Technical Field
[0001] The present disclosure relates to a process control
system for controlling a process of removing an internal
5 defect layer included in a carbon steel product, and an
operating method thereof.
Background Art
[0002] A bearing shell or the like for a vehicle, produced
10 using a carbon steel product, may receive continuous and
repeated loads on a surface thereof. Therefore, strict
surface quality may be required for a carbon steel product
used in production of such a bearing shell or the like.
[0003] It may be necessary to strictly control a thickness
15 of an internal defect layer and the like included in the
carbon steel product, and the internal defect layer may be
removed by an etching process or the like. The etching
process may be a process of removing the internal defect
layer by contacting an etching solution with the carbon steel
20 product.
[0004] This prior art can be easily understood with reference
to Korean Patent publication No. 10-2019-0124019.
Summary of Invention
25 Technical Problem
3
[0005] One of the problems to be solved by the technical
idea of the present disclosure is to provide a process
control system for improving efficiency and productivity of
an etching process by controlling the etching process
5 according to a thickness of an internal defect layer included
in a carbon steel product, and an operating method thereof.
Solution to Problem
[0006] According to an aspect of the present disclosure, a
10 process control system includes a first system generating
thickness information about an internal defect layer
included in a carbon steel product; and a second system
receiving the thickness information about the internal
defect layer from the first system through a network, and
15 using the thickness information about the internal defect
layer to control an etching process removing at least a
portion of the internal defect layer from the carbon steel
product, wherein the first system provides the second system
with a calculation module necessary for the second system to
20 control the etching process, and the second system provides
the first system with information necessary for the first
system to update the calculation module.
[0007]
[0008] According to an aspect of the present disclosure, a
25 process control system includes a storage device storing
4
control data necessary for controlling an etching device
removing at least a portion of an internal defect layer
included in a carbon steel product; and a processor
controlling the etching device based on the control data,
5 wherein the carbon steel product includes a first region and
a second region, different from the first region, wherein a
thickness of the internal defect layer included in the first
region is different from a thickness of the inner defect
layer included in the second region, and the control data
10 includes a first transporting speed at which the first region
passes through the etching device, and a second transporting
speed at which the second region passes through the etching
device, wherein the first transporting speed is different
from the second transporting speed.
15 [0009]
[0010] According to an aspect of the present disclosure, a
process control system includes a storage device storing a
calculation module generating thickness information about an
internal defect layer included in a carbon steel product,
20 based on at least one of a component, a cooling rate, a phase
fraction, or a temperature of the carbon steel product; a
communication unit connected to a network; and a processor
transmitting at least one of the thickness information about
the internal defect layer or control data for controlling an
25 etching process removing at least a portion of the internal
5
defect layer, to an external server controlling the etching
process, through the communication unit.
Advantageous Effects of Invention
5 [0011] According to an aspect of the present disclosure, a
process control system of improving efficiency and
productivity of an etching process and an operating method
thereof may be provided by controlling the etching process
based on optimal control data, while each of the regions
10 defined in the length direction of the carbon steel product
is in contact with the etching solution.
[0012] In addition, according to an aspect of the present
disclosure, by measuring a thickness of a residual internal
defect layer included in a pickled carbon steel product on
15 which an etching process is completed, and training a
calculation module generating control data for controlling
the etching process using the measured thickness of the
residual internal defect layer, the etching process may be
performed based on optimized control data.
20 [0013] Various advantages and effects of the present
disclosure are not limited to the above, and can be more
easily understood in the process of describing specific
embodiments of the present disclosure.
25 Brief Description of Drawings
6
[0014] FIG. 1 is a view illustrating a manufacturing process
of a hot-rolled steel sheet according to an embodiment of
the present disclosure.
[0015] FIG. 2 is a view simply illustrating a hot-rolled
5 steel sheet according to an embodiment of the present
disclosure.
[0016] FIG. 3 is a block diagram illustrating a process
control system according to an embodiment of the present
disclosure.
10 [0017] FIG. 4 is a block diagram simply illustrating a
process control system according to an embodiment of the
present disclosure.
[0018] FIG. 5 is a view illustrating an initial training
method of a calculation module included in a process control
15 system according to an embodiment of the present disclosure.
[0019] FIG. 6 is a view illustrating a training model
included in a process control system according to an
embodiment of the present disclosure.
[0020] FIG. 7 is a view illustrating a method of operating
20 a process control system according to an embodiment of the
present disclosure.
[0021] FIG. 8 is a flowchart illustrating a method of
operating a process control system according to an embodiment
of the present disclosure.
25 [0022] FIG. 9 is a block diagram simply illustrating a
7
process control system according to an embodiment of the
present disclosure.
[0023] FIG. 10 is a view illustrating a method of operating
a process control system according to an embodiment of the
5 present disclosure.
[0024] FIG. 11 is a view illustrating a training method of
a calculation module included in a process control system
according to an embodiment of the present disclosure.
[0025] FIG. 12 is a view illustrating an etching process
10 according to an embodiment of the present disclosure.
[0026] FIG. 13 is a graph illustrating an etching process
according to an embodiment of the present disclosure.
[0027] FIG. 14 is a view illustrating an initial training
method of a calculation module included in a process control
15 system according to an embodiment of the present disclosure.
[0028] FIG. 15 is a view illustrating a training method of
a calculation module included in a process control system
according to an embodiment of the present disclosure.
[0029] FIG. 16 is a flowchart illustrating a method of
20 operating a process control system according to an embodiment
of the present disclosure.
[0030] FIG. 17 is a view illustrating a method of operating
a process control system according to an embodiment of the
present disclosure.
25
8
Best Mode for Invention
[0031] In the present specification, a carbon steel product
may include 0.01% to 2.0% carbon as an alloy of iron and
carbon, and representatively, may include a hot-rolled
5 product, a thick plate product, a wire rod product, and the
like. For example, the hot-rolled product may be a hot-rolled
steel sheet made by hot-rolling a slab, winding the hotrolled slab to have a coil shape, and cutting the wound coil
to have a hot-rolled coil or sheet, and may have a thickness
10 of 1 mm to 25 mm. The thick plate product may be a plateshaped product made by hot-rolling a slab, and may have a
thickness of 4 mm to 200 mm. The wire rod product may be a
coil-shaped product having a circular cross-section by corolling a billet in a hot state, and may have a cross15 sectional diameter of 3 mm to 100 mm.
[0032] A process control system of the present disclosure
may produce a carbon steel product (hereinafter referred to
as a ‘pickled carbon steel product’) pickled by controlling
a transporting speed of the carbon steel product while an
20 etching process for the carbon steel product is in progress.
Therefore, surface quality of the carbon steel product may
be improved.
[0033] Hereinafter, the technical idea of the present
disclosure will be described focusing on a hot-rolled steel
25 sheet or a hot-rolled coil in which the hot-rolled steel
9
sheet is wound to have a coil shape. However, the technical
spirit of the present disclosure is not limited to the hotrolled steel sheet or the hot-rolled coil, and may be applied
to all carbon steel products within a range easily understood
5 by those skilled in the art.
[0034]
[0035] Hereinafter, preferred embodiments of the present
disclosure will be described in detail with reference to the
accompanying drawings. The same reference numerals may be
10 used for the same components in the drawings, and duplicate
descriptions of the same components will be omitted.
[0036]
[0037] FIG. 1 is a view illustrating a manufacturing process
of a hot-rolled steel sheet according to an embodiment of
15 the present disclosure.
[0038] FIG. 1 may be a view simply illustrating a hot-rolled
steel sheet production device for producing a hot-rolled
steel sheet, and cooling and winding the hot-rolled steel
sheet to produce a hot-rolled coil. Referring to FIG. 1, a
20 hot-rolling process of rolling a slab heated in a heating
furnace to a predetermined thickness using a roughing mill
and a finishing mill may be performed. A hot-rolled steel
sheet (strip) produced by the hot-rolling process may be
transferred to a run-out table (ROT) cooling zone, which may
25 be a cooling section. The hot-rolled steel sheet may be
10
cooled by cooling water sprayed from the ROT cooling zone,
and a cooling temperature, a cooling time, or the like may
be determined according to quality required for the hotrolled steel sheet.
5 [0039] After cooling, the hot-rolled steel sheet may be wound
to have a coil shape in a winder for convenience of storage
and/or movement. A hot-rolled coil (HC), in which a hotrolled steel sheet is wound to have a coil shape, may be
placed in a yard and air-cooled before shipment, and
10 thereafter, an etching process for removing an internal
defect layer or the like included in the hot-rolled steel
sheet may be performed. In an embodiment, a manufacturing
process of a hot-rolled steel sheet, as described with
reference to FIG. 1, and an etching process for removing an
15 internal defect layer of the hot-rolled steel sheet may be
performed by different entities. Also, in an embodiment, a
manufacturing process of a hot-rolled steel sheet and an
etching process for removing an internal defect layer of the
hot-rolled steel sheet may be performed by a single entity.
20 [0040]
[0041] FIG. 2 is a view simply illustrating a hot-rolled
steel sheet according to an embodiment of the present
disclosure.
[0042] Referring to FIG. 2, a hot-rolled steel sheet may be
25 divided into a plurality of regions in a length direction
11
(an X-axis direction). For example, the hot-rolled steel
sheet may include a region A, a region B, a region C, and
the like, which may be sequentially arranged in the length
direction. In an embodiment illustrated in FIG. 2, in the
5 hot-rolled steel sheet, region A may be a region firstly
wound, and region C may be a region lastly wound. Region B
may be a region located between region A and region C in the
length direction.
[0043] In an embodiment, the hot-rolled steel sheet may
10 include a surface defect. For example, the surface defect
may include at least one of a scale or an internal defect
layer. The scale may develop during a rolling process, and
may exist on a surface of a material. The internal defect
layer may be included below the surface of the material,
15 e.g., within the material, and may be defined as an internal
oxide layer and/or a decarburization layer. The internal
oxide layer may occur in a process of oxidizing a component
such as chromium (Cr), manganese (Mn), silicon (Si), zinc
(Zn), magnesium (Mg), aluminum (Al), or the like, which may
20 have higher oxygen affinity than iron (Fe), in a base
material. The decarburization layer may occur in a process
of combining carbon in steel with oxygen in an atmosphere
and a scale and then discharging the combined into the
atmosphere in a form of gas. A thickness of an internal
25 defect may be changed depending on a component of the hot-
12
rolled steel sheet, a temperature when the hot-rolled steel
sheet is wound to be a hot-rolled coil (HC), a cooling time
after winding, a width, a thickness, and a length of the
hot-rolled steel sheet, or the like. An internal defect,
5 such as the internal defect layer or the like may be a factor
in lowering durability of a product produced using the hotrolled steel sheet.
[0044] As an example, a temperature of the wound hot-rolled
coil (HC) may be about 500 to 700°C, and the wound hot-rolled
10 coil (HC) may be cooled by air cooling in a state exposed to
air. In the hot-rolled coil HC having a wound state, regions
A and C exposed externally may be cooled relatively quickly,
whereas region B not exposed externally may be cooled
relatively slowly. Therefore, a thickness of an internal
15 defect layer included in region B of the hot-rolled steel
sheet may be greater than a thickness of an internal defect
layer included in each of regions A and C of the hot-rolled
steel sheet. Therefore, there may be variations in thickness
of an internal defect layer according to a region of the
20 hot-rolled steel sheet. For example, the thickness of the
internal defect layer included in region A and/or region C
may be less than a predetermined reference thickness, and
the thickness of the internal defect layer included in region
B may be greater than the reference thickness.
25 [0045] In addition, in a width direction of the hot-rolled
13
steel sheet, a thickness of an internal defect layer may be
changed according to a region. For example, regions adjacent
to a corner of the hot-rolled steel sheet in the width
direction may be cooled relatively quickly, and a difference
5 in thickness of the internal defect layer according to a
cooling rate may occur in the width direction as well.
[0046] An etching process for removing at least a portion of
the internal defect layer may be performed by contacting the
hot-rolled steel sheet with an etching solution. For example,
10 the etching process may be performed by transferring the
hot-rolled steel sheet in a state in which the hot-rolled
steel sheet is immersed in the etching solution accommodated
in an etching tank. Alternatively, the etching process may
be performed by spraying the etching solution onto a surface
15 of the hot-rolled steel sheet in the etching tank, or
brushing the surface of the hot-rolled steel sheet with a
brush or the like wetted with the etching solution, or the
like. The etching process may be at least one of a pickling
process, a dry etching process, or a wet etching process.
20 [0047]
[0048] For example, the etching process may be performed by
sufficiently contacting the hot-rolled steel sheet with the
etching solution, regardless of a region of the hot-rolled
steel sheet, to sufficiently remove the internal defect layer
25 included in the hot-rolled steel sheet in the etching process.
14
The above method may lead to an increase in time of the
etching process and/or an increase in an amount of the
etching solution input to the etching process, to reduce
productivity.
5 [0049] According to an embodiment of the present disclosure,
a thickness of the internal defect layer included in the
hot-rolled steel sheet may be calculated and/or measured in
the length direction of the hot-rolled steel sheet, and the
etching process may be controlled to have optimum efficiency,
10 according to thickness information about the internal defect
layer. Therefore, productivity may be improved by shortening
a period of the etching process and reducing an amount of
the etching solution used. In addition, it is possible to
reduce a variation in thickness of the internal defect layer
15 appearing for each region in a pickled steel sheet in which
the etching process has completed.
[0050]
[0051] FIG. 3 is a block diagram illustrating a process
control system according to an embodiment of the present
20 disclosure.
[0052] According to an embodiment of the present disclosure,
a process control system 1 may include a first system SYS1
generating thickness information about an internal defect
layer included in a hot-rolled coil in which a hot-rolled
25 steel sheet is wound to have a coil shape, and a second
15
system SYS2 using the thickness information about the
internal defect layer received from the first system SYS1,
to control an etching process of removing at least a portion
of the internal defect layer from the hot-rolled steel sheet
5 from which the hot-rolled coil is unwound. Also, the first
system SYS1 may provide the second system SYS2 with a
calculation module necessary for the second system SYS2 to
control the etching process. In addition, the second system
SYS2 may provide the first system SYS1 with information
10 necessary for the first system SYS1 to update the calculation
module. The first system SYS1 and the second system SYS2 may
communicate with each other through a network 30.
[0053] Referring to FIG. 3, a process control system 1
according to an embodiment of the present disclosure may be
15 operated by a first entity performing a hot-rolling process
and a second entity performing an etching process. In an
embodiment, the first entity may produce a hot-rolled steel
sheet, and may wind the hot-rolled steel sheet to manufacture
a hot-rolled coil, and the second entity may receive the
20 hot-rolled coil from the first entity, and may perform an
etching process removing an internal defect layer of the
hot-rolled steel sheet. Referring to FIG. 3, the first system
SYS1 may be operated by the first entity, and the second
system SYS2 may be operated by the second entity.

WE CLAIMS:
1. A process control system comprising:
a first system generating thickness information about
an internal defect layer included in a carbon steel product;
5 and
a second system receiving the thickness information
about the internal defect layer from the first system through
a network, and using the thickness information about the
internal defect layer, to control an etching process removing
10 at least a portion of the internal defect layer from the
carbon steel product,
wherein the first system provides the second system
with a calculation module necessary for the second system to
control the etching process, and
15 the second system provides the first system with
information necessary for the first system to update the
calculation module.
2. The process control system of claim 1, wherein
20 the first system provides the second system with the
calculation module determining at least one of a transporting
speed of the carbon steel product in the etching process, a
concentration of an etching solution contacting the carbon
steel product in the etching process, a temperature of the
25 etching solution, a component of the etching solution, or
86
whether or not an accelerator is used.
3. The process control system of claim 1, wherein
the second system provides the first system with at least
5 one of a thickness of a residual internal defect layer
included in a pickled carbon steel product on which the
etching process has been completed, or control data measured
by an etching device performing the etching process.
10 4. The process control system of claim 1, wherein
the second system adjusts at least one of a transporting
speed at which an etching device performing the etching
process transports the carbon steel product, a concentration
of an etching solution contacting the carbon steel product
15 in the etching device, a temperature of the etching solution,
a component of the etching solution, or whether or not an
accelerator is used, to control the etching process.
5. The process control system of claim 4, wherein
20 the carbon steel product comprises a first region in which
the internal defect layer has a first thickness, and a second
region in which the internal defect layer has a second
thickness, different from the first thickness, and
the second system transports the carbon steel product
25 at a first transporting speed while the first region is in
87
contact with the etching solution, and transports the carbon
steel product at a second transporting speed, different from
the first transporting speed, while the second region is in
contact with the etching solution.
5
6. The process control system of claim 5, wherein
the first thickness is less than the second thickness, and
the first transporting speed is faster than the second
transporting speed.
10
7. The process control system of claim 1, wherein
the etching process is at least one of a pickling process,
a dry etching process, or a wet etching process.
15 8. The process control system of claim 1, wherein
the first system stores the calculation module and a training
model training the calculation module.
9. The process control system of claim 1, wherein
20 the first system measures a thickness of the internal defect
layer included in the carbon steel product, to generate the
thickness information about the internal defect layer.
10. The process control system of claim 9, wherein
25 the first system measures a thickness of the internal defect
88
layer in each of a plurality of regions defined in a length
direction of the carbon steel product.
11. The process control system of claim 1, wherein
5 the first system uses at least one of a phase fraction of
the carbon steel product, a component of the carbon steel
product, and a temperature of the carbon steel product, to
calculate a thickness of the internal defect layer.
10 12. The process control system of claim 11, wherein
the calculation module calculates a thickness of the internal
defect layer in each of a plurality of regions defined in a
length direction of the carbon steel product.
15 13. A process control system comprising:
a storage device storing control data necessary for
controlling an etching device removing at least a portion of
an internal defect layer included in a carbon steel product;
and
20 a processor controlling the etching device based on
the control data,
wherein the carbon steel product includes a first
region and a second region, different from the first region,
wherein a thickness of the internal defect layer included in
25 the first region is different from a thickness of the inner
89
defect layer included in the second region, and
the control data includes a first transporting speed
at which the first region passes through the etching device,
and a second transporting speed at which the second region
5 passes through the etching device, wherein the first
transporting speed is different from the second transporting
speed.
14. The process control system of claim 13, wherein
10 the storage device stores a calculation module generating
the control data.
15. The process control system of claim 13, further
comprising a communication unit connected to a network,
15 wherein the processor receives a calculation module
generating the control data through the communication unit,
to store the received calculation module in the storage
device.
20 16. The process control system of claim 13, further
comprising a communication unit connected to a network,
wherein the processor receives thickness-related
information of the internal defect layer through the
communication unit, and inputs the thickness-related
25 information of the internal defect layer to a calculation
90
module generating the control data, t