Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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~0~197
FllE~ 0~ llIE INV~3NTIC)N
The prescnt invention relates lo an internally cooled roll wherein ~he core is co~nposed
Of ~ ul~ up~x:r or a wpper alloy so as [o Incre~se heal
conducti~rity between a bar and the surf~ce of a roll.
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)'7
BA~C~KGRO~ OF ~lE INYEN'I'ION
The present invcntion relales to an int~rnally cooled roll, of lhe ~ype usec-i in a
continuolls c~9ting plant, such as supyort and guide ~ollers, havin~ 2~ shell which surrounds ~nd
is attached to ~ ~or~ ~f ilon material.
]t has been a ~oal in continuous castin~, in additiQn to increasing the casting rate,
to dispense with se~ondary eoolillg by spray water of ~n emerging bar, as well as all the inherent
disatlvMta~es tl1erein (i.e., ~ge cracks). One proposal along these lines is referenced in paîent
1~ 20 972 from the Pederal Republic of ~erm~ny. The patent relates to a device for the indirect
coolin~ of an emergin~ bar frorn ~ continuous castillg Inold~ e bar is cooled an(l guidecl vla
resiliently appl;eci coolant-wettecl sli~ie shoes and ~uide rolls. Tlle slid~ shoes and g~lide rolls
are ar~anged alte~lately one behind lh~ other in the directiQIl of cas~ . Tb~ obJect Or tlle guide
rolls ig tQ level the surface of lhe bar after passage throug~h ~he zones h~v;ng slide shoes.
}lowever, the derormation of the outsid~ of lhe bar, wh;ch is inherent thereill, leads tP
segregations and internal cracks upon the casting of sla~ sections~
From yel anolher paten~, namely patellt 3~ 31 433 C2 from the Pederal Republic
of Germany, an internally cooled support and/or pinch roll is disclosed. The pinch roll consists
of A stcel core Md a jacket of sleel ~hich surrounds the core and which ig attached to il. On
the surf~ce of the corc there is provided a cool~nl ch~lnel which i9 connected wilh coolant
cvnnections conta~lled ill journals of lhe core. The jacket is weld~ to the arms of lhe core
which remains between the coolant channels over the cntire length of lheir mu~ual contac~
~urhcc. ~hc wclding of thc j~c};ct and the corc t~ cach olhc:r ovcr their entire surfac~ ~f conlacl
N~ 45-93.~T
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4~'78~.
reslllts in a roll o~ st~ble shape. As a result, Ihe roll diameter ~nd ~he distance between ~he
individunl rolls when pl~c~t one behind the oliler can be simul~aneously ~ ced. Moreover,
kul~ing of the bar c~ also b~ redllcecl. :Howevcr, w;th tllc re~luclion in th~ di~m~.~er, the.
useable heat exchan~e surf.tce of the roll which is in linear contact wilh t1~e bnr i9 also redu~¢d,
Ulldc~ these circumst~nces an~ in eombinatioll with the poor ile~t collductlvity of the sleel jackcl,
dispensing with secondary coolin~ requires a reduction ;n ~he casting rate,
~ urthermol~e, since t~le roll~ are sul~jected to a large amount of wear by ~he bar,
rega~dless of whether the bar is pllllecl ~elween the rolls or is conveyecl by driven rolls, it has
beell attempt~d ~o use materials ~or the shell of the rolls whicll ~re as resis~t to wear as
possible, Prlor arl, n~tnely Stahl an~l ~isen, ~ (8~ o~ 22, ~a~e 117~ sllows tllat, f~r
exan~ple, 21 Cr Mo V S l l was ~onsidered a par~lculMly advan~a~eous material for lhc corc of
con~int~ous ~sling rolls whi~e stccl with a 12 ~o 15% chromium ~onlent was COllSiti~l`ed
particularly advantng~ous for use as a wcar t~nd corrosion resist~nt coaîinX for the rolls~
N:3245.5~3.PAT -3-
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g'7~3L
SU~E~Y OF ~IE INVlE~TON
An object of the present invention is to provide a dimensioll~lly stable roll with
internal cooling and high heat conductivity which, a~ the same lilne, is of simple construcliol~.
This object is achieved in the case of an inlernally cooled roll in an extr~Jsion
casting plant by producing a shell compose~ of a n~e~al comprising of copper or copper alloys.
In accordance with the in-~ention, the us¢ of copper of coppcr alloys for the shell
as a heat-exch~n~e wall be~ween coolant and bar resul~s in a roll having high heat con~uctivity.
Due to the high heat conductivity of the copper shell, the heat to bc 1~1 away from the bar is
dislributed over the circumference of the shell, The r;ldial ~emperalllr~ proflle in lhe sllell is
more uniform Rnd, there~ore, the thermal cxpansion stresses and thus th~ heat alternatin~ stresses
per revolutlon are slight as comp.lred with a shell uf steel uf ~ow therlnal c onductivity~ As a
res~lll of less thermal stress, the roll, despite pc>orer s~ren~th v~}ues of thc shell, is dlmensionally
stable~ Accordlngly, the bar is not subjected to any detrimental deformation by eccentrically
rotatin~ roller~ as a result of ~lis~ortion occurring during opera~ion. Furthermore, due lo lhe
dimensional stability, the roll can be n~ade witll a relatively small dia(ncter. ~s a result of the
small diameter, a r~lction in the spacing Qf the rolls one behind the other in the diroction of
travel ~f the bar is possible, so as ~o oplimi~e lhe gllidance Or ~he ~ar. Allhough Ihe heal
exchange surf~ce ~etween the roll and the bar is reduced by lhe ~educlion in ~he diame~er,
secondary cooling can be dispensed wilh, wish lhe roll Or lhe presen~ invenLion, even in the case
of slab sections, as a result of the hi~h thermal cond~lctivi~y of the shell which consists of c~pper
or a copper alloy. I~olls, in accord~nce with paten~ 32 31 433 C2 ~rom the Federal Republic
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of C;erlllany previously menlioned, have a solidincalion Çac~or of about 24.6 mm/millS WittlUUt
sp~y water and 26.4 mm/minU5 with spray water In compar~son, Witll the roll of the present
inven~ion, these values are incre~ased to at least 26.0 mrm/mill~S without spray ~vater and to
28.0mm/min~ 5 wilh spr~y w~ter. ~ue ~o ~he po~sibili~y of hi&her castin~ speuls, an incrc519c
in lhe capacil~ of the plant are realized.
Furthermore, because of its high thermal conductivity, a roll in accordance with
the present lnvention does not become as st~ongly heated as rolls having a steel shel~ This leads
to a reduction in the susceptibility to heat cracks, an increase in the resistancc to wear, and a
reaiuctioll in the dan~er o.f melting the ~oll shell togethel with molten mate~al in the event of
bar l)reak-out. Purthermo~e, ~le roll i~ part3cll1a~1y t^eslst~n~ lo corroslon, especi~lly ill the
region of the foot roll and jn an oven directly acljacent to support an(l &uide rolls, where
corro~lve casling slags h~ combin~ion with spray wa~er ~re present~
The n~t~chment between the core and the ~acket whieh Is cicveloped as a snug ~It,
for e~atnple~ particularly~ as a shrtnk attachment, represents a slrucluraily simple solution. In
addition, there is the addcd advant~e that liftin~ of the sllell from the care due to thelltlal
expansion during ope~tion does n~t take place in view of the hi~h ~hermal conductivity of the
shell. In thls manner, a means for dependably gui~lin~ c coolant in the ch~nnels without
leakage is obtained. Furlhermore, th~ shell/core connectioll makes it p~ssible ~o at~ach ~he she]l
to lhe core o~lly at one edge, such as by a wGld connection. It is, of ~ou~e, AISO possible to
weld the shell to the core on bot~l edges~
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F I~ESCRIlPT~C:)N OF TlIE D~AYVING
The invention will be explnined below wi~h refi~rence to ~he drawing, in wllich
FIG. I s~ows a lol~gitudin~l ~w~ion ~hrou~h ~ roll wi~h a helical cool~nt cllannel.
N:3245-9~.PAT -6-
;S I ~ I 2 ~, 2 5 413 ~ C l:l H E II P Q II T I~
i78~1.
I)ETAILED DESCR~PrION
OF TI~E P~I3NTLY rI~EFEI~lED E~C);~)II\~ENT
The roll as s71own in Fla. I consisl~s essenti~ily of æ. c~re I of iron ma~erial and
a shell ~ of a copp~r or coppcr alloy surroundin~ Ille co~c 1. Tlle shell 2 is connccted wilh lhc
core 1 by a snug fit, such as a shrink att~chment. ~urthermore, the shell 2 is fastened to the
core I at le~st at one ecige ~ by a wcld connec~ion 4. Of coursel other nlanners of attachment
are possible, I`or instanee via screweci stops. A sin~le or multiple thread or flighted coolant
~hannel S in the form of i~ llelical grooYe in ~he longitudln~ ion 1, of thc core I is ~vorke~l
inlo ~he~ sur~ace of thc core 1. The ~ool~u~t ~hannel 5 is covered by the cylintiric~ll shell 2.
Within the re~ion of the eclges ~3 of thG shell 2, th~ cOOl~llt channel 5 is connect~i to Coo].~lt
connections 7 by a .radially extendillg holcs ~ The coolant conneclions 7 ar~ arr~nged
con~enlnca11y in the core 1 nnd adjoining journals 8. The diamelef of the roll is desi~nated ~
and is within the range of abo~lt 80 - 400mm. Thc wa.ll thickn~ss of the shell d is at le~st aboul
5mm and increases up to about 7ûmm in lhe case of rolls of lar~e diarneter.
Thc ;n~ention has ~een described, with ref~rence to a roll having a helic~l coolant
channel but it can ~Iso be used in rolls having other configurations ior the coolant chanllels (for
inst~lce, radially ~r axially extending channels, channels formed aS grooves in the shell, or
worked partiaily in the shell and partially in the co~.)
It should be understood that the prererre~i embodin~ent considcred is for illustrative
purposes only and is not ~o be constmed as limi~ing ~he scope of tile pres~nt in~ention which Is
properly delineated only in the appended claims.
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