated by correcting with the pull-out arc of the laser sensor LASER provided on the 100 and the winder 3. Therefore, the output value A from the tracking calculation section 701 indicates the position of the current work top section.

In addition, the injection section setting unit 702 compares the output value A of the tracking calculation unit 701 with the reference value K, and the front end portion of the raw material is a rapid cooling water injection position (that is, upper and lower partial nozzle assembly 110, 110). ), And when the distal end portion of the material reaches the rapid cooling position, the relay transistor R1 is operated by turning on the switching transistor TR1 for a predetermined time from the time point.

While the relay R1 is operating, an operating power source 12 is applied to the solenoid valve 12 to open the on / off valve 122.

Accordingly, the coolant is supplied to the upper and lower partial nozzle assemblies 110 and 110 ′ while the on / off valve 122 is opened to rapidly cool the front end of the material (that is, 50 m from the top).

As described above, the injection point of the upper and lower part nozzle assembly (110, 110 ') is the point of time when the position of the top of the material corrected by the material detector 100 reaches the rapid cooling position, the injection stop point is arbitrarily selected by the operator For example, if the top portion of the work piece is set up to 50m as a part to be rapidly cooled, the electronic switch after the time it takes to wind up to 50m from the work saw part, depending on the winding speed of the winder 2. You can program it so that SW1) is on.

As described above, the present invention by installing a near rapid cooling device in the front of the winder to cool the water-free water section immediately before the winding, it does not cause not only winding failure but also material deviation of the material, thereby improving quality as well. There is an excellent effect to reduce the cost due to the cut off part.

Claims (3)

In the cooling device provided in the upper and lower portions of the table roll for transporting the steel sheet discharged from the rolling mill to the pinch roll, and the cold-free end portion cooling device of the hot rolled steel sheet provided in the gunch device consisting of a pinch roll and a winder, Upper and lower nozzle assemblies installed at upper and lower portions of the pinch rolls and the upper and lower sides of the winder and guide the steel sheet to the winder so that the spraying direction is directed to the steel sheet; Hot rolled steel sheet characterized in that the water-free end of the hot rolled steel sheet is provided with a control means for supplying cooling water to the upper and lower nozzle assemblies when passing through the upper and lower nozzle assembly to cool the water-free end of the hot rolled steel sheet before winding. Waterless tip cooler The method of claim 1, wherein the control means An on / off valve installed in the cooling water supply pipe of the upper and lower nozzle assemblies to control the cooling water flow; An electromagnetic valve for controlling the opening and closing operation of the on / off valve; A central controller that receives the rolling data while the rolling command is sent and receives the rolling data to classify and set the hot rolled steel sheet into a totally free end portion, a partial end portion casting portion, and a total casting portion according to the thickness; When the hot-rolled steel sheet from the central controller is set to completely free of water, the solenoid valve passes the tip of the hot-rolled steel sheet without water, and the solenoid valve is controlled to open while the tip portion passes through the upper and lower nozzle assemblies. And, if it is classified as a part of the main material, while operating the part of the cooling device installed on the table roll while the front end passes, and controls the solenoid valve to open the valve when passing through the upper and lower nozzle assembly, When classified as handmade, the cold-free end of the hot rolled steel sheet is characterized in that the programmable controller for controlling the solenoid valve to close the on-off valve while operating the entire portion of the cooling device. The method of claim 2, wherein the central controller When the thickness of the hot rolled steel sheet is 2.0mm or less, it is classified and set as a complete no-water free material.The thickness of the hot rolled steel sheet is thicker than 2.0mm and 2.5mm or less, and it is classified and set as some casting material when the temperature is 600 ℃ or less. Cooling device for the endless end of hot rolled steel sheet characterized in that if the thickness is greater than mm or the temperature is higher than 600 ℃.