JP2002137017A - Method and equipment for manufacturing hot-rolled steel strip and hot-rolled steel strip coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and equipment capable of detecting simply and easily surface defects appearing in steel strip being rolled and confirming information on kinds, grades and positions of the defects without cutting the defective portions after the sheet steel has been shipped in the shape of a coil. SOLUTION: The equipment of this invention which rolls steel into a sheet of a given gauge by means of a hot-rolling mill and winds the sheet in the shape of a coil is provided with a tracking machine 9 which tracks the travel length of the sheet by detecting the feed speed of the steel strip 1, an inspection machine 5 using an optical system which is located down the hot-rolling mill and which performs the surface inspection of the steel strip, a processing means which determines the positions of defects of the steel strip on the basis of the information obtained from the tracking machine 9 if any surface defect is detected in the steel strip with the information on the inspection by the inspection machine, and a marking unit 6 which marks the positions of the defects in the steel strip 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-rolled steel sheet which, in a hot rolling process, inspects the surface of the steel sheet while rolling the steel sheet, and when a defect is detected, gives the defect information to a defective portion of the steel sheet. The present invention relates to a manufacturing method and apparatus and a hot-rolled coil.

[0002]

BACKGROUND OF THE INVENTION In the hot rolling process, iron, copper,
A metal slab of aluminum or the like is heated, and this is hot-rolled by a roughing mill and a finishing mill having a plurality of rolling rolls to produce a steel sheet having a constant thickness, and the steel sheet is wound into a coil by a winder. taking it.

[0003] By the way, various defects may appear on the surface of the steel sheet due to segregation of impurities in the material itself, flaws generated during rolling, and the like.

Conventionally, defects such as flaws on the surface of a steel sheet generated in the process of manufacturing a hot-rolled steel sheet are visually inspected while unwinding a hot-rolled coil wound in a coil shape. When a defect appears on the surface, the defective part is cut off before shipping.

[0005]

However, the presence or absence of surface defects on the coiled steel sheet must be visually checked, and if a defect appears, the defective portion must be cut off. There is a problem that it takes time and effort. In addition, from the viewpoint of the user, if there are too many cuts, handling and operability are poor.

[0006] Further, since the type and degree (grade) of the surface defects of the steel sheet are different and some of the defects do not always need to be cut, even if the coil has a surface defect in the steel plate under agreement with the customer, the defective portion is not removed. It is suggested to ship with the mark.

The present invention has been made in view of the above circumstances, and it is possible to easily and easily detect a surface defect appearing on a steel sheet while rolling the steel sheet, and ship the coil as a coil without cutting the defective part. It is an object of the present invention to provide a method and apparatus for manufacturing a hot-rolled steel sheet and a hot-rolled coil capable of confirming the type and grade of a defect and the position information of the defect after the defect.

[0008]

In order to achieve the above object, the present invention comprises a method and an apparatus for manufacturing a hot-rolled steel sheet and a hot-rolled coil by the following means.

According to a first aspect of the present invention, there is provided a method for producing a hot-rolled steel sheet in which a steel sheet having a predetermined thickness is rolled by a hot rolling mill and wound up as a coil. A surface inspection of the steel sheet is performed by an inspection means using an optical system provided downstream from the hot rolling mill while tracking the movement, and when it is detected that the surface of the steel sheet has a defect from the inspection result, the inspection is performed. In addition to determining the type and degree of the defect, the position of the defect in the steel sheet is determined from the tracking information and the information is output.

According to a second aspect of the present invention, there is provided a method for producing a hot-rolled steel sheet in which a steel sheet having a predetermined thickness is rolled by a hot-rolling mill and wound up as a coil. Performing a surface inspection of the steel sheet by an inspection means by an optical system provided downstream from the hot rolling mill while tracking the movement, when it is detected that the surface of the steel sheet is defective from the inspection result, A mark is provided at a position of a defect of the steel sheet determined by the marking information from the tracking information.

According to a third aspect of the present invention, in the method for manufacturing a hot-rolled steel sheet according to the second aspect, when it is detected that a defect is present on the surface of the steel sheet, the type and degree of the defect are determined. The discrimination is made by the marking means to a mark at the defect position of the steel sheet so that the type and degree of the defect can be identified.

According to a fourth aspect of the present invention, there is provided an apparatus for manufacturing a hot-rolled steel sheet which is rolled into a steel sheet having a predetermined thickness by a hot rolling mill and wound as a coil, comprising: a tracking means for tracking the movement of the steel sheet. An inspection unit provided with an optical system for inspecting the surface of the steel sheet, which is provided downstream from the hot rolling mill, and when it is detected that the surface of the steel plate has a defect from information inspected by the inspection unit. Processing means for determining the type and degree of the defect, determining the position of the defect on the steel sheet based on information obtained from the tracking means, and outputting the information.

According to a fifth aspect of the present invention, there is provided an apparatus for manufacturing a hot-rolled steel sheet in which a hot-rolling mill rolls the steel sheet into a predetermined thickness and winds it as a coil. An inspection unit provided with an optical system for inspecting the surface of the steel sheet, which is provided downstream from the hot rolling mill, and when it is detected that the surface of the steel plate has a defect from information inspected by the inspection unit. Processing means for determining the position of a defect on the steel sheet based on information obtained from the tracking means; and marking means for marking a position of the defect on the steel sheet determined by the processing means.

According to a sixth aspect of the present invention, in the apparatus for manufacturing a hot-rolled steel sheet according to the fifth aspect of the present invention, when the processing means detects that the surface of the steel sheet has a defect, the processing means detects the defect. The type and degree are determined, and the marking means gives a mark, at which the type and degree of the defect determined by the processing means can be identified, to the defect position of the steel sheet.

According to a seventh aspect of the present invention, there is provided a hot-rolled coil formed by winding a steel sheet rolled to a predetermined thickness by a hot-rolling mill, wherein a mark corresponding to a defect position appearing on the surface of the steel sheet. Is attached.

According to an eighth aspect of the present invention, in the hot-rolled coil according to the seventh aspect of the present invention, marks provided in correspondence with the defect positions of the steel sheet are surrounded by circles or squares.

According to a ninth aspect of the present invention, in the hot-rolled coil according to the seventh aspect of the present invention, the marks provided in correspondence with the defect positions of the steel sheet are linear, planar, point-like, and symbolic. , One of the characters.

According to a tenth aspect of the present invention, there is provided a hot-rolled coil formed by winding a steel sheet rolled to a predetermined thickness by a hot rolling mill, wherein a magnetic field corresponding to a defect position appearing on the surface of the steel sheet is provided. It is marked with either a laser or a scratch from a grindstone.

According to an eleventh aspect of the present invention, there is provided a hot-rolled coil formed by winding a steel sheet rolled to a predetermined thickness by a hot rolling mill, wherein a magnetic material corresponding to a defect position appearing on the surface of the steel sheet is provided. A mark is formed by either a laser or a scratch by a grindstone, and an oxide film formed on the surface of the steel plate is removed by immersion in an acid solution.

According to a twelfth aspect of the present invention, in the hot rolled coil according to any one of the seventh to eleventh aspects, the mark has information capable of identifying the type and degree of the defect. .

A thirteenth aspect of the present invention is the method for manufacturing a hot-rolled steel sheet according to any one of the first to third aspects of the present invention. This is performed immediately before the steel sheet winding device based on the information.

The invention corresponding to claim 14 is the method for manufacturing a hot-rolled steel sheet according to any one of claims 1 to 3, wherein the inspection information is obtained in another step after winding the steel sheet. The marking is performed on the defective portion of the steel sheet based on the above.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment for explaining a method and an apparatus for manufacturing a hot-rolled steel sheet according to the present invention.

In FIG. 1, reference numeral 2 denotes a final rolling roll of a finishing rolling mill for sequentially hot rolling a steel sheet 1 from a rough rolling mill (not shown) to a thickness of about 3 to 1 mm using a plurality of rolling rolls. Reference numeral 3 denotes a table roll for feeding the steel sheet 1 rolled to a predetermined thickness by a finishing mill to a winder 4.

In such a hot rolling process, an inspection device 5 for inspecting the front side of the steel sheet 1 is disposed at a position L1 m downstream from the center position of the final rolling roll 2 of the finishing mill,
Further, a marking device 6 for marking a defective portion of the steel plate 1 is disposed at a position L2 m downstream from the position to be inspected by the inspection device 5.

The inspection apparatus 5 comprises a light source lamp, a light source 5a comprising a light projector for irradiating the steel sheet 1 with light guided from the light source lamp through the bundle fiber, and a line sensor camera for receiving reflected light from the steel sheet 1 through a filter. 5b.

The marking device 6 has a marker 6a for marking a mark corresponding to the type and grade of the defect at a position corresponding to the defective portion of the steel plate. Here, a marker that marks a defective portion with an ink-jet pen is used as the marker 6a.

Further, reference numeral 7 denotes a steel sheet 1 to be wound by the winder 4.
A pulse generator provided on the final rolling roll 2 of the finishing mill, and the pulse generator 8 interlocked with the rotation of the final rolling roll 2 For example, steel plate 1 is 1m
One pulse is generated every m movements.

On the other hand, a tracking device 9 starts counting by counting pulses transmitted from the pulse generator 8 when a detection signal of the leading end of the steel plate 1 is input from the passing plate detecting device 7.

Further, 10 receives a luminance signal from the inspection system 5 by inspecting the optical system of the surface of the steel plate 1 and judges the presence or absence of a defect based on the luminance signal. 9 is a processing device that fetches tracking information from the processing device 9 and determines the type, degree, and location of the defect. The processing device 10 operates the marking device 6 based on the determination result. A function of giving a command and displaying the determination result on the display device 11.

Next, the operation of the apparatus for manufacturing a hot-rolled steel sheet having such a configuration will be described with reference to the flowchart shown in FIG.

Now, in the hot rolling process, when the production of the steel sheet is started, the steel sheet 1 which has exited the final roll 2 of the finishing mill is sent to the winder 4 by the table roll 3.
Then, in step S1, the steel sheet 1 is detected by the threading detecting device 7.
When the leading end of is detected, a tracking start command is given to the tracking device 9 in step S2. The tracking device 9 tracks the movement of the steel plate 1 by counting the pulses transmitted from the pulse generator 8.

In step S3, it is determined whether or not the surface of the steel sheet 1 inspected by the inspection device 5 has a defect. If it is determined that there is a defect, the movement tracking information (map) of the steel sheet 1 is determined in step S4. The defect information. In step S5, an operation command is issued from the processing device 10 to the marking device 6 based on the tracking information and the defect detection result. In step S6, the marker 6a is operated to
Mark is added to the defect position of.

Here, FIG. 3 shows an example of a mark provided on the surface defect position of the steel plate 1 by the marker 6a using an ink-jet pen in the marking device 6.

Thereafter, in step S7, the threading detecting device 7
It is determined whether or not the end of the steel sheet has been detected, and if the rear end of the steel sheet has not been detected, the process returns to step S3 to perform the same processing as described above. If the rear end of the steel sheet has been detected, coil winding ends. Then, the process proceeds to step S8.

In step S8, a coil defect map corresponding to the defect type and grade is created based on the map to which the defect information has been added in step S4, and output to the display device 11.

As described above, the surface of the steel sheet is inspected while hot rolling is performed over the entire length of the steel sheet. If a defect is detected, a mark is given to a corresponding defect position of the steel sheet based on the defect information and the tracking information. Then, it is wound up as a coil.

In the above-described embodiment, an ink-jet pen is used as a marker in the marking device. However, other means may be used as long as a mark can be formed on the surface of the steel plate. However, the coil wound by the steel sheet winding machine is often immersed in an acid solution in the pickling process in order to remove the oxide film formed on the surface of the steel plate. The condition is that it does not disappear.

For example, a magnetic marker for attaching a magnetic mark,
There are a marker for marking by spraying powder such as lime, a marker for marking by scratching with a grindstone, and a marker for marking by burning with laser.

Further, in the above embodiment, a linear mark as shown in FIG. 3 is provided corresponding to the position of the surface defect of the steel sheet, but a mark surrounding the defective portion with a circle or a square is provided. Is also good. In other words, the "position corresponding to the defect position of the steel sheet" is the center in the width direction of the steel sheet at the position where the defect exists, the end portion, or the defect portion itself.

Further, according to the type and degree of the defect, the way of marking and the type of mark are represented by, for example, a thin line and a thick line as shown in FIG. 4A, or a dot as shown in FIG. The shape-like mark may be represented by a dense interval and a coarse interval, or may be represented by characters such as A, B, and C as shown in FIG.

By changing the way of marking and the type of the mark in accordance with the type and degree of the defect as described above, the user can simply confirm the mark on the defective portion of the coil by checking the type and the type of the defect. The degree can be determined.

In the above embodiment, a line sensor camera is used for the optical system of the inspection apparatus. However, observation using a strobe and a normal television camera may be performed, and a laser beam often used in a cold rolling process may be used. A scanning surface defect meter may be used. Furthermore, in the case of the optical inspection method, the appearance of the defect differs depending on whether the light of the light source is received by specular reflection or irregular reflection, but the present invention does not depend on the projection / reception angle, It may be a system inspection device.

In the above embodiment, the case where the front side of the hot-rolled steel sheet is inspected to detect a defect has been described. However, as described above, the case where the front side of the hot-rolled steel sheet is inspected to detect a defect. Is processed in the same manner as described above, and a mark is added to the defect position.

Further, there is a method of simplifying the mark inspection by attaching a mark to only one side of the steel plate.
In this case, for example, even if there is a defect on the back side, it is possible to operate such that the mark is attached to the front side, and if a mark is found, it is determined that there is a defect on the back side and that part is removed.

In this embodiment, the marking is performed while the hot-rolled steel sheet is manufactured. However, the marking may be performed when the coil is opened again in another step. For example, a light pressure reduction process or a pickling process called a skin pass. When the marking is performed in another process as described above, the marking is performed by another marking device or hand-drawing based on the inspection information created in the hot rolling process. The inspection information may be supplied through a computer network, or a printed defect map may be used.

[0048]

As described above, according to the present invention, it is possible to easily and easily detect a surface defect appearing in a steel sheet while rolling the steel sheet, and after the coil is shipped as a coil without cutting the defective part. A method and apparatus for manufacturing a hot-rolled steel sheet and a hot-rolled coil capable of confirming the type and grade of a defect and the position information of the defect can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment for describing a method and an apparatus for manufacturing a hot-rolled steel sheet according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment.

FIG. 3 is a diagram showing an example of a mark added in correspondence with a surface defect position of a steel sheet in the embodiment.

FIG. 4 is a view showing examples of different types of marks added according to the type and degree of surface defects of a steel sheet in a process of manufacturing a hot-rolled steel sheet according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Steel plate 2 ... Rolling roll of finish rolling machine 3 ... Table roll 4 ... Winding machine 5 ... Inspection device 6 ... Marking device 7 Passing plate detecting device 8 ... Pulse generator 9 ... Tracking device 10 ... Processing device 11 ... Display device

Claims (14)

[Claims] 1. A method for producing a hot-rolled steel sheet, wherein the steel sheet is rolled into a steel sheet having a predetermined thickness by a hot rolling mill, and the hot-rolled steel sheet is rolled as a coil. The surface of the steel sheet is inspected by an inspection means using an optical system provided downstream of the cold rolling mill, and if it is detected from the inspection result that there is a defect on the surface of the steel sheet, the type and degree of the defect are determined. A method of manufacturing a hot-rolled steel sheet, comprising determining the position of a defect in the steel sheet from the tracking information and outputting the information. 2. A method for producing a hot-rolled steel sheet in which a steel sheet having a predetermined thickness is rolled by a hot rolling mill and wound as a coil. A surface inspection of the steel sheet is performed by inspection means using an optical system provided downstream from the inter-rolling mill, and when it is detected that the surface of the steel sheet has a defect from the inspection result, the tracking information is obtained from the tracking information by marking means. A method for producing a hot-rolled steel sheet, wherein a mark is provided at a position corresponding to a position of a defect of the steel sheet to be determined. 3. The method of manufacturing a hot-rolled steel sheet according to claim 2, wherein when it is detected that the surface of the steel sheet has a defect, the type and degree of the defect are determined, and the steel sheet is marked by the marking means. A method for producing a hot-rolled steel sheet, wherein a mark corresponding to the type of defect is provided at a position corresponding to the defect position. 4. A hot-rolled steel sheet manufacturing apparatus for rolling a steel sheet having a predetermined thickness by a hot rolling mill and winding the steel sheet as a coil, wherein: a tracking means for tracking the movement of the steel sheet; Inspection means provided by the optical system for inspecting the surface of the steel sheet provided on the downstream side, and when it is detected that the surface of the steel sheet has a defect from information inspected by the inspection means, the type and degree of the defect are determined. A hot rolled steel sheet manufacturing apparatus, comprising: a discriminating means for judging a position of a defect in the steel sheet based on information obtained from the tracking means and outputting the information. 5. A hot rolling mill for rolling a steel sheet having a predetermined thickness by a hot rolling mill and winding the rolled steel sheet as a coil, comprising: a tracking unit for tracking the movement of the steel sheet; Inspection means provided on the downstream side by an optical system for inspecting the surface of the steel sheet, and obtained from the tracking means when it is detected that the surface of the steel sheet has a defect from information inspected by the inspection means. Processing means for determining the position of the defect on the steel sheet based on the information; and marking means for providing a mark at a position corresponding to the position of the defect on the steel sheet determined by the processing means. Hot rolled steel sheet manufacturing equipment. 6. The apparatus for manufacturing a hot-rolled steel sheet according to claim 5, wherein when the processing means detects that a defect is present on the surface of the steel sheet, the processing means determines the type and degree of the defect and the marking means. Is a device for manufacturing a hot-rolled steel sheet, wherein a mark identifying the type and degree of the defect determined by the processing means is provided at a position corresponding to the defect position of the steel sheet. 7. A hot-rolled coil obtained by winding a steel sheet rolled to a predetermined thickness by a hot-rolling mill, wherein the hot-rolled coil is marked corresponding to a defect position appearing on the surface of the steel sheet. . 8. The hot-rolled coil according to claim 7, wherein the mark provided in correspondence with the defect position of the steel sheet is surrounded by a circle or a square. 9. The hot-rolled coil according to claim 7, wherein the mark provided in correspondence with the defect position of the steel sheet is any one of a linear shape, a dot shape, a planar shape, a symbol, and a character. coil. 10. A hot-rolled coil formed by winding a steel sheet rolled to a predetermined thickness by a hot-rolling mill, wherein any one of magnetism, laser, and a flaw caused by a grindstone corresponds to a defect position appearing on the surface of the steel sheet. Hot-rolled coil marked with. 11. A hot-rolled coil formed by winding a steel sheet rolled to a predetermined thickness by a hot rolling mill, wherein any one of a magnet, a laser, and a flaw caused by a grindstone corresponds to a defect position appearing on the surface of the steel sheet. A hot-rolled coil which is marked with a mark and has an oxide film formed on the surface of the steel plate removed by dipping in an acidic solution. 12. The hot-rolled coil according to claim 7, wherein the mark has information capable of identifying the type and degree of the defect. 13. The method for manufacturing a hot-rolled steel sheet according to claim 1, wherein a mark is attached to a defective portion of the steel sheet based on inspection information. A method for producing a hot-rolled steel sheet, which is performed immediately before. 14. The hot-rolled steel sheet manufacturing method according to claim 1, wherein in another step after winding the steel sheet, a defect portion of the steel sheet is removed based on inspection information. A method for producing a hot-rolled steel sheet, wherein a mark is provided.