KR100838722B1 - Device for detecting the defects on the strip surface - Google Patents

Abstract

The present invention reduces the incidence of defective products by automating the roll mark or scalability defect inspection on the surface of the strip, which has been performed by the neck of a conventional worker, so as to promptly take appropriate measures by outputting a warning signal visually and acoustically. The present invention relates to a strip surface defect detection device in a hot rolling process.

The strip surface defect detection device in the hot rolling process of the present invention described above is for detecting a defect occurring on the surface of the strip coil 6 produced in the hot rolling process and notifying the operator of the surface defect occurrence state. In the apparatus, a surface flaw detector (7) for converting the surface state of the moving strip (6) into image information and outputting the image is inputted from the surface flaw detector (7). A control server 9 for detecting roll mark defects and scale defects formed on the surface and judging the surface state of the strip 6 according to a built-in program to generate and output a warning message file; and the control server (9) If a warning message file related to defects is inputted, the operator is notified through the monitor and the speaker. To include the finishing rolling for the PC (8) and the intermediate test PC (10) for deleting.

Hot, rolled, strip, surface, defects, blemish, flaw

Description

Device for detecting the defects on the strip surface in hot rolling process

1 is a schematic diagram of a process for manufacturing a strip steel sheet by conventional hot rolling;

2 is a schematic view of an installation state of a search apparatus according to the present invention;

3 is a flowchart showing a flaw detection state in the rolling step according to the present invention;

4 is a flowchart illustrating a periodic determination state according to the present invention;

5 is a distribution state diagram of a roll mark flaw generated on a surface of a hot rolled strip steel sheet;

6 is a distribution chart showing the degree of fatality according to the scale defect classification;

7 is a defect distribution diagram of roll mark defects.

※ Explanation of symbols about main part of drawing ※

1: continuous casting machine 2: heating furnace

3: roughing mill 4: finishing mill

5: winder 6: strip

7: Surface flaw detector 8: Finish rolling PC

9: control server 10: intermediate inspection PC

51-66: Surface defect L1-L7: Search range

The present invention reduces the incidence of defective products by automating the roll mark or scalability defect inspection on the surface of the strip, which has been performed by the neck of a conventional worker, so as to promptly take appropriate measures by outputting a warning signal visually and acoustically. The present invention relates to a strip surface defect detection device in a hot rolling process.

In general, in the hot rolling process, the raw material (slab) supplied from the continuous casting machine 1 is reheated and extracted at a temperature suitable for rolling in the furnace 2 apparatus, and then the width rolling and thickness rolling are performed in the roughing mill 3, After the final thickness rolling in the finishing mill (4) to the product of the desired thickness, the strip rolled in the winder (5) in the form of a coil (Coil), the surface of the strip by the operator If there is no surface flaw afterwards, the operation is terminated. If any abnormality is found, necessary measures such as removal of the substance causing the surface flaw or change of the control condition are carried out in the furnace (2), roughing mill (3), finishing mill ( 4) (or finishing mill), etc. to complete the work.

When explaining the inspection process for product defects in the hot (hot rolling) process as follows.

First, since the rolled material extracted from the heating furnace 2 is generally operated at a high temperature of 1100 to 1200 ° C, while passing through the roughing mill 3, the finishing mill 5, etc. together with a surface defect called scale. Due to the foreign matters that are inserted, defective products such as rolling roll mark generation or poor flowability due to damaged rolls are generated. Due to these defects, the strip coil may be sold as a normal product or a low-order off-order product depending on the consumer's use and the occurrence of surface defects.

As described above, the defects on the surface of the strip have a great adverse effect on the quality of the product because the defect occurs once in a continuous process throughout the entire process. In order to prevent the occurrence of such product defects, an intermediate inspection panel is conventionally used to inspect the occurrence of surface defects and the severity of surface defects.

In the intermediate inspection group, when the operator inspects by the neck side, if severe scale surface defect occurs, the finishing rolling group lowers the rolling temperature of the rolled material and checks the cooling system of the rolling roll. In addition, after checking the pressure and nozzle status of the descaling device to remove scale defects, proceed to the next work. In addition, when a roll mark surface defect occurs, necessary measures such as detailed inspection and replacement of the rolling roll used during rolling are taken.

However, these surface inspections require a lot of time difference to recognize defects according to the proficiency of the operator who performs the intermediate inspection, and the intermediate inspection does not have the full length inspection but the sample inspection of 3 ~ 4m at the end part, so the reliability is very low and accurate. Rapid defect inspection is difficult.

In addition, the above series of measures are applicable only when the product surface defects can be detected in the intermediate inspection group, and in case of failure in defect detection and found in the temper rolling process, which is the final work process, a large amount of strips is already present. Since the coil is in a rolled state, there was a problem that a large quantity of defects occurred.                         

In addition, if the surface defects generated during the hot rolling process fail to be retrieved as a normal product, it will lead to the claim of the consumer, and it will cause huge trouble in the business by causing equipment failure and process stop during processing at the factory. This results in social losses.

The present invention is to solve the above problems, an object of the present invention is to search the surface of the strip during the hot rolling process, and to determine the defects formed on the surface by referring to the surface data searched to the operator to determine the fatal defect The present invention provides a strip surface defect search apparatus in a hot rolling process in which notification through visual and audio means can immediately take necessary measures for the occurrence of defects.

Another object of the present invention is to provide an apparatus for detecting strip surface defects in a hot rolling process, which can reduce a consumer's dissatisfaction and provide a reliable product.

Strip surface defect detection device in the hot rolling process of the present invention for achieving the above object, to detect a defect generated on the surface of the strip coil produced in the hot rolling process and to notify the operator of the surface defect occurrence state An apparatus for a surface, comprising: a surface flaw detector for converting a surface state of a moving strip into image information and outputting the image; and a roll mark defect formed on the surface of the strip using image information input from the surface flaw detector; A control server for detecting a defect and determining the surface state of the strip according to a built-in program, and generating and outputting a warning message file. Notify and enter the action taken by the driver to confirm this and prompt Includes finishing rolling PCs and intermediate inspection PCs for deleting files.

Hereinafter, a strip surface defect detection device in the hot rolling process of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, the surface defect detector 7 according to the present invention may detect the surface of the strip 6 passing between the conventional finishing mill 4 and the winder 5. It is installed at a predetermined position. The installation position is a position that can easily recognize the surface of the strip 6 and does not interfere with the progress of the strip. The distance from the surface of the strip 6 may vary depending on the performance of the surface flaw detector 7 used.

The surface flaw detector 7 is connected to a control server 9 in which a program is embedded to determine a defect on the surface of the strip 6, and transmits a signal output from the surface flaw detector 7. The control server 9 is connected to the network via a cable so as to interlock with the finishing rolling PC (8) and the intermediate inspection PC (10). The finishing rolling PC (8), the control server (9) and the intermediate inspection PC (10) all have a monitor and a sound card, and have the same configuration as a general personal computer. In addition, the finishing rolling PC (8) and the intermediate inspection PC (10) outputs a warning message to the workers of the finishing work and the intermediate inspection work.

The surface flaw detector 7 detects the surface state of the hot rolled strip 6 and converts the surface state into a video and outputs the image in real time. The output video information is input to the control server 9 and stored. The stored state is used to determine the defect state.

The control server 9 processes the video signal input from the surface flaw detector 7 and outputs it on the monitor screen. The operator can monitor the output and recognize the surface defect. In addition, the control server 9 judges the degree of the defect of the defective portion of the surface of the strip 6 by using the program embedded at the same time. An example of a determination algorithm for determining a defect state is described later.

The finishing rolling PC 8 and the intermediate inspection PC 10 are installed adjacent to the workplace and used to inform the workers of the defect condition of the strip 6 and to instruct them to take appropriate measures.

The operation state and the surface defect determination state of the inspection apparatus of the present invention having the above configuration will be described with reference to the flowcharts of FIGS. 3 and 4.

In the control server 9 receives the image information of the surface of the strip 6 from the surface flaw detector (7) in the step S1 of performing a normal rolling operation (S2), the defect sequence (Ri) primarily by using this ) And the position information such as the defect length Rj and the defect width Wj are recorded in the storage device of the control server 9 (S3). This information is used to detect rollmark and scalability defects. Image information performed by the surface flaw detector (7) is performed over a certain period.

The control server 9 performs the inspection using the surface information of the strip 6 recorded as above. At this time, if the roll mark defect is first detected (S4), the control server 9 performs a periodicity check to determine whether it is repeated with periodicity (S5). The periodicity test will be described later.

If the periodicity defect inspection result is periodicity (S8), a message file (TXT file) containing information on the occurrence of a defect is generated (S9).

If there is no periodicity as a result of periodicity test (S6), a scale defect test is performed (S7). If no defect is found as a result of the scalability test, the control server 9 ends the inspection and maintains the standby state, and then performs defect detection using the surface flaw detector 7 when the next normal rolling operation is performed (S2).

If there is periodicity in the scale defect inspection result, a message file (TXT file) containing information on the occurrence of a defect is generated (S9). When the message file is created as described above, the roll mark defect is first checked and the scale mark defect is checked, so that the roll mark defect has periodicity or the scale defect is found.

If a roll mark or scale defect is found by defect inspection as described above, the control server 9 transmits the generated message file to the finishing rolling PC 8 and the intermediate inspection PC 10 (S10). . When transmission is completed to the finishing rolling PC 8 and the intermediate inspection PC 10 (S11), the control server 9 deletes the generated message file (S12). The above process is a process performed in the control server (9). The transmission of the message file as described above may optionally be performed.

On the other hand, the finishing rolling PC (8) and the intermediate inspection PC (10) received a message that a defect was found after confirming the transmission of the message file (S13, S14), according to the contents of the message file to the workers and The voice is output (S15). The message is output through the monitor screen connected to each PC (8, 10), and the voice is output through the speaker connected to the sound card. An example of the message screen includes the fact that a roll mark defect or a scale defect has been found in the strip coil currently completed. In addition, the audio output through the speaker can be the same.

As above. After the message and voice output, the finishing rolling PC 8 and the intermediate inspection PC 10 remain in a standby state. Operators, finishing rolling operators and / or intermediary inspectors who see and hear messages and voice outputs in this standby state can directly identify defect findings, remove the product and eliminate the causes that cause roll mark or scale defects. (S16) The removal result is inputted to the finishing rolling PC 8 or the intermediate inspection PC 10 (S17).

If it is input as described above, the finishing rolling PC (8) or the intermediate inspection PC (10) deletes the message file related to the defect to complete the defect inspection operation (S18). After the deletion operation, the standby state is again maintained to check whether a new defect discovery message file is transmitted from the control server 9.

The periodicity determination logic of the roll mark defect will be described with reference to FIGS. 4 and 5. In the following, the range in the longitudinal direction means the range of the length error of the roll mark which can be regenerated after one rotation of the final finish rolling roll in use, which corresponds to L1-L7 of FIG. 5.                     

The periodic determination first checks the presence of the defect portion detected at the periodic determination position in the control server 9 by using the image information data input from the surface flaw detector 7 (S51), and has the same line or the predetermined width. Defects detected in the line range are checked (S52), and the number of defects is determined to be three or more (S53). When three or more are determined, the defects having periodicity are determined and roll mark defects (S8; S8 in Fig. 3). Is the same as

The determination process as described above will be described with reference to an example of the specific defect part of FIG. 5. If the first roll mark defect part 51 is confirmed (S4; same as S4 of FIG. 3), the defect part which exists in a predetermined range (2000 ± 100mm) in the longitudinal direction from the confirmed 1st defect part 51 is shown. If all defects are checked within the range 10 times in succession as a target (S51), and if there are no defects, the next defective portion 52 (the Nth) is checked (S5-1), and if there is a defective portion 51, each defect Among the parts, the defect parts 58, 60, and 65 on the same line (within ± 200 mm: D1) as the first defect part 51 are checked (S52). If there is no defect, the next defect 52 is checked (S5-1), and if there is a defect, the number of defects 51, 58, 60, 65 in the longitudinal range L1-17 is determined. (S53). If the number is three or more, it is determined that there is a periodicity (S8) and proceeds as described in FIG. If less than three, the next defective portion 52 is checked (S5-1) and continuously checked in the same manner as the first one. If there is no continuity until the final defect Ai, it is determined that there is no periodicity (S6). Steps S54-S56 are the same processes as steps S51-S53. The message file is created after the determination on the roll mark defect is performed as described above. In the above embodiment, the width of the strip (6) is based on having a size of about 2000mm, if the size of the width is different, the size of the other range and the like can be changed.

On the other hand, since the scalability defects are mainly generated by clustering, the scalability defects are usually compared to determine the fatal scalability. Two areas are used for this area judgment. One is the area K1 occupied by the scale defects recognized by the camera device of the surface flaw detector 7 and the other is the area K2 occupied by the scale defects calculated from the internal processing program of the control server 9. Each area is expressed in units of pixels representing the area on the PC. If each area displayed in this way exceeds this in comparison with a predetermined value, it is judged as a scale defect part. The predetermined value may be set for the areas K1 and K2, respectively, and for example, the scale defect is a value determined as a fatal defect.

When it is determined that the roll mark defect or the scale defect is generated as described above, the monitor screen of the finishing rolling PC 8 or the intermediate inspection PC 10 may be recognized by the finishing rolling operator or the intermediate inspection inspector. Print a message to It also generates an audible alarm through the speaker to prevent workers from recognizing other tasks.

6 is a comparison of the degree of fatality and the detection area when the operator checks the scalability defects found in the surface flaw detector 7, and the item (No. 6) classified as a fatal defect has a large pixel size of " We can see that it's larger than 56034 ". When it is detected by the system internal processing criterion, it can be confirmed that the pixel is "614" or more, and a message file can be created when the defect part belonging to the pixel range or more is detected. Of course, the range of the pixel can be changed according to the width and the unit range of the strip (6).

Fig. 7 shows the verification result according to the flaw detection number of the mark defect part, and shows the probability of determining the defect. In general, when the number of the roll mark defects is three or more, it can be seen that 90% or more appear as defects. Indeed these values are applied for the above embodiments.

According to the present invention, there is an effect that can significantly reduce the product defects caused by the late recognition in the conventional inspection process and the temper rolling process at the time of roll mark defect and scale defect in the hot rolling process.

Claims (4)

In the device for detecting a defect generated on the surface of the strip coil 6 produced in the hot rolling process and to notify the operator of the surface state, A roll formed on the surface of the strip 6 using the surface flaw detector 7 for converting the surface state of the moving strip 6 into image information and outputting the image information input from the surface flaw detector 7. A control server 9 for detecting mark defects and scale defects, determining the surface state of the strip 6 by means of a built-in program, and generating and outputting a message file upon detection of a defect occurrence; and the control server (9) includes PCs (8, 10) for notifying a worker through a monitor and a speaker when a fault-related message file is inputted, and confirming this by inputting an action performed by the driver and deleting the message file; The detection of the roll mark defect portion is performed by first confirming the existence of the defect portion detected at the periodic determination position by the control server 9 by using the image information data input from the surface flaw detector 7, In the hot rolling process, it is possible to check the defects detected in the range of the wide line, determine whether the number of defects is three or more, and if the number is three or more, determine the defects having periodicity and recognize them as roll mark defects. Strip surface flaw detection device. In the device for detecting a defect generated on the surface of the strip coil 6 produced in the hot rolling process and to notify the operator of the surface state, A roll formed on the surface of the strip 6 using the surface flaw detector 7 for converting the surface state of the moving strip 6 into image information and outputting the image information input from the surface flaw detector 7. A control server 9 for detecting mark defects and scale defects, determining the surface state of the strip 6 by means of a built-in program, and generating and outputting a message file upon detection of a defect occurrence; and the control server (9) includes PCs (8, 10) for notifying a worker through a monitor and a speaker when a fault-related message file is inputted, and confirming this by inputting an action performed by the driver and deleting the message file; The detection of the scale defects is based on the area K1 occupied by the scale defects recognized by the camera apparatus of the surface flaw detector 7, or the area K2 calculated by the internal processing program of the control server 9 (K2). And flank defect detection apparatus according to the hot rolling process, characterized in that the judgment is made by comparing with a reference value set as a threshold value at which the scalability defect portion is generated. The video information input from the surface flaw detector (7) to the control server (9) is a position such as a defect order (Ri), a defect length (Rj), a defect width (Wj), and the like. Apparatus for retrieving strip surface defects in a hot rolling process comprising information. delete

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