KR20100000230A - Method and apparatus for removing surface defect of strip - Google Patents

Abstract

PURPOSE: A method for removing the surface defect of a strip and a system thereof are provided to position the surface defect portion of a strip in a grinding work section by automatically stopping the process after gradually reducing the speed of a correction process line. CONSTITUTION: A method for removing the surface defect of a strip comprises the steps for checking whether or not the surface defect is generated in a strip wound after hot rolling is finished, obtaining the rolling base defect position, converting the rolling base defect position into the corrected base defect position if the correction re-winding is executed after moving the strip in which the defect is generated to a correction process line(S5), slowing down and stopping the moving of the strip according to the corrected base defect position(S6,S7), and obtaining and informing the surface defect change state of the strip if the grinding work is finished in the corrected base defect position(S8).

Description

Method and apparatus for removing surface defect of strip

The present invention relates to a method and a system for reducing defects on a strip surface produced in a hot rolling process, and more particularly, a strip surface defect generation portion in a grinding work section of a correction process line through one line stop operation. The present invention relates to a method and a system for removing strip surface defects that can be accurately positioned to maximize the efficiency of the grinding operation.

In general, since the rolled material extracted from the heating furnace is generally operated at a high temperature, the roll roll is damaged by a roll damaged by foreign materials borrowed while passing through rough rolling mill, hot rolling mill, etc. together with surface defects called scale. Various scale surface defects are generated due to poor descaling of the hot rolled steel sheet surface due to the occurrence of marks or poor plateability or clogging of the spray nozzle.

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.

The surface defects of the strip as described above have a great adverse effect on the quality of the product because the surface defects are generated continuously once throughout the entire process.

Therefore, in the related art, as shown in FIG. 1, a surface defect detector 7 is installed between the hot rolling mill 4 and the winding machine 5, and thus, a faster response is performed by detecting surface defects of the strip in real time. To be possible.

For example, if the surface defect level of the strip detected by the surface defect detector 7 is serious or if the intermediate inspector determines that a precise visual inspection of the strip is necessary, the coil is not sent directly to the cold rolling process. Transfer to the correction process line.

After the coil is branched to the cooling station of the correction process line and cooled to the temperature at which the correction process can be performed, the operator knows the overall defect occurrence tendency and the location where the grinding operation is required through the above defect information, and then manually After rewinding, the defect generated on the surface of the strip is visually judged, and then grinding is performed.

In this case, however, the operator had to manually adjust the line operation speed and stop the operation of the line, so it was difficult to position the strip so that the operator's position coincided with the position where the defect occurred.

In addition, if the operator does not continuously check the unwinding length at the entrance of the correction process line through the work screen, a phenomenon in which a defect occurrence part passes through the grinding work section frequently occurs.

Then, the operator repeatedly performs the repeating operation of inverting or advancing the line again, causing trouble to locate the defect occurrence part in the grinding work section, which causes a lot of problems in customer management due to work delay and delay in delivery. .

Therefore, in the present invention, the strip surface defect removal method and system to maximize the efficiency of the grinding operation by accurately positioning the strip surface defect generation portion in the grinding operation section of the correction process line through one line stop operation. To provide.

According to a first aspect of the present invention, as a means for solving the above problems, the step of obtaining a rolling reference defect position by confirming whether or not the surface defect of the strip to be wound hot rolled is completed; Transferring the strip on which the surface defect has occurred to the correction process line, and then converting the rolling reference defect position into a correction reference defect position when correction rewinding is performed; Slowing and stopping the transfer of the strip according to the correction criterion defect location; And acquiring and notifying a surface defect change state of the strip when the grinding operation at the correction criterion defect position is completed.

The step of stopping the transfer of the strip of the present invention comprises the steps of receiving the correction reference defect position through the defect position length setting window of the correction operation screen; Lowering the feed rate of the strip when the correction criterion defect location is close to a grinding operation section; And stopping the feeding of the strip when the correction criterion defect position is located in the grinding work section.

In this case, the rolling reference defect position may be a surface defect occurrence position based on the head portion of the strip, and the correction reference defect position may be a surface defect occurrence position based on the tail portion of the strip.

According to a second aspect of the present invention, as a means for solving the above problems, the intermediate inspection control unit for obtaining a rolling reference defect position by checking whether or not the surface defects of the strip to be hot rolled is completed; The strip having the surface defects is transferred to a correction process line, and when correction rewinding is performed, a correction check is performed to switch the rolling reference defect position to a correction reference defect position and to slow and stop the feeding of the strip according to the correction reference defect position. Detection unit; And a final result checker for acquiring and notifying the surface defect change state of the strip after the cold rolling process is completed, when the grinding operation at the correction reference defect position is completed and transferred to the cold rolling process. To provide.

The correction confirmation detector of the present invention lowers the feed speed of the strip when the strip is transferred to the correction process line and the correction reference defect position approaches the grinding work section, and then when the correction reference defect position is located in the grinding work section. Characterized in that the transfer of the strip is stopped.

In this case, the rolling reference defect position may be a surface defect occurrence position based on the head portion of the strip, and the correction reference defect position may be a surface defect occurrence position based on the tail portion of the strip. .

As described above, the strip surface defect removing method and system of the present invention receives the strip surface defect position in advance, and accordingly, automatically stops the speed of the correction process line and then stops automatically, whereby the defect occurrence portion of the strip is ground. Make sure it is positioned exactly at.

This eliminates the need for the operator to continuously check the unwinding length at the entrance of the correction process line through the work screen. Thereby maximizing the efficiency of the grinding operation.

And it minimizes the work delay and delivery delay problem caused by additionally performing the correction process line.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing in detail the operating principle of the preferred embodiment of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, the same reference numerals are used for parts having similar functions and functions throughout the drawings.

Figure 2 illustrates a system for removing strip surface defects in accordance with one embodiment of the present invention.

Referring to Fig. 2, the system of the present invention includes an intermediate inspection control unit 11 installed in the rolling process line 21, a correction confirmation detection unit 12 and a correction grinding work unit 13 installed in the correction process line 22, and The final result confirming unit 14 installed on the cold rolling process line 23 is provided.

The intermediate inspection control unit 11 detects the surface defect of the strip by using a surface defect detector as in the prior art, and detects the result of the detection (for example, the surface defect image 31, through the rolled surface defect image image screen of FIG. 3). Surface defect location information 32, surface defect information 33 and strip information 33, etc.) are notified to the operator of the rolling process line. Accordingly, the operator judges that the defect needs to be checked once more for the severity of the defect or whether the defect is corrected in a subsequent process. After activating the intermediate inspection result screen of FIG. Is changed from the cold rolling plan branch 42 to the correction process line 43, the current detection result is converted into a database, and the correction confirmation detection unit 12, the correction grinding work unit 13, and the final result confirmation unit 14 are described. To share).

The correction confirmation detection unit 12 branches the strip to the cooling field of the correction process line, cools it to the correct operation temperature through natural cooling and forced cooling, and then enters the correction process line, that is, the payoff reel of the correction process line. When mounted on the Pay Off Reel, the operator of the correction process line is once again notified of the detection result of the intermediate inspection control unit 11 through the rolling surface defect image image screen. When the operator selects the surface defect of the strip to perform the grinding operation with reference to the detection result of the intermediate inspection control unit 11, the position position (51 ~ ~) of the selected surface defect is activated by activating the defect position length setting window as shown in FIG. 53)). When setting the position value of the surface defect is completed, proceed with strip feeding at the normal speed, but gradually decrease the strip feeding speed when the grinding work zone and the surface defect occurrence area are close, and then place the surface defect occurrence site on the grinding work zone. Allow strip transport to stop.

In addition, if necessary, the operator may visually determine the position of the surface defects more accurately and affordably according to the reduced strip feeding speed, and then stop the feeding of the strip directly.

Accordingly, the correction confirmation detection unit 12 of the present invention can accurately position the surface defect generation portion on the grinding work section through one line stop operation.

For reference, since the correction confirmation detection unit 12 acquires the defect occurrence position value of the strip to be wound, the strip defect occurrence position value at this time is calculated based on the strip head portion. However, in the correction process line, uncoiling the wound strip again grinds the surface defects of the strip. Accordingly, in the correction process line, it is convenient to perform the grinding operation with reference to the defect occurrence position value obtained based on the tail portion, not the head portion of the strip.

Accordingly, the correction confirmation detection unit 12 of the present invention is the surface defect position of the strip calculated on the basis of the strip head portion (hereinafter referred to as a rolling reference defect position) of the surface defect position of the strip calculated on the tail portion of the strip (that is, the correction criteria) And position of surface defects on the strip.

The operator can then calculate and recognize the location of the surface defects on the strips based on the position values of the uncoiled strips, allowing for quicker and easier identification of the grinding work position.

The correction grinding work unit 13 provides a grinding work result input window as shown in FIG. 6, and after the operator performs a substantial grinding work, inputs the grinding work result 61 through the grinding work result input window of FIG. 6. Database it and store it.

At this time, the grinding operation is preferably carried out according to the grinding amount reference and the surface defect tolerance standard reference as the number of coil thickness grinding, as shown in Table 1 and Table 2.

<Table 1>

<Table 2>

The final result confirming unit 14 proceeds to the cold rolling process of the completed strip grinding process, and every time the cold rolling and annealing process and the plating process passes, the surface defects of the strip is photographed and analyzed, the cold rolling of Figure 7 Through the off-line surface defect detection image image screen, the grinding operation result image 71 and the cold rolled coil history information inquiry screen of FIG. 8 are notified of the degree of surface defect 81 changed after the grinding operation.

As described above, in the present invention, when the operator position and the surface defect position of the strip are close to each other, the speed of the correction process line is lowered, so that the surface defect position of the strip is always located in the grinding work section through one line stop operation.

9 is a view showing a strip surface defect removal method according to an embodiment of the present invention.

When the rolling process is finished, the intermediate inspection control unit 11 detects and notifies the surface defect of the strip on which the rolling process is completed, thereby confirming whether the surface defect generated at present is serious or needs to be checked again in a later process. It is determined whether to perform a correction grinding operation (S1).

If it is determined in step S1 that the correction grinding operation is necessary, the cold rolling planning branch of the strip is changed to the correction process line (S2), and the wound strip is branched to the cooling field of the correction process line.

In the state where the wound strip is cooled to the temperature at which the correction process can be performed (S3), when a correction operation instruction is generated (S4), the strip is advanced to the correction process line.

Accordingly, when the strip is mounted on the entrance side of the correction process line, that is, the pay off reel, and the correction rewind is started, the correction confirmation detection unit 12 switches the rolling reference defect position to the correction reference defect position, and then corrects it. The reference defect location and the surface defect image of the strip obtained through step S1 are provided to the operator of the correction process line (S5).

When the operator of the correction process line selects the surface defect of the strip on which the grinding operation is performed through the information provided through step S5, and inputs the correction reference defect position of the selected surface defect as the grinding operation position value, the correction process line is operated at normal speed. When the strip is started to be transferred, but the grinding work section and the surface defect generation area gradually approaches, the feed rate of the strip is gradually reduced (S6).

And if the surface defect generation site is located on the grinding work section the transfer of the strip is stopped, the operator performs a substantial grinding work at the corresponding position (S7).

When the grinding work is completed through step S7, the operator reports the grinding work result (S8), and then transfers the strip on which the grinding work is completed to the cold rolling process line.

When the cold rolling process is completed, the grinding operation result is finally confirmed to determine a defect rating and a grade of the strip (S9).

In other words, through the cold rolling, annealing and plating process of the strip transferred to the cold rolling process line, the genuine and out-of-order evaluation grades for the grinding operation results, and the cold rolled off-line surface defect image image is confirmed, cold rolled coil The total length is divided by the total length of the hot rolled coil to apply the increased ratio during cold rolling to compare the hot roll grinding point and the cold roll detection position to identify and analyze how the defect shape has changed.

 The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those skilled in the art.

1 illustrates a system for removing strip surface defects according to the prior art.

Figure 2 illustrates a system for removing strip surface defects in accordance with one embodiment of the present invention.

3 is a view showing a rolling surface defect image image screen according to an embodiment of the present invention.

4 is a diagram illustrating an intermediary inspection record screen according to an embodiment of the present invention.

5 is a view showing a defect position length setting window according to an embodiment of the present invention.

6 is a view showing a grinding operation results input window according to an embodiment of the present invention.

7 is a view showing a cold-rolled offline surface defect detection image image screen according to an embodiment of the present invention.

8 is a diagram illustrating a cold rolled coil history information inquiry screen according to an embodiment of the present invention.

9 is a view showing a strip surface defect removal method according to an embodiment of the present invention.

Claims (8)

Obtaining a rolling reference defect position by checking whether a surface defect of the strip to be wound due to hot rolling is completed; Transferring the strip on which the surface defect has occurred to the correction process line, and then converting the rolling reference defect position into a correction reference defect position when correction rewinding is performed; Slowing and stopping the transfer of the strip according to the correction criterion defect location; And And acquiring and notifying a surface defect change state of the strip when the grinding operation at the correction criterion defect position is completed. The method of claim 1, wherein the step of stopping the feeding of the strip Receiving the correction reference defect position through a defect position length setting window of a correction operation screen; Lowering the feed rate of the strip when the correction criterion defect location is close to a grinding operation section; And Stopping the transfer of the strip when the correction criterion defect location is located in the grinding work section. The method of claim 1, wherein the rolling reference defect position is And a surface defect generation position with respect to the head portion of the strip. The method of claim 1, wherein the correction reference defect location is And a surface defect generation position with respect to the tail portion of the strip. An intermediate inspection control unit which checks whether a surface defect of the strip to be wound after hot rolling is completed and obtains a rolling reference defect position; The strip having the surface defects is transferred to a correction process line, and when correction rewinding is performed, a correction check is performed to switch the rolling reference defect position to a correction reference defect position and to slow and stop the feeding of the strip according to the correction reference defect position. Detection unit; And And a final result checker for acquiring and notifying the surface defect change state of the strip after the cold rolling process is completed, when the grinding operation at the correction criterion defect position is completed and transferred to the cold rolling process. The method of claim 5, wherein the correction confirmation detection unit When the strip is transferred to the correction process line and the correction reference defect position approaches the grinding work section, the feeding speed of the strip is lowered. When the correction reference defect position is located in the grinding work section, the feeding of the strip is stopped. System for removing strip surface defects. The method of claim 5, wherein the rolling reference defect position is And a surface defect occurrence position relative to the head portion of the strip. 6. The method of claim 5 wherein the correction criterion defect location is And a surface defect occurrence position relative to the tail portion of the strip.

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