ma~neof Docu~
[Title of the Inv~
[Tecln~icalF ield
[OOOll
5 The
table rolls, the ti
[Background Ar
[0002]
In a 1
10 the heated slab
material, and thc
of rolling stands
Then, after the
cooled down to
15 steel plate is coil
[0003]
Ill tll
disposed over tl
cooling nozzles
20 thus, the coolin;
surface of the pa
[0004]
Here
steel plate that 11
25 The trouble ten(
steel plate is SIT
~ tD] ESCRIPTION
ion] HOT-ROLLED PLATE PASSING GUIDE
:sent invention relates to a hot-rolled plate passing guide placed between
:rolls conveying a hot-rolled steel plate in a hot-rolling line.
.rolling line, a slab is heated to a given telnperature in a heating filmace,
rolled to a given thickness in a roughing ~nillto obtain a rough-rolled
,ugh-rolled material is rolled in a finishing rolling mill having a plurality
I thereby rnanufach~re a hot-rolled steel plate having a given thich~ess.
t-rolled steel plate that has been rolled in the finishing rolling ~nilli s
sivell tenlperature in a cooling bed inclt~dingta ble rolls, the hot-rolled
in a coil shape by a coilel:
I i
ooling bed mentioned above, an upper cooling device having llozzles is
hot-rolled steel plate to be conveyed, a lower cooling device having
disposed between table rolls conveying the hot-rolleci steel plate, and
led has a structure for cooli~lg down the upper surface and the lower
ng hot-rolled steel plate.
I the coolillg bed, there may occur a trouble that an end of the hot-rolled
been rolled by the finishing rolling ~nillf alls in between the table rolls.
to occur particularly in the case where the thickness of the hot-rolled
, since the end of the hot-rolled steel plate easily deforms because of
insullicient rigiciiiy of the hot-rolled steel plate. Accordingly, in the hot-rolling line, in
I
order to prevent tl'e end of the hot-rolled steel plate from falling in between the i table rolls,
a hot-rolled plate passing guide (apron) as shown in Patent Literatures 1 to 3 is disposed
between the table 1.011s.
5 [0005]
hot-rolled plate passing guide disposed between, the table rolls, nozzle
holes are provide+ at a position corresponding to the above-mentioned coqling tiozzles in
order to cool do&i tlie lower slirface of the hot-rolled steel plate. Here, in the place
I
where the hot-rollkd plate passing guide is disposed, cooling water jetted fiom the cooling
10 nozzles collides with the lower surface of the hot-rolled steel plate, and after that, the
I
cooling water rerdains on tlie hot-rolled plate passing guide. As a result, the cooling of
the part where tli 1 hot-rolled plate passing guide is disposed is accelerated, and thus, the
I
lower surface is not unifornily cooled, which may cause a proble~nin the quality thereafter,
[0006]
15 Accor f mgly, each of tlle hot-rolled plate passing guides described in Patent '
in whicli a drainage hole is formed in addition to the
water remaining on the hot-rolled plate passing guide is
[Patent Literature b] JP 20 10-42445A
[Patent Literatare L] JP 50150348
25 [Sunul~aryo f the 1 ,nvention]
20 [Patent ~iteratureds)]
[0007]
[Patent Literature 11 JP 2002-239623A
[Problem(s) to Be Solved by the Invention]
Howe el; in Patent Literature 1, si~ice the hot-rolled plate passing I guide is provided across the full width of tlie table rolls, the cooli~lg water is liable to remain
I
between the hot-Jolled steel plate and tlie hot-rolled plate passin; guide. Most of the
8 I . 5 remaining cooling water 1s to be ejected from an end part of tlie guide, which leads to
I
occurrence of cooiing deviation in a plate-width direction.
!
[0009] I
Patent Literature 2, nozzles for jetting cooling water are provided in
at some of through-holes out of a plurality of tlx~ou~h~lioles
10 fortried in a gri pattern in the hot-rolleci plate passing guide, anti the remaining f tlxougli-holes are used as drainage holes. Here, in Patent Literature 2, a large atllount of
high pressure water is 11sed as cooling water. Accordi~igly, it 'is considered that the
I
cooling water is at lligli pressure onto a surface of tlie steel ;/ate under the state that
the space hot-rolled steel plate anci the hot-rolled plate passing guide is almost
15 filled Therefore, the drainage performance of the hot-rolled plate
I
passing guide is n t sufficie~lat lso in Patent Literature 2.
[OOl 01 I. The problem of non-unifor~inityin cooling temperature of the hot-rolled steel
I
plate caused by tlie water remaining on the hot-rolled plate passing guide also applies to
I
20 the longitudinal direction of the hot-rolled steel plate in addition to the width direction of
the hot-rolled ste 1 I plate. In the case where the hot-rolled steel plate obtained by the
I
hot-rolling line is I subjected to cold rolling, variation in plate tl~cknessm ay occur ill the '
longitudinal direc1 i on at one end side of the hot-rolled steel plate. As a restrlt of studying the cycle of the plate thickness variation, it has been found that the cycle corrcsponds to 1 25 the teniperature \ariation of the hot-rolled steel plate before reaching tlie coiler of the
hot-rolling line. I
I
Here
hot-rolled steel 1
finishing rolling
5 steel plate being
hot-rolled steel
downward come
te~ilperature dec~
reaching the coil
10 described above.
[0012]
Ill th
contact with the
and tlie tempera+
15 passing guide.
guide has not bt
temperature vari
have been supp~
hot-rolled steel 1
20 drainage perforn
[0013]
From
plate passing gu~
nozzle 27, and d
25 located between
adva~itageous efi
n the hot-rolling line described above, since tension is not acting on the
ate during a period fioni the hot-rolled steel plate being rolled by the
ill to the hot-rolled steel plate being coiled by the coilel; the hot-rolled
oriveyed nlay wind up and down greatly. It has been fot~ndth at, in the
ate that has been wound up and down greatly, a part that is convex
close to or into contact with the hot-rolled plate passing guide, tlitls, the
ases, and therefore, the teniperature of the hot-rolled steel plate before
r of the hot-rolling line varies cyclically in the longitudinal direction as
way, since the part that is convex downward conles close to or into
ot-rolled plate passing guide, the hot-rolled steel plate is locally cooled
re decreases greatly if tlie cooling water renlains 011 the hot-rolled plate
ccordingly, the cooling water remaining on the hot-rolled plate passing
tl ejected suficiently by simply providing the drainage holes, and the
ion of the hot-rolled steel plate in the longitudinal direction could not
ssed. That is, in order to suppress the temperature variation of tlie
ate in the longitudinal direction, it is necessary to f~lrtllere nhance the
uce of the hot-rolled plate passing guide.
he above-mctitioned viewpoint, Patent Literature 3 proposes a hot-rolled
e 3 as shown in FIG. 7 including nozzle lioles 3a eacli provided with a
inage holes 3b each having a linear shape in the plate passing direction
the nozzle holes 3a. However, altl~onglt~h is system has certain
cts, it is necessary to fitrther enhance the drainage performance of the
I . . . i hot-rolled plate passnlg gu~de in order to suppress the temperature variation of tlie
I
hot-rolled steel pliite in the width direction and in the longitudinal direction.
I
In addition, the hot-rolled plate passing guide is worn away by conling into
I
5 contact with the I/ ot -l.o lled steel plate. Particularly in the case wliere the hot-rolled plate
passing guide is dade of a nlaterial softer than the hot-rolled steel plate so that no scratch
I
is generated on ill1 Iio&rolled steel plate, there is a problem that tl~eh ot-rolled plate passing
I
guide is worn awaI y at an early stage and the life thereof decreases. There has recently
I !
been an attempt td increase plate passing speed in order to e ~ a n c kth e productivity in the
I I
10 hot-rolling line, arid hence, the wear of the hot-rolled plate passing guide at an early stage
1. tends to be accelelated. Since the operation is interl.upted if tlie hot-rolled plate passing
guide is changed 1 o another hot-rolled plate passing guide, it is desired that the life of the ,
I hot-rolled plate pIa ssing guide is increased from the viewpoint of ed~ancementi n the
productivity.
15 [0015]
The present invention has been niade in view of the drcumstances described I above, and an object of the present invention is to provide a hot-roiled plate passing guide
I which is capable qf supplessing the temperature variation of the hot-rolled steel plate in the
longih~dinal directial, by effectively ejecting tlle cooling water jetted onto the lower
20 silrface of the lildt-rolled steel plate fron~ over the hot-rolled plate passing guide, and
capable of attenlp 1 ing to decrease the wear at an early stage to increase the life.
I [Means for Solving the P~oblem(s)]
[0016]
'i
In order to solve tlie above problems, the inventors of the present invention 1 . . . 25 have observed in deta~ltl ie flow of water jetted on tlie lower surface of a hot-rolled steel
plate from nozzle! by using a testing macl~it~we,h ich is an imitation of a hot-rolling line.
I
I
part whose distan e from tlie collided part on the lower surface of the acrylic plate f is small, there are little differences in nionienta of colliding flows of water per unit region and
20 speeds of collidin 6 flows of water in the respective parts. Accordingly, the collided flows
of water drops tl!ro~igli the drainage hole 3b maintaining a high force, witliout being
I
diffi~sed. I
I
I
[OOl 81 I On tlie other hand, it has been found that water flowed'to a part whose distance
25 from the collided ba'~o tn tlie lower surface of the acrylic plate is large collicles not only at
To be specific, (egarding a transparent acrylic plate as the liot-rolled steel plate, a
I
hot-rolled plate pissing guide is placed on the lower surface of tlie acrylic plate, water is
jetted onto the lo\?er surface of tlie acrylic plate froni nozzles provided to nozzle Iioles of
I
tlie hot-rolled plaie passing guide, and tlie inventors have observed the flow of the water I . 5 from an upper surface s~deo f the acrylic plate. As a result thereof, the irivetitors have
itiimediately abode an end part of the drainage hole 3b or a part extending therefrom, but
found that the jetted
[0017]
water has behaved as follows.
In the iot-rolled plate passing gnide 3 shown in FIG. 7, tlie cooling water jetted I froni the nozzles !27 collides with tlie lower surface of tlie acrylic plate and flows on the
10 lower surface oft (j e acrylic plate in concentric circles when seen from the upper surface.
In this case, since tlie speed of tlie cooling water is high and tlie object to be collided witli
is liquid, most of the water collided with the acrylic plate does not imtnediately bonnce and
drop, and flows Along the lower surface of tlie acrylic plate. 6f the water flowed in
between the adjacent nozzles 27 after colliding witli the lower surface of the acrylic plate,
I
15 water flowed to a part whose distance fro111 the collided part on tlie lower surface of the 1 acrylic plate is SI la11 collides with water supplied f'ro~n another nozzle at imtnediately
above a drainage r ole 3b, and tlie water drops tllrougli tlie drainage hole 3b (Sl). In the
collides at a peri ~hery thereof in a spreading and zigzag manner (S2). This nlay be
caused, because tl e distance fro111 the collided part on the lower surface of the i acrylic plate is large, and incfeasing influences of tlie following factors tnay generate differences in
~no~nenatnad spchds of colliding flows of water flowed Lom two directions. In addition,
5 the momenta a ~\dhe speeds of the flows of water vary with tirile, ' nd hence, the flows of
I B water are considered to collide in a zigzag manner. 'She following are considered to be
factors for such fl d ws of water.
[OO 1 q
1) Slight difference in a surface state, a movement (corresponding to the
I 10 movement of a steel plate during conveyance), or a tilt of the acrylic plate that is in contact
with water
2) Snl I 11 deviation in a direction of the nozzle that supplies water I 3) Ai bubbles contained in water causing s~nall variation in direction of I nozzle-discharge ow with the random attachment and detachment of air bubbles on the
1 5 inner side of tile .bZzle
The s nall tilt occnrs to the direction of the nozzle-discharge flow due to
attachment of air bubbles on the inner side of the nozzle. When tlle air bubbles are
detached, the dire 1 tion of tla nozzle-discliarge flow retlmms to the slraigbt direction. This
i pl~enomenon rs randomly and repeatedly in various parts, and thus rnay cause small
20 variation in of the nozzle-discha~.gefl ow.
[0020]
On thd basis of the above novel findings, in order to 'solve probletns, there is
l~mvided a hot-rblled plate passing guide according to the present invention placed
between table rolls, the table rolls conveying a hot-rolled steel plate in a hot-rolling line,
I
25 the hot-rolled plade passing guide including a plurality of nozzle holes each provided at a
I
position correspoiding to a cooling nozzle disposed between tlie table rolls, and a drainage
i 1 hole formed between the nozzle holes which are adjacent to each other in the plate-width
I direction of the 11 t-rolled steel plate to be conveyed. Tlle drainage hole includes a first P hole part that extends in a plate passing direction in wlUcll the /lot-rolled steel plate is
I
conveyed, and a sIe cond hole past that is formed at each of both elid parts of tlie first hole
5 part in.tlle plate p ssing direction and is expanded in the plate-width direction.
[00211 I The 11 t-rolled plate passing guide accordi~lgto the present invention includes a 7 plurality of nozzle liolcs each provided at a position corresponding to a cooling nozzle
disposed between I thc table rolls. 'Slle cooling water jetted through the nozzle Iloles onto 10 the lower surface of the hot-rolled steel plate collides with the lower surface of the I hot-rolled steel plate and spreads radially, and the flows of cooling water jetted fro111 the I . adjacent 11ozzle holes in the width direction collide with each otllec Here, in the present
invention, since tl e dla~nageh ole is ronlled between tlie nozzle holes which are adjacent to
each otller in the plate-width direction of the hot-rolled steel plate to be conveyed, the
15 drainage hole is i lace,d. i n a region in wlliclich the flows of cooling water jettedfrom the 1 8, i
I I adjacent nozzle 11 les collide with each other, and Iience, ejection of the cooling water that
11
is present between the hot-rolled plate passing guide and the lower surface of the hot-rolled
I
steel plate is accelkrated.
[0022]
20 Here, 1I1 1 tlle hot-rolled plate passing guide according lo the present invention,
I
the drainage hole k , xtends in the plate passing direction in which the hot-rolled steel plate is
conveyed, In tlldP casc an opcning area of t11e drainage hole can be ena~redin the region in which the flowI? of cooling water jetted fronl the ~~ozzIlloel es that are adjacent to each
other in the widti1 direction collide with each other, and hence, ejection of the cooling
1
I Further, in the hot-rolled plate passing guide accordirig to the present invention,
I I.
the second hole 11 rt is provided at each of the end parts of the dramage hole in the plate
passing direction nd is expanded in tlie plate-width direction. The cooli~lgw ater jetted
through the nozzl 1 holes onto the lower surface of the hot-rolled steel plate collides with
5 tlie lower surface of the hot-rolled steel plate and spreads radially, and also flows in the plate passing dire1 t ion. Accordingly, by providing tlie second liolk part at each of the end
parts of tlie drain ,ge hole in tlie plate passing direction, ejection of tlie cooling water car1
I be reliably accele~ated.
[0024]
10 Here, t is desired that the drainage hole be for~ileds uch that a width W1 of the
iirst hole part and a width W2 of tlle second hole part satisfy the following Expression (1).
1.00< 1/W211.70 (1)
[0025] 1 Fu~the;i n the hot-rolled plate passing guide according to~ 1 the present invention,
! 1
15 the hot-rolled plate passing guide may be made of a resin, which is a material softer than
I
tlie hot-rolled ste$ plate. In this way, scratches can be suppressed froni being generated
on the hot-rolled steel plate when the hot-rolled plate passing guide comes into contact'
with the hot-rolled steel plate. For example, Vickers hardness cif a material for forniing
the hot-rolled plat passlng gmde lilay be more than or equal to 36 and less thau 125.
20 [00261 I -
In addition, in the present invention, when seen from above in a vertical
is set to more than or equal to 0 13, the opening area.
ratio Sh being a r of ope~iinga reas of the nozzle holes and the rarliage hole to an area I ':
of a wllole upper of the hot-rolled plate passing guide. Accordingly, the cooling
25 water that is tlie hot-rolled plate passing guide ancl the lower surface of the
ejected fro111 the drainage hole, and tlie cooling water
call be supplessed from being remained on the hot-rolled plate passing guide. Therefore,
even in the case hlere the hot-rolled steel plate winds ap and down greatly and tlie part
that is convex do nward comes close to or into contact with the hot-C rolled plate passing guide, large-scale ! temperature decrease in the hot-rolled steel plate is sl~ppressed,a nd the
5 temperature varia'tion of the hot-rolled steel plate in the lotigih~dinal direction call be
I . suppressed. Further, in the present invention, since the opening area ratio Sh is set to less
than or equal to "!IS, a co~itacta rea with the hot-rolled steel plateis ensured, tlie wear of I . . the hot-rolled plate passlng gu~deat an early stage can be suppressed, and hence, the life is
I
increased.
10 [0027]
the hot-rolled plate passing guide according to the present illvelition is
art of each of roll widths of the table rolls, and width of the hot-rolled
plate passing guide nlay be less than or equal to half the roll width; of the table rolls. In
this way, the cooliI .g water call be Illore easily ejected.
IS [Effect(s) of the ~tjventio~
[OOZS] I
I
I . Accord~ng to the present invention, the hot-rolled plate passing guide can be
I provided, which call suppless the temperature variation of the hot-rolled steel plate in tile
lo~igitudinal direcltion by effectively ejecting the cooling water jetted onto the lower I 20 surface of the hot rolled steel plate fro111 over the hot-rolled plate passing guide, and call
suppress the to increase the life.
[0029]
explanatory view of a hot-rolliug line in whicli a
25 hot-rolled plate passing guide according to an embodiment of the present invention is used.
I I [FIG, el FIG. 2 is a side expla~~atorvyi ew showilig a state in which the
hot-rolled plate
table rolls.
[FIG.
hot-rolled plate
the table rolls.
[FIG.
according to the
[FIG.
cooli~lgn ozzles i
embodiment is u
[FIG.
plate passing gui
[FIG.
a conventional h~
[Mode(s) for Cal
[0030]
<1. C
I-Ierei
according to an E
passing guide 3(
shown in FIG. 1,
[003 11
[I-1.
The t
a slab 1, a rougl
rough-rolled mat
;sing guide according to tlie present embodiment is disposed between
I
pr j'le
1'
'sI\7 d
I 7' I
de
I 11 3t-1 I . ry1
'T
'T :ml
I FIG. 3 is a plan explanatory view showing tlie state in which the
sing guide according to the present en~bodinienti s disposed between
3
FIG. 4 is an explanatory view of the hot-rolled plate passing guide
a
sent embodiment.
FIG. 5 is an explariatory view showing behavior of cooling water from
I case where the hot-rolled plate passing guide according to tlie present
1:
1' liin
FIG. 6 is a plan view sllowing a modified example of the hot-rolled
according to the present embodiment.
FIG. 7 is an explanatory view illustrating behavior of cooling water in
olled platc passing guide.
ng out tlie Invention]
rview of hot-rolling l i n e
ftel; with reference to FIGS. 1 to 4, a hot-rolled plate passing guide
Iodiment of the present invention will be descrided. A hot-rolled plate
ccording to tlie present enlbodi~nerit is used 6 a hot-rolling line 10
. exanlple.
,ucture example of hot-rolling line]
-rolling line 10 showri in FIG. 1 includes a heating furnace 11 tliat heats
g mill 12 tliat perfortiis rough rolling of the dated slab 1 to riiake a
a1 5a, and an induction heating device 13 tliat reheats the rough-rolled
I
material 5a. Th hot-rolling line 10 includes a finishing rolling ~ilill 15 that + rolls the
rough-rolled matelial 5a atitl manofactures a hot-rolled steel plate haying a given tliickness,
l
a cooling bed 20 /that cools a hot-rolled steel plate 5 having been subjected to finislhg rolling to a given Ie tiiperature, and a coiler 18 that coils tlie cooled hot-rolled steel plate 5.
Here, Ps shown in FIG. 2, tlie cooling bed 20 includes a plurality of table rolls 21, 21 disposed a\ intervals in a plate passing direction F of tlie liot~rolleds teel plate 5, an
I. upper cooli~lgd e$;ce 22 wliicli cools the upper surface of tlie hot-rdlled steel plate 5 to be
co~iveyed,a nd a loI wcr cooling device 25 wliicli is disposed betweeh tlie table rolls 21, 21
I . 10 and cools the lowel surface of the hot-rolled steel plate 5 to be conveyed. The hot-rolled
I
plate passing guide 30 according to the present embodiment is placed in tlie plate passing
direction F betwedo the table rolls 21,21.
100331 I Tlie upper cooling device 22 includes a water supply line 23 from wliicli
I
15 cooling water is st i pplied, and a laminar ~lozzle2 4 wliicli is connected to tlie water supply line 23 and supplies the cooling water toward tlie upper surface of the hot-rolled steel plate
I
5 to be conveyed. I LO0341 I
As sli4 w n in FIG. 2 and FIG. 3, tlie lower cooling device 25 includes a water 20 supply line 26 fro/ I 1 whicll cooling water is supplied, and a plurality of cooling nozzles 27
disposed on the whter supply line 26. As shown in FIG. 3, the water supply line 26 of the
I
lower cooling dekice 25 is provided so as to extend in a plate-width direction of tlie
I a hot-rolled steel pl te 5 to be conveyed, and tlie plurality of cooling iiozzles 27 are provided
I
so as to be arrang tlie plate-width direction of the hot-rolled steel plate 5.
25 100351
Tlie hdt-rolled plate passing guide 30 is disposed between tlie table rolls 21,21,
wliich are adjacent to each other in the plate passing direction F, in order to prevent an of the hot-rolled st eel plate 5 rolled by the finishing rolling mill 15 fro111 falling in beatnw eereidn
tlie table rolls 21, i21. In the present embodiment, the hot-rolled plate passing guide 30 is
made of a material softer than the hot-rolled steel plate 5, to be specific, the hot-rolled plate
5 passing guide 30Ii s made of a resin. By forming tlie hot-rolled plate passing guide 30 with a liiaterial s fter than the hot-rolled steel plate 5, scratches can be sl~ppressecfir o111 0 ; 1
being generated o the hot-rolled steel plate 5 even in the case wlikre the hot-rolled steel
1 i
plate 5 comes into contact with the hot-rolled plate passing guide 30.
[0036]
10 'Ib be 1 specific, in order not to generate scratches that, influerice the quality of
the hot-rolled steel plate 5, such as a scrape, the hot-rolled plate passing guide 30 is tnade
of a material softdr than the hot-rolled steel plate 5 For exaliiplej the degree of hardness (Vickers l~ardnesIs;o 'f p lain steel is about 125 Hv. Since the scratclies are likely to be
generated on tlie :hot-rolled steel plate 5 in the case where the plain steel is used, it is
15 desirable that the liardness of the hot-rolled plate passing guide 30 be less than or equal to
125 Hv On the b tlier hand, Sro~n a viewpoillt of durability of the hof-rolled plate passing
I
guide 30, it is desirable that tlle hot-rolled plate passing guide 30 ha've a saff~cienht ardness
so as not to be wo1l.n away even if the hot-rolled plate passing guide 30 comes into coiitact with the hot-rolled steel plate 5. For example, it is desirable tliat the hot-rolled plate
20 passing guide 30 1-
[0037]
ave a hardness more than or equal to 36 Hv. I
As sli w ~iin FIG. 2, the hot-rolled plate passing guide 30 is placed such that the
upper surface of 1 t,ie hot-rolled plate passing guide 30 is at a position one step lower than the uppermost po Ji tioh of a table roll 21. Furtlier, as show~iln FIGi . 3, the hot-rolled plate
25 passing guide 30 ?s placed in the center part of each of roll widths of the table rolls 21, and
is compatible wi\h hot-rolled steel plates 5 having different plate widths. Here, it is
preferred that the idth of the hot-rolled plate passing guide 30 in the plate-width direction
direction of the table roll 21) be less than or equal to 11alf the roll width
of the table roll . In this way, the portion in which the hot-rolled plate passing guide 30
is placed in en the table rolls 21, 21, wliicli are adjacent to each other in the plate
I
5 passing direction is set to be small, wl~iclnl lakes it more difficult for the coolillg water F I to remain in between the hot-rolled steel plate 5 and the hot-rolled plate passing guide 30.
[0038]
I
As s11Qwn in FIG. 3 and FIG. 4, the hot-rolled plate.passing guide 30 has a
nozzle hole 31 at a position corresponding to the position of the cooling nozzle 27 of the
10 lower cooling device 25. As shown in FIG. 4, three nozzle lioles 3 1 are disposed on the I . hot-rolled plate passlng guide 30 according to the present embodiment, such that the nozzle
area ratio Sh bein a ratio of opening areas of the nozzle holes 3 1 and the drainage liole 32
Iioles 31 are arrai ge d in the plate-width direction of the hot-rolled steel plate 5 to be conveyed. Furtliel; a drainage hole 32 is provided between the nozzle holes 31, 31. As
shown in FIG. 3 a 1 id FIG. 4, in the present embodiment, the drainag hole 32 extends in the 1
k I
15 plate passing dire tion F in which the hot-rolled steel plate 5 is coiiveyed. The drainage
hole 32 is placed between the nozzle holes 31 which are adjacent to each other in the
plate-width direction, and has an extended part 34 which is a first hole part that extends in
the plate passing c 1 irection F of the hot-rolled steel plate 5, and a wibe hole part 33 which is
a second hole par I that is formed at each of both end parts of the kxtended part 34 in the
20 plate passing dire tion F of the drainage hole 32 and in which an opening area is expanded 1 in the plate-width direction.
[0039]
In addition, in the hot-rolled plate passing guide 30 according to the present
embodiment, seen fioni above in the vertical direction, the opening area ratio Sh is
25 set to be in a of more than or equal to 0.13 and less than or equal to 0.18, the opening
to an area of the $hole upper surface of the hot-rolled plate passing guide 30. Note that
the shape of the drainage hole 32 and tlie opening area ratio SIi will be described in detail
5
I
[I-2.P rocedure of nianufacturing hot-rolled steel plate using hot-rolling line]
Next,
hot-rolling line 10
the heating furliaLe 11, is conveyed from an ellt~yp ort to an exit port, and is heated
a procedure of nianufachiring the hot-rolled steel plate 5 using the
will be described. As shown in FIG. 1, first, tlie slab 1 is charged into
(heating process).
rolling process).
[0041]
Next,
The heated slab 1 is charged into the roughing inill 12. The roughing
:he rough-rolled inaterial 5a is charged into tlie i~~ductiohrei ating device
13, and is relieaded (reheating process). Then, tlie rough-rolled material 5a that has
15 passed tlxough tli 1 induction lieating device 13 is supplied to the finisl~ingro lling mill 15.
I. . \ Tlie finishing mll~ng1 n11l 15 performs finishing rolling, and man(1factures tlie hot-rolled I . . steel plate 5 having a glveu thickness (finishing rolling process). 1
[0042]
In tlie cooling bed 20, tlie hot-rolled steel plate 5 rolled in the finishing rolling 20 mill 15 is convey1 d in tlie plate passing direction F by the table roll 21, and is also cooled
to a given ternpel'ature by the upper cooling device 22 and the lower cooling device 25
10 mill 12 perfolmsl rough rolling, and inanufactures the rough-rolled material 5a (rough
I
(cooling process). Then, tlie hot-rolled steel plate 5 cooled to tlie given temperature is
coiled by the coilor 18 (coiling process). [0043] I
i
'~
25 <2. H t-rolled plate passing guide> 'I , I
I11 order that tlie hot-mlled plate passing glide 30 ac~olding to the present
! !
! 1
embodiment enhances tlie cooling water-draining performance and tlie strength, the wide
I
liole pan 33 of tlij drainage hole 32 in tlie plate-width direction is expa~idedS O as to have a
I
larger width than {lie width of the extended part 34, so that more collided flows are ejected
by tlie drainage hole 32.
5 [0044]
First, bitti reference to FIG. 5, there will be described a state of lower
surface-cooling iti the coolitig process in which the cooling bed 20 cools tlie hot-lulletl
steel plate 5. FI 5 is a diagram seen from the front side in the plate passing direction F
!
of the hot-rolled sieel plate 5 taken along the cutting line 1-1 of FIG. 4. 111 tlie cooling bed
1 I
10 20, cooling water 'W is jetted fro111 tlie cooling nozzles 27 inserted through the nozzle holes
3 1 of tlie hot-rolled plate passing guide 30 to the lower surface of the hot-rolled steel plate
1
5. The cooling W collided with the lower surface of tlie hot-rolled steel plate 5
spreads radially iI i the space between the upper surface of the hot-rolled plate passing guide 30 and tlie owes surface of the hot-rolled steel plate 5. Then, the flows of cooling
15 water W from the cooling riozzles 27,27 inserted tl~ougltih e adjacent nozzle holes 31, 3 1,
I
respectively, colli e with each other in the space between the adjacent nozzle holes 3 1, 3 1. + Most of the cooli g water W collided with the lower surface of the hot-rolled steel plate 5
I
behaves like this. 1 I
[0045]
20 As de cribed above, the hot-rolled plate passing guide 30 accordit~g to tlie
present emboditn t t it~cludesth e plurality of nozzle holes 31 each provided at a position
I
corresponding to hie cooling nozzle 27 disposed between the table rolls 21, 21, and the
I
drainage hole 32 ornied between the nozzle holes 31, 31 which are adjacent to each other i I in the plate-width direction. The drainage hole 32 is placed in a region in wlucli the flows
25 of cooling water 4 are collided with each other, tlie flows of cooling water W being jetted
I
from the cooling ozzles 27 through the nozzle holes 31, 31 which are adjacent to each
other in the plate-width direction, I11 this way, ejection of the cooling water W is
accelerated. i
[0046] I
In mod.e detail, as shown in FIG. 4, the drainage hole 32 is placed between the
5 nozzle holes 31 which are adjacent to each other in the plate-width direction, and is formed
of the extended part 34 that extends in the plate passing direction F of the hot-rolled steel
plate 5, and the w de 11ole part 33 that is fonned at each of both end parts of the extended
part 34 and in wh 1' ch an opening area'is expanded in the plate-widt 1 direction. When the
amouats of ejection of the flows of cooling water W jetted from the respective 10 nozzles 27, 27 ar1 s ubstantially the same, the flows of cooling water Wr,e swpheiccthiv ea rceo jeotltiendg
from the respecti e cooling nozzles 27, 27 and spread radially, collide wit11 each other
linearly along the
the space in w11ic:h
extended part 34
plate passing direction F between the adjacent nozzle holes 31, 3 1. In
!
the flows of cooling water W collide with each other linearly, the
of the drainage hole 32 is placed. Further, the cooling water W flows to
15 a downstream sid in the plate passing direction F with the passing of the hot-rolled steel T i plate 5. The wide hole part 33 is formed at the dow~lstream side in the plate passing
!
direction F in which the cooling water W accompanying the passing of the hot-rolled steel I plate 5 flows.
[0047]
20 Accor iingly, the flows of cooling water W collided ;it11 each other on the
: I
extended part 34 re rapidly ejected toward the lower side of the dot-rolled plate passing I I
guide 30 through the drainage hole 32. Further, althot~ghc ollided flows of some of the
cooling water, wl ich has not been ejected from the extended part 34, flow in the plate
passing direction
25 effectively ejected
30 is formed
F in a manner to escape fro111 the extended part 34, the collided flows are
from the wide hole part 33. That is, the hot-rolled plate passing guide
suc11,that the cooling water W is not remained on the upper sltrface of the
I . . Iiot-rolled plate passlng gu~de3 0. Note tliat, in the drainage liole 32, the wide liole part
33 is also formed gt ao upstrean1 side in tlie plate passi~~dgir ection F Tlie wide liole part
I
33 at the upstreaiii side in the plate passing directioli F is also u~sefi~fol r ejecting the
the strengtli of tlik part at which the wide hole part 33 is forliled in the hot-rolled plate
cooli~igw ater W bowing accompa~iyiligth e rotation of the table roll 21, the table roll 21
5 being placed at t11 upstream side in the plate passing direction F and being one of the table I i rolls 21,21 over liicli the liot-rolled plate passi~lgg uide 30 is placed.
[004S]
Here, the drainage hole 32 is preferably fornied such tliat a width W1 of the
passing guide 30 decreases. Accordingly, the width W1 of the wide hole part 33 is
wide hole pait 33
10 plate-width direct
(1). Here, thew
preferably up to 1 70 tinies the widtli W2 of the extended part 34. . 1
in the plate-width direction and a width W2 of tlie extended part 34 in
.on satisfy tlie following relatioliship shown in t~ikfo llowing Expression
dth W1 and the widtli W2 represent maxitllum {idtlis in the plate-width
[0051] I 25 Note t iat, although it is more preferred that the lellgtli L of the drainage hole 32
in tlie plate passiqIg direction F be largel; there may be a case wliere it is difficult to open
direction of the w%deh ole part 33 and the extended part 34, respectibely. I '
[0049]
~' 1.00< 1/W251.70 (1)
15 [0050]
As de cribed above, since tlie collided flows on tlie extended part 34 flow in
the plate passing irection F, the cooling water that is not ejected froni the extended part 34
can be effectively ejected by allowing tlie widtli W1 of the wide llole part 33 that is formed I at each of both end parts of the extended part 34 to be larger than the width W2 of tlie
20 extended part 34.
; 8
8 1 On the other hand, if tlie widtli W1 of tlie wide liole part 33 is too large,
embodiment, loca temperature decrease in the hot-rolled steel plate 5 can be suppressed,
and the te1nperatu.e i variation of the hot-rolled steel plate 5 in the longitodinal direction can
of the hot-rolled plate passing guide 30 and the
table rolls 21, 21. The lengtll~of tlie drainage hole
32 is taking those into consideration.
5 [0052]
passing guide 30 according to tlie present etnbodiment is
above in tlie vertical direction, the opening area ratio Sh
25 be suppressed.
is set to be more
areas of tlie nozzle
10 of the hot-rolled
han or eclual to 0.13, the opening area ratio Sh &ing a ratio of opening
holes 3 1 and tlie drainage hole 32 to an area of t'lie whole upper surface
I'
date passing guide 30. In this way, tlie opening area can be enstired,
which can eject from the drainage hole 32 the cooling water W that is present
plate passing guide 30 and the lower surfaek of tlie hot-rolled steel I . plate 5, and tlie eoolnig water W can be suppressed from being rerriained on the hot-rolled
plate passing guide 30.
15 [0053]
including coolirlg the hot-roiled steel plate 5 on tlie
the liot-rolled steel plate' 5 until an end of tlie
I !
coiler 18. ~ccordinglyi,n the hot-rolled steel
plate 5 that has bken wo~lnd up and down greatly, a part that is convex downward conies
20 close to or into contact with the hot-rolled plate passing guide 30. However, since tlie
cooling water W suppressed fioni being remained on the hot-rolled plate passing guide
30 owing to the of the hot-rolled plate passing guide 30 according to the present
Furtl
embodiment is
opening area rati
a ratio of openir
whole upper sur
increase the ope
ejection eficienc
durability of tlte
area ratio Sh to
guide 30 with t
hot-rolled plate
guide 30 can be
life.
[0055]
<3. S
Here
structure and op
embodiment.
embodiment, tlic
passing directior
extended part 3
direction. Accc
the collided flov
are ejected from
which the flows
to each other in 1
the hot-rolled plate passing guide 30 according to tlie present
ned such that, wlieil seen fiorn above in the vertical direction, tlte
11 is set to be less than or equal to 0.18, the opening area ratio Sh being
reas of the nozzle holes 3 1 and the drainage hole 32 to an area or the
: of the hot-rolled plate passing guide 30, Altliottgli it is preferred to
3 area of the hot-rolled plate passing guide 30 in order to enhance tlte
f the cooling water W, an excessively large opening area influences tlle
t-rolled plate passing guide 30. Accordingly, by setting the opening
than or equal to 0.18, tlie contact area of tlie hot-rolled plate passing
hot-rolled steel plate 5 that comes close to o;. into contact with the
sing guide 30 is ensured. In this way, tlie hot-rolled plate passing
)pressed fro111 being worn away at an early stage and can increase the
i maty> I
;
i
Ire, there ltave been described an overview of the hot-rolling line and a
:ion of the hot-rolled plate passing guide 30 according to the present
the hot-rolled plate passing guide 30 according to the present
ainage hole 32 i~lcludesth e exterided part 34 .that extends in the plate
and the wide hole part 33 that is formed at each of both end parts of the
1 tlte plate passing direction F and is expanded in the plate-width
ngly, an opening area of the drainage hole 32 can be ensured, such that
f the cooling water W jetted through the adjacknt ilozzle holes 3 I, 3 1
extended part 34, the extended part 34 being formed in tlle region in
:ooling water W jetted tlxough the nozzle ltoles 3 1,3 1 that are adjacent
plate-width direction collide with each otlier, and hence, ejection of the
passing guide is hisposed on the cooling bed of tlie hot-rolling line having the structure
I
cooli~igw ater W
[0056]
I
can be fi~rtliera ccelerated. I I
In add tion, since tlie hot-rolled plate passing guide 30 according to the present
embodiment is m I de of a resin, wluch is a material softer than the liot-rolled steel plate 5,
5 scratches can be s I~ ppressedf iom being generated on the hot-rolled steel plate 5 even in tlie 1, case where the hot-rolled steel plate 5 comes into coritact with the hot-rolled plate passing
guide 30. Pllrtli~re, ven ill tlie case where the hot-rolled plate passing guide 30 is ~naileo f
a soft material, since tlie opening area ratio Sli is set to less than or equal to 0.18 as
described above, lie hot-rolled plate passing guide 30 can be suppressed from being worn \ 10 away at an early tage. In addition, tlie hot-rolled plate passing guide 30 is placed at a S center part each of roll widths of tlie table rolls, and a width of the hot-rolled plate passing 1 guide 30 is set to ess than or equal to half tlie roll widtli of the table roll 21. By allowi~lg
: i
tlie installation aria of the hot-mlled plate passing guide 30 to be small in this way, the cooling water W i etted onto the lower surface of the hot-rolled ste; ei l plate 5 can be more
15 easily ejected.
LO0571
In tlie
:I
st~~~ctduerscer ibed above, tlie cooling water jetted onto the lower surface
of the hot-rolled steel plate 5 is effectively ejected from over tlie hot-rolled plate passing
I
guide 30, and tbs, tlie temperature variation of tlie hot-rolled steel plate 5 in the
I. 20 longitudinal direct~onc an be suppressed and tlie wear at an early stage can be suppressed.
[OOSS]
Heretofore, tlie hot-rolled plate passing guide accbrding to the present I . . described, but the present invention is npt l~ni~lecthle reto, and
may be made without departing frhm the spirit and scope
example, it has been described that the hot-rollecf plate
sliowa in FIG. 1, 40s example, but tile liot-rolled plate passing guide is not limited thereto, I . and may be the oye d~sposedo n a hot-rolling line having aiiotlier stri~ctt~lre.
[00591
Furtliel;
~
the nu~libera nd the shapes of the nozzle holes and tlie number and tlie
5 shapes of the drainage hole are not limited to those shown in the figures in the embodiment,
and may be chan 1 ed as appropriate. In addition, it has been described that the liot-rolled
I . ! plate passing guide IS made of a resin, but the niaterial for forniing tlie hot-rolled plate
passing guide is 11 t l~mitedth ereto, and may be another material.
[0060] 1.' 10 For e ample, as a hot-rolled plate passing guide 30A slioomi in FIG. 6, an
upstream side an8 a downstream side in tlie plate passing direction bf a drainage liole may
I 'I
have different s h a k . Cotnpariag tlie liot-rolled plate passing guide 30A sbown in FIG. 6
j
with the hot-rolled plate passing gnide 30 shown in FIG. 4, a shapeof a drainage hole 32A
is different fiom t 1 ie shape of the drainage hole 32. Tlie drainage hole 32A shown in FIG.
15 6 i~icludesa wide
hole part 33b at the
hole part 33a at the upstream side in the plate passing direction, a wide
downstream side in the plate passing direction, and an extended part 34
!
wliicli is formed between nozzle holes 3 1A and connects the wide hole part 33a to the wide
liole part 33b. Iso in this case, it is preferred iliat tlie drainage hole 12 be formed sucli
that tlie a widtli 4, 1 of the wide hole paits 33a and 3313 in the plate-width direction and a 20 widtli W2 of theI e xtended part 34 in tlie plate-width direction satisfy the relationsliip
sliown in the abo e Expression (1).
[0061]
I
It is c nsidered tliat, as for tlie collided flows of sotiie of the cooling water, P wl~ichh as not bee 1 ejected fioni the extended part 34, the amount of flows that flow to the I i
25 down st re an^ side in the plate passing direction with tlie passing of the hot-rolled steel plate
is larger than the amount of flows that flow to tlle upstream siAe in the plate passing
direction. ~ c c o r ' d i ~til~iel c~o,o ling water can be ejected more effectively by allowing the
I
wide hole part 33$ at the downstream side in the plate passing direction to be longer in the
plate passing direition tlian the wide hole part 33a at the upstreanl side in the plate passing
I
direction. I
5 [Example 11 1
100621
Hereir after, in order to check effects of the hot-rolled plate passing guide
according to the resent i~lventioa, results of experiments that whe carried out will be b
described. In E$ample 1, the temperature variation of the hot-rolled steel plate in the
11
10 longitudinal direc ion was checked. As Exanlples of the present ,invention, as shown in
I
FIG. 4, the hot-r plate passing guide 30 was used in which the drainage hole 32
extending in the passing direction is fo~med between the nozzle holes 31 that are
adjacent to each in the plate-width 'direction. Further, as Comparative Examples, a
hot-rolled plate guide (Comparative Exa~nple1 ) with no drainage hole show~iln
15 FIG. 4 was used. I
[0063]
plate passing guide described above wBs placed between the
bed, cdoling of the hot-rolled steel plaie was carried out, and
dispersion in tem?eratnres of regions 50 meters away fiom of the hot-rolled steel '
20 plates that passed cooling bed was measured. The temperature of the hot-rolled steel
plate was measur a single color tliernlo~neter at a center part of the plate width
guide is disposed and at a 113 position of tlie plate width
!
fiorn the width el hot-rolled plate passing guide is not disposed. Using
the measured variation range E iilfluenced by the hot-rolled
25 plate passing expression.
(temperature varidtion range at 113 position)
I
the teniperatt~re Jariation range E influenced by the hot-rolled plate passing guide was I
[0064]
In the
I
case of using a hot-rolled plate passing guide of Conventional Example,
5 10.3"C. In contliast, in tlie case where a hot-rolled plate passing guide according to exatilple of tlie pr ts ent invention was used, the temperatnre variation range E influencetod bayn
tlie hot-rolled plate passing guide was 5.S°C. It was confirmed that the teniperature
I i!
variation of tlie got-rolled steel plate in tlie longitudinal directioll! call be suppressed by I !I
using tlie hot-rolled plate passing guide according to an example of the present invention.
10 [Exaniple 21
[0065]
In Example 2, experiments were carried out on the drainage perfolmance of tlie 1 : . Iiot-rolled plate passtng gulde when the ratio (WllW2) of tlie width of the wide hole part of
the drainage liole to the width of the extended part of tlie drainage hole and tlie opening
of tlie present invention, as shown in FIG. 4, ~
was used in which the drainahe liole 32 extending in between tlie nozzle holes 3 1 t Il at are adjacent to each
Further, as Conlparative Examples, the hot-rolled plate
7 which had the drainage hole with no wide liole part
20 was used. I
i
[0066] i
drainage perfornlance and tlie di~iabilito~f each of tlie
of Exanlples and Coniparative Examples were checked, by
using a testing which is a siniulation of the hot-rollitig line 10 as shown in FIG. 2.
1 ,
25 The following shows the results thereof. Here, the drainage performance was
evaluated by an arnount of ejection of cooling water per unit time. The
Note that the wader' anlount density of the cooling nozzle 27 was set to 0.52m3/m2~min.
1
drainage perfonliance
Further, the durab lity was evaluated by llleasrlring the wear atnoutlt of the I hot-rolled plate
evaluation was carried out on the basis of the following Table 2.
passing guide month. The, durability evaluation was carried out on the basis of the
i
Exaninle (6'1)
[~ablel2]
I peDrfroaminlaa"ene c e I +I mount of ejection [Lls] I
evaluation
0.4 to 0.7
I I Durability I Monthly wear amount I
I evaluation I 1 [1&111ontli]
I
As sl
as can be seen fr
found that the dl
opening area of
Nos. 10 and 11,
drainage perforn
the drainage holt
[0071]
Furtlequal
to 0.13 an
wide hole pait o
was less than 1
because the wid1
Further, as can b
part of the drain
than 1.70, an ex
extended part a1
portion and the r
[0072]
On tl
Sh was more tha
the widtl~o f the
More than 1.2 or
vn in Table 1, in the case where the opening Sh was changed,
I Nos.1 and 2, when the opening area ratio Sh was less than 0.13, it was
bility was good but the drainage performance deteriorated, because the
drainage hole was too small. On the other hand, as can be seen from
[en the opening area ratio Sh was more than 0.18, it was found that the
ce was good but the durability deteriorated, because the opening area of
as too large. I
I
I
I even in the case where the opening area rati Sh was more than or 1 ess than or equal to 0.18, when the ratio (WllW2) of the width of the
le drainage hole to the width of the extended pait of the drainage hole
as can be seen from No. 3, the drainage performance deteriorated,
,f the wide hole part was smaller than the width of the extended part.
een from No. 4, when the ratio (WllW2) of the,widtll of the wide hole
: hole to the width of the extended part of the drainage hole was more
;sive load was applied to a neck portion, which is a boundary of the
the wide hole part. Accordingly, a crack was generated in the neck