KR19990052832A - Underwater hot rolling apparatus and method - Google Patents

Abstract

The present invention is to prevent the damage and deformation of the equipment due to the collision with the material to be rolled through the nozzle to penetrate the nozzle on the upper surface of the wiper frame to enable stable underwater rolling, and to adjust the spray pressure of the coolant to scale The present invention relates to an improved underwater hot rolling apparatus and method for easily removing surface defects.

According to the present invention, a plurality of one-side injection nozzles are mounted in a width direction through a wiper frame for fixing a wiper at a right angle, and the one-side injection nozzles are inserted into and fixed to a nozzle assembly hole which is processed at an angle to the cooling water jetting side, and a lower end thereof. A coolant spray unit configured to not protrude from the surface of the rolled material side of the wiper frame; A coolant pump connected to the one-side injection nozzle through a coolant supply pipe to continuously supply coolant; It is equipped with a variable cooling water supply valve mounted on the cooling water supply pipe to automatically control the opening degree to control the injection pressure, a pressure variable signal generator connected to the variable cooling water supply valve, and a submersible rolling control computer and a host computer of rolling line In accordance with the rolling information of the rolled material, the control unit for adjusting the opening degree of the variable cooling water supply valve and adjusts the coolant pressure injected to the rolled material provides a hot underwater rolling apparatus comprising a.

Description

Underwater hot rolling apparatus and method

The present invention relates to an underwater hot rolling apparatus and a method for spraying and rolling a cooling water of a suitable pressure between the rolled material and the finishing rolling roll immediately before the rolled material is rolled by a rolling roll during hot rolling of a metal plate. By spraying the cooling water through the nozzle on the upper surface of the wiper frame, it is possible to prevent damage and deformation of the equipment due to collision with the material to be rolled, so that it can be rolled stably and the surface defects such as scale by adjusting the spraying pressure of the cooling water. The present invention relates to an improved underwater hot rolling apparatus and method for easily removing the same.

In general, the hot rolling is performed by spray cooling between the stands of the finishing mill to suppress the growth of the oxide film formed on the surface of the plate, and to control the scale of oxidation, but this requires a large amount of cooling water at a time. In addition, the temperature loss caused by such cooling has also been a cause of tissue nonuniformity inside the plate.

As shown in FIG. 7, the spray header 230 is installed at the mouth just before the rolled material 220 enters and rolls between the rolling rolls 210 of the finishing mill 200, and the nozzle ( 232 has been adopted to spray the cooling water, but the spray header 230 and the nozzle 232 is located inside the wiper frame 240, the collision with the distance to the rolled material 220 is close There is a problem of equipment accidents due to frequent damages, and when the type of the rolled material 220 is changed by spraying the coolant at a predetermined pressure, the amount of coolant does not match the amount of cooling of the rolled material 220. Insufficient cooling or subcooling of 220 resulted in insufficient control of the generation of oxidized scale on the surface of the rolled material.

The present invention is to solve the conventional problems as described above, the object is to spray the cooling water of the appropriate pressure between the finishing roll and the rolled material to locally cool the surface, the water film between the rolled material and the rolling roll during rolling Improved underwater hot rolling device to easily prevent the occurrence of scale defects, which are surface defects of the hot rolled sheet through the underwater rolling to form a system, and to prevent deformation caused by collision with the rolled material in advance. It is in providing a method.

1 is a block diagram showing a cooling water injection unit of the underwater hot rolling apparatus according to the present invention;

2 is an exploded perspective view showing a state in which the one-side injection goggles of the underwater hot rolling apparatus according to the present invention are assembled to the wiper frame;

3 is a cross-sectional view showing a state in which the one-side injection goggles of the underwater hot rolling apparatus according to the present invention are assembled to the wiper frame;

4 is a schematic view showing the overall underwater hot rolling apparatus according to the present invention;

5 is a graph showing the relationship between the underwater injection pressure and the scale defect generation as an embodiment of the present invention;

6 is a flow chart showing the underwater hot rolling method according to the present invention;

7 is a cross-sectional view showing a cooling water injection device according to the prior art.

Explanation of symbols on the main parts of the drawings

7 ..... Coolant jet 10 ..... Single side injection nozzle

12 .... Cooling water supply hose 22 ..... Nozzle

30 .... Variable coolant supply valve 35 ..... Coolant supply pump

40 .... Pressure variable generator 45 ..... Underwater rolling control computer

50 .... host computer 200 .... finishing mill

210 ... rolling roll

In order to achieve the above object, the present invention is directed to an underwater hot rolling apparatus for rolling by spraying cooling water of appropriate pressure between the rolled material and the finishing rolling roll just before the rolled material is rolled by a rolling roll during hot rolling of a metal plate. A plurality of one-side injection nozzles are mounted in the width direction by passing through the wiper frame for fixing the wiper at right angles. A coolant spray unit configured not to protrude from the surface of the rolled material side of the frame; A coolant pump connected to the one-side injection nozzle through a coolant supply pipe to continuously supply coolant; It is equipped with a variable cooling water supply valve mounted on the cooling water supply pipe to automatically control the opening degree to control the injection pressure, a pressure variable signal generator connected to the variable cooling water supply valve, and a submersible rolling control computer and a host computer of rolling line In accordance with the rolling information of the rolled material, a control unit for adjusting the opening degree of the variable cooling water supply valve and for adjusting the coolant pressure injected to the rolled material;

In the present invention, in the hot-rolling method of underwater rolling, in which hot rolled material is hot rolled by a rolling roll, a cold water of appropriate pressure is injected between the rolled material and the filament rolling roll to roll the rolled material. Detecting a state of approaching the rolling mill side; Converting the cooling water proper injection pressure on the basis of the rolling information of the rolled material in the control computer; Adjusting the cooling water injection pressure by adjusting the opening degree of the variable cooling water supply valve based on the cooling water injection pressure converted from the control computer; And spraying the rolled material such that the coolant impact pressure is at least 18 kgf / cm 2 or more.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

An underwater hot rolling apparatus 1 according to the invention is shown in FIGS. 1 to 4. This is when the rolled material 220, which has been subjected to the rough rolling process, enters and rolls between the rolling rolls 230 of the finishing mill 200, and varies the cooling water between the rolls 230 and the rolled material 220 according to the rolling load. By spraying to cool the surface of the roll 230 and the rolled material 220 immediately before rolling, and to form a water film between the rolled material 220 and the rolling roll 210 during rolling.

The underwater hot rolling apparatus 1 of the present invention is a wiper 242 for removing foreign materials from the rolling roll 210 of the finishing mill 200 and preventing the cooling water from falling on the surface of the rolled material 220. And, as shown in Figures 2 and 3, the upper surface of the frame 240 for fixing the wiper 242, the coolant injection unit 7 is formed, which is a number of one-sided injection nozzle 10 in the width direction ) Is installed, and the one-side injection nozzle 10 has a structure connected to the cooling water supply hose 12, respectively.

On the other hand, the one-side injection nozzle 10 penetrates at right angles to the wiper frame 240, and press-fits into the nozzle assembly hole 20 in which the injection port 22 is formed by machining the cooling water injection side at an angle so that the cooling water injection does not interfere. It is inserted in the manner, the upper end portion is formed with a screw portion (10a), the screw portion (10a) is fixed to the cooling water supply hose 12 by a fixed socket 24. In addition, the one-side injection nozzle 10 has a lower end portion 10b of the rolled member 220 of the wiper frame 240 in order to prevent damage due to a collision when the front end portion of the rolled member 220 enters the rolling roll 210. Assembled in a structure that does not protrude beyond the side surface (240a).

The cooling water supply hose 12 is connected to the variable cooling water supply valve 30, and the cooling water supply valve 30 is connected to the cooling water pump 35 through the cooling water pipe 32. In addition, the variable coolant supply valve 30 is connected to the control unit 42, the control unit 42 is connected to the pressure variable signal generator 40, the pressure variable signal generator 40 is the underwater rolling control computer ( 45), the underwater rolling control computer 45 is connected to the host computer 50 of the rolling line is configured to transmit information. Further, the underwater rolling control computer 45 is connected to the roll rolling pressure detection device 60, the rolled material detection device 65 and the like.

Underwater hot rolling apparatus 1 of the present invention configured as described above has a rolling method 100 as follows. This is first performed by detecting the state in which the rolled material 220 approaches the finishing mill 200, and titrating the coolant based on the rolling information of the rolled material 220 in the control computers 45 and 50. Step 110 of converting the injection pressure and adjusting the opening degree of the variable coolant supply valve 30 based on the coolant injection pressure converted from the control computer 45 to adjust the coolant injection pressure 120 It is made, and the step of spraying 130 to the rolled material 220 so that the coolant impact pressure is at least 18kgf / cm 2 or more.

In the step 100, when the tip of the rolled material 220 approaches the finishing mill 200, an approach state is detected by the rolled material detection device 65, and the signal is transmitted to the underwater rolling control computer 45. At this time, in step 110, the rolling information of the rolled material 220 is transferred from the host computer 50 to the underwater rolling control computer 45, and the underwater rolling control computer 45 is based on the rolling information. Convert the proper injection pressure of and transmit the injection pressure signal to the pressure variable signal generator (40). Therefore, in the next step 120, the pressure variable signal generator 40 receiving the injection pressure signal provides the valve opening signal to the variable cooling water supply valve 30 again to improve the opening degree of the variable cooling water supply valve 30. In the next step 130, the coolant of the predetermined pressure indicated by the underwater rolling control computer 45 is set from the cooling water pump 35 along the cooling water pipe 32 to the variable cooling water supply valve ( 30) and the cooling water supply hose 12, the upper and lower rolling rolls 210 and the rolled material 220 are in contact with each other by the one-side injection nozzle 10 to spray the cooling water of the appropriate pressure. In this case, the pressure at which the coolant injected from the one-side injection nozzle 10 impinges on the rolled material 220 is about 18 Kgf / cm 2 or more.

Accordingly, the hot rolled material 220 is locally cooled by underwater cooling to locally cool the surfaces of the rolled roll 210 and the rolled material 220 and to form a water film between the rolled material 220 and the rolled roll 210 during rolling. This is to easily suppress the occurrence of scale defects, which are surface defects.

5 is a graph illustrating the effect of suppressing the impact of impact pressure and scale defects of the sprayed cooling water by mounting the underwater hot rolling apparatus 1 according to the present invention on a hot rolling mill 200. In the case where the impact pressure was 18 Kgf / cm2 or more, scale defects on the surface of the steel sheet could be completely suppressed, and scale defects occurred in the case of 13 Kgf / cm2 or less.

Meanwhile, as shown in FIG. 7, the conventional cooling header 230 provided between the upper and lower wiper frames 240 and the rolled material 220 has a line, a rear end, and a cooling header 230 of the rolled material 220. It is difficult to spray the coolant to the proper position effectively due to frequent breakage and deformation of the equipment, and the installation space of the coolant supply pipe 32 is narrow, which is difficult, but in the case of the present invention, the one-side injection nozzle 10 is inserted into the nozzle assembly hole 20 having the injection hole 22 which is penetrated at right angles to the wiper frame 240 at an angle so that the cooling water jetting side is obliquely processed so that it does not interfere with the cooling water injection. It has a firmly fixed structure.

Therefore, since the one-side injection nozzle 10 is assembled so as not to protrude from the surface of the rolled material 220 side of the wiper frame 240, the tip portion of the rolled material 220 is prevented from being damaged by collision when entering the rolling roll 210. Will be able to easily secure a space for cooling water supply.

According to the present invention as described above, the hot water is sprayed between the filament rolling roll 210 and the rolled material 220 during hot rolling to locally cool the surface, and the rolled material 220 and the rolling roll during rolling The surface quality of the rolled material 220 can be improved by easily suppressing the occurrence of scale defects, which are surface defects of the hot-rolled sheet, through underwater rolling forming a water film between the 210 and By penetrating the 10 and spraying the cooling water, it is possible to prevent damage and deformation of the equipment due to the collision with the material to be rolled 220 so that stable underwater rolling is possible.

Claims (3)

During hot rolling of a metal plate, the rolled material 220 is rolled by spraying a cooling water of appropriate pressure between the rolled material 220 and the finishing roll 210 just before rolling the rolled material by the rolling roll 210. In this case, a plurality of one-sided injection nozzles 10 are installed in a width direction through the wiper frame 240 that fixes the wiper 242 at right angles, and the single-sided injection nozzles 10 are inclined at the cooling water injection side. The cooling water injection unit 7 inserted into and fixed to the nozzle assembly hole 20 having a 22, and configured so that the lower end 10b does not protrude from the surface 220a of the rolled material 220 side of the wiper frame 240. ; A coolant pump 35 connected to the one-side injection nozzle 10 through a coolant supply pipe 32 to continuously supply coolant; Equipped with the cooling water supply pipe 32 is provided with a variable cooling water supply valve 30 to automatically control the opening degree to control the injection pressure, the pressure variable signal generator 40 connected to the variable cooling water supply valve 30 ) And the submersible rolling control computer 45 and the host computer 50 of the rolling line to adjust the opening degree of the variable cooling water supply valve 30 according to the rolling information of the rolled material 220, and the rolled material 220. Underwater hot rolling apparatus comprising a; control unit 42 for adjusting the coolant pressure sprayed on. The underwater hot rolling apparatus according to claim 1, wherein the underwater rolling control computer (45) is connected to a roll rolling pressure detecting device (60) and a rolled material detecting device (65). In the hot-rolling method of underwater rolling in which the rolled material 220 is hot rolled by the rolling roll 210 and then rolled by spraying a coolant with an appropriate pressure between the rolled material 220 and the finishing roll 210. In the step (100) of detecting the state in which the rolled material 220 is approached to the finishing mill (200) side; Converting the coolant proper injection pressure based on the rolling information of the rolled material 220 in the control computer 45 or 50; Adjusting the cooling water injection pressure by adjusting the opening degree of the variable cooling water supply valve 30 based on the cooling water injection pressure converted from the control computer 45; And spraying (130) the rolled material such that the coolant impact pressure is at least 18 kgf / cm < 2 >.