JPH10263678A - Descaling equipment for hot rolling mill array arranged with straightening machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the length of a defective descaled part, or to improve the descaling ratio by arranging a warp straightening device of an intermediate stock on the forward stage of a high pressure fluid spray descaling device to bring a high pressure fluid spray nozzle close to the intermediate stock. SOLUTION: A scale breaker, etc., is placed on the rear stage of a heating furnace 1, and a slab is rolled into an intermediate stock S by a roughing mill 2. The intermediate stock S is fed to a finish tandem rolling mill 5 through a high pressure fluid spray descaling device 4, and a straightening machine 3 is arranged on the forward stage of the high pressure fluid spray descaling device 4. The straggling machine 3 comprises, for example, five rollers, and the appropriate draft is applied by a draft cylinder 31 to straighten the warp of the intermediate stock S. The finish tandem rolling mill 5 is arranged on the downstream side of the high pressure fluid spray descaling device 4, to perform the finish rolling of the intermediate stock S. The distance between the high pressure fluid spray nozzle and the intermediate stock S can be reduced to about 50 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a series of rolling equipment for hot-rolled steel sheets, and more particularly to a series of hot rolling equipment having a device for descaling an intermediate material rolled by a rough rolling mill by a high-pressure fluid injection descaling device. It relates to a descaling device.

[0002]

2. Description of the Related Art In the production of a hot-rolled steel sheet, a raw material slab is charged into a heating furnace in an oxidizing atmosphere, and is usually 1100-13.
After heating for several hours in the temperature range of 00 ° C., hot rolling is performed.
In this case, if the primary scale generated during heating and the secondary scale generated after extraction are not sufficiently removed and are rolled,
The scale cuts into the material surface and remains as scale flaws, which significantly impairs the surface properties of the product. In particular, in a steel sheet having a high content of Si (silicon), Si is selectively oxidized during high-temperature heating in a heating furnace, and the oxide is not sufficiently removed by a conventional descaling apparatus.
A surface defect called red scale was formed on the surface of the steel sheet.

In order to prevent such surface defects due to insufficient scale removal, for example, materials and processes, 5 (199)
5) As shown on page 307, a high-pressure fluid injection descaling device (hereinafter referred to as FSB) is arranged on the entrance side of the finishing mill, and the high-pressure fluid (specifically, water) injection nozzle and the intermediate material are interposed. Means have been taken to make the distances closer. In the above disclosure, the distance between the injection nozzle and the intermediate material is 120 mm, and the shorter the distance, the better the separation of the surface scale due to the collision of the high-pressure fluid can be improved. Si
A steel sheet having a high content can be manufactured without surface defects.

Therefore, it is necessary to minimize the distance between the intermediate material and the injection nozzle. However, in an actual machine, if the nozzle is made to approach a steel plate, the intermediate material collides with the nozzle due to warpage of the intermediate material. An accident occurs. If a protector guide is installed on the nozzle side to prevent this accident, the intermediate material will collide with this guide, making it impossible to feed the material, leading to operation stoppage or flaws on the surface of the product steel plate. Problems arise.

FIG. 6 shows an example of a conventional hot-rolled steel plate rolling equipment line. When the slab is rolled by this equipment line, the intermediate material 5 is warped to reach 100 to 400 mm. This warpage is caused by factors such as the difference in the surface condition of the upper and lower rolling rolls of the rough rolling mill 2 and the roll position, and then the top and rear ends are cut or corrected by the cutting action by the crop shear 6 to obtain 50 to 100 mm. Although reduced to a level, the nozzle of the FSB 4 still cannot be sufficiently close to the intermediate material.

As disclosed in Japanese Patent Application Laid-Open No. 1-178312, as a means for bringing the nozzle of the FSB close to the intermediate material, a high-pressure water header can be moved up and down, an injection header is attached to a fixed base, and a lower end of the fixed base is provided. And positioning guide rolls corresponding to the upstream and downstream of the injection header,
A method is disclosed in which this is applied to a material to be rolled as an intermediate material to make the distance between the nozzle and the intermediate material constant. However, in this method, at the front and rear end portions, only one of the positioning guide rollers is in contact with the intermediate material, so that the distance between the jetting slip and the intermediate material cannot be made constant, and scale residue occurs. .

There is also known a method of detecting a warped shape on the upstream side of a descaling device, raising and lowering the height of a high-pressure injection header according to the detected value, and appropriately adjusting the position of the header with respect to an intermediate material. ing. However, in this method, when the transport speed of the intermediate material is increased, the elevation of the injection header cannot follow the change in the warped shape, and scale residual may occur. In addition, both of the above-mentioned means have a problem that the mechanism of the lifting and lowering device of the injection header of the FSB becomes complicated and maintenance of the high-pressure water piping system becomes difficult.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem of the prior art.
When descaling the intermediate material, the gap between the intermediate material and the FSB injection nozzle is set to an extremely small distance so that the descaling of the intermediate material can be completed completely, and the occurrence of scale flaws and red scale on the surface of the product steel plate The purpose is to prevent. It is another object of the present invention to provide a descaling facility that facilitates maintenance of a high-pressure water piping system by facilitating the passing of an intermediate material by FSB without causing an accident or the like. And

[0009]

Means for Solving the Problems In order to solve the above problems, the present inventors have repeated various studies and it is extremely effective to correct the shape of the intermediate material fed to the FSB in advance by using a straightening machine. Thus, the present invention has been completed. Accordingly, the present invention provides a descaling device of a row of hot rolling equipment for descaling an intermediate material rolled by a rough rolling mill by a high-pressure fluid injection descaling device, in which a device for correcting the warpage of the intermediate material is arranged in front of the FSB. It should be. Further, in the present invention, a crop shear for cutting a leading end and / or a trailing end of an intermediate material rolled by a rough rolling mill is arranged at a stage preceding a high-pressure water jet descaling device, and a warped shape of the intermediate material is detected. It is assumed that the device is arranged at the front stage of the straightening machine and, if necessary, at the rear stage.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below along with functions based on examples. FIG. 1 is an arrangement diagram of an apparatus showing a basic embodiment of the present invention. A scale breaker (not shown) or the like is placed after the heating furnace 1, and the slab is rolled into an intermediate material (sheet bar) S by the roughing mill 2. The intermediate material S is sent to the finishing tandem rolling mill 5 via the FSB 4, but in the present invention, the straightening machine 3 is arranged before the FSB 4. The straightening machine 3 is composed of five rollers in the present embodiment, and can be appropriately reduced by a reduction cylinder 31 to correct the warpage of the intermediate material. The type and structure of the straightening machine may be any known ones, and may be appropriately selected according to the size of the intermediate material S and the amount of warpage. FSB4 of a known type is also used. In the present example, guides 41 and 43 are provided on the entrance side and the exit side, respectively, to convey the intermediate material S into the high-pressure fluid ejection zone, and the intermediate material S is moved by the upper high-pressure fluid ejection header 42a and the lower high-pressure fluid ejection header 42b. Is performed. A finishing tandem rolling mill 5 is arranged downstream of the high-pressure fluid descaling device 4 so as to finish-roll the intermediate material S.

FIG. 2 shows a crop shear 6 before the straightening machine 3.
Is an example in which. The crop shears 6 are generally arranged to cut off the defective shape at the front and rear ends of the intermediate material and to smoothly operate the finishing mill. Further, when the crop shear 6 is operated, the crop shear 6 presses the front and rear ends of the intermediate material S, and has a correcting action. Therefore, by arranging the crop shear in the front stage of the correcting machine, the specifications of the correcting machine can be set lower. However, in a case where the intermediate material can be rolled by the rough rolling mill 2 without shape defects at the front and rear ends, the crop shear 6 may not be disposed as shown in FIG.

FIG. 3 shows an example in which a warp detector 7 is arranged in front of the straightener 3 in the basic configuration shown in FIG. Although not explicitly shown in the figure, the amount of warpage of the intermediate material S is detected by the warp detector 3, and the press-down cylinder 31 of the straightening machine 3 is adjusted according to the detected amount. It becomes possible to send. Also in this case, a known warp detector 7 can be used,
For example, it is also possible to use a type that measures the amount of warpage by measuring the distance from a predetermined location. In addition,
It is preferable that the warp detectors 7 are provided above and below the pass line so that the amount of warp can be measured even when the intermediate material S has an extremely upward or downward warp shape.

FIG. 4 shows a crop shear 6 before the straightening machine 3.
FIG. 5 shows an example in which a warp detector 7 is placed on the front surface of the straightening machine 3.
This is an example where a and 7b are placed. By adopting such an arrangement, the intermediate material S in which the warp has been reduced by the crop shear 6 can be corrected in accordance with the amount of warpage, and the degree of straightening is checked on the straightening machine exit side, and the straightening machine is used as necessary. Since the amount of warpage correction can be fed back, FSB4
Can be operated closer to the intermediate material S.

FIG. 7 shows the results of measurement of the distribution of warpage when applied to the example of the present invention (corresponding to claim 2) shown in FIG. 2 on the crop shear entrance side, the crop shear exit side, and the straightening machine exit side. As is clear from this figure, the maximum warpage of 400 mm on the entrance side of the crop shear is reduced to a maximum of 200 mm on the exit side of the crop shear, and the maximum is 20 mm on the exit side of the straightening machine, which hinders the operation of the high-pressure fluid descaling device. You can see that it is gone.

The results of applying the present invention to actual operation will be described below. The operation of the actual machine is shown in FIG.
Equivalent), width 1000 mm, thickness 35-50
mm, and two types of steel, low carbon steel and high silicon steel, were used. The results were as follows: (1) Low carbon steel material Slab heating temperature: 1180 ° C Nozzle-pass line distance Conventional method The present invention method 240mm 50mm Scale removal performance (length of the front and rear end scale removal failure part) Conventional method The present invention method 1.5m 0.3m (The scale removal situation at the center of the intermediate material in the longitudinal direction is the same.) (2) High silicon steel Slab heating temperature: 1240 ° C Distance between nozzle and pass line Conventional method Method of the present invention 100mm 50mm

[0016]

As a result of applying the present invention, the amount of warpage is reduced by 20 mm.
The distance between the high-pressure fluid injection nozzle and the intermediate material could be reduced to about 50 to 200 mm, while the distance between the high pressure fluid injection nozzle and the intermediate material could only be reduced to about 150 to 200 mm in the past. As a result, the high-pressure fluid collision force can be increased 9 to 16 times. Thereby, the length of the scale removal defective portion can be reduced, or the scale removal rate can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a layout diagram showing a basic layout example of a descaling device according to the present invention.

FIG. 2 is an arrangement diagram when a crop shear of the descaling device according to the present invention is arranged.

FIG. 3 is an arrangement diagram when a warp detector of the descaling device according to the present invention is arranged.

FIG. 4 is an arrangement diagram of a descaling device according to the present invention in which a crop shear and a warp detector are arranged.

FIG. 5 is a layout view of a descaling apparatus according to the present invention, in which a cropping detector and a warp detector are arranged on front and rear surfaces of a straightening machine.

FIG. 6 is an example of an arrangement diagram of a conventional descaling device.

FIG. 7 is a relationship diagram showing a change in a tip warpage amount distribution of an intermediate material according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Rough rolling mill 3 Straightening machine 31 Reduction cylinder 4 High-pressure fluid injection descaling device 41 Inlet guide 42a Upper high-pressure fluid injection header 42b Lower high-pressure fluid injection header 43 Outlet guide 5 Finish tandem rolling mill 6 Crop shear 7 Warp Detector S Intermediate material (seat bar)

Claims (5)

[Claims] An intermediate material descaling device for descaling an intermediate material rolled by a rough rolling mill by a high-pressure fluid injection descaling device, wherein the intermediate material warp straightening device is provided in front of the high-pressure water injection descaling device. A descaling device for a row of hot rolling equipment in which a straightening machine is arranged. 2. The straightening machine according to claim 1, wherein a crop shear for cutting the leading end and / or the trailing end of the intermediate material rolled by the rough rolling mill is arranged at a stage preceding the high-pressure water jet descaling device. Descaling equipment for hot rolling equipment line. 3. The descaling device of a hot rolling equipment line in which a straightening machine is arranged, wherein the device for detecting the warped shape of the intermediate material is arranged before the high-pressure water jet descaling device. 4. The apparatus according to claim 1, wherein a crop shear for cutting a front end and / or a rear end of the intermediate material rolled by the rough rolling mill and a device for detecting a warped shape of the intermediate material are arranged in front of the descaling device. A descaling device for a row of hot rolling equipment with straightening machines. 5. A descaling device for a row of hot rolling equipment, in which a straightening machine is arranged, wherein a device for detecting a warpage of an intermediate material is provided on a rear surface of the straightening machine.