KR102314632B1 - Method of controlling the roughing mill process using descaling pattern database and rougher press apparatus using the same - Google Patents

Abstract

The present invention provides a rough rolling control method using a descaling pattern database wherein the rear surface temperature and residual scale of rough rolling are controlled by controlling the spray conditions of descaling. According to the present invention, the rough rolling control method using a descaling pattern database comprises the steps of: constructing a descaling pattern database including the number of times of spraying a descaling material and a spray position; selecting a first descaling pattern from the descaling pattern database; performing the first rough rolling of a steel material while performing first descaling according to the first descaling pattern; measuring the actual temperature of the steel material after performing the first rough rolling; and determining whether to replace the first descaling pattern by comparing the actual temperature of the steel material with a predicted temperature.

Description

Method of controlling the roughing mill process using descaling pattern database and rougher press apparatus using the same

The technical idea of the present invention relates to steel manufacturing, and more particularly, to a rough rolling control method using a descaling pattern database and a rough rolling apparatus using the same.

General steel manufacturing consists of a steelmaking process to produce molten iron, a steelmaking process to remove impurities from molten iron, a continuous casting process in which liquid iron becomes a solid, and a rolling process to turn iron into a steel plate or wire rod.

In the rolling process, the steel supplied from the continuous casting machine of the steelmaking process is charged into a heating furnace, reheated to a suitable temperature in the range of 1100°C to 1300°C, and then width and thickness roughing are performed through the roughing mill, and the customer in the finishing mill After final rolling is performed to a product having a desired thickness, the produced strip is wound with a winder and wound into a winding coil in the form of a roll.

During the rough rolling process of steel, scale, which is an oxide film formed on the surface of the steel, can cause defects in the rough rolled steel, so descaling is required to remove the scale before rough rolling. The descaler that performs descaling is a device that removes the surface of the steel moving to the roughing mill by spraying it with high-pressure coolant. The injection conditions such as the injection pattern and number of injections of the coolant sprayed from the descaler affect the temperature distribution of the steel after rough rolling, which is related to the quality of the steel.

If the temperature of the back side of rough rolling does not match the target temperature, the dimensional quality of the steel is affected, and in particular, it is difficult to manage the width margin. The width margin means an amount that is added or subtracted from the target width standard during rolling. Since the factor that has the greatest influence on the width margin is temperature, if the temperature control of the rear surface of rough rolling is incorrect, a deviation of the width margin is greatly generated, which affects the dimensional quality. The width margin is calculated by setting and learning, and when the temperature is smaller than the set value, the hardenability of the actual material increases to increase the width margin, and when the temperature is larger than the set value, the steel is stretched in the longitudinal direction rather than in the width direction. Accordingly, the width margin also becomes smaller. In addition, if there is a deviation from the target temperature of the measured rough-rolled material during rough rolling, the temperature is affected even in the finishing rolling section. If the actual temperature of the steel is too high compared to the target temperature, the scale of the specific steel may remain. If the actual temperature of the steel is too low, the rolling load increases, which adversely affects the sheet-feeding properties, and in severe cases, kinking or malfunctioning problems occur. In order to reduce the deviation from the target temperature, a change in the descaling setting including the spray pattern or the number of sprays may be performed.

Korean Patent Application No. 10-2011-0137855

It is important to achieve the temperature target by controlling the spray conditions during descaling in the rough rolling process, but even if such a temperature target is achieved, the shape or aspect of scale remaining on the surface of the steel changes depending on the spray conditions. Therefore, when descaling, the conditions should be optimized by considering not only the temperature of the rear surface of the rough rolling but also the aspect of the remaining scale.

The technical problem to be achieved by the technical idea of the present invention is to provide a rough rolling control method using the descaling pattern database for controlling the rear surface temperature of the rough rolling and the residual scale by controlling the spray conditions of the descaling, and a rough rolling apparatus using the same.

However, these tasks are exemplary, and the technical spirit of the present invention is not limited thereto.

According to one aspect of the present invention, there is provided a rough rolling control method using a descaling pattern database.

According to an embodiment of the present invention, the rough rolling control method comprises the steps of: establishing a descaling pattern database including the number of injections and the injection positions of the descaling material; selecting a first descaling pattern from the descaling pattern database; performing a first rough rolling of the steel while performing a first descaling according to the first descaling pattern; measuring the actual temperature of the steel material after performing the first rough rolling; and comparing the actual temperature and the predicted temperature of the steel material, and determining whether to replace the first descaling pattern.

According to an embodiment of the present invention, the step of constructing the descaling pattern database may include: setting a preliminary descaling pattern including the number of times and locations of spraying of the descaling material; performing preliminary rough rolling of the preliminary steel while performing preliminary descaling according to the preliminary descaling pattern; determining whether to select the preliminary descaling pattern according to the state of the scale remaining in the preliminary rough-rolled preliminary steel; and storing information on the preliminary descaling pattern selected in the determining step in the descaling pattern database.

According to an embodiment of the present invention, the determining whether to select the preliminary descaling pattern may include determining whether to select the preliminary descaling pattern according to the type and residual degree of the scale.

According to an embodiment of the present invention, in the determining step, if the absolute value of the deviation between the actual temperature and the predicted temperature of the steel is smaller than or equal to the allowable temperature deviation, according to the first descaling pattern It may further include; performing a second rough rolling of the steel while performing the second descaling.

According to an embodiment of the present invention, in the determining step, if the absolute value of the deviation between the actual temperature and the predicted temperature of the steel is larger than the allowable temperature deviation, the second descaling from the descaling pattern database selecting a pattern; replacing the first descaling pattern with the second descaling pattern; and performing a second rough rolling of the steel material while performing a second descaling according to the second descaling pattern.

According to an embodiment of the present invention, the first rough rolling of the steel is performed in a first roughing mill, and the first descaling is performed before the steel enters the first roughing mill, the first roughing mill It can be carried out after being discharged from, or both.

According to an embodiment of the present invention, the second rough rolling of the steel is performed in a second roughing mill, and the second descaling is performed before the steel enters the second roughing mill, the second roughing mill It can be carried out after being discharged from, or both.

According to an embodiment of the present invention, the first rough rolling and the second rough rolling of the steel may be performed in a first rough rolling mill.

According to an embodiment of the present invention, the steel is rough rolled while moving in the forward rough rolling direction or the reverse rough rolling direction in the first roughing mill, or while moving in the second roughing mill in the forward rough rolling direction or in the reverse rough rolling direction can be rolled.

According to an embodiment of the present invention, the actual temperature of the steel is measured after the steel is rough-rolled by moving in the forward roughing mill in the first roughing mill, or is rough-rolled in the second roughing mill by moving in the forward direction. can be measured after

According to another aspect of the present invention, a rough rolling apparatus using a descaling pattern database is provided.

According to an embodiment of the present invention, the roughing apparatus includes a first roughing mill for first roughing the steel; a second roughing mill for second roughing the steel material roughed in the first roughing mill; a first descaler disposed on the front side of the first roughing mill and spraying a descaling material to the steel; a second descaler disposed at a rear side of the first roughing mill and spraying the descaling material to the steel; a third descaler disposed in front of the second roughing mill and spraying the descaling material to the steel; a fourth descaler disposed at a rear side of the second roughing mill and spraying the descaling material to the steel; a first temperature measuring unit disposed at the rear of the first roughing mill to measure the temperature of the steel; a second temperature measuring unit disposed at the rear of the second roughing mill to measure the temperature of the steel; and a descaling pattern database, and performing descaling by controlling the first to fourth descalers according to a descaling pattern selected from the descaling pattern database, and measuring from the first and second temperature measuring units. and a control unit configured to acquire the temperature and replace the descaling pattern.

According to the technical idea of the present invention, the rough rolling control method can effectively predict and efficiently control the rear surface temperature of the rough rolling by using the descaling pattern database. In addition, the descaling pattern database includes information on the quality state according to the descaling pattern with respect to the type of steel, so that an optimal descaling pattern can be set within an allowable range of defects in the steel. By performing the rough rolling process according to the descaling pattern, it is possible to effectively control the rear surface temperature of the rough rolling while minimizing the scale defects of the steel.

The above-described effects of the present invention have been described by way of example, and the scope of the present invention is not limited by these effects.

1 is a schematic diagram illustrating a rough rolling apparatus for performing a rough rolling control method using a descaling pattern database according to an embodiment of the present invention.
2 is a flowchart illustrating a rough rolling control method using a descaling pattern database according to an embodiment of the present invention.
3 is a flowchart illustrating a step of constructing a descaling pattern database in a rough rolling control method using a descaling pattern database according to an embodiment of the present invention.
4 is a flowchart illustrating steps performed after determining whether to replace the first descaling pattern in the rough rolling control method using the descaling pattern database according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely explain the technical idea of the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, The scope of the technical idea is not limited to the following examples. Rather, these embodiments are provided so as to more fully and complete the present disclosure, and to fully convey the technical spirit of the present invention to those skilled in the art. In the present specification, the same reference numerals refer to the same elements throughout. Furthermore, various elements and regions in the drawings are schematically drawn. Accordingly, the technical spirit of the present invention is not limited by the relative size or spacing drawn in the accompanying drawings.

The hot rolling system to which the rough rolling control method according to an embodiment of the present invention is applied includes a heating furnace, a widening mill, a rough rolling mill, a finishing mill, a cooler, and a winder. Through the hot rolling system, the steel is converted into the form of a slab, a bar, and a coil. The roughing mill may include one or more roughing mills. A descaler for spraying a descaling material to remove scale may be disposed before and after each roughing mill.

If a deviation occurs compared to the target temperature during the current rough rolling rear temperature management, the driver changes and manages the rough rolling condition. Hereinafter, the driver's change of the rough rolling condition will be described in detail. By changing the rough rolling speed of the roughing mill, it is possible to control the rear surface temperature of the rough rolling. For example, the temperature and the rough rolling speed are inversely proportional to each other. If the rear surface temperature of rough rolling is higher than the target temperature, the operation speed of the roughing mill is slowed down. You can control the temperature by increasing the speed. However, there may be problems such as difficulty in managing the rolling pitch when the rough rolling speed is changed in the roughing mill, and the bonding is not performed during continuous rough rolling.

Therefore, in order to control the rear surface temperature of the rough rolling, a method of controlling the number of injections of the descaler may be used. When the rough-rolled rear surface temperature is higher than the target temperature, the number of injections of the descaler is increased than the set number, and when the crude-rolled rear surface temperature is lower than the target temperature, the number of injections of the descaler is decreased. Since such rough-rolling rear surface temperature control is essential for maintaining dimensional accuracy and surface precision of the final product, the rough-rolling rear surface temperature needs to be managed by the set target temperature for each product and dimension.

1 is a schematic diagram illustrating a rough rolling apparatus 100 for performing a rough rolling control method using a descaling pattern database according to an embodiment of the present invention.

Referring to FIG. 1 , the roughing apparatus 100 includes a first roughing mill 110 , a second roughing mill 120 , first to fourth descalers 130 , 140 , 150 , 160 , first and It includes second temperature measurement units 170 and 180 , and a control unit 190 .

The first roughing mill 110 may perform a first rough rolling of the steel (M). The second roughing mill 120 may perform a second rough rolling of the rough-rolled steel M in the first roughing mill 110 .

The first descaler 130 may be disposed on the front side of the first roughing mill 110 to spray the descaling material on the steel M. The second descaler 140 may be disposed on the rear side of the first roughing mill 110 to spray the descaling material onto the steel M. The third descaler 150 may be disposed on the front side of the second roughing mill 120 to spray the descaling material on the steel M. The fourth descaler 160 may be disposed on the rear side of the second roughing mill 120 to spray the descaling material onto the steel M. The descaling material is a material used for removing scale, for example, may be composed of high-pressure coolant, or may be a liquid including fine particles such as aluminum oxide particles.

The first temperature measuring unit 170 may be disposed on the rear side of the first roughing mill 110 to measure the temperature of the steel (M). The second temperature measuring unit 180 may be disposed on the rear side of the second roughing mill 120 to measure the temperature of the steel material (M). The temperature of the steel material M measured by the second temperature measuring unit 180 may be referred to as a rough rolling rear surface temperature.

The controller 190 includes a descaling pattern database, and performs descaling by controlling the first to fourth descalers 130, 140, 150, and 160 according to a descaling pattern selected from the descaling pattern database. Then, the descaling pattern may be replaced by acquiring the temperatures measured from the first and second temperature measuring units 170 and 180 . The controller 190 may be electrically connected to the first to fourth descalers 130 , 140 , 150 , and 160 to control them. In addition, it may be electrically connected to the first and second temperature measuring units 170 and 180 to control them.

The rough rolling process direction is a direction from the first roughing mill 110 to the second roughing mill 120, and this will be referred to as a rough rolling forward direction. On the contrary, the direction from the second roughing mill 120 to the first roughing mill 110 is referred to as a reverse roughing direction. In addition, the front side means a position before rough rolling is performed in the first roughing mill 110 or the second roughing mill 120 , and the rear side is the first roughing mill 110 or the second roughing mill 120 . 2 means a position after rough rolling is performed in the roughing mill 120 .

The steel (M) may be rough-rolled by moving in the forward direction of the rough rolling in the first roughing mill 110, on the contrary, it may be moved in the reverse direction of the rough rolling to be rough-rolled. For example, as the first roughing mill 110 rotates in the forward roughing direction, the steel M is moved in the first roughing mill 110 in the forward roughing direction to perform primary rough rolling, then the first roughing mill As the 110 rotates in the reverse direction of the rough rolling, the steel M is moved in the reverse direction of the rough rolling in the first roughing mill 110 to perform secondary rough rolling, and then the first roughing mill 110 is again By rotating in the forward roughing direction, the steel (M) may be moved in the first roughing mill 110 in the reverse direction of the roughing to perform third rough rolling.

In this case, the first temperature measuring unit 170 may measure the temperature of the steel material M after the first rough rolling and after the third rough rolling.

In addition, the steel (M) may be rough-rolled by moving in the forward direction of the rough rolling in the second roughing mill 120, on the contrary, it may be moved in the reverse direction of the rough rolling to be rough-rolled. For example, as the second roughing mill 120 rotates in the forward roughing direction, the steel M is moved in the second roughing mill 120 in the forward roughing direction to perform 4th roughing, then the second roughing mill As 120 rotates in the reverse direction of the rough rolling, the steel M is moved in the second roughing mill 120 in the reverse direction of the rough rolling, so that the fifth rough rolling can be performed, and then the second roughing mill 120 is again By rotating in the forward roughing direction, the steel (M) is moved in the second roughing mill 120 in the reverse direction of the roughing, so that the sixth roughing can be performed.

In this case, the second temperature measuring unit 180 may measure the temperature of the steel material M after the fourth rough rolling and after the sixth rough rolling.

However, the number, arrangement, control, number, etc. of the above-described components are exemplary, and the technical spirit of the present invention is not limited thereto.

2 is a flowchart illustrating a rough rolling control method ( S100 ) using a descaling pattern database according to an embodiment of the present invention.

Referring to FIG. 2 , the rough rolling control method ( S100 ) includes: constructing a descaling pattern database including the number of times and locations of spraying of the descaling material ( S110 ); selecting a first descaling pattern from the descaling pattern database (S120); performing a first rough rolling of the steel while performing a first descaling according to the first descaling pattern (S130); Measuring the actual temperature of the steel material after performing the first rough rolling (S140); and comparing the actual temperature and the predicted temperature of the steel material, and determining whether to replace the first descaling pattern (S150).

3 is a flowchart illustrating the step (S110) of building a descaling pattern database in the rough rolling control method (S100) using the descaling pattern database according to an embodiment of the present invention.

Referring to FIG. 3 , the step of constructing the descaling pattern database (S110) includes: setting a preliminary descaling pattern including the number of times and locations of spraying of the descaling material (S111); performing preliminary rough rolling of the preliminary steel while performing preliminary descaling according to the preliminary descaling pattern (S112); Determining whether to select the preliminary descaling pattern according to the state of the scale remaining in the preliminary rough-rolled preliminary steel (S113); and storing information on the preliminary descaling pattern selected in the determining step (S114) in the descaling pattern database.

In the step of setting the preliminary descaling pattern ( S111 ), the number of injections and the injection positions of the descaling material may be set in relation to the first to fourth descalers 130 , 140 , 150 , and 160 .

The step of performing preliminary rough rolling of the preliminary steel ( S112 ) may be performed in the first roughing mill 110 and the second roughing mill 120 of FIG. 2 .

In the step of determining whether the preliminary descaling pattern is selected ( S113 ), it may be determined whether the preliminary descaling pattern is selected according to the type and residual degree of the scale.

In the step (S114) of storing in the descaling pattern database, the information of the preliminary descaling pattern selected by repeating the steps (S111) to (S113) while changing the preliminary descaling pattern can be repeatedly stored. have. The information of the preliminary descaling pattern may include the number of injections of the descaling material and the injection location, and the type and residual degree of the remaining scale according thereto, and whether or not the preliminary descaling pattern is selected.

4 is a flowchart illustrating steps performed after determining whether to replace the first descaling pattern (S150) in the rough rolling control method (S100) using the descaling pattern database according to an embodiment of the present invention; am.

4, when the absolute value of the deviation between the actual temperature of the steel and the predicted temperature in the determining step (S150) is less than or equal to the allowable temperature deviation (│predicted temperature-actual temperature│≤ allowable) temperature deviation), performing a second rough rolling of the steel material while performing a second descaling according to the first descaling pattern (S190); may further include.

On the other hand, when the absolute value of the deviation between the actual temperature of the steel and the predicted temperature of the steel in the determining step (S150) is larger than the allowable temperature deviation (│predicted temperature-actual temperature│>allowable temperature deviation) , selecting a second descaling pattern from the descaling pattern database (S160); replacing the first descaling pattern with the second descaling pattern (S170); and performing a second rough rolling of the steel material while performing a second descaling according to the second descaling pattern (S180).

The predicted temperature may be previously calculated and set from a typical heat transfer related equation. For example, the predicted temperature may be calculated in consideration of heat transfer during air cooling and heat transfer during rough rolling processing occurring while the steel is running. The heat transfer during air cooling may be derived from a heat transfer equation considering forced convection, natural convection, and mixed convection. Heat transfer during the rough rolling process may be derived in consideration of machining heat, friction heat, and roll contact heat transfer.

Here, the first rough rolling of the steel may be performed in a first roughing mill, and the second rough rolling may be performed in a second roughing mill.

If the condition that the first descaling is performed temporally earlier than the second descaling is satisfied, the first descaling and the second descaling may be performed in a first roughing mill or a second roughing mill.

The steel may be rough-rolled while moving in the forward rough rolling direction or the crude rolling reverse direction in the first roughing mill. Alternatively, the steel may be rough-rolled while moving in the forward rough rolling direction or the crude rolling reverse direction in the second roughing mill.

The actual temperature of the steel may be measured after the steel is rough-rolled by moving in the forward rough rolling mill in the first roughing mill. Alternatively, the actual temperature of the steel may be measured after the steel is rough-rolled by moving in the forward roughing mill in the second roughing mill.

Hereinafter, an experimental example for helping the understanding of the present invention will be described. The following experimental examples are presented to help understanding of the invention, and are not limited to the following experimental examples of the present invention.

descaling Construction of the pattern database

First, preliminary rough rolling of the preliminary steel material for building the descaling pattern database was performed.

Table 1 is a table showing the conditions of preliminary rough rolling of preliminary steel for building a descaling pattern database according to an embodiment of the present invention.

Spare
steel
Kinds pattern
number gun
jet
number spray pattern Article 1 roughing mill Article 2 roughing mill forward reverse forward forward reverse forward 1st wrought rolling 2nd wrought rolling tertiary rolling Quaternary rolling 5th wrought rolling 6 wrought iron rolling mouth out mouth out mouth out mouth out mouth out mouth out JS-
SS400 #One 3 O X X X X X O X X X O X #2 4 O X X X O X O X X X O X #3 4 O O X X X X X X O X O X #4 5 O X X X O O O X O X X X #5 2 O X X X X X O X X X X X HSCED
-E #6 3 O X X X X X O X X X X O #7 2 O X X X X X X X X X O X #8 4 O X X X O X O O X X X X #9 2 O X X X X X O X X X X X #10 3 O X X X O X O X X X X X

In Table 1, the preliminary steel is primary rough rolling, secondary rough rolling, and tertiary rough rolling in the first rough rolling mill 110, the fourth rough rolling in the second rough rolling mill 120, the fifth rough rolling , and the sixth rough rolling. "Forward direction" means a rough rolling forward direction, and "reverse direction" means a rough rolling reverse direction. "Input" means before the preliminary steel material enters the first roughing mill 110 or the second roughing mill 120, and "out" means that the preliminary steel material enters the first roughing mill 110 or Article 2 It means after being discharged from the rolling mill (120). In addition, "O" is a case in which descaler injection is performed, and "X" is a case in which descaler injection is not performed. "Pattern number" refers to a descaling pattern number.

For example, in the case of descaling pattern number #1, before the preliminary steel material enters the first roughing mill 110 during the first rough rolling, it is sprayed by the first descaler 130, and the fourth rough rolling Before the preliminary steel material enters the second roughing mill 120, it is sprayed by the third descaler 150, and before the preliminary steel enters the second roughing mill 120 during the sixth rough rolling, the third It is sprayed by the descaler 150 .

Table 2 is a table showing the results of the preliminary rough rolling of the preliminary steel of FIG.

Spare
steel
Kinds pattern
number scale (average)
0: not remaining,
1 -> 5: Residual degree permit
standard permit
Whether JS-
SS400 #One red type 1, sand type 2, landscape type 1,
Scale type 2, peel type 1 Red type 2 points or less
Sand type 2 points or less
Arithmetic type 2 points or less
Linear type 3 points or less
2 spindles or less
Peelable 2 points or less O #2 Red Type 3 , Sand Type 1 , Landscape Type 2 X #3 Arithmetic 2, red 1 O #4 spindle type 2, linear type 3, peel type 2 O #5 Red 3 , Landscape 2 X HSCED
-E #6 scaly 2 Scale type 2 points or less
Arithmetic type 2 points or less O #7 scaly 4, arithmetic 3 X #8 arithmetic 1, scale 1 O #9 arithmetic 2 O #10 scaly 2 O

Referring to Table 2, the type of scale remaining in the preliminary steel material, the degree of remaining, and whether or not allowable is shown. "Pattern number" refers to a descaling pattern number. The descaling pattern numbers #2, #5, and #7 are not allowed as rough rolling conditions, and other descaling pattern numbers may be accepted as rough rolling conditions. Based on the results as described above, the descaling pattern database can be built. However, the conditions of Table 1 and the results of Table 2 are only examples for building the descaling pattern database, and the technical spirit of the present invention is not limited thereto.

rough rolling rear temperature control

Then, rough rolling of the steel was performed while controlling the rear surface temperature of the rough rolling using the descaling pattern database.

Table 3 is a table showing the results of performing the rough rolling control method of steel using the descaling pattern database according to an embodiment of the present invention.

steel
Kinds pattern
number 1st wrought rolling pattern
number tertiary rolling pattern
number Quaternary rolling pattern
number 6 wrought iron rolling prediction
Temperature
(℃) real
Temperature
(℃) prediction
Temperature
(℃) real
Temperature
(℃) prediction
Temperature
(℃) real
Temperature
(℃) prediction
Temperature
(℃) real
Temperature
(℃) JS-
SS400 #One 1102 1108 #One 1092 1104 #4 1051 1045 #4 1020 1017 #4 1105 1106 #4 1094 1102 #4 1052 1043 #4 1020 1015 HSCED
-E #8 1121 1109 #6 1084 1076 #6 1061 1052 #6 1030 1019 #6 1122 1112 #6 1080 1088 #6 1060 1066 #6 1030 1024 #6 1122 1114 #6 1080 1070 #9 1060 1068 #9 1030 1036

Referring to Table 3, the results for JS-SS400 steel and HSCED-E steel are shown.

In Table 3, the actual temperature measurement of the steel material was carried out only after the steel material moved in the rough rolling forward direction and rough-rolled. "Pattern number" refers to a descaling pattern number. Specifically, after performing the first rough rolling and the third rough rolling of the steel material using the first roughing mill 110, the temperature was measured using the first temperature measuring unit 170, and also the steel material was manufactured After the fourth rough rolling and the sixth rough rolling were performed using the second roughing mill 120 , the temperature was measured using the second temperature measuring unit 180 . In addition, the allowable temperature deviation was set to 10°C. However, the allowable temperature deviation is exemplary, and the technical spirit of the present invention is not limited thereto.

As a first experimental example, for JS-SS400 steel, after selecting descaling pattern #1 as an initial descaling pattern and performing primary rough rolling, the predicted temperature (1102°C) and actual temperature (1108°C) of the steel material ) was 6℃, which was small compared to the allowable temperature deviation. Accordingly, the second rough rolling and the third rough rolling were performed without changing the descaling pattern. After performing the third rough rolling of the steel, the deviation was 16° C., which was large compared to the allowable temperature deviation. Accordingly, the fourth rough rolling was performed by changing the descaling pattern #1 to the descaling pattern #4. After performing the fourth rough rolling of the steel, the deviation was 6 ℃, which was small compared to the allowable temperature deviation. Accordingly, the subsequent 5th rough rolling and 6th rough rolling were performed with the descaling pattern #4 without changing the descaling pattern. After performing the 6th rough rolling of the steel, the deviation was 3 ℃, which was small compared to the allowable temperature deviation. Therefore, descaling pattern #4 can be evaluated to be suitable for rough rolling of JS-SS400 steel.

As a second experimental example, for the JS-SS400 steel, the first to sixth rough rolling was performed on the steel by selecting the descaling pattern #4 as the initial descaling pattern. As a result, in all temperature measurements, the deviation between the predicted temperature and the actual temperature of the steel was smaller than the allowable temperature deviation. Therefore, the descaling pattern #4 can be evaluated as appropriate for the rough rolling process of the JS-SS400 steel.

As a third experimental example, for HSCED-E steel, after selecting descaling pattern #8 as the initial descaling pattern and performing primary rough rolling, the predicted temperature (1121°C) and actual temperature (1109°C) of the steel material ) was 12℃, which was larger than the allowable temperature deviation. Accordingly, the descaling pattern #8 was changed to the descaling pattern #6, and secondary rough rolling and tertiary rough rolling were performed. After the third rough rolling of the steel was performed, the deviation was 8° C., which was small compared to the allowable temperature deviation. Accordingly, the subsequent quaternary rough rolling was performed with the descaling pattern #6 without changing the descaling pattern. After performing the fourth rough rolling of the steel, the deviation was 6 ℃, which was small compared to the allowable temperature deviation. Accordingly, the subsequent 5th rough rolling and 6th rough rolling were performed with the descaling pattern #6 without changing the descaling pattern. After performing the 6th rough rolling of the steel, the deviation was 11° C., which was large compared to the allowable temperature deviation. Therefore, it can be evaluated that it is not appropriate to perform rough rolling of the HSCED-E steel while changing the descaling pattern #8 to the descaling pattern #6.

As a fourth experimental example, for the HSCED-E steel, a descaling pattern #6 was selected as an initial descaling pattern, and the first to sixth rough rolling of the steel was performed. As a result, in all temperature measurements, the deviation between the predicted temperature and the actual temperature of the steel was smaller than the allowable temperature deviation. Therefore, the descaling pattern #6 can be evaluated as appropriate for the rough rolling process of the HSCED-E steel. However, in this case, after performing the sixth rough rolling, the actual temperature of the steel was lower than the predicted temperature.

As a fifth experimental example, with respect to the HSCED-E steel, by selecting descaling pattern #6 as the initial descaling pattern, the first rough rolling to the third rough rolling was performed on the steel. As a result, in all temperature measurements, the deviation between the predicted temperature and the actual temperature of the steel was smaller than the allowable temperature deviation. However, the deviation after performing the third rough rolling was shown to be 10 ℃. Accordingly, the fourth rough rolling was performed by changing the descaling pattern #6 to the descaling pattern #9. After performing the fourth rough rolling of the steel, the deviation was 8 ℃, which was small compared to the allowable temperature deviation. Accordingly, the subsequent 5th rough rolling and the 6th rough rolling were performed with the descaling pattern #9 without changing the descaling pattern. After performing the 6th rough rolling of the steel, the deviation was 6 ℃, which was small compared to the allowable temperature deviation. In addition, after performing the sixth rough rolling, the actual temperature of the steel was higher than the predicted temperature. Therefore, the descaling pattern #9 can be evaluated to be suitable for rough rolling of HSCED-E steel.

The technical spirit of the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is the technical spirit of the present invention that various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in the art to which this belongs.

100: a roughing device, 110: a first roughing mill.
120: a second roughing mill, 130: a first descaler,
140: a second descaler, 150: a third descaler,
160: a fourth descaler, 170: a first temperature measuring unit,
180: a second temperature measurement unit, 190: a control unit;
M: steel,

Claims (11)

constructing a descaling pattern database including the number of injections and positions of the descaling material;
selecting a first descaling pattern from the descaling pattern database;
performing a first rough rolling of the steel while performing a first descaling according to the first descaling pattern;
measuring the actual temperature of the steel material after performing the first rough rolling; and
Comparing the actual temperature and the predicted temperature of the steel material, determining whether to replace the first descaling pattern;
In the determining step, if the absolute value of the deviation between the actual temperature and the predicted temperature of the steel is larger than the allowable temperature deviation,
selecting a second descaling pattern from the descaling pattern database;
replacing the first descaling pattern with the second descaling pattern; and
Performing a second rough rolling of the steel material while performing a second descaling according to the second descaling pattern; further comprising,
Rough rolling control method using descaling pattern database. The method of claim 1,
The steps to build the descaling pattern database are:
setting a preliminary descaling pattern including the number of times and locations of spraying of the descaling material;
performing preliminary rough rolling of the preliminary steel while performing preliminary descaling according to the preliminary descaling pattern;
determining whether to select the preliminary descaling pattern according to the state of the scale remaining in the rough-rolled preliminary steel; and
Storing information on the preliminary descaling pattern selected in the determining step in the descaling pattern database; including,
Rough rolling control method using descaling pattern database. 3. The method of claim 2,
The step of determining whether the preliminary descaling pattern is selected includes:
determining whether to select the preliminary descaling pattern according to the type and residual degree of the scale,
Rough rolling control method using descaling pattern database. The method of claim 1,
In the determining step, if the absolute value of the deviation of the actual temperature and the predicted temperature of the steel is smaller than or equal to the allowable temperature deviation,
Performing a second rough rolling of the steel material while performing a second descaling according to the first descaling pattern; further comprising
Rough rolling control method using descaling pattern database. delete The method of claim 1,
The first rough rolling of the steel is performed in a first roughing mill,
wherein the first descaling is performed before the steel enters the first roughing mill, after it exits the first roughing mill, or both.
Rough rolling control method using descaling pattern database. The method of claim 1,
The second rough rolling of the steel is performed in a second roughing mill,
The second descaling is performed before the steel enters the second roughing mill, after it exits the second roughing mill, or both.
Rough rolling control method using descaling pattern database. The method of claim 1,
The first rough rolling and the second rough rolling of the steel is performed in a first rough rolling mill,
Rough rolling control method using descaling pattern database. The method of claim 1,
The steel is rough-rolled while moving in the forward or reverse rough-rolling direction in the first roughing mill,
Or, rough rolling while moving in the forward direction of rough rolling or the reverse direction of rough rolling in the second roughing mill,
Rough rolling control method using descaling pattern database. 10. The method of claim 9,
The actual temperature of the steel is measured after the steel is rough-rolled by moving in the forward roughing mill in the first roughing mill,
Or measured after the rough rolling is moved forward in the second roughing mill,
Rough rolling control method using descaling pattern database. a first roughing mill for first roughing steel;
a second roughing mill for second roughing the steel material roughed in the first roughing mill;
a first descaler disposed on the front side of the first roughing mill and spraying a descaling material to the steel;
a second descaler disposed at a rear side of the first roughing mill and spraying the descaling material to the steel;
a third descaler disposed in front of the second roughing mill and spraying the descaling material to the steel;
a fourth descaler disposed at a rear side of the second roughing mill and spraying the descaling material to the steel;
a first temperature measuring unit disposed at the rear of the first roughing mill to measure the temperature of the steel;
a second temperature measuring unit disposed at the rear of the second roughing mill to measure the temperature of the steel; and
including a descaling pattern database, and performing descaling by controlling the first to fourth descalers according to a descaling pattern selected from the descaling pattern database, and measuring the measured values from the first and second temperature measuring units. Including; a control unit that acquires a temperature and performs replacement of the descaling pattern;
constructing a descaling pattern database including the number of injections and positions of the descaling material;
selecting a first descaling pattern from the descaling pattern database;
performing a first rough rolling of the steel while performing a first descaling according to the first descaling pattern;
measuring the actual temperature of the steel material after performing the first rough rolling; and
Comparing the actual temperature and the predicted temperature of the steel material, determining whether to replace the first descaling pattern;
In the determining step, if the absolute value of the deviation between the actual temperature and the predicted temperature of the steel is larger than the allowable temperature deviation,
selecting a second descaling pattern from the descaling pattern database;
replacing the first descaling pattern with the second descaling pattern; and
performing a second rough rolling of the steel material while performing a second descaling according to the second descaling pattern; performing a rough rolling control method further comprising:
Rough rolling device using descaling pattern database.

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