KR101322179B1 - Hot rolling apparatus and method for preventing irregular thickness profile - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling apparatus and a hot rolling apparatus having a function of preventing abnormal thickness profile by abrasion, and a hot rolling apparatus according to an embodiment of the present invention includes a work roll for rolling an incoming material; A profile predicting unit for generating an expected profile of the work roll; Cooling means for separating the work roll into a plurality of cooling regions along the longitudinal direction of the work roll and cooling the cooling regions individually in accordance with each of a plurality of input cooling temperatures; And a cooling control unit for setting the plurality of cooling temperatures using the predicted profile and outputting the set cooling temperature to the cooling unit.

Description

Technical Field [0001] The present invention relates to a hot rolling apparatus and a hot rolling apparatus having a function of preventing abnormal thickness profile caused by abrasion,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot rolling apparatus and a hot rolling apparatus having a function of preventing an abnormal thickness profile due to abrasion and, more particularly, to a hot rolling apparatus and hot rolling apparatus capable of controlling a cooling temperature of a work roll, And a hot rolling method.

The hot rolling process is a process of manufacturing a strip by heating a material such as a slab, a bloom, or a billet produced in a continuous casting process and then rolling it.

In the case of a work roll which is rolled in direct contact with the heated work in the hot rolling step, the more the number of rolled work rolls is increased, the more the wear of the work roll is increased. Generally, abrasion of the working roll occurs more at both ends than at the center of the working roll. Therefore, as shown in Fig. 1 (a), a profile in which the abrasion at both ends of the work roll is relatively advanced, the abrasion at the center of the work roll progresses little, and the central portion of the work roll is convex Lt; / RTI >

The work roll for rolling the material in the hot rolling process can receive heat energy possessed by the material by contact with the material and can be thermally expanded by the heat energy. In particular, when the work roll comes in contact with the work continuously such as continuous continuous rolling, a large amount of heat is transferred to the work roll, and the work roll may be greatly expanded. Generally, the thermal expansion of the work roll can occur at the center rather than at both ends.

It is referred to as a thermal crown of the work roll that a difference in thickness occurs at the center and both ends of the work roll due to the thermal expansion of the work roll.

Therefore, when the hot rolling process is performed, a thermal crown due to thermal expansion of the work roll may occur together with wear of the work roll. In this case, as shown in Fig. 1 (b), the difference between both ends and the central portion of the work roll becomes more evident. As in the case of the above-mentioned working roll, when the work is rolled by using a working roll which has been brought up to the thermal crown together with the abrasion, the rolled material may be defective.

Particularly, a center buckle defect may appear at the central portion of the material to be rolled due to the portion a in Fig. 1 (b), that is, the central portion of the work roll deformed convexly.

1 (b), that is, both end portions of the concavely deformed work roll may cause an abnormal thickness profile such that both edges of the rolled material are raised upward.

That is, due to the wear and thermal crown of the work roll, the profile of the work roll may be convex at the central part and concave at both ends as shown in FIG. 1 (b). In this case, have.

Conventionally, in order to prevent the defects of the rolled materials, a conventional grinding machine such as an ORG (online roll grinder) is used for idle time of equipment to cope with wear of the work roll, Device corresponding to the thermal crown.

However, when there is no idle time as in continuous continuous rolling, a polishing machine such as the ORG can not be used, and according to the conventional cooling apparatus, it is difficult to effectively remove the thermal crown of the work roll.

An object of the present invention is to provide a hot rolling apparatus capable of controlling the degree of cooling of a work roll to prevent an abnormal thickness profile due to abrasion of the work roll.

The present invention also provides a hot rolling method capable of controlling the degree of cooling of the work roll to prevent an abnormal thickness profile due to abrasion of the work roll.

According to an embodiment of the present invention, there is provided a hot rolling apparatus having a function of preventing an abnormal thickness profile by abrasion, comprising: a work roll for rolling an incoming material; A profile predicting unit for generating an expected profile of the work roll; Cooling means for separating the work roll into a plurality of cooling regions along the longitudinal direction of the work roll and cooling the cooling regions individually in accordance with each of a plurality of input cooling temperatures; And a cooling control unit for setting the plurality of cooling temperatures using the predicted profile and outputting the set cooling temperature to the cooling unit.

The profile predicting unit may generate the expected profile by calculating a change amount of the profile of the work roll by the thermal crown of the work roll and a profile change amount of the work roll due to the wear of the work roll.

Here, the cooling control unit may set the cooling temperature to a higher temperature as the amount of change in the profile of the work roll due to abrasion of the work roll is greater.

The hot rolling method for preventing abnormal thickness profile by abrasion according to another embodiment of the present invention includes calculating a degree of thermal expansion of a work roll and a change amount of a profile of the work roll due to wear of the work roll, A profile predicting step of calculating an expected profile of the profile; A cooling region distinction step for discriminating a cooling region of the work roll along a longitudinal direction of the work roll; A cooling temperature setting step of setting a cooling temperature of the cooling zone using the expected profile; And a cooling step of individually cooling the cooling region of the work roll in accordance with the set cooling temperature.

The profile prediction step may generate the expected profile by calculating a change amount of the profile of the work roll by the thermal crown of the work roll and a change amount of the profile of the work roll due to the wear of the work roll.

The cooling temperature setting step may set the cooling temperature to a higher temperature as the amount of change in the profile of the work roll due to wear of the work roll is greater.

According to the hot rolling apparatus and the hot rolling method having the abnormal thickness profile preventing function by abrasion of the present invention, it is possible to prevent an abnormal thickness profile which may be caused by abrasion of the working roll.

According to the hot rolling apparatus and the hot rolling method having the abnormal thickness profile preventing function by abrasion of the present invention, since the wear temperature can be controlled by changing the cooling temperature for each cooling region of the work roll, It is possible to utilize it also in continuous continuous rolling in which continuous rolling is carried out without the above.

Fig. 1 (a) is a graph showing the wear profile of the work roll, and Fig. 1 (b) is a profile obtained by joining the wear crown of the work roll to the wear profile of the work roll.
2 is a block diagram showing a hot rolling apparatus according to an embodiment of the present invention.
Fig. 3 (a) is a graph showing a difference in profile between the cooling rolls of the present invention and the cooling system of the present invention. Fig. 3 (b) It is a profile that combines thermal crown.
4 is a flowchart showing a hot rolling method 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, in order that those skilled in the art can easily carry out the present invention. In the following detailed description of the preferred embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In the drawings, like reference numerals are used throughout the drawings.

In addition, in the entire specification, when a part is referred to as being 'connected' to another part, it may be referred to as 'indirectly connected' not only with 'directly connected' . Also, to "include" an element means that it may include other elements, rather than excluding other elements, unless specifically stated otherwise.

2 is a block diagram showing a hot rolling apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the hot rolling apparatus according to an embodiment of the present invention may include a work roll 10, a cooling unit 20, a cooling control unit 30, and a profile predicting unit 40.

Hereinafter, a hot rolling apparatus according to an embodiment of the present invention will be described with reference to FIG.

The work roll 10 can roll the incoming material. The incoming material may be obtained by heating a slab, a bloom or billet produced in a continuous casting process in a furnace at a hot rolling temperature of, for example, 100 ° C to 1300 ° C, have.

As described above, in the work roll 10, a wear and a thermal crown are generated in the process of rolling the work, and the central portion of the work roll 10 protrudes convexly as shown in FIG. 1 (b) The profile can be formed in a concave shape.

Generally, the change of the profile of the work roll 10 due to the abrasion of the work roll 10 is performed by flattening the work roll 10 using a grinder such as an ORG (online roll grinder) A method of dispersing the abrasion generated in the work roll 10 by using a separate facility is utilized.

However, since there is no idle time during continuous continuous rolling, it is difficult to cope with the abrasion by using the ORG, and not all rolling mills are equipped with a facility for dispersing the abrasion of the work roll 10, There is still a need for measures to cope with wear of the work roll 10.

The work roll 10 can receive heat energy from the material to be rolled and can be thermally expanded. The degree of thermal expansion of the work roll 10 can be determined by the cooling temperature for the work roll 10. Therefore, it is possible to cope with the wear of the work roll 10 by adjusting the degree of thermal expansion of the work roll 10.

The profile predicting unit 40 can generate an expected profile of the work roll 10.

The profile predicting unit 40 may calculate an expected value of the profile of the work roll 10 by using a mathematical prediction model of wear and thermal crown generated in the work roll 10. The profile predicting unit 40 may generate an expected profile of the work roll 10 using the calculated predicted value. The prediction model may be a known thermal crown and a prediction model that predicts wear.

The profile predicting unit 40 predicts the profile change amount of the work roll 10 by the thermal crown of the work roll 10 and the profile change amount of the work roll 10 due to the wear of the work roll 10 To generate the expected profile.

Specifically, the profile predicting unit 40 can calculate the amount of profile change due to the thermal crown and the wear through a method such as a regression analysis.

The cooling means (20) is configured to separate the work roll (10) into a plurality of cooling regions along the longitudinal direction of the work roll (10), cool the cooling regions individually can do.

As shown in Fig. 2, the cooling region of the work roll 10 can be distinguished from the central portion B and both end portions A and C. In FIG. 2, the cooling region of the work roll 10 is divided into three regions, but it is not limited thereto and can be further divided into cooling regions.

The cooling means (20) can cool the work roll (10) at different cooling temperatures for the respective cooling regions. The cooling temperature for each of the cooling zones may be input from the cooling control unit 30. [

The cooling means 20 may be anything that can cool the work roll 10, but here, cooling the work roll 10 using cooling water will be described as an example.

The cooling means 20 may be provided with injection nozzles and piping separately for each of the cooling regions in order to provide cooling water having different cooling temperatures for the respective cooling regions.

Since the degree of cooling for each of the cooling regions can be varied by the cooling means 20, the degree of thermal expansion occurring in each of the cooling regions can be controlled.

Since the thermal expansion is caused by the thermal energy absorbed by the work roll 10, the thermal expansion of the work roll 10 can be removed by taking the heat energy absorbed by the work roll 10 using the cooling water have,

Conventionally, cooling water having the same cooling temperature as that of the entire work roll 10 is used to uniformly remove thermal expansion generated in the entire work roll 10.

However, as mentioned above, since the work roll 10 may be deformed by abrasion, it may be considered to remove the thermal expansion generated in the work roll 10.

That is, it is possible to cool the work rolls 10 at a relatively high cooling temperature with respect to both ends of the work roll 10, where the abrasion is more likely to occur, so that the thermal expansion occurring in the work rolls 10 can be reduced. In addition, the central portion of the work roll 10 in which wear is less likely to occur can be cooled to a relatively low cooling temperature, thereby greatly removing thermal expansion generated in the work roll 10.

3 (a) is a graph showing the difference in profile of the work roll according to the conventional cooling system and the cooling system of the present invention.

As shown in FIG. 3 (a), in the case of the conventional cooling method, the central portion of the work roll 10 has a thicker profile than both ends. However, in the cooling method of the present invention in which the cooling temperature is different for each cooling region, the both ends of the work roll 10 may have a thicker profile than the central portion thereof.

Therefore, considering the abrasion of the work roll 10 and the thermal crown of the work roll 10 by the conventional cooling method, the thickness of the central portion and both ends of the work roll 10 as shown in Fig. 1 (b) The difference becomes larger, and the defects of the rolled material increase accordingly.

On the other hand, considering the abrasion of the work roll 10 and the thermal crown of the work roll 10 by the cooling method of the present invention, the profile of the work roll 10 is uniformly .

Referring to FIG. 3 (b), it can be seen that there are no convex or concave portions as in the portions a and b in FIG. 1 (b). Since the center buckle, the abnormal thickness profile, and the like have occurred in the rolled material by the portions a and b, the cause of the defect can be removed according to the present invention.

The cooling control unit (30) sets the plurality of cooling temperatures using the expected profile, and outputs the set cooling temperature to the cooling means (20).

The cooling temperature for cooling the work roll 10 by the cooling unit 20 can be set by the cooling control unit 30. [ The cooling control unit 30 may generate a control signal for cooling the work roll 10 at the set cooling temperature and transmit the control signal to the cooling means 20. As described above, the degree of thermal expansion of the work roll 10 can be adjusted by varying the cooling temperature for each cooling region of the work roll 10.

The cooling temperature may be set using the expected profile. The predicted profile may be one generated by the profile predicting unit 40 and calculated using a mathematical prediction model of the wear and thermal crown.

For example, after the generation of the predicted profile in consideration of the wear and thermal crown of the work roll 10, the change of the predicted profile according to the change of the cooling temperature for the cooling region of the work roll 10 can be examined . The cooling temperature at which the predicted profile uniformly appears among the changes of the prediction profile can be set as the cooling temperature. More specifically, if the difference between the thickness of the central portion of the work roll 10 and the thickness of both ends is less than a preset value, the cooling temperature can be set to the cooling temperature of the cooling region.

The cooling control unit 30 can set the cooling temperature to a higher temperature as the amount of change in the profile of the work roll 10 due to wear of the work roll 10 is greater.

The thermal expansion of the work roll 10 is largely maintained as the abrasion of the work roll 10 largely occurs and the thermal expansion of the work roll 10 is reduced as the abrasion of the work roll 10 is reduced . Since the wear of the work roll 10 reduces the thickness of the work roll 10 and the thermal expansion of the work roll 10 increases the thickness of the work roll 10, And the thermal expansion of the work roll 10 are controlled, the wear and the thermal expansion are canceled each other, so that the profile of the work roll 10 can be maintained uniformly.

Therefore, as the amount of change in the profile of the work roll 10 due to abrasion of the work roll 10 is increased, the amount of thermal expansion of the work roll 10 must be suppressed so as to reduce wear of the work roll 10 For this, the cooling temperature of the work roll 10 may be set at a relatively high temperature.

4 is a flowchart showing a hot rolling method according to an embodiment of the present invention.

4, a hot rolling method according to an embodiment of the present invention includes a profile prediction step S10, a cooling region distinction step S20, a cooling temperature setting step S30, and a cooling step S40 .

Hereinafter, a hot rolling method according to an embodiment of the present invention will be described with reference to FIG.

The profile prediction step (S10) can calculate the expected profile of the work roll by calculating the degree of thermal expansion of the work roll and the amount of change of the profile of the work roll due to wear of the work roll.

The profile prediction step S10 may calculate an expected value of the profile of the work roll using a mathematical prediction model for the wear and thermal crown that occurs in the work roll. The predicted profile may be generated using the calculated expected value. The prediction model may be a known thermal crown and a prediction model that predicts wear.

Here, the profile prediction step S10 may generate the expected profile by calculating a change amount of the profile of the work roll by the thermal crown of the work roll and a variation amount of the profile of the work roll due to wear of the work roll.

Specifically, the profile predicting unit 40 can calculate the amount of profile change due to the thermal crown and the wear through a method such as a regression analysis.

The cooling region distinguishing step (S20) can distinguish the cooling region of the work roll along the longitudinal direction of the work roll. It is possible to differentiate the cooling zones of the work rolls in accordance with the longitudinal direction of the work rolls. Particularly, the cooling region of the work roll can be largely divided into three portions, i.e., the center portion and both end portions of the work roll. The degree of cooling of the work roll may be varied according to the separated cooling region.

The cooling temperature setting step (S30) can set the cooling temperature of the cooling region using the expected profile.

The predicted profile may be calculated using the mathematical prediction model for the wear and thermal crown, as calculated in the profile prediction step (S10).

For example, after the generation of the predicted profile in consideration of the wear and thermal crown of the work roll, the change of the predicted profile according to the change of the cooling temperature for the cooling region of the work roll can be examined. It is possible to set the cooling temperatures at which the prediction profile uniformly appears among the changes of the prediction profile to the cooling temperature. More specifically, if the difference between the thickness of the central portion of the work roll and the thickness of both ends is less than a predetermined value, the cooling temperature can be set to the cooling temperature of the cooling region.

Therefore, it is possible to set the cooling temperature for the cooling zone using the expected profile, and the degree of thermal expansion of the work roll can be adjusted by changing the cooling temperature according to the set cooling temperature.

Here, the cooling temperature setting step (S30) may set the cooling temperature to a higher temperature as the amount of change in the profile of the work roll due to abrasion of the work roll is greater.

The amount of thermal expansion of the work roll must be reduced so as to cancel the wear of the work roll as the amount of change in the profile of the work roll due to abrasion of the work roll is increased. To this end, the cooling temperature of the work roll is set to a relatively high temperature Can be set.

By setting the cooling temperature as described above, the profile of the central portion and both ends of the work roll can be uniformly maintained.

The cooling step S40 can cool the cooling regions of the work rolls individually in accordance with the set cooling temperatures.

Due to the individual cooling of the cooling zones of the working rolls, the degree of thermal expansion of the cooling zones can be controlled. It is possible to cope with the deformation of the profile due to the wear of the work roll by adjusting the thermal expansion degree and to maintain the profile of the work roll uniformly.

The present invention is not limited to the above-described embodiments and the accompanying drawings. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims, .

10: work roll
20: cooling means
30: Cooling control section
40: profile prediction unit
S10: profile prediction step
S20: Cooling zone distinction step
S30: Cooling temperature setting step
S40: cooling step

Claims (6)

A work roll for rolling the incoming material;
A profile predicting unit for generating an expected profile of the work roll;
Cooling means for separating the work roll into a plurality of cooling regions along the longitudinal direction of the work roll and cooling the cooling regions individually in accordance with each of a plurality of input cooling temperatures; And
And a cooling control section for setting the plurality of cooling temperatures using the expected profile and outputting the set cooling temperature to the cooling means,
Wherein the cooling temperature is a temperature of cooling water for cooling the work roll by being sprayed onto the work roll.
2. The apparatus of claim 1, wherein the profile predicting unit
Wherein the predicted profile is generated by calculating a change amount of the profile of the work roll by a thermal crown of the work roll and a variation amount of the profile of the work roll due to wear of the work roll.
The refrigeration system according to claim 2, wherein the cooling control unit
And sets the size of the cooling temperature in proportion to a magnitude of a change amount of a profile of the work roll due to abrasion of the work roll.
A profile predicting step of calculating a predicted profile of the work roll by calculating a degree of thermal expansion of the work roll and a variation amount of the profile of the work roll by abrasion of the work roll;
A cooling region distinction step for discriminating a cooling region of the work roll along a longitudinal direction of the work roll;
A cooling temperature setting step of setting a cooling temperature of the cooling zone using the expected profile; And
And a cooling step of individually cooling the cooling region of the work roll in accordance with the set cooling temperature,
Wherein the cooling temperature is a temperature of cooling water for cooling the work roll by being sprayed onto the work roll.
5. The method of claim 4, wherein the profile predicting step
Wherein the predicted profile is generated by calculating a change amount of a profile of the work roll by a thermal crown of the work roll and a change amount of a profile of the work roll due to abrasion of the work roll.
6. The method according to claim 5, wherein the cooling temperature setting step
And sets the size of the cooling temperature in proportion to a magnitude of a change amount of a profile of the work roll due to abrasion of the work roll.

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