JPH0619908U - Descaling device for hot rolled steel end surface - Google Patents

Abstract

(57) [Summary] [Purpose] The descaling property of the side end face is made constant in response to various slab widths. [Structure] At least one set of nozzle headers 7 arranged so as to be capable of advancing and retracting in the slab width direction so as to face the side end surface 9 of the moving slab 5, and a retract mechanism for advancing and retracting the nozzle header 7 corresponding to the slab width. 12, the front and rear end detectors of the slab 5, the slab-side end face 9 and the spray nozzle 10 corresponding to the slab width by the signals from the detectors.
The distance is set to a predetermined distance, and the spray control unit opens and closes the high-pressure water supply valve to the nozzle header 7. [Effect] Scale biting is prevented during width pressing by the sizing press, and the edge quality of the final product is improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a descaling device for the slab-side end face in the preceding stage of a sizing press for adjusting the width of a continuously cast slab.

[0002]

[Prior art]

 In recent years, the steelmaking method in the steelmaking industry has been dominated by slab production by continuous casting, which has characteristics such as improved yield, energy saving, improved productivity, and stable slab quality compared to conventional steel ingot methods. It is a well-known fact that it is becoming. Changing the slab width during casting in continuous casting not only has mechanical problems, but also has many obstructive factors such as problems such as taper slab generation and reduced efficiency. Therefore, from the standpoint of casting in continuous casting, there was a strong demand for the consolidation of slab widths.

Conventionally, for the purpose of continuously obtaining slabs of various cross-sectional dimensions from slabs of the same cross-section, and for continuous casting, casting was performed with a cross-sectional dimension that is easy to cast, and it was responded to the requirements of rolling mills. For the purpose of sizing to the cross-sectional size, after exiting the secondary cooling zone or pinch roll of the continuous casting machine, a reheating furnace and a rolling machine with 1 to 4 stands with vertical rolls are installed to perform direct rolling. Although width reduction was carried out by installing reduction equipment, when it is strongly pressed, it causes buckling in the width direction and increases crop loss due to defective shape of the front and rear edges of the material to be rolled. Had.

Therefore, recently, a sizing press has been developed in which a die having a taper portion, an R portion, and a straight portion in the plate width direction is used to press from both ends of the slab toward the center portion. Since this sizing press is placed between the heating furnace and the vertical scale breaker, it is necessary to remove the scale generated on the slab surface in the heating furnace in advance before the sizing press. Descaling of the upper and lower surfaces of the slab does not need to be carried out upstream of the sizing press because it corresponds to the rough rolling, but descaling of the slab side end surface removes the scale of the slab side end surface before the sizing press. If not, scale entrapment phenomenon occurs during width pressing, and quality problems such as bald scratches appear near the edge after finish rolling, which is essential from the viewpoint of preventing edge defects.

Conventionally, as a scale removing device for the end face of the slab, a contactor for removing the scale on the end face of the slab, which is rotatably attached to a vertical shaft near the end face of the moving slab, and the contact There has been proposed a device (Japanese Utility Model Laid-Open No. 62-72713) including a pressing means for elastically pressing a child against the end surface of the slab. In addition, as a method for removing scale from the slab surface, in a hot rolling mill train in which a vertical rolling mill and a horizontal rolling mill are arranged in a skewer, the material to be rolled is cut just before the vertical rolling mill bites into the horizontal rolling mill. There is proposed a method (Japanese Patent Application Laid-Open No. 2-6010) in which a steam / water mixed fluid is sprayed on the surface of the metal slab from a steam / water injection nozzle provided on the lateral side of the metal slab to remove oxide scale. There is. Further, as a method and apparatus for removing scale on the surface of hot-rolled steel material by high-pressure water injection, Japanese Patent Application Laid-Open Nos. 57-14414, 58-44909, 59-45019, and Many proposals have been made, such as Kaihei 3-294016, Kokai 56-60517, and Kokai 60-71417.

[0006]

[Problems to be solved by the device]

 The descaling device disclosed in Japanese Utility Model Laid-Open No. 62-72713 removes the scale on the end face of the slab mechanically by the contact, so that the uneven scale of the end face of the slab becomes uniform when uneven wear of the contact occurs. There is a drawback that it cannot be removed and man-hours are required for maintenance of the descaling device. Further, Japanese Patent Application Laid-Open No. 2-6010 and Japanese Patent Application Laid-Open No. 57-14414 disclose that a scale on a slab surface or a hot-rolled steel surface is sprayed with a steam-water mixed fluid or high-pressure water. However, the scale removal on the slab side end face is not mentioned.

An object of the present invention is to provide a descaling device for a side end surface of hot-rolled steel, which has a constant descaling property of the side end surface corresponding to various slab widths and can improve the edge quality of a final product. Especially.

[0008]

[Means for Solving the Problems]

 The present inventors have made various studies to achieve the above object. As a result, a high-pressure water jet nozzle facing the slab-side end face is installed between the heating furnace and the sizing press so that it can move back and forth, and the high-pressure water jet nozzle keeps a certain distance between the slab-side end face and the high-pressure water jet nozzle according to the slab width. By advancing and retracting the water injection nozzle, the descaling performance of the end face on the slab side became constant, and it was concluded that the edge quality of the final product could be improved, and the invention was reached.

That is, according to this invention, at least one set of nozzle headers that are arranged to face the side end surface of the moving slab so as to move forward and backward in the slab width direction, and advance and retract the nozzle header corresponding to the slab width. The retract mechanism, the slab front and rear end detectors, and the signals from the detectors set the distance between the slab side end face and the spray nozzle to a predetermined distance according to the slab width, and also supply high-pressure water to the nozzle header. It consists of a spray control unit that opens and closes the valve.

[0010]

[Action]

 The descaling device of the present invention uses a nozzle header arranged in the slab width direction facing the side end surface of the slab according to the slab front end and rear end detection signals, and the spray control unit corresponds to the slab width and the slab side end surface The distance between the nozzle header and the nozzle header is advanced and retracted by the retract mechanism, and the high-pressure water supply valve to the nozzle header is opened and closed, so the distance between the slab-side end surface and the nozzle header can always be kept constant. The side surface descaling performance can be kept constant corresponding to the slab width of.

The nozzle headers arranged on both sides in the width direction of the slab according to the present invention may be moved back and forth independently, or the nozzle headers on both sides may be moved toward and away from each other in synchronization. . Further, as the retracting mechanism of the nozzle header, a hydraulic cylinder or an air cylinder can be provided independently of each other, or a screw rod can be used so that the nozzle headers on both sides in the slab width direction can approach and separate in synchronization. . The position of the slab width can be confirmed using an end face detector such as an optical type, an electromagnetic type, or a microwave type, or preset control is performed according to the slab width of rolling schedule information without using a sensor. You can also

The descaling water used in this invention is high pressure water of 100 to 250 kgf / cm ² , and the spray nozzle is of a type that spreads over a wide angle because the straight nozzle cannot cover the entire slab thickness. . The distance between the spray nozzle and the end face on the slab side depends on the spread angle of the spray nozzle, but if it is too close, the spray will not spread over the entire end face on the slab side, and if it is far away, the descaling pressure will decrease and the scale removal performance will decrease. Is about 200 to 700 mm, which is desirable. Further, the scale removing performance can be increased by rocking the nozzle header itself vertically and horizontally to make the spray pressure an impact pressure.

【Example】

 Example 1

The details of the present invention will be described below with reference to FIGS. 1 to 3 showing an example of an embodiment. 1 is an overall side view showing the installation position of the descaling device of the present invention, FIG. 2 is a schematic side view of the descaling device of the present invention, and FIG. 3 is a plan view of FIG. In FIG. 1, 1 is a slab heating furnace, 2 is a sizing press for width rolling the slab, 3 is a descaling device arranged between the heating furnace 1 and the sizing press 2, 4 is a descaling device 3 and a heating furnace. The slab front and rear end detectors provided between the slabs are heated in the heating furnace 1. The slabs are descaled by the descaling device 3 to remove the scales on the side end faces, and then width-rolled to a predetermined width by the sizing press 2. It

In FIGS. 2 and 3, 5 is a slab, 6 is a table roller that conveys the slab 5, and 7 and 8 are spray nozzles 10 and 11 at the tips facing the slab-side end face 9 in the width direction of the slab 5. It is a nozzle header having. 12 and 13 are fluid cylinders that move the nozzle headers 7 and 8 forward and backward in the width direction of the slab 5, 14 is a sliding mechanism, and 15 and 16 are racks that mesh with pinions 17 and 18 provided below the rear portions of the nozzle headers 7 and 8. Is. The spray control unit (not shown) operates the fluid cylinders 12 and 13 according to the width detector of the slab 5 (not shown) or the slab width of the rolling schedule information, and the distance between the nozzle headers 7 and 8 and the slab side end face 9 is increased. The nozzle headers 7 and 8 are moved back and forth in the width direction of the slab 5 so as to be 400 mm. Further, a high-pressure water supply pipe 20 having an open / close valve (not shown) is connected to the rear portion of each nozzle header 7, 8 via a flexible tube 19. When the tip of the slab 5 reaches the position of the nozzle header 7 in response to the detection signals of the slab front end and rear end detector 4, the spray control unit (not shown) opens the open / close valve (not shown) to supply high-pressure water to each spray nozzle 10, It is configured to start injection from 11 to the slab-side end surface 9 and, when the rear end of the slab 5 reaches the position of the nozzle header 8, close the on-off valve (not shown) to stop the injection of high-pressure water from the spray nozzles 10 and 11. . Reference numeral 21 is a scale scattering prevention cover.

Because of the above-described configuration, the spray control unit (not shown), prior to the passage of the slab 5, detects the width detector of the slab 5 (not shown) or the fluid cylinder 12, depending on the slab width of the rolling schedule information. 13 moves each nozzle header 7 and 8 forward and backward in the width direction of the slab 5, and adjusts the distance between each nozzle header 7 and 8 and the slab side end surface 9 to 400 mm. Next, when the tip of the slab 5 reaches the position of the nozzle header 7 in response to the tip detection signal of the slab tip and trailing edge detector 4, the spray control section (not shown) opens the open / close valve (not shown) to open each spray nozzle 10 , 11 from which high-pressure water is jetted to the end face 9 on the slab side at an angle of 30 °, and the scale removal on the end face 9 on the slab side is started. Then, when the rear end of the slab 5 reaches the nozzle head 8 position in response to the rear end detection signal of the slab front end and the rear end detector 4, the on-off valve (not shown) is closed and high pressure water from each spray nozzle 10, 11 is closed. Spraying stops. While the slab 5 passes through the descaling device 3, the scale of the slab side end surface 9 is removed by the high pressure water jetted from the spray nozzles 10 and 11. The slab 5 from which the scale of the slab-side end surface 9 has been removed is supplied to the sizing press 2 and width-pressed, but since the scale of the slab-side end surface 9 has been removed, scale squeezing during width-pressing is performed. The phenomenon is prevented and the edge quality of the final product can be improved.

Embodiment 2 For each of the conventional fixed type slab-side end surface descaling device and the slab-side end surface descaling device of the present invention of Embodiment 1, the side end surface of a slab having a width of 600 to 1800 mm and a thickness of 227 mm is provided. Descaling was performed. In this case, the distance between each spray nozzle of the conventional descaling device and the center position of the table roller is 1100 mm, the distance between each spray nozzle of this invention and the end face on the slab side is 400 mm, and both nozzle headers are 2 on both sides. The pressure of the high-pressure water was 150 kgf / cm 2, and the spray angle was 30 °. After the sizing press, rough rolling and finish rolling were performed, and then the occurrence of edge defects was investigated. The result is shown in FIG. In the conventional fixed type slab-side end face descaling device shown in FIG. 4B, the narrower the slab width, the worse the downgrading rate due to edge flaws becomes. However, the slab of the present invention shown in FIG. In the side edge descaling device, the rate of downgrade due to edge defects was almost constant even if the slab width varied. This shows that the slab side end surface descaling device of the present invention can always maintain the side surface descaling performance uniform with respect to the slab width.

[0017]

[Effect of device]

 As described above, according to the present invention, even if the slab width changes variously, the slab side end face scale is always removed with a constant performance in response to this, so that the scale is not caught during the width press by the sizing press. It can be prevented, the edge quality of the final product is improved, and the downgrade rate can be reduced.

[Brief description of drawings]

FIG. 1 is an overall side view showing an installation position of a descaling device of the present invention. FIG. 3 is a schematic side view of the descaling device of the present invention, and FIG. 3 is a plan view of FIG.

FIG. 2 is a schematic side view of the descaling device of the present invention.

FIG. 3 is a schematic plan view of a descaling device of the present invention.

FIG. 4 is a graph showing the relationship between the slab width and the downgrade rate in Example 2.

[Explanation of symbols]

 1 Heating Furnace 2 Sizing Press 3 Descaling Device 4 Slab Tip and Back Edge Detector 5 Slab 6 Table Roller 7, 8 Nozzle Header 9 Slab Side End Face 10, 11 Spray Nozzle 12, 13 Fluid Cylinder 14 Sliding Mechanism 15, 16 Rack 17 , 18 Pinion 19 Flexible tube 20 High-pressure water supply pipe 21 Scale scattering prevention cover

Claims (1)

[Scope of utility model registration request] 1. A at least one set of nozzle headers arranged so as to be able to advance and retreat in the slab width direction so as to face a side end surface of a moving slab, and a retract mechanism for advancing and retracting the nozzle header according to the slab width. A spray that opens and closes the high-pressure water supply valve to the nozzle header, with the distance between the slab-side end face and the spray nozzle set to a predetermined distance corresponding to the slab width by the signal from the front and rear end detectors of the slab. Descaling device for hot-rolled steel side end face consisting of control part.