[Technical Field of the Invention]
[000 I]
The present invention relates to a slab warpage detection apparatus detecting
warpage of a slab drawn from a mold in continuous casting equipment, and a method
of detecting wmpage of a slab using the slab warpage detection apparatus.
Priority is claimed on Japanese Patent Application No. 2016-018309, filed on
February 2, 2016, the content of which is incorporated herein by reference.
(Background Art]
[0002]
In a case where a slab is subjected to continuous casting in continuous casting
equipment, sometimes the slab is not unifom1ly cooled due to a water leak from
cooling water piping, clogging of spray chips, and the like, and warpage is generated in
the slab. There is concem that if a warpage amount of a slab exceeds a prcdctem1incd
amount, the slab interferes with a conveying apparatus and the like, so that an
operation is halted.
[0003]
Therefore, in the conventional mi, a method of reducing waqmge of a slab
drawn ft·om a mold in continuous casting equipment has been proposed.
For example, Patent Document I has proposed a method of straightening
warpage of a slab using a reduction roll in a slab conveyance table.
In addition, Patent Documents 2 and 3 have proposed a method of
straightening warpage of a slab by restricting conditions for cooling a slab.
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[Prior Art Document]
I Patent Document] ,, '"j' •. ' •. •
[0004] d'
[Patent Document I] Japanese Unexamined Patent Application, First
Publication No. H06-335755
[Patent Document2J Japanese Unexamined Patent Application, First
Publication No. 2000-176616
[Patent Document 3) Japanese Unexamined Patent Application, First
Publication No. 2003-019546
[Disclosure of the Invention]
[Problems to be Solved by tl1e Invention]
[0005]
In methods according to Patent Documents l to 3, methods of straightening
warpage of a slab are disclosed. However, a unit sensing warpage of a slab and a unit
measuring a warpage amount are not disclosed. For example, it may be conceivable
to measure the amount of displacement of a slab using a laser displacement meter or
the like. However, in continuous casting equipment, the use environment is poor, and
the laser displacement meter or the like deteriorates in an early stage due to heat, vapor,
and the like. Accordingly, it is assumed that the amount of displacement of a slab
cannot be stably measured for a long period of time .
. (0006]
Here, in a roll segment suppmiing a slab drawn tl·mn a mold in continuous
casting equipment, since a slab is fixed by the roll segment, watpage is not manifested.
Warpage is manifested at the point of time a slab comes out of the roll segment.
However, the amount of displacement thereof itself is not significant, and wmpage is
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sensed for the first time at the point of time a slab is drawn long. Therefore, there has
been a problem that warpage cannot be sensed in an early stage and an operation stop
cannot be avoided.
[0007]
Pm1icularly, in vertical-type continuous casting equipment in which a slab is
drawn downward in a vetiical direction and the slab is cut into predetermined lengths
by a cutter, if significant warpage is generated in the slab, there is a problem that the
slab rides on a conveying roll which pinches and supports the slab on a side below the
cutter, so that the slab cannot be supported m1y longer and an operation stops.
1l1erefore, there is demand for sensing warpage of a slab in an early stage and
appropriately straightening warpage.
[0008]
1l1e present invention has been made in consideration of the foregoing
situations, and an object thereof is to provide a slab warpage detection apparatus which
senses watpage of a slab drawn li-mn a mold in an early stage and is capable of
measuring a watpage amount thereof, and a method of detecting warpage of a slab
using the slab warpage detection apparatus.
(Means for Solving the Problem]
[0009]
(I) In order to solve the problem above, according to an aspect of the present
invention, there is provided a slab warpage detection apparatus detecting watpage of a
slab drawn 11-om a mold in continuous casting equipment. The slab warpage detection
apparatus includes a pair of pressing rolls that pinches the slab on an exit side of a roll
segment supporting the slab drawn ti·om the mold, a movement unit that supports the
pair of pressing rolls to be movable in a thickness direction of the slab, and a position
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detecting unit that detects positions of the pressing rolls in the thickness direction of
the slab. -: ·''
(0010]
According to the slab wmvage detection apparatus having this configuration,
the slab wmvage detection apparatus includes the pair of pressing rolls that pinches the
slab, the movement unit thai supports the pair of pressing rolls to be movable in the
thickness direction of the slab, and the position detecting unit that detects the positions
of the pressing rolls in the thickness direction of the slab. Therefore, the pair of
pressing rolls moves in the thickness direction of the slab in a manner following a
shape of the slab, and warpage of the slab is sensed by detecting the positions of the
pair of pressing rolls in the thickness direction of the slab, so that a warpage amount
thereof can be accurately· measured. In addition, a situation of warpage of the slab
can be continuously detected.
In the present invention, in a case of considering a cross section including a
drawing direction of the slab, warpage denotes displacement of a position in a direction
perpendicular to the drawing direction of the slab. In the present invention, wmvagc
of a slab in thickness becomes a target to be detected by the slab wa•vage detection
apparatus. In addition, the thickness direction of the slab in the present invention
indicates a thickness direction of the slab immediately below the roll segment.
In addition, in the present invention, the pressing rolls and the movement unit
are provided at the rear of the roll segment, supporting the slab drawn tl·01n the mold,
in the slab drawing direction (direction in which a slab is conveyed). Therefore, the
warpage amount of a slab can be measured in an early stage, and a stop of an operation
due to warpage of the slab can be avoided by taking appropriate countermeasures such
as straightening this warpage.
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[00 II J
(2) Here, in the slab waq}age detection apparatus according to the aspect
described above, it is preferable that watpage of the slab is straightened by adjusting a
balance of pressing forces of the pair of pressing rolls, for example, in a case where an
amount of displacement of the positions of the pressing rolls in the thickness direction
of the slab exceeds a predetennined value. The prcdetem1ined value of the amount of
displacement of the positions of the pressing rolls in the thickness direction of the slab
is a value obtained based on the past perfonnancc from an allowable value of the
waqlage amount with which a slab can be stably conveyed without riding on a lower
conveying roll. This predetem1ined value is set in accordance with a roll size of the
lower conveying roll.
In this·case,waqlage of the slab can be straightened in an early stage by
adjusting the pressing forces of the pair of pressing rolls at the point of time the
amount of displacement of the positions of the pressing rolls in the thickness direction
of the slab exceeds the predetennined value is sensed, so that an operation stop due to
waq}age of the slab can be avoided. That is, in regard to a slab which is being
conveyed at a predetennined speed, an operation stop due to waqlage of the slab can
be avoided by straightening the waqlage of the slab at the point of time the waqlage of
the slab can be straightci1cd.
[00 12]
(3) In the slab warpage detection apparatus according to (I) or (2), the slab
having a center solid phase ratio of 70% or higher may be used as a detection target.
In this case, the slab is prevented t!·om expanding due to static pressure, so that
warpage can be more accurately detected.
[00 13]
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( 4) In the slab warpage detection apparatus according to any one of (I) to (3),
the continuous:casling equipment may be a vertical tyJ>e. In this case, .. in>\'Crtical-typc
contiimous casting equipment in which a slab is drawn downward in a vertical
direction, the warpage amount thereof can be measured by sensing warpage of a slab,
in an early stage, conveyed without going through a step such as bending after being
drawn n·om the mold.
[0014]
(5) According to another aspect of the present invention, there is provided a
method of detecting warpage of a slab using the slab warpage detection apparatus
according to any one of(l), (3), and (4). The method of detecting warpage of a slab
includes detecting warpage of a slab by causing the position detecting unit to detect the
positions of the pressing mils· when the pair of pressing rolls moves in the thickness
direction of the slab in a manner following a shape of the slab in a state where the slab
is pinched by the pair of pressing rolls.
According to the method of detecting watpage of a slab having this
configuration, the slab wmvage detection apparatus described above is used.
Therefore, warpage of the slab can be sensed in an early stage and the warpage amount
thereof can be accurately measured when the positions of the pressing rolls when the
pair of pressing rolls moves in the thickness direction of the slab in a manner following
the shape of the slab is detected by the position detecting unit.
In a case where a slab is pinched by the pair of pressing rolls, the pressing
rolls may be in a state of being in contact with the slab.
On the other hand, the slab may be pressed and pinched by the pair of
pressing rolls with pressing forces equal to each other. In this case, there is no need
for each of the pressing forces to striclly coincide with each other. A ditTerence may
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be present between pressing forces to the extent that a slab is not deformed. An
allowabh:•difference between pressing forces varies due to .the material, the crosssectional.
shape, and the like of a slab. Generally, it is preferable that the allowable
difference is 20 tor lower.
(00 15]
(6) In addition, according to another aspect of the present invention, there is
provided a method of detecting warpage of a slab using the slab warpage detection
apparatus according to (2) to (4). The method of detecting warpage of a slab includes
detecting warpage of a slab by causing the position detecting unit to detect the
positions of the pressing rolls when the pair of pressing rolls moves in the thickness
direction of the slab in a manner following a shape of the slab in a state where the slab
is pinched bythe·pairofpressing rolls, and straightening warpage of the slab by
adjusting pressing forces of the pair of pressing rolls in a case where an amount of
displacement of the positions of the pressing rolls in the thickness direction of the slab
exceeds a predetem1ined value.
According to the method of detecting warpage of a slab having this
configuration, the slab warpage detection apparatus described above is used.
Therefore, wmpage of the slab can be sensed in an early stage and the Wat1Jagc amount
thereof can be accurately 1neasurcd.
Then, in a case where the amount of displacement of the positions of the
pressing rolls in the thickness direction of the slab exceeds the predetermined value,
warpage of the slab is configured to be straightened by adjusting pressing forces of the
pair of pressing rolls. Therefore. warpage of the slab can be straightened in an early
stage, so that an operation stop due to warpage of the slab can be avoided.
(Effects of the Invention]
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(00 16]
."-.o.'l.ir.';c'i>l According to each of the aspects of the present im~otititih described above, it is
possible to provide the slab warpage detection apparatus which senses warpage of the
slab drawn from a mold in an early stage and is capable of measuring a warpage
amount thereof, and the method of detecting warpage of a slab using the slab warpage
detection apparatus.
(Brief Description of the Drawings]
[00 17]
FIG. l is a view describing continuous cide and the pressing rolls 21 on
the lower side, and a distance B between the pressing rolls 21 on the lower side and the
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lower conveying rolls 17 which are set in advance, an amount C of displacement oft he
positions of the pressing rolls 21 on the lower side and an amount D of displacement of· '. :.
the positions of the pressing rolls 21 on the upper side are calculated. A warpage
amount X in parts of the lower conveying rolls 17 is calculated by the following
(Expression I). For example, the unit of mm can be used as each of the variables.
X=(C-D)xB/A+C ... (Expression I)
[0027]
If this warpage amount X exceeds a prcdctcnnincd value, there is concern that
the slab I rides on the lower conveying rolls 17, so that conveyance of the slab I has to
be stopped. Therefore, at the point of time the slab I comes out ofthe roll segment
13, there is a need to straighten warpage of the slab I as necessary by sensing warpage
of the slab I based on infonnation of the positions oft he pressing rolls 21.
In the present embodiment, as illustrated in FIG. 5, warpage is straightened by
adjusting pressing forces of the pressing rolls 21 (21 A and 21 B) and causing the slab I
to be subjected to bending deformation. That is, warpage of the slab 1 is straightened
by generating a difference between pressing forces of the pressing rolls 21 A on one
side and pressing forces of the pressing rolls 21 B on the other side and applying
bending defommtion to the slab I, in the pair of pressing rolls 21 (21A and 21 B)
pinching the slab I. ·
In the present embodiment, as illustrated in FIG. 5; warvagc is straightened by
causing the pair of pressing rolls 21 (21A and 21 B) on the upper side and the pair of
pressing rolls 21 (21 A and 21 B) on the lower side to be relatively move in the opposite
directions and causing the slab l to be subjected to bending deformation.
[0028]
According to the slab wmvage detection apparatlls 20 and the method of
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detecting slab warpage according to the present embodiment having a configuration as
described above, tho.shlb!\yarpage detection apparatus 20 includes the pair of pressihg
rolls 21 (21 A and 21 B) tiiat presses and pinches the slab I, the movement units 24 ihat
supp01t these pressing rolls 21 to be movable in the pressing direction F, and the
position detecting units 28 that detect the positions of the pressing rolls 21 in the
pressing direction F. Therefore, in a state where the slab I is pressed by the pair of
pressing rolls 2I (21 A and 2I B) with pressing forces equal to each other, warpage of
the slab I can be sensed by causing the position detecting units 28 to detect the
positions of the pressing rolls 21 when the pressing rolls 21 move in the pressing
direction F in a manner following the shape of the slab I.
[0029]
In addition,· the pair of pressing rolls 21 (2IA and 218) is provided at the exit
pan of the roll segment 13 fixing and supporting the slab I drawn from the mold fl.
Therefore, at the point of time waq>age is manifested, warpage of the slab I can be
sensed in an early stage, so that the warpage amount can be accurately measured.
Moreover, in the present embodiment, as illustrated in FIG. 4, the wmpagc
amount X of the positions of the lower conveying rolls 17 can be estimated from the
amount of displacement of the positions of the pair of pressing rolls 21 (21 A and 21B)
in the pressing direction F provided at the exit pati oft he roll segment I 3. Thus,
before the slab I arrives at the lower conveying rolls· 17, the slab I can be prevented
from riding on the lower conveying rolls I 7 by straightening warpage, so that an
operation can be stably performed.
[0030]
In addition, in the present embodiment, a case where two sets of the pair of
pressing rolls 21 (21 A and 21 B) are vertically provided is illustrated. In the case of
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such a fonn, warpage of the slab I can be sensed from a difference bdwecn the amount
of displacemcntofthe positions of the pressing rolls 21 on the upper side.in:tli<;><'
pressing direction. F and the amount of displacement of the positions of the pi·cssing
rolls 21 on the lower side in the pressing direction F.
Moreover, when waq>age of the slab 1 is straightened, warpage of the slab I
can be straightened in a relatively simple manner by causing the pair of pressing rolls
21 (21Aand 21B) on the upper side and the pair of pressing rolls 21 (21A and 21B) on
the lower side to move in directions opposite to each other by applying bending
defonnation to the slab I.
[0031]
Hereinabove, the slab waq>age detection apparatus and the method of
detecting slab warpage according to the embodiment of the present invention have
been described. However, the present invention is not limited to only the fom1s
described above, and suitable changes can be made within a range not departing from
the technical ideas of the invention.
For example, in the description of the present embodiment, as illustmtcd in
FIG 2, the movement units supporting the pair of pressing rolls 21 (21 A and 2 IB) on
the upper side and the movement units supporting the pair of pressing rolls 21 (21A
and 21B) on the lower side arc fixed to the same frame 29. However, the
embodiment is not limited thereto. As illustrated in FIG. 6, the movement units 24
supporting the pair of pressing rolls 21 (21A and 21 B) on the upper side and the
movement units 24 supporting the pair of pressing rolls 21 (21 A and 21 B) on the lower
side may be fixed to the frames 29 different from each other.
[0032)
Moreover, in the description of the present embodiment, two sets ofthe pair
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of pressing rolls arc provided. However, the embodiment is not limited thereto. As
illustratc{j·.j,f FIG. 7, one set of the pair of pressing rolis21 (21A and >2Hl) may be
provided. '".Even in this case, the warpage amount of the slab I cati be'lneasured fl·om
a distance between a pinching roll 14 and the pressing rolls 21 constituting the roll
segment 13, and the amount of displacement of the positions of the pair of pressing
rolls 21 (21A and 21 B) in the pressing direction F. For example, as illustrated in FIG.
7, in a case where a distance between the pinching rolll4 of the lowennost portion and
the pressing rolls 21 is A', a distance between the pressing rolls 21 and the lower
conveying rolls 17 is B ', and the amount of displacement of the positions of the
pressing rolls 21 in a pressing direction is E in a plurality of pinching rolls 14
constituting the roll segment 13, similar to the case described above, the warpage
amount X can·be calculated by the following (Expression 2). For example, the unit of
nun can be used as each oft he variables.
X=ExB'/A'+E ... (Expression 2)
In addition, in the description of the present embodiment, the position
detecting units 28 are provided in the movement units 24 on both sides of the pair of
pressing rolls 21 (21 A and 21 B). However, the embodiment is not limited thereto.
The position detecting unit 28 may be provided on only the movement unit 24 on one
side.
In addition, in the description of the present embodiment, the movement unit
24 has a cylinder structure. However, the embodiment is not ·limited thereto. For
example, the movement unit 24 may move a mechanical screw using an electric motor.
[0033]
In addition, in the description of the present embodiment, the pressing rolls 21
(21 A and 2113) are configured to straighten warpage of the slab 1. However, the
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embodiment is not limited thereto. There is no limitation for the method of
straigl1t>O'.ning warpage. For example, cooling may be perfonm•dkin only one surface
orthe slab I. . When cooling is performed on only one sui-face.ofthe slab I, a
temperature difterence is generated in the thickness direction of the slab I so that the
slab I is deformed. Warpage of the slab I can be straightened by utilizing this
defommtion. It is preferable that a cooling device for the slab I is provided
immediately below the slab warpage detection apparatus 20 according to the present
embodiment.
[0034]
In the present embodiment, the slab I having a thickness of 50 mm or greater
in a cross section perpendicular to the drawing direction of the slab I is preferably used.
In a case where the slab ·l satisfies this condition, a problem of warpage of the slab I is
manifested, and the slab warpage detection apparatus 20 according to the present
embodiment is preferably used. The cross-sectional shape of the slab l may be a
rectangular shape, a circular shape, an elliptic shape, an H-shape or the like.
[0035]
As in the continuous casting equipment 10 according to the present
embodiment, the slab warpage detection apparatus 20 is provided between the roll
segment 13 and the cutters 15. Therefore, particularly, before the slab I is drawn
downward in the vctiical direction and the slab I is cut into predetermined lengths by
the cutters 15, it is possible to prevent the slab 1 fi·01n riding on the conveying rolls 17
which support a slab on a side below the cutters 15, to prevent the slab I tl·om being
not able to be suppotied any longer, and to prevent an operation from stopping.
[0036]
In addition, the continuous casting equipment I 0 according to another
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embodiment of the present invention includes the mold II, the roll segment 13 that is
Wd~·ldlsposed in a plurality of stages below this mold II and;~iijlports the slab I drawn from
.. the mold II, and the slab warpage detection apparati1s 20.ihat detects warpage of the
slab 1 drawn from the mold ll, The continuous casting equipment 10 includes the
slab wmpage detection apparatus 20 that has the pair of pressing rolls 21 pinching the
slab I on the exit side of the roll segment 13, the movement units 24 supporting this
pair of pressing rolls 21 to be movable in the thickness direction of the slab I, and the
position detecting units 28 detecting the positions of the pressing rolls 21 in the
thickness direction of the slab; the cutters 15 that cut the slab I; and the lower
conveying rolls 17 that support and convey the slab I on a side below the cutters 15,
[0037)
In addition; the method according to still another embodiment of the present
invention is a method including detecting of warpage of the slab I by causing the
position detecting unit 28 to detect the positions of the pressing rolls 21 when the pair
of pressing rolls 21 move in the thickness direction of the slab 1 in a manner following
the shape of the slab I in a state where the slab 1 is pinched by the pair of pressing
rolls 21 by using the continuous casting equipment I 0 including the mold II, the roll
segment 13 that is disposed in a plurality of stages below this mold II and suppmis the
slab I drawn from the mold II, and the slab wmvagc detection apparatus 20 that
detects warpage of the slab I drawn ft·mn the mold 11, The continuous casting
equipment I 0 includes the slab warpage detection apparatus 20 that has the pair of
pressing rolls 21 pinching the slab I on the exit side of the roll segment 13, the
movement units 24 supporting this pair of pressing rolls 21 to be movable in the
thickness direction of the slab I, and the position detecting units 28 detecting the
positions of the pressing rolls 21 in the thickness direction of the slab I; the cutters 15
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that cut the slab 1; and the lower conveying rolls 17 that support and convey the slab I
[0038]
[Example]
Hereinafter, the resulis of an experiment perfonned to confirm the ellects of
the present invention will be described.
A slab having a rectangular cross section with a thickness of250 mm and a
width of 2,200 mm was subjected to continuous casting using continuous casting
equipment (vertical-type continuous casting apparatus) described in the present
embodiment.
In Comparative Example, the slab warpage detection apparatus was not
provided, and warpage· was not straightened.
[0039]
In Example of the present invention, the slab warpage detection apparatus
described in the present embodiment was used. Here, A distance A between a pair of
pressing rolls on the upper side and a pair of pressing rolls on the lower side in FIG 4
was set to 600 mm, and A distance B between the pair of pressing rolls on the lower
side and a lower conveying roll was set to 5,660 mm.
In addition; fi:om the past pcrfonnancc, a lower conveying roll, which had a
size used when the slab rode on the lower conveying roll and conveyance stopped in a
case where the warpage amount of a slab in the lower conveying roll became 30 mm or
greater, was used.
In regard to pressing forces of the pair of pressing rolls, pressing forces of
both rolls were set to be approximately equal to each other.

CLAIMS
I. A slab wvrpa,gc.,jetection apparatus detecting warpage of a slab drawn'
from a mold in contit\uous casting equipment, the slab warpage detection apparatus
compnsmg:
a pair of pressing rolls that pinches the slab on an exit side of a roll segment
suppotiing the slab drawn from the mold;
a movement unit that supports the pair of pressing rolls to be movable in a
thickness direction of the slab; and
a position detecting unit that detects positions of the pressing rolls in the
thickness direction of the slab.
2. The slab warpage detection apparatus according to claim I,
wherein warpage of the slab is straightened by adjusting pressing forces of the
pair of pressing rolls in a case where an amount of displacement of the positions of the
pressing rolls in the thickness direction of the slab exceeds a predetennined value.
3. The slab warpage detection apparatus according to claim 1 or 2,
wherein the slab having a center solid phase ratio of70% or higher is used as
a detection target.
4. The slab warpage detection apparatus according to any one of claims I to
3,
wherein the continuous casting equipment is vertical-type continuous casting
equipment.
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5. A method of detecting warpage of a slab using the slab warpage detection
apparatus according:to;any one of claims 1, 3, and 4, the method comprising1·"·'''';,
detecting warpage of a slab by causing the position detecting unit. to detect the
positions of the pressing rolls when the pair of pressing rolls moves in the thickness
direction of the slab in a manner following a shape of the slab in a state where the slab
is pinched by the pair of pressing rolls.
6. A method of detecting warpage of a slab using the slab warpage detection
apparatus according to any one of claims 2 to 4, the method compdsing:
detecting warpage of a slab by causing the position detecting unit to detect the
positions of the pressing rolls when the pair of pressing rolls moves in the thickness
direction of the slab· in·a manner following a shape of the slab in a state where the slab
is pinched by the pair of pressing rolls; and
straightening warpage oft he slab by adjusting pressing forces of the pair of
pressing rolls in a case where an amount of displacement of the positions of the
pressing rolls in the thickness direction of the slab exceeds a prcdctcnnincd value.