KR100836451B1 - Method for decreasing the amount of the surface defect by the roll mark in the hot roll process - Google Patents

Abstract

The present invention comprises the steps of supplying the rolled material from the continuous casting machine, the step of heating the rolled material to a predetermined temperature in a heating furnace controlled by a furnace control computer, a rolling mill controlled by the rolling mill control computer A method comprising rough rolling and finishing rolling in a surface, surface inspection of a rolled rolled material on a surface flaw detector, and winding a rolled rolled material having a good surface to a winder, wherein the surface The data of the surface inspection by the flaw detector is provided to the server computer, and the server computer controls the furnace control computer and the rolling mill so that the operation of the furnace and the rolling mill is controlled in accordance with the data of the surface inspection provided from the surface flaw detector. Since it further comprises the step of providing a control signal to the computer, When the surface of the roll mark surface defect detected on the surface of the rolled material is detected by the surface flaw detector during hot rolling, information about the roll mark can be provided to the heater control computer and the rolling mill control computer to effectively prevent the production of poor surface products.

Surface flaw detector, rolling mill control computer, furnace control computer, server computer

Description

Method for decreasing the amount of the surface defect by the roll mark in the hot roll process}             

1 is a flow chart showing a general rolling process;

2 is a flow chart showing a rolling process according to the present invention;

3 is a flowchart illustrating a control process of a rolling process according to the present invention;

4 is a flow chart showing a control process of the rolling process according to an embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

7: surface flaw detector

8: Furnace Control Computer

9: rolling mill control computer

10: server computer

The present invention relates to a method for reducing surface defects caused by roll marks occurring on a strip surface produced in a hot rolling process, and more particularly, data of surface defects caused by roll marks generated during hot rolling of a strip. The present invention relates to a method for reducing surface defects of a roll mark in a hot rolling process, by controlling a heating furnace and a rolling mill in real time to prevent surface defects caused by additional roll marks.

In general, the hot rolling process is a process for producing slabs supplied from a continuous casting machine into strips having a width and a thickness of a predetermined size. That is, referring to FIG. 1, the slab supplied from the continuous casting machine (first step) is reheated in the heating furnace (second step) and then width-rolled and thickness-rolled in the roughing mill (third step). After this, the slab is finally rolled into the product having the desired thickness in the finishing mill (step 4), and then wound in the form of a coil in the winding machine (step 5). The operator of the inspection team performs a surface inspection for the final confirmation of the coil wound around the winder (sixth step).

At this time, the furnace is controlled by a furnace control computer and the roughing mill and the finishing mill are controlled by a rolling mill control computer.

As such, the surface defects generated during the hot rolling process lose their value as products. Therefore, preventing occurrence of surface defects is an important management factor in the rolling process.

That is, in the rolling process, the coil wound after the rolling process is checked in the inspection panel for intermediate defects, and the result data is provided to the worker in another process. At this time, the operator can take a series of measures, such as whether online roll polishing in the finish rolling and whether or not to replace the rolling roll or waiting for subsequent coils waiting for rolling, malfunction processing according to the result data provided by the inspection panel.                         

However, such a series of measures are possible only when surface defects are detected in the intermediate inspection process, and if the surface defects are not detected, the rolling process proceeds to the final temper rolling process to produce defective products.

And even if surface defects are found in the final temper rolling process, since the coils after the surface defects are already rolled, they must be judged out of grade.

In addition, the intermediate test as described above, the difference occurs in the efficiency of detecting the surface defects and how to cope with it according to the skill of the inspector. In addition, the above-mentioned intermediate test is not a full test, but a sample test, for example, about 3 to 4m of the coil final part is less reliable, and as a result, the test results are processed based on the tester's knowledge and experience surface defects There has always been a possibility of misjudgment due to the lack of discovery

In addition, due to the nature of the process, in the hot rolling process operated on-line, the damaged parts of the rolling rolls continuously cause roll mark surface defects on the product until appropriate measures are taken.

Therefore, it is necessary to take appropriate measures as soon as possible, and in the way that existing drivers and inspectors take, it is difficult to process the above series of inspections, judgments, and measures in a short time. There was a problem that the roll mark surface defects must be generated for the coil.

That is, if a surface defect occurs, the surface defect is generated until the action is taken to the trailing coil after the surface defect is generated. In addition, since the sale of the defective product is impossible to be scrapped, there is a problem in that the cost of scrap is added to increase the production cost.

The present invention has been made to solve the conventional problems as described above, to provide a method that can reduce the roll mark surface defects of the rolled material by controlling the rolling process in real time when the surface defects of the rolled material occurs in the hot rolling line Its purpose is to.

In order to achieve the above object, according to the present invention, the step of supplying a rolled material from the continuous casting machine, the step of heating the rolled material to a predetermined temperature in a heating furnace controlled by a furnace control computer, and the heated rolled material Rough rolling and finishing rolling in a rolling mill controlled by a rolling mill control computer, surface inspection of the rolled rolled material on a surface flaw detector, and winding the rolled rolled material having a good surface to a winder The method includes the data of the surface inspection by the surface flaw detector is provided to the server computer, the server computer is the heating so that the operation of the heating furnace and the rolling mill is controlled in accordance with the data of the surface inspection provided from the surface flaw detector Providing control signals to the furnace control computer and the rolling mill control computer; It is characterized by.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 to 4, and the same components are assigned the same reference numerals.                     

First, the heater for heating the rolled material supplied from the continuous casting machine is controlled by the heater control computer (SCC1) 8. The roughing mill and the finishing mill for rolling the rolled material heated in the heater are controlled by the rolling mill control computer (SCC2) 9.

According to the present invention, a surface flaw detector 7 is provided between the finishing mill and the winding machine for winding the rolled rolled material to check the surface defect of the strip. Data on the surface defects of the strips detected by the surface flaw detector 7 is provided to the server computer 10. At this time, the server computer 10 is connected to the network via the intranet to enable signal transmission to the heater control computer (SCC1) and the rolling mill control computer (SCC2).

Therefore, data on the surface defects of the strip detected by the surface flaw detector 7 are provided to the heater control computer SCC1 and the rolling mill control computer SCC2, and the heater control computer SCC1 and the rolling mill control computer SCC2 are provided. Controls the operation of the heater and the mill according to the data provided.

The surface flaw detector 7 is provided between the rolling mill and the winder to detect defects on the surface of the rolled material by using infrared rays, ultrasonic waves, or laser. When the surface defect of the rolled material is detected, a detection signal is sent to the server computer ( 10) to transmit.

Furnace control computer (SCC1) is a computer that controls the operation of the furnace, when data from the server computer 10 is provided that the surface defects occurred in the strip, the operation of the furnace is stopped and the rolled material is transferred to the furnace Do not allow charging.

The rolling mill control computer (SCC2) is a computer for controlling rolling mill operations such as rough mills and finishing mills. Do not allow material to enter.

When the server computer 10 receives the data on the surface defects of the rolled material from the surface flaw detector 7 as described above, the server computer 10 calculates the data and transmits the data to the furnace control computer SCC1 and the rolling mill control computer SCC2.

Hereinafter, the implementation of the method for reducing the roll mark surface defect in the hot rolling process according to the present invention will be described.

After the heated rolled material is extracted from the furnace, width rolling and thickness rolling are performed in a rough mill. Then, the rough rolled rolled material is rolled in the winding machine after passing through the upper portion of the defect flaw detector (7) after the final thickness rolling process in the finish rolling mill. This completes the rolling control operation for the coil.

At this time, the server computer 10 continuously displays the position and state information of the rolling material in the heating process, the rough rolling process, and the finish rolling process, which are the unit processes, and the furnace control computer SCC1 and the rolling mill control computer SCC2. Collect through). The server computer 10 is provided with information on the surface defect state of the rolled material from the surface flaw detector 7.

The server computer 10 causes the furnace and the rolling mill to operate continuously if the surface defect of the rolled material is not detected while analyzing the information thus collected. However, if a surface defect of the rolled material is detected, the server computer 10 determines whether rolling is possible. As a result, the server computer 10, if it is determined that the rolling operation is possible to perform the operation of the rolling mill continuously, and if it is determined that the rolling operation is impossible, proceeds with the preparation work for grinding the rolling roll.

That is, when it is determined that the rolling operation is impossible, as shown in FIG. 4, the furnace control computer SCC1 determines whether there is a rolling material waiting to be extracted inside the heating furnace, Continuously waiting for extraction, and if there is no extraction waiting rolled material is determined whether there is a rolling material being extracted. At this time, if there is a rolled material being extracted, the furnace control computer (SCC1) immediately stops the extraction of the rolled material and reloads the rolled material into the furnace to keep it in the extraction standby state.

In addition, the furnace control computer (SCC1) determines whether there is a rolled material that has been extracted if there is no rolled material being extracted, and if there is a rolled material that has been extracted, it is charged into the furnace to continue extraction and the extracted rolled material is If not, proceed to the next task.

When the control operation of the furnace control computer SCC1 is finished, rolling mills such as rough rolling mill and finishing mill are controlled by the rolling mill control computer SCC2.

That is, the rolling mill control computer SCC2 determines whether there is a rough rolling atmospheric rolling material, and if there is a rough rolling atmospheric rolling material, determines whether the length thereof is smaller than a predetermined length, for example, a length of 12 m. If the length of the rolled material in the air is less than 12m, it is charged to the heating furnace to continue the extraction. However, if the length of the rolled material in the air is longer than 12m, it is rough rolled.

At this time, the rolling mill control computer SCC2 determines whether there is a rolling material that is being subjected to the rough rolling operation, and performs rolling roughly in a predetermined order if there is a rolling material that is being rolled.

On the other hand, the rolling mill control computer (SCC2) confirms that there is no rolling material being rolled in the roughing mill and determines whether there is a rolling material being rolled in the finishing mill. And if there is no rolling material which finish rolling is being performed, the rolling mill control computer SCC2 stops operation of a rolling mill. At this time, the rolling material waiting to enter the finishing mill by the rolling mill control computer (SCC2) continues to enter.

As described above, if the operation of the heater and the rolling mill is stopped and there is no rolling material entering the heater and the rolling mill, the server computer 10 immediately performs on-line roll grinding. While online roll grinding is performed in the finishing mill, the rolled material waiting for the rough mill is reciprocated at the current position.

When the online roll grinding operation is completed, the rolled material in the roll is preferentially rolled and then proceeds to the normal rolling operation.

At this time, if it is determined that the rolling operation is impossible even after grinding, replace the rolling rolls and then perform the normal rolling operation.

According to the present invention, if a roll mark surface defect appearing on the surface of a rolled material is detected by a surface flaw detector during hot rolling, information about the roll mark is provided to the heater control computer and the rolling mill control computer to effectively produce a defective product. You can prevent it.

The foregoing is merely illustrative of the preferred embodiments of the present invention and those skilled in the art to which the present invention pertains recognize that modifications and variations can be made to the present invention without departing from the spirit and gist of the invention as set forth in the appended claims. shall.

Claims (3)

Supplying the rolled material from the continuous casting machine, and controlling the furnace by heating the rolled material Heating to a predetermined temperature in a heating furnace controlled by a computer; roughly rolling and finishing rolling the heated rolled material in a rolling mill controlled by a rolling mill control computer; and rolling the rolled rolled material on a surface flaw detector Step of checking, good table In the method comprising the step of winding the rolled rolled material having a face in a winder hurry, The data of the surface inspection by the surface flaw detector is provided to the server computer. The server computer provides control signals to the furnace control computer and the rolling mill control computer to control the operation of the furnace and the rolling mill in accordance with the data of the surface inspection provided from the surface flaw detector, and the surface polishing of the rolling mill rolling roll. The method for reducing roll surface defects in a hot rolling process, further comprising the step of providing a roll polishing device to determine whether or not a polishing signal is determined. delete The method of claim 1, When the data on the surface defect occurrence is provided from the server computer, the rolling mill control computer enters the furnace in the rough rolling material having a length of less than 12m and the rough rolling material having the length of more than 12m is roughly rolled. Roll mark surface defect reduction method in the hot rolling process, characterized in that the control operation.

Images