Note: Descriptions are shown in the official language in which they were submitted.
10~9173
Specification
This invention is for an improvement in the method and
apparatus disclosed in my application ftled in Canada on March 1,
1974 as Serial No. 193,859, and which issued as Canadian Patent
No. 1,015,107 on August 9, 1977.
In the usual process of casting molten metal, and
pa~ticularly steel for the production of solid sections to be ;
subsequently converted into finished products, as, for example,
the process of continuous casting, the molten metal is charged -~
into an open-ended mold where the molten metal entering the mold
next to the cold mold walls solidifies to a skin which at first ~;
rapidly thickens as initial solidification continues. However, ~-
the rate of solidification progressively decreases as the
solidification toward the center of the casting increases. The
solidification time, "T`', of a billet, whether it be round, -
square or rectangular, is usually expressed by the formula
T = kD2 where k is a factor depending on cooling conditions and
D is the diameter or thickness from one surface to the other and
can be roughly approximated as proportional to the square of the -~
diameter or thic~ness.
It is, of course, well known that when molten metal, ~ ;
particularly steel, solidifies rapidly, the casting has a fine
grain structure while the quick solidification prevents or ~~-
minimizes segregation of some elements, as, for example, alloying ~ --
: . .,
elements in steel, but slower solidification leads to larger or
coarser and less desirable grain structure with accompanying
rejection by the crystals as they form of some of the alloying
. ;~ . ' '' '~
~ 30 ~ ~
d
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8~173
elements, as well a~ "i~puritie~," (~hlch, in the ca~e o~ steel
~ay include S, P, AS, ZN, SN, etc.) and thelr resulting concen-
tration in the area o~ the casting la~t to ~olidify. As a ~ -
re~ult, the outer portion o~ the casting, o~ten reierred to a~
"the chill zone layer" i8 superior from the ~tandpoint o~ its
~ine graln stru¢ture, and also because it moYt nearly corresponds -~
to the composition of the ~elt fro~ which it ~as produced. To
more nearly approach a uniformity of sectlon across a con-
ventionally cast ingot, irom either a mold or contlnuous casting,
heat-treating, rolling and forging operation~ are neces~ar~ ~ ~
which would not be neces~ary if a chill zone composition and ~ -
structure prevailed across the entire section of the ingot.
In my pending application Serial No. 193,859, there is
disclosed a method wherein ~everal continuously $ormed thin
strands, or parallel portions of a single strand, are con-
tinuously brought together in face-to-face contact at a solidus
temperature desirably above a usual hot rolling temperature but
~here liquid metal i8 not visible. When light pressure less - ;
than that required for deforming the solidified metal i~ applied
to the contacting suriaces, iusing or welding occurs by inter- `
cry8talline dii~usion ~hich takos place under these conditions.
This may be referred to as "flowless ~elding" or "pressure
~elding. M
Thus, ~hen forming a billet for example o~ diameter D
according to this method of combining several individual layers
or strands, the solidiiication time, being based on the thick-
ne~s of the individual layers, is accelerated, so that the
formula, instead of being expressed as expressed above, T ~
will be approximately only T ~ K (D) , where S de8ignates the
number of layers. In pressing together a number of strands to
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1()~9173
effect welding, there 1~, at least in mo~t cases, a reductlon ln
thickness o~ the order o~ no more than about 2% so that to secure
the di~en~ion D this reduction o~ thickne~ must be taken into
consideration in determining the dimension D o~ the ~i~ished
casting. In other words, a ton o~ thln metal solidi~ying in
~eparate layer~ from a molten condition solidiiieg much more
rapidly than a ton oi metal cast as a ~ingle ca~ting into a
billet or slab o~ the dimension D.
With perhap~ t~o or three separate layers or strands ~ .-
being combined into a semi~inished product, as di~closed in my
copending application, the formation o~ each separate layer
using separate casting roll~ ~or each layer is commercially
practical, even with a ~eparate pressure roll ~ean~ ~or each
additional lay~r over two, but with perhap~ ~our, iive or even
ten or more layers being combined into a single slab or billet,
the complication and space requirement~ ~or a plant having a :~
separate ca~ting unit ~or each layer together ~ith pressure roll
pa88e8 for each layer above two layers, and the investment
involred in such a plant rapidly offsets the econo~y and ~ ~:
advantages o~ the process of my earlier application. ~ ~
The present invention involves a method of and ~: -
apparatus ior converting ~olten metal, e~pecially ~teel, into a ~` :
~inished product ~here the nolten metal is cast into thin layers -
by contacting the moving chill suriace with molten metal against
which a thinlayer o~ the metal solidi~ies, either a~ a succes-
sion o~ separate pieces or as a continuous wide flat strip that
iB cut into lengths or strip~ and these are delivered to a single
layering or stacking unit where they are brought together with a ~ :
common means for pressure welding the~ progressively as they are
placed one layer against another. There may, in come case~, be
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101~9173
optionally employed t~o casting units, but their output will be
co~pacted and one layer ~used to the next in a common pressure
~elding unit.
The graln structure and composition oi a thin layer
cast in the manner herein disclosed ls determined at the time a
chilled layer forms on a moving chill surface and the combinlng
o~ several layers into a com~on product, such as a billet or
~lab, slowing down the rate of heat trans~er from the thicker
product, is of little, i~ any, consequ~nce at this time.
In the follo~ing description, the tsrm "strand" i8
used to designate the e~erging casting, ~hether continuously or
intermittently produced on a cold sur~ace ~oving in contact
~ith a body of molten metal resulting in a solidiiied layer
~hich is thereafter stripped ~ro~ the moving cold or chill sur~
iace. It is desirably about 3 ~m thick and has the iine grain ;
structure and unii'orm compo~ition, ior all practical purpo~es,
of the melt iro~ which it i8 formed and ~hich is oiten referred
to as being of chill zone thickne~s. The term "strip" i8 used, ~;~
unle~s otherwise indicated, to designate division formed by ~-
slitting the strand longitudinally, and the terms "piece" or
"pieces" or "lengths" deslgnate individual pieces for~ed by
cutting a strand or strip cro~swise or formed in fised lengths
iD the casting unit. The output of a complete unit, ~hatever
the shape or size, is generally designated "product," "unitary
product," or "semiiini~hed product."
~ here several strands are being ~iaultaneously cast
and combi~ed as in my original application, a higher rate o~
production can be achieved than ~ith the herein di~closed
improvement, a#suming dimen~ions to be the sa~e, because ~everal
~trands are being si~ultaneously produced and co~bined into a
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1()89173
semi~inished product. However, the i~provement herein disclosed
will nevertheless result in a rate o~ conversion oi liquid metal
into a billet or slab ~aster than the same tonnage could be
secured by conventional continuous or semicontinuous casting.
Thi~ results from the exponential increase ln solidification
speed with decreased thickne~s o~ the solidiiying product.
Taking as an exa~ple, ~ 1 meter wide and 150 mm. ~ -
thick steel ~labs are belng made by iusing together 3 m~. thick
layers, this thickness will be achieved in approximately 1
second. Using a traveling belt conveyor as a chilling wall
which, over a length of 1 meter is brought in contact with
liquid steel, the belt speed can be 1 meter per Recond ~or with-
drawing said 3 mm. thick solidi~ied layer. Thi~ corresponds to
a production of approximately 1400 kg. per minute. To achieve
this ~igure by conventional continuous casting in one strand, a
rather sophisticated and axpeneive continuous casting machine
would be required, considering that it would take about 6
minutes to get the section completely solidified at a minimu~
withdrawing speed o~ 1.24 moter per minute, giving an interior ~0
liquid pool of at least 7.5 meter length. During this time the
strand has to be properly cooled and supported over this
length. On the contrary, the ~ethod according to a simple
embodiment of this invention needs a rather short traveling -~
belt or a rotating drum, a shear for cutting the layer or strand
to desired lengths a~ter leaving the belt, and means stacking -~
them one upon another along with means for pressing the stacked
length~ as they are progressively added onto the top o~ a pre~
viou~ layer or layer~. An even higher production rate would be
obtained i~ the strand as cast is kept thinner while the length
over ~hich the belt is in contact with the liquid steel i8 again
., . ~, . . .
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1~)89173
only 1 meter. Theoretically, 1 m~. thick layer would enable
a ~ithdrawal speed of apprnximately 540 meter~ per minute (due
to the exponential lncrease oi solidiflcation rate ~ith
decreased thickness) corresponding to appro~imately 4 tons per
minute. This productlvlty is hardly achlevable at continuous
casting with present casting technique~ where there would be
a liquid pool of approximately 21 meter~ at a ca~ting speed oi
approximately 3.5 ~et~rs per minute. If the width o~ the
layer or 6trand would be split longltudinally into 100 ~. ~
wide strips to be fused together into 100 m~. sq. billets, an ;-
output of the order of about 54 meter billets per ~inute would
be theoretically achieved.
One primary advantage of the invention i~ that all
oi the layers that are integrated into a single sectlon in this ;~
manner are pro~ided on a ~ingle moving chill suriace and one
body of molten metal. Hoaever, i~ desired, ~ection~ cut
alternately fron one casting unit ~ay be interleaved with
sections formed and cut irom another and also a ~ectlon formed
on ~ single casting unit may be alternately or successively -
s*acked on difierent castings being si~ultaneously iormed.
Little change-over is required in a wide machine to
simultaneously produce a plurality of narrower semifinished
castings of the same or of different widths at the ~ame time~
The invention may be more iully explained in
~ conJunctio~ ~ith the acco~panying drawings ~here certain
¦ specific embodiments Qi apparatus for and methods o~ practicing
my invention are disclo~ed and in ~hich:
Figure 1 ~ho~s schematically a longltudinal section ~-
through a casti~g plant e~bodying the apparatus and for the
practice oi the method of this invention;
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lC~1~9~73
Flgure 2 ls a top pl~n view oi Figure l;
Flgure 3 represents a transverse vertical sectlon in
the plane o~ line III-III of Figure 2;
Figure 3A i~ a ~che~atic repre~entation oi a mean~ ior
movlng the base plate in timed relatlon to the placi~g oi a
length oi metal on it or on a previously deposited length;
Figure 4 i8 a modiiication illustrating fichematically
a ~lde view of an apparatus and ~ethod whereln the wide thln
strand is slit length~ise into ~ plurality o~ strips, which are
oi selected ~idths, whlch, as here ~ho~n, are progressively
narro~er iro~ one edge o~ the cast strand toward the other edge,
but ~hich of cour~e could be of the ~ame ~idth or there ~ay be
a di~erent nwmber and the several ~trips are then ~evered -~
transversely to pieces and piled on top of one another to pro-
duce blooms or billet~, ior e~a~ple, oi preselected di~en~ion;
Figure 5 i~ a top plan view oi Figure 4;
Figure 6 is a modi~ication oi the aethod ~ho~n in
Figure~ 4 and 5 ~herein the thin cast strand i8 contlnuously
~ormed on a belt, slit longitudinally into a number of ~trip~
of equal width and bent over ~hile in such manner that the
parallel ~trip~ are superimposed one upon another and the stack
is then pressed together and the resulting contlnuous casting ~
~o produced by the interfacial ~elding or iuse-~elding oi the ; ~ ;
~uperi~po ed strips i8 then ~evered in pieces oi predeter~ined
selected length;
Figure 7 shows a ~ethod ~imilar to Figure 6 wherein
there i~ a ~eparate ca~ting and ~litting unit indicated in broken : ~ :
lines along~ide the ilrst to be used ~here a thic~er ca~tlng i~
required, the unit at the leit providing the ~irst several ~ -
strips onto which the strips produced by the unit at the right ~ -
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.. .. ~ : . ; .. :" " :, . . .
1089173
are immediately stacked, or alternately the ~trips fro~ the
unit at the r~ght could be interleaved between tbe strips from
the unit at the left. This ~igure also discloses ~everlng the
lndividual strtp~ prlor to assembly lnto a stack before,
lnstead of aiter, they have been as~embled;
Figure 8 18 a side view and Figura 9 is a top plan
view of an apparatu~ in which ~ucce~sive pieces cut from a
continuous strand are dellvered vertically onto a space between ~ :~
opposed pressure plates, one of which is lnclined from a ver~
tical plane to provide proper support ior each successlve piece
as it i3 severed at the lead end o~ the continuously cast
~trand; :~rr~
Figure 10 is a schematic illu#tration of an apparatus -~
~herein succe~sive pieces cut fro~ a contlnuou~ ~trand are ;~
delivered alternately onto a reciprocating ~upport lnto the roll
pass of a rever~ing pressure roll and the direction of travel
oi the sheet plece is therefore the same as the direction of
travel o~ the reciprocating support, or stack of prevlou~
depo6ited pieces already on the ~upport; -~
Figure 11 is in general a modification of the method ;`
and apparatus disclo~ed in Figure 10; :~
~ , .
Figure 12 i8 a schematic vie~ representing a
longitudinal vertical section through another embod~nent
especially designed for the production of flat slabs;
Figure 13 i~ a top plan view of the apparatus ~hown
in Figure 12;
Figure 14 i8 a staggered transverse vertical section
in about the plane of line XIV-XIV oi Figure 13;
Figure 15 is a schematic dlagra~ illustrating the
conver~ion of the molten metal by thi~ process to the fini~hed ~:
product;
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~089173
Figure 16 shows schematically a ~odiiication
lllustrating the layering oi the ~trand, end-over-end, to ~or~
a ~lab ~rom a contlnuou~ly caet length oi chlll c~t metal
which is a aultiple oi the length o~ the iini~hed ~lab;
Figure 17 i~ a top plan view oi Figure 16;
Flgure 18 i~ a iragmentary longitudlnàl section on ~ -
a larger scale showlng the electrlcally heated inlay oP
theraal in6ulation in the top oi the rev~r~ely travellng table ~-
o~ ~hich the slab i~ formed; ~
Figure 19 i8 a sche~atic ~ie~, partly in longltudinal ~`
Yertical section but mainly in ~lde elevation, o~ a casting
unit where successi~e pieces oi aetal oi the required length ~.
are inter~ittently produced, eliminating cutting oi the ~etal; ~ ::
and
Figure 20 is a top plan vie~ o~ the apparatus ~hown .~ ;
in Figure 19.
In Figure~ 1, 2 and 3, sho~ing ~chematically one ~ :
siaple apparatus and ~ethod i~or the practice o$ the invention, ; ~-
2 designates a ca~ting ladle ~ith a discharge tube 3 that -~
20 e~tends into an lntermedlate container 4 in ~hich aolten metal
is normally aaintained at a depth to i~erse the di~charge end : `
of the tube. A ilow control ~alve i~ indicated in the tube 3 ~ :
at 5. For assuring that a depth o~ molten metal in the con~
tainer 4 ~111, ~nder normal operating condition , i~er~e the
lo~er end o~ th~ tube 3, the container 4 has an internal ~elr
6 o~er which the ~olten aetal iloo~, and aore importantly to ~ -
assure ~loatation and removal oi ~lag irom the metal. From the
out~n OQ ~ide of the weir, the ~etal ~lo~ through a connecting
pQs~age 7 o~ generally U-shape into a ve~sel 8.
By mean~ oi a continuou~ly moving endles~ coollng ~all,
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1089~73
here represented by the suriace oi an internally cooled drum 9
dipping into the ve~el 8 and operating at a uni~orm speed, a
thin continuous layer oi solidif~ing metal i8 depo~ited on the
drum and withdra~n by the drum ~rom the ve~sel. Thi~ layer,
de~ignated 10, i~ stripped ~rom the upper sur~ace oi the drum
at or close to the temperature where it i~ substantially entir~y
~olidified and moved horizontally between leveling rolls 11,
Aiter emerging iro~ the leveling rolls, it i~ sheared by a
$1ying ~hear 12 into pleces oi uniiorm length. A limit s~itch,
~hich term includes an electric eye circuit o~ a known con-
struction, ~ indicated at 13 to eiiect operation oi the shear.
At the time o~ shearing, each piece will have ~oved over
parallel ~upports 14, one oi which is suspended at each side
oi the machine by links 15 hung irom respective rock-shaits
16. Various mechanisms oi known con~truction, schematically
indicated at 17, operate these sha$ts in unison to move the
plates apart to drop each still intensely hot succe~ive length
onto a movable receiving bed hereinafter described.
The very thin hot layer as removed from the drum i~
extremely ~eak and ilexible and must be supported in some way
both before and aiter shearing to avoid damage. Usual 9Up~
porting and transierring ~eans would requlre cooling to avoid --
destruction or the sticking of the cast metal layerj or lengths,
thereto. This would result in the undesirable removal of heat
that would later ne~d to be replenished, adding to the cost of
equipping and operating the ~achine. The present invention
contemplates that the ~upporting, guidiDg and even transport oi
the layers may be accomplished by generating alternating electro-
magnetic iield which ~ould provide a repelling ~orce to levitate
the layer or piece~ or strip~, and ~hich might additionally
supply heat to the moving ~etal.
.: - ,,.,. :, :
1~'8~173
To thi~ end there are ~upporting plates lndicat0d at
18 and 19, the latter comprising part oi the movable ~upportlng ~ `~
means 14 within ~hich are tubular ~ater-cooled tubes charged
with alternating electrlc current oi a ~requency and strength,
which, according to well-established ~ormula, ~ill g0nerate a
field ior the purpo~e both of repelling the layer or ~evered
pieces clear oi the plates and inductively generating heat ln
the layer or piQces. The iorce lmparted to the metal fro~ the
drum 9 and leveling roll 11 will normally be su~ficient to :~
carry the leading end oi the layer to the limit switch means 13
to eirect operation of the shear, but, with long pieces, the
coil~ may be energized to progressively urge the metal in the :~
dlrection oi the limit switch and thereby supplement the iorce
supplied by the drum 9 and rolls 11. ~eans ior the generation
o~ such traveling magnetic iields are ~ell kno~n in the art.
As above explained, the layer or ~trand to be severed ~`
by the operation oi the ilying shear will already be ~upported
over the supports 14 and their plates 19 so that the mechanism `
17 ¢an al~o be controlled by operation oi the limit switch to
move supports 14 apart to allow the severed pieces to drop
bet~een them. Variou~ means totrigger the operation oi the
mechani~m to open and close the supports 14 in relation to the
operation o~ the shear con~titute no part per se o~ the present
invention and are ~ell known in automatic iurnace and other
door-operating mechanis~s, .
Below the movable supports 14 there is a layering oi
~tacking unit comprising a bed-plate 20 having a iluid pressure ~;~
cyllnder and piston means 21 oi a length to move the bed-plate
; a iull back and ior~ard stroke which i8 at least as great or
; 3~ greater than twi¢e the length oi the pieces being sheared irom :
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108~173
the continuously cast layer. The operation of the piston i~ so
tlmed that the bed-plate i~ positioned to receive each piece a~
it drop~ from the ~upport to lie flat on the bed-plate or
directly on top o~ the piece la~t dropped ~ one or more piece~
have previously been dropped in starting or iorming a stack.
Immediately a~ter each piece i9 received on the top
of the ~tack on the bed-plate then in progre~, or being laid
on the bed-plate in the initlal stage o~ ~aking a stack, the
piston operate~ to move the bed-plate toward the right as vie~ed
in Figure 2 batueen a pair of rolls 22 and 23, the upper roll
of the pair 22 beiDg arranged to ~ove or be moved up~ard as
the height o~ it8 stac~ of pieces on the support increases but
e~ert a predeter~ined light pressure on the top of the newly
placed piece a~ the bed-plate reciprocates between the rolls.
In Figure 3A there i~ ~chematically lllustrated one
simple type of means ior controlling the movement of the base
plate in timed relation to the dropping of the lengths o~ hot
metal onto it and merely indicate~ in a ~imple diagram one ~ar
of doing this. ~hen one o$ the hinged supports 14 drops to a
vertical position, it closes a switch 24 to energize solenoid ~-
25, operating a iour-~ay valve 26 to admit ~luid pressure to the
left end of the cylinder of the cylinder-piston unit 21 and
relea~e pressure in the opposite end of said cylinder to ~ove
the plate 20 from the left limit o~ its travel as shown in
Figure 3~. At the same time s~itch 24 is closed, 6witch 27 i5
opened, but, as soon as plate 14 s~ings out oi` engage~ent ~ith
~itch 24, the ~itch means is biased to open ~witch 24 and
close switch 27, ~hereupon solenoid 28 is energized to rever~e
the ~our-way valve and return the base plate through the rolls
2~ and 23.
1089173
There i~ a ~loating type o~ switch indicated at 30 ~or
opening the circuit to both solenoids when the base plate i~ at
the retracted or right end o~ its travel when the ~tack oi
pieces or lengths reache~ a predetermined height. This pro-
vides a pause in its operation to enable the ~inished product
to be p w hed sideway~ irom the base plate ~or sub~equent com-
plete removal ~rom the casting unit, a8 indicated by the arrows ~ -
ln Figure 2 and as be~t shown in Figure 3. A pusher such as,
~or e~ample, a pu~her mechanis~ herei~a~ter described may be ~ :~
used.
The right end o~ the base plate 20, as ~ho~n in
Figure 1, has an elevated end portion 20a that ~lopes at 20b . ~.
to the ~lat level o~ the ~ain area of the bed-plate. This
elevated level i8 bet~een the rolls 22 and 23 at the e~tended -~
or leit li~it o~ the travel oi the ba~e plate as here illus~
trated 80 as to lower the upper roll onto the ac¢umulating
stack ~ith each pa~s o~ the base plate toward the right or
retracted poeition.
The broken lines, de6ignated 31, indicate an enclosure
beginning ~orwardly of the vessel 8 and extending past the rear ~ -
! ' ` :
o~ the roller table over ~hich the base plate move~, the
enclosure having side walla and a botto~ ~all so that a con- .
trolled, inert at~osphere, that is, a nonoxidizing at~o~phere,
may be maintained around the ~oregoing apparatu~, and, to a .
considerable extent, heat 1088 is retarded~ At the dlscharge
end o~ the machine, that i8 the right end as shown in Figures 1 :~
and 2, there is a liquid seal 32 indicated by a liquid-filled :~
ves~el into which the edge oi the enclosure 31 dips and the
product being shoved side~ay~ ~ro~ th~ base plate enters this
pit and is re~oved, as indicated by the curved dotted arro~ 33,
~,, ,~ ' . - ` -~ - '
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1(~89~73
the conveyor or other means for re~oving the product ~ormlng
no part o~ this ~vention. The molten metal bet~een the ve~el
4 and the ves~el 8 constitutes a trap to prevent air entering
the enclosure at the polnt ~here the ~olten ~etal i~ introduced
into the enclosure.
In the operation o~ thl~ apparatue, a continuous
layer Or metal, typically about 3 ~m. in thlckness, is iormed, ,~
cut into uniior~ length~, and the~e are stacked in the manner
described to ~orm a slab or billet o~ the required thickness.
Each piece, aiter the $ir~t one, is placed on the hot piece
beneath it and because o~ its high temperature and clean sur-
~ace, including the ellmination or substantial elim~nation of ~ -
air irom the encloaure and, thereiore, prevention o~ any
appreciable o~idation oi the metal, a ~usion ~elding oi the
metal bet~een the contactlng suriaces occurs under applicatlon ~
oi appropriate pressure.
; The appropriate pres~ure depends upon the phy~ical `
propertie~ oi the layers. It must be su~iicient to i~ediately
establi~h inti~ate contact oi the conironting suriaces. ~hen
~0 a ~etal ~ith poor pla~tic properties is produced, it ~ay be
: ~-
more fea~ible to iirst apply the pressure after the metal ha~
reached a temperature ~here it can ~tand a higher pressure ~ith-
out rupturing, in ~hich case t~o or more base plates arranged
for alternate operation may be u~ed. In the ca~e of other
grades oi metal, e.g., lo~ carbon ~teel, ~hich quickly reach
good plasticlty (hot ~orking properties), relatively high pre~-
~ure can be applied i~ediately since the material quickly
beco~es stiif. Absolute parameters ~or part1cular grades of
'; ; ,
carbon and alloy steels ~ay have to be deter~ined according to
the size and shape o~ the product, the co~position o~ the ~etal,
. ' .
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^` 1089173
the manner of applying pre~sure, as by roll~ or by a pres~,
oscillating plates or the like.
Taklng as an e~ample o~ thls operation, it ~ay be
assumed that 150 ~. thick slabs ~ith a length oi 3 meters
will be made by iusing together layers which are 3 m~. thl¢k
as they leave the solidi~ylng apparatus, with the water-cooled
drun 9 operating at a ~peed oi 1 ~eter per second, at least 50
pieces cut from the continuously iormed strip ~ill be required
to be stacked on the base plate Z0. She piston and cylinder
10 unit 21 should ~ake a full back-and-forth stroke ~ithin 3
seconds. Thus, a ~lab ~ould be completed every 150 seconds.
Ho~ever, a certain degree of height reduction, due to the pres-
sure to ~hich the hot metal is sub~ected, ~u~t be taken into `;
eonsideration 80 that some additional pleces or layer~ ~ill be
needed for achieving the deslred thickDess oi 150 D~. of the ~- ;
iinished piece. However, since the reduction oi thickness
result~ in a corresponding extension of the length, the pieces --
or length~ can be cut slightly shorter. Thus, the stroke cycle
of the piston may be ~ome~hat shorter and the productlon rate
per unit oi time re~ains the ~ame, that i8, the iinished ~eight
per time unit i9 the same or approxi~ately the same.
In Flgures 4 and 5 there is schematicallr disclosed a
method oi and apparatus for simultaneously forming bodies oi
n~rro~er width iro~ a wide cast layer. As here sho~n, ~our ~-
billets or integrated bodies oi progressively narrower ~dth /~
are iormed from a single wide strand oi metal emerging irom a `~
casting unit.
~ hile a rotary drum as disclo~ed in Figures 1 to 3
could be u~ed to ~orm the thin continuously cast layer, Figures
4 and 5 dlsclose an arrangemant ~here a continuously moving
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1()1~173
heat-re~istant belt 35, the upper run o~ ~hich travel~ in the
dlrection oi the arrow fro~ a aolten metal ve~sel 35a at an
incline up~ardly irom qaid ves~el around a roll 36 at the di~-
charge end and the return reach o~ the bel~ then pa~e~ around
roll 37 at the lower end of the belt. The ve~sel 35a is of
up~ardly decreasing depth and the upper reach o~ the belt, a~
here shown, mcves along under the ~olten ~etal, ~or~ing a chill
bottom wall for the pool o~ molten metal on the belt over which
a thin layer of metal rapidly forms. This layer o~ metal ha~
solidi~ied when it reache~ the upper end o~ the belt ~uiiicient
to be ~tripped therefrom and slit longitudinhlly by slitter 38
into parallel ~trips, here de~ignated ~1, s2, S3 and S4. While
the ætrips may be the sa~e width, or various combination~ of
~idths, as here illu3trated Sl i~ the widest and they are pro-
gressively narrower, S4 being the narrowest.
The parallel strips then are 3heared by a flying or
rotating shear 39 into pieceY oi uniform length.
BelGw the casting unit where the strips are formed
and cut to length, there i8 a roller table 40 with plates 41
between ~paced rollers 42. These plates retard radiant heat
los8 and ~ay have reæistance or induction heating mean~ incor-
porated therein to heat the ~trips. About midway between the
ends of the roller table there is a pair of pre~surerolls 43
and 44, the upper one, 43, being vertically movable as in ;~
Figure 1 to apply appropriate pressure to the stac~ of layer~
passing between them. There i~ a rever~ible drive indicated at
45 for driving one or both of these rollers. Guides are
indicated at 46 ~or directing and con~ining the sheared length~
of metal into spaced parallel channel~ ad~acent the bight of
the rolls 43 and 44 and other guides 47 along the roll table
maintain such parallelism.
.
-17-
1(~89~73
.
In order to direct the piece~ ~hich leave the ~hear
39 in close side-by-side relatlon lnto ~p~ced parallel path~,
the casting un~t 1B at an angle to the roll table and the
e~erglng pieces oi strips are looped do~n~ardly iro~ the ~hear
to a guide roller mean~ 48 about a radlu~ o~ curvature ~hlch
1~ progres~ively larger ior the ~ucce~sive piece~ irom ~1 to
B40 By rea~on oi thl~, each piece cro~s~ise oi the strips
travel a longer loop, but in the same period of tlme, and
undeslrable distortion oi the pieces i8 avolded.
In Flgures 4 and 5, the parallel stacks being iormed -~
are indicated as B, and each ~tack extends iro~ one slde oi
the rolls 43 and 44. In operation, assume that stack B i~
traveling to the right as ~ho~n in Figures 4 and 5, there i~
a li~lt s~ltch 50 at the right end oi the roller table ~hlch
~ill be engaged by the end oi at least one billet (or other
, '" , ~:
product being ioraed) to reverse the rolls 43-44 when the
trailing end~ oi the billets have cleared these rolls and ~-
rever~e the travel oi the bil}et into the bight oi the roll~
.~ ,;.
~hich are no~ turniDg in the reverse direction, There i8 also
a li~it ~itch 50a at the leit end of the roll table.
The 100PB bet~een the shear 39 and the bight of the
rolls Qust, ~or products oi ~ubstantial length, be nearly as -~
long as the iinished products, and the rolls 43-44 ~ust opernte
~aster than the speed oi the piece~ e~erging iro~ the shear 90
', .'.' :
that when one set oi pieces are entlrely deposlted on the
~ roller table or stack being ior~ed on the roller table, they ~ill -`
3 reverse and their reverse travel will be co~pleted and the leit
I ends oi the several side-by-side billets ~ill be in a po3it~on
to receive the leading ends oi the next series oi parallel
severed piece~.
. ~ ,'
" ,, ~.
-18-
........... . . . .. . . . .~ .... . . . . . .
1089173
~hen the required number o~ layers ha~e bee~ applled
to each ~tack and rolled, a ~ast-operating pusher compri~ing
the bar 51 and pi~ton and cylinder unit~ 52 ~ill be op~rated
either ~anually or autonatlcally by limlt s~itch 50a to move
the successive bodies lnto a ~eal 53, euch aY described at 32
in con~unction ~ith Flgure 3, the ~eal being part of a co~plete
enclo~ure 54 surrounding the remainder oi the ca~ting unlt.
As in Figures 1 and 2, a trap ~ill usually be provided in the
molten metal inlet, indicated at S5.
There ~ill be provided loop~ng guides for directing
the several pieces Sl - S4 into their proper positions bet~een
the pressure rolls 43-44, but for clarity o$ illustration they
have not been shown and iorm no part, per ~e, oi the in~ention.
8ince such guides ~ill remove heat iro~ the length or pieces
oi metal passlng therethrough, electro~agnet~ energized iro~ an
alternating current ~ource and, a8 lllustrated in Flgure 1, ~111
be assoclated with the guides to provide heat to the metal
pieces and relieve, to some extent, the contact pressure oi ~;
the ~etal pieces ~ith the guide~.
In Figure 6 there i~ a casting unit oi the endles~
belt type, as ~ho~n in Figures 4 and 5, oeith an up~ardly ~-
lnclined endles~ belt 60 a~ descrlbed in those iigures and means
61 for holding a body oi ~olten ~etal at a ~nlform depth irom a
supply inlet (not shown) but slmllar to that ~hown in Figure 5
and al~o Figure 7, to be hereinaiter described. The molten
metal is contained above the top run oi the endless belt 60,
which ior~s a botto~ ior the pool oi ~etal retained by 61 and
al~o provides a constantly moving chill suriace, a~ previou~ly
explained, on whlch a thin layer oi molten metal i~ continuou~ly
congealed. This contlnuously ~ormed layer is stripped irom the
~ -
,, :
-19-
. ~ ... ....
," , , :. ~ ,... .. .
. - . : . .. . . ~ .
1(~89~73
top run o~ the belt at its upper end and pas~ed bet~een
slittlng roll means 62 that dlvides the cont~nuously for~ed
layer longitudinally lnto à plurality oi continuou~ parallel
strlps S9 oi equal ~idth, ~hich then pa~s bet~een guidlng
rolls 63. As in Figure 5, the casting unlt i~ angularly di~
posed with re~erence to the longitudlnal axis oi the
hereinafter-described means to which the strips are dellvered.
The means for recei~ing the strips co~prise~ first
a pair of pre~sure rolls 64 ~ith a guide means 55 in advance ~ ~;
oi the bight of these rolls o~ a ~idth to receive, ~ith only ~;
a working clearance, the strip 89, but of a depth to permit
all oi tha strips, one upon the other, to enter the pass -~ -
between rolls 64. At the emerging side of these rolls there
is a guide 66 simllar to 65 but rever~ed thereto. Other
gulde~ are provided, as indicated at 67, and else~here i~
needed. m ere is a second pair of upper and lower rolls 68
;~ which are ilanged to provide a pass between them, and botween
~ , :
67 and 68 is another pair oi groo~ed rolls 69 which rotate
~!~ about vertical axes~ They bear against the ~ides of the iused
bundle o~ strip~ emerging ~rom bet~een rolls 64.
The stacking of the several strips S9 i8 e~iected as
.. .. .
in Figures 5 aDd 6 by having the parallel strip~ emerging ~rom
the rolls 63, each traveling through successively larger loops
irom the right side, ior example of rolls 63 to~ard the left
end while ei~ecting a 180~ twist in such manner that the strip
S9 at the leit side of the series, as here illustrated, becomes
,.
the lowermost strip to enter the pass between pressure rolls 64, ;;
and each strip thereafter from leit to right is guided in
~uccession onto the strip beneath, iorming a ~tack or bundle ~'
of strlps, all at a temperature where they are pressed and
-
., .
-20-
, .... ... .. . . . . .. .
, . ~ ,
1089173
fuse-welded or pressure-welded as before descrlbed, and at a
te~perature as explalned where ~elding under relatively llght
or appropriate pressure (as hereinbeiore defined) will take
place. By looping the parallel strips in the ~anner described,
the ~trips are easily brought to a po~ition where they ~ill
come together without destructively twisting or bending the
metal.
The product o~ the process and apparatus as shown in
Figure 6 may be cut into billets oi uni~orm length, or oi
varying length by a ilying shear indicated at 70. The hot
continuously formed product could then be delivered, for
e~ample, to a rod or bar mill and reduced to a rod or bar oi
indefinite length or into bar3 ~hich subsequentlr would be cut
to length.
Figure 7 ~hich is a modi~ied top vie~ of Figure 6
~hereln the corresponding parts are dasignated by corresponding ~-
re~erence characters. All strips, S9, are o~ equal ~idth and,
in place o~ guiding rolls at 63, there is a rotary shear 63A
~ith staggered cutter~ for progressively ~evering each oi the
e~erging str~ps S9 into piece~ of unifor~ length 80 that ~hile
the loops may be progre~sively larger in dia~eter iro~ one side
oi the unit to~ard the other, the lengths oi all o~ the pie¢es
~ill be equal, or appro~imately so, and they will stack or
bundle one upon another with both the lead and trailing ends of
all of the plece~ approximately square with and vertically
aligned with the corresponding ends o~ the other pieces.
Another di~i'erence between the structures shown in
Fig~res 6 and 7 is that Figure 7 illustrates in dotted lines a
~econd casting, slitting, and cut-off unit 71 ahead o~ the
first. ~ith this arrangement, oue bundle o~ strip~ ma~ be
' '
., .
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' ~
1089173
assembled and lntegrated and then the other unit may operslte to
add additional pieces where the product to be produced 1EI o~ a
dimension, either in width or thickness, or both, too groat to
be produced Irall a single casting unit Also, instead of
u~ing the two casting units in succe~sion, both ~ay operate at
the same time and the pieces Irom one unit be interleaved ~ith
tho~e OI the other to form an integrated billet.
In Figure 7 a flying shear 70 is al80 indicated, to
be used as in Figure 6, or, with the piec~ sheared bei'ore
stac~ingO The ~inished billets may be discharged 3ide~rays a~
sho~n in Figure 3 but ~ithout reversing direction at a loca~
tion Iollowing rolls 68 or discharged end~i~e iram the enclo~ure.
As in the other figures, an enclo~ure around the entire casting ;-and product-Iorming unit is indicated by chain lines, this
enclosure being designated 73 so that a nono~idlzing atmosphere
may be maintained thereabout. The ~etal inlet to the casting
unit, ~hich, as previo~ly explained, al80 constitu~ a tr~p or
seal, is designated 74. The apparatus OI Figures 6 and 7 ma~
be 80 interchanged that either may operate in the ~a~e way.
The arrangeDIents sho~n sche~atically in Figures 8 and
9 are designated primarily Ior the production slabs ~here they
need be only o~ a relatively short length. As in the other
e~bod~ents OI my lnvention, the product i8 formed b~r pro~
gressively callbining layers OI metal, one on another, and
pressure-~elding each layer in turn to the next préceding one
until a product of the required thickness has been produced.
In these Iigures, 8 and 9, the casting unit is shown
as con~prising an endless belt type as previou~ly described, and
it i8 de~ignated generally as 80, without further description
OI the details. Erall the discharge end 81 oi the endle3s belt, ~ -
--22--
,.. .
1089173
the continuously iormed layer at a temper~ture above a
temperature ~here it ~till has lnsuiiiclent plastlcity ~or
nor~al hot rolling 1~ deilected do~n~ardly into the space
between two con~ronting reiractory block~, The lo~er or leit
one o~ the~e blocks, a~ here ~ho~n, designated 83, 18 secured
to a ~et~l supporting structure 82, The upper or right one o~
these blocks 84 is carried on a metal ~upporting ~tructure 85,
The reiractory plate and it~ support 82-83 i5 hinged at 86 to
swing ln a vertical arc irom one upright position where it i8
steeply incllned from a vertical plane to a horizontal po~i-
tion, a ~luid pre~sure cylinder and pi~ton unit 87 being
provided to effect this pivoting ~ovement.
The oppo~ite re~ractory plate and its support, 84-85,
i8 supported to move toward and ~way ~rom a~se~bly 82-83.
The~e t~o assemblie~ 82-83 and 84-85 comprise pressure plates -~
or pre~s platen~ with iluid pres~ure cylinder and pi~ton
element~ 88 ior movlng the plate 84-85 to~ard and away fron
~ the other one. ~-
'~ The pre~sure plate~ in the po~ition shown in Figure
8 are located 80 that the descending layer of metal irom the
end oi the casting ~achine enters the space between the t~o
plates ~ith the inclination of the plate 83 being such that
sQme support i8 provided for the layer of hot metal as it ~oves
down to prevent it irom buckling or collap~ing. ~hen the
leading end oi the layer oi ~etal has about reached the sup-
porting ledge 86 at the lo~er end oi plate 82-83, a ~lying
~hear 89 ~ill sever the descending layer o~ ~etal.
As~u~ing that there are already one or more sheared ;~
- lengths of metal bet~een the two pre~ure plate~, the pre~-
.,~
sure plate 84-85 ~ill be operated to pre~ each added length
,
. ..
. .
-23- ~
" ' "
~ . . .
1()89173 ~:
:; .
o~ metal again~t the face oi the preceding one. The re~ractory
plate# 82 and 84 are heated to retard the 108g oi heat irom the
metal piece 80 that pre~sure-welding o~ the successlve pieces
is rapidly and e~ectively initiated. When the slab or billet
has reached the required thickness to yield the ultimate
desired product, the lower pressure plate 82-83 i8 ~uung down
to the horizontal position indicated by dotted lines. ~hen ~`~
this position has been reached, a pusher 90 (~ee Figure 9) i8
operated by fluid pressure mean~ indicated at 91 to sllde the ~;
freshly ~ormed product 92 onto a roller table 93. It is tran~-
ported by the roller table to a reversing roll stand 94, here
indicated as a three-high stand 80 arranged that the slab may
be alternately pas~ed through the upper pass in one direction
and the lower pa~s in the other direction. The roll stand is
someti~es referred to as a "~u~ping ~ill." This rolls the hot -
product to assure complete unity oi the several layers and com-
pact it to the required thickness for sub~equent processing ;~
into a iinished product. Although not shown, the product cGuld
pas~ directly irom mill 94 to an adJacent rolling mill to be
iurther rolled, perhap~ to iinished dimensions without reheating.
Also, ~ince the ~labs ~ay be too hot to have attained
the desired pla~iticity ior proces~ing in the rolling ~ill 94,
the roller t&ble 93 may be o~ a length to support ~everal o~
the freshly ~ormed ~labs at each side o~ the roll stand until
they have cooled to a suitable temperature. Also, there is a
third roller table 95 alongside o~ table 93 so that after pas-
sage o~ the product 92 through the mill, it may be moved side-
ways Prom table 93 to table 95 ~or ~urther rolling, or carried
to the discharge end (not shown) o~ table 95, the ~everal
arrow~ in Figure 9 indicating these options. An enclosure, as
-24-
1089173
in the other ~igures, ~ould desirably surround the mill o~
Figures 8 and 9 80 that the casting, formlng and rolllng
operations may be periormed in a nonoxidizlng atmo~phere, but,
~or the purpo~e~ o~ clarity, thi~ enclosure has not been shown
in the~e figures.
Figure 10 illustrates schematically an arrangement
in which a continuous layer 100 of ~etal ca~t on a moving chill
suriace, as previously described but not sho~n in this iigure,
is cut by a flying shear lQl into pieces of uniform length.
These pieces are delivered to a supporting and conveying table
102. The table 102 i8 pivoted at 103 near the shear for
oscillation in a vertical arc, as indicated in the drawing.
The oscillation of the table 102 is effected by an operating ~ -
mechanlsm, here indicated as a fluid pressure ¢ylinder 104 ~ith
a piston rod 105. There is a pair of pre~sure rolls, co~pri~ing
an upper roll 106 and a lo~er roll 107. Reversible driving
means for these rolls may be of a kn~wn construction, and such
means i9 not shown in the dra~ings.
There is a roller table 108 extending to each side of
this pair of rolls on ~hich is a bed plate 109 that is shuttled
back and ~orth through the pass between the t~o pressure roll~
and the reversing travel oi the bed plate over the roll table
; fro~ end to end is initiated by a iluid pressure cyllnder and
piston unit 110 at the left end of the roll table, and a
similar unit 111 at the right.
The roller table is supported for controlled vertical -~
movement ~hich ~ill enable it to lo~er a~ the ~eight on the bed~
plate increases. Thi~ is indicated schematically by dashpots ~ ~-
- or like fluid pressure-controlled ele~ents 112, at various
positions along the roller table fra~e. At a level ~hich is `
-25-
1()89~73
normally fi~ed with respect to the upper roll 10~ during the
operatlon o~ the mlll, there 1B an entrance guide 113 on the
leit side oi ~aid roll and on the oppoRite ~ide there i8 an
oppositely facing entrance guide 114.
Finally, at the iree end oi the pivoted table 102
there is a supporting plato ~ection or table 115 spaced above
the roll 106, and which, in efiect, forms a continuation oi
table 102 ~hen the free end oi said table i~ in lts upper~o~t
position. Beyond section 115 there is another table section
116 o~ a length so~e~hat greater than the length oi the pieces
lnto which the contlnuously caat layer~ o~ metal are cut.
Sectlon 116 i~ pivoted at 117 between its ends to rock in a
vertical arc 80 as to tilt irom the position sho~n in iull ~;
lines in Figure 10 to the position sho~n in dotted lines. In
the latter position it form~ an e~ten#ion oi table 115, but ~-
~hen tilted to the full-line po~ition, its left end, as bere
sho~n, is ilush ~ith the inclined top surface oi roll pass -~ -
entrance guide 114. There is a cylinder and piston unit 118
i~ rocking table 114 up and do~n.
~hen the table 102 is rocked about pivot 103 to the
lo~er limit oi its move ent, its iree end then ior~s, in ei~ect,
a continuation oi the leit roll pass guide 113.
In operation, a length or piece of the continuous
casting, upon leaving the ~hear, oves down conveying table
102. ~ith the table 102 in its upper position, as sho~n in
Figure 10, the cut piece ~ill move over ~ection 115, at ~hich
ti~e section 116 ~ould be in the dotted-line position to receive
it. ~hen the picce i8 0~ the tilting section 116, that table ;~
will tilt to the full-line position, and its lead end will
pass ~rom the right under the upper pressure roll 106 onto the -;
. ~
-26-
1(38~173
bed-plate, which i~ then also Just entering the roll pa~ ~rom
the right, and the p~ece ~111 move through the roll pass belng
thereby pre~sure-~elded to the last piece previously placed on
the roll tableO Lower roll 107 ~111 exert pressure agalnst
the bed-plate 108 whlch holds the cast layer up against upper
roll 106 at the appropriate pre~sure. The machine will be 80
timed by any one of several well-known type8 of control systems
~o that the lead end of the bed-plate, then mov~ng to the le~t,
~ill enter the roll pass to meet and support the lead end of
the cut piece. In ~igure 10, a partially for~ed billet or
~lab i9 ~hown on the bed-plate.
When the bed-plate ha~ reached the limit of its
travel toward the le~t and has cleared or about cleared the
pass between the pressure rolls 106 and 107, cylinder 110 will
operate to start it back through the roll pas~ in the oppo~ite
direction. By this time the table 102 will have been lowered
to direct the next piece sheared from the casting over the ~ -
le~t guide llS to enter the roll pass and deposit the leading
end of that piece on the then leading or right end o~ the bed-
plate or the la~t previously deposited piece on the bed-plate.
This cycle of operation i~ repeated until the required number
of piece~ have been integrated into a homogenous mas3. Then
the now finished slab or billet will be pushed or otherwise
.,~ ~ .-. .-
removed from the bed-plate, as, for example, by pushing means ~-
(not shown), but in the ~a~e manner as previously described in ~-
other figures. Sequencing relays and other well-known circuitry
may control the operation although manual operatlon can be pro- ~ ~-
vided ~or. An enclosure 120, as in previous figures, is
indicated in broken lines to keep a nonoxidizing at~osphere
around the operation to prevent scaling of the ~etal and assure
,
-27-
11~89~73
R clean sur~ace-to-suriace contact o~ the ~ucce~sive piece~.
The lower pres~ure roll 107 i8 yieldably supported by a cyllnder
and piston means 107' to ~pply the required approprlate pres-
sure upward tow~rd roll 106 but to lower as the thickness o~
the product build~ up o~ the bed-plate. 8imilarly, the roll
table 108 can lo~er as the lower roll 107 lo~ers.
In Figure 11 the construction i8 ior the ~ost part
the sa~e as in Figure 10, and the same re~erence nu~erals are
used to designate corresponding parts in the t~o figure~. The
signii'icant dii'i'erence i8 the more simple ~itching arrangement
ior alternating the direction of travel of ths succes~ive
pieces. In thi~ view there i8 a guide 125 at the le~t side oi
the uppsr pressure roll 106 with an upwardly and rearwardly
turned extension 126. A generally similar guide 127 at the
right of this pressure roll 106 has an upwardly curved exten~
sion 128 that passes above the upper roll 106 and extends above
the gu~de extension 126, but ~hich is spaced above it. In the
space bet~een the extensions 126 and 128 there i8 a iixed gulde
129 having diverging branche~ 130 and 131 providing two pa~-
sages, one o~ which, 133, extending in ~paced relation to guide
e~tension 126, provides a pa~sage ior directing the leading end
of a ~evered piece of a cast layer under the upper pressure
roll i'ro~ the lei't and onto the bed-plate which i9 then moving ;~
to~ard the right. The upper branch 131 together with guide
extension 128 provide a passage arranged to direct piece~ over
~ the top oi the upper roll and then do~nwardly under the upper
< pre~sure roller i'rom the right toward the leit and against the
bed-plate which is then moving toward the left. In this case
the piece i~ turned over in relation to its original top and
botto~ suriaces. The tilting conve~ing table 102 in this case
,~
-28-
.. . . . . .
1089~'73
~oves between the ~ull-line posltion ~hown in Flgure 11 where
it confronts and 1~ ~lu~h with the end o~ guide exten~ion 12ff
and the end of~ixed gulde 129, as indicated in dotted llnes, and
back down to the ~ull-line po~ition to alternately ieed the
strlps under the upper pre~sure roll from the le~t toward the
right and then rrom the right to~ard the le~t in isochronism
with the travel oi the bed-plate, fir~t ~rom the le~t toward
the right and then from the right toward the left, The move- ~
ment o~ the bed-plate may, ~or example, be timed by the opera- -
tion of the flying ~hear 101, as can al80 the raisine and
lowering oi the conveying table, control~ suitable for thi~ -
purpoee being ~ell known.
In order to supply heat to the sheared pieces as they
are alternately guided to one side of the upper pres3ure roll
and then the other in the arrangement shown in either Figure 10 -`
or 11, the spaced dots in the drawlngs indicate conductors in
section designed to be energized from a source of alternating
current (not shown) enclo6ed or contained in the conveying
table 102 and the several conveyor sections and guides to there~
by reduce the contact between the ~uccessive pieces and the
tables and guides by generating repulsion iorces and perhaps
also aid in efiecting their travel, and, as previously des~
cribed, inductively heat the pieces to maintain them at a
temperature where they can be pre~sure welded.
Figures 12, 13 and 14 disclose schematically a mill
for producing slabs or plates at a high rate of production. To ~ -
this end, there is a reversing pressure roll stand 140, here
illustrated as a 3-high stand ofthe type so~etimes referred to
as a "jump roll." In such a roll stand the pass in one direc-
tion is between the top and middle roll, as shown in the dra~ing,
29-
, .......... - ~ ........ . . ~
1089173
but between the middle and bottall roll in the opposite
direction ~th means ior moving the roll~ vertlcally to
maintain the roll pa~3~3 in both directions at the same level.
There is a roller table 141 at the le~t oi the
pres~ure roll ~tand at a level to recei~e slab lengths of
metal and support the material being rolled, and a ~imilar ::~
roller table 142 at th~s right o~ the pressure roll stand,
There are two lines Ior producing ~lab length castings, one,
designated generally at 143, belng along one slde o~ and
parallel with the roll tables 141 and 142, and the other line, ~-
al~o parallel ~ith the roll tables but on the opposite side
OI said roll tables, i# designated generally as 144. There is
a continuou~ casting unit 145 at one end oi each of ~aid line~
143 and 144. 'rhey are here ~hown at the left end of the respec-
tive lines. ~hey are illustrated as being o~ the belt type
units previously described. Each has a ~olten metal retaining
vessel 146 with a molten ~etal supply inlet 147. At the di~
charge end of the continuouE~ belt there is a Ilying shear 148
that cuts the respective contlnuous thin ~lat casting pro- ~-
~0 duced by the re~pective casting unit# a~ter they have been
~tripped iron- the belt into slab length pieces 149, aE~ best
seen at the le~t end o~ line 143 in Figure 13. The~e pieces, --
as they are sheared, pats~ over a #ectional receiving table 150
ior line 143 and table 151 ior line 144.
Sectional table 150 in line 143 i~ elev~ted above the
level oi the roller table 141 and i8 co~pri~ed of two iixed
~ections 150a and 150c and t~o transversely tiltable sections ~ -
150b and l50d. AB best seen in Figure 14, the tiltable ~ec~
tion~ are on ~upports 155 arranged to rock or tilt side~ays
about a longitudlnal a~-is 156 ~ra~ the iull-line hori~ontal
--30--
~(~89173
position in Figure 14 to the tilted posltion sho~n in dotted
lines. There i8 a movable ~top 157 between sections 150b and
150c which, in the po~ition sho~n, will block the movement oi
a ~evered length 149 to retain lt on the tilt ~ection 150b, but
~hich, ii moved out oi blocking po~ition, as sho~n ln dotted
lines, enables a severed length to pass along onto the second
tilting ~ection 150d. By tilting one oi the table ~ections
150b or 150d, a piece supported thereon can be caused to
gravitate onto the then ad~acent bed-plate 160 which i~ movable
10 bet~leen the pressure rolls of stand 140 onto one or the other
o~ the roll tables 141 or 142 to be then rolled by the pressure
rolls. ~ -
All of the sections oi table 150 are provided ~ith ~
multiphase alternating current ~indings designated in Figure 12 ~ ;;
by the spaced, staggered, parallel lines to move the pieces 149
to the ~top 157 ii the piece ~ to be discharged onto a bed-
plate 160 which is at that time entirely ~upported on table 141
to the leit oi roll stand 140. If, ho~ever, the stop 157 is
withdra~n from its operating poe~ition, the piece may travel to
the end oi the runway, that is, to a po~ition ~here it is
centered on the tilt-table section 150d to be discharged ~lde-
~ays onto the bed-plate 160 ~hich ~ill then be to the right oi -
the pressure roll stand 140 and then supported on roll table
142. The alternating current ~indings may, as previously
explained, also inductively heat the successive pieces of metal
as they are moved along over the table sections.
llith the arrangement of tilting ~ection 150b and l50d,
selected lengths of thin cast flat metal can, for exan~ple, be
alternately placed on the bed-plate 160 a~ it travels back and
forth, ~ir~t when the bed-plate is to the left of the pressure
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~ .. . . . ..
1089173
roll Qtand, and then to the right, and as each plece ifi placed
on the one preceding, it i9 pressure-~elded and integrated with
the underlying plece.
The line 144 along the other side of the mill ls
arranged to operate somewhat di~ferently ~rom line 143,
although it has a supporti~g table 16S for receiving the sheared
pieces $rom its casting unit. Table 165, like table 150, i~
also at a level above the pre~ure roll tables 141 and 142, but
it is spaced laterally rrom these tables a ~ubstantially
greater di~tance than the section~ o~ table 150 on the other
side o~ the mill. The successive pieces are moved along the
table from the casting unit by polyphase magnetic ~eans (not
shown) but arranged similarly to the mean~ in the table sec-
tions of 150 as above described. There i~ a ~op 166 over table
165 ~imilar to stop 149 on the other line. I~ the stop 166 i8
in the blocking position ~hown in full lines in Figure 13, a
ca~t piece ~ill be stopped on the table 165 to the le~t of the
pressure roll stand 140, but, if the ~top is ~oved out d
po~itlon to block the cast pieces or layerQ, they will travel
along the table to stop at the other side of the pressure roll
~tand 140.
A~ best seen in Figure 14, there is a transver~sly
sloping lower platen 170 alongside the table 165 and to the
ad~acent side of roll table section 141. Above this platen
there is a vertically movable platen 171 which i5 moved up and
down by power cylinder units 172 on fixed parallel ~upporting
rails173, the upper platen being movable in a plane where it~
lower face is parallel with the top sur$ace of the transvers~y
~loped lower platen. Alongside this portion o$ the table 165
there are pushQrs 174 which operate simultaneouslr to pu~h a
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~heared ~ection tran~ver~elr ~rom the sur~ace o~ the table 165
to the le~t o~ the stop 166 onto the platen 1700 A second length
or plece may then be pushed onto the ~irst plece and ths upper
platen lowered to ~use or pre~sure ~eld the second ple~e over
the first and thi~ cycle may be repeated until an integrated
slab ot the desired thickness has been built up on the platen
171.
At the right end oi the table lff5 there i~ a similar
press arrangement with a lower platen 170' ~ith a vertically
movable transverse b inclined upper platen 171' powered by
cylinders 172', also supported on the spaced rails 173. There
are pusher means 174' which operate simultaneously to move
successive pieces or lengths of metal that are delivered to
the right end of table 1~5 to the leit from the table 165 to
platen 170' to form an integrated stack o~ piece~
80th platens 170 and 170' and 171 and 171',
respectively, oi each of the t~o presses have electric heating
means encased therein or otherwise arranged to assure that
fu3ion o~ the succes6ive layer into a unitary body, although
they may not be as thoroughly fused as desired. There is a
do~nwardly moYable side plate 17Qa along the lower edge of the ~ ~-
lo~er platen 170'. By selectively moving one or the other oi' ~ ?
these side plate~ down, the ~used stack o~ plates thereon may
~lide onto roller table 141 or 142, as the ca~e may be, and
pas~ed between the pressure rollæ 140 one or more times to ~re
co~pletely efiect the ~usion welding oi the ~everal ~heet~ or
l~yers in the stack~ 80 processed, the body of the slab~ at this
tlne being o~ sufficient ma~ to retain enough heat to enable -
such consolldatlon to be s~fectively per~ormed. ~hen this
operation just de~cribed i~ being done, the bed-plate, ~hich is
~ .
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lQ89173
not n~ required, may be run out oi the ~ay onto a roller
table 180 indicated in dotted line~ at the end oi roller table
141 and the product may be run o~f onto a conveyor table 181,
also lndicated in dotted lines in Figure 13. At thls time,
end stop 182 at the leit end oi roll table 141 is lowered and
end stop 183 at the right end oi roller table 142 i8 lowered
to enable the ilni~hed slab to be removed.
An enclosure 190, indicated by broken lines,
surrounds the mill 80 that a controlled nonoxidi~ing atmo~-
phere may be maintained around the mill during its operation.
A seal i8 provided, such, ~or example, as that sho~n in Figure
3 but at the end oi roll table 142 through which the slabs are
discharged end~ise. However, ~ome othersealed outlet for the
di~charge oi the ~labs to the atmosphere may be provided, as
ior example a "decompression" type oi multiple doors used in
other industries.
Figure 15 i~ a bloc~ diagram lllustrating the entire
pro e~s iro~ the conversion oi the molten metal to an inter-
mediate product and then to a iini~hed product. In this diagram,
200 designates a ladle which receive~ molten metal and 201
designates both the casting unit and the mill ior con~olidating
the pieces into a product, such as the mills herein previou ly
de~cribed in Figures 1 to 14 or the like. The intermediate pro-
duct, e1ther billets or ~labs 202, may pass directly to a
rolling or finishing mill 203 and converted to a iinished pro-
duct, indicated by the coil 204. Some o~ all oi the ~nter-
mediate product may be direrted in adrance o~ unit 203, as
indicated in dotted lines, to be stored at 205. They may then
be sub~equently charged into areheating iurnace 206 and entered,
a~ indicated by the dotted line 207, into the 8ame or other
~inishing unit 203.
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3L08~173 b
As thu~ illustrated, tbe molten metal is continuouslg
converted into a layer or strip, then lnto a billet or slab or
like body as an intermediate product of greater thic~nes~ than ~`~
the original cast layers than the ~inal product into which the
metal is to be converted, and thiæ intermediate body i8 there-
after rolled or ~orged into the ~inished product.
In all o~ the foregoing embodiments, a siDgle casting ~-
unit produces a multiple oi lengths or widths, or both, ~rom a
continuous strand that ig then cut into lengths or strips or
both and layered together to produce a unitary casting by
layering one above another and pres~ure welding them. In the
subsequent figure~, a single casting unit is arranged to pro-
duce pieces which are the length of the product to be formed
and ~hich are layered to produce integrated bodie~, or, alter-
natlvely produce a strand which is a m~ltiple o~ the length of -
the product to be produced and which are layered by folding the
casting on itself untll a product of the required thickness -~
results.
In Figures 16, 17 and 18, there is disclosed a method
and apparatus ~here1n a continuously formed strand is delivered
to a layering device ~herein the strand is folded upon itseli
and the layers pressure ~elded. The strand is ~evered a~ter a
length, corresponding to a multiple o~ the product length and
sufficient to produce a product of the desired thickness, has ~; -
been formed and most of lt has been supplied to the folding '~
unit ~here it i9 then severed and the formation oi a succeeding ;~
slab or billet then ~ollows in the sa~e manner. ~-
In the ~igures, 210 is a reciprocable table having ~ ~;
a reversing drive, schematically indicated at 211. The table
has a reces~ in the top filled with a heat insulating material
'' ,
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'' . .` ` . ' . ` ' `. . ` ' ', : . . , . ~ !
1(~89173
212 of a length and width greater than the corresponding
dimension~ o~ the product to be ior~ed, and, when desired, it
may be provided wlth e~bedded electric reststance or inducti~e
heating conductors (see Figure 18) 213 connected wlth an
energizing current source, not shown~
There is a tiltable frame 214 with trunnion~ 215 at
oppo~ite side~ carried ln iixed supports 216, ~hown irag~entarily
in Figure 17 only and about which the frame 214 may rock in a
vertical arc. At equal distances from the axes of the trun-
nionæ there are pre~ure rollers 217 and 217a and the axes of
the trunnions are desirably centered on the line of centers
between the rollers 217 and 217a. An estension 214a oi the
fra~e at 214 at each side of the frame is pivotally connected
to the upper end# oi piston rods 218a ~ith pistons, not shown,
in fluid pressure cylinders 218, one such piston and cylinder ;
being at each side o~ the frame, and each of which is pivoted --
at 219 to a ~upporting frame, not sho~n, in a manner ~ell kno~n
in the art to accommodate ior the arcuate movement of the
exten~ions 214a as the piston rods move up and down. -
` 20 The heated layer or ~trand 8 of ~etal, for~ed in
variou~ ways as hereinbefore described, is directed do~n~ardly
through a heat insulating and, if nece~sary, ~n electrically
heated enclosure 2~0 into the bight bet~een rolls 217 and 217a.
' There i~ a ~hear 221 at the exit end of the enclosure 220. ;~-
Assu~ing that the table i~ moYing to~ard the right as
indicated by the iull line arrow in Figure 16~ the roll 217 is
depressed to bear on the hot strand descending between the
rolls 217 and 217a to be pre~ed onto the top of the partially
formed product 222 and thereby pressure roll and weld it to
-~ 30 the underlying layer of metal on the product being formed on
.
.,
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.
., , . , . ~. ~ . . .
.
1()89~73
the table. When table 210 reaches lts rlght limit of travel,
the pressure cyllnder~ 218 will be operated to lift roll 217
and lower the leit roll 217a and the carrlage will re~erse to
fold the metal the other way and then be flattened down by roll
217a and pressure welded to the previously completed layer, the
dotted arro~ indicating this rever~e travel of the table.
As the product reaches the deslred iinal thicknes~,
the shear 221 will be operated by a counter or thickness
detecting switch mean~ of any well known or preferred type 80
that the last layer will be complete and the product will com-
pri~e a single length o~ metal, layered and fused, the length
oi metal in the strand being a multiple of thenu~bgr oi
individual layers of wh~h the finished product is comprised. `~
No arrangement for removing the slab or casting when
finished has been shown, but one tnble may be provided to be ~ ;
run into place to replace the one to be unloaded or the ca~ting
may be slid endwise from the table onto a receiving conveyor or
carriage. As indicated by broken lines in Figures 16 and 17,
the apparatus is pre~erably contained within an enclosurs to
which an inert, i.e. nonoxidizing, gas is supplied and ~rom -~
which air is removed to avoid oxidation of the metal.
Figures 19 and 20 show in schematic longitudinal
vertical section and in a top plan vie~, respectively, a further
modlf~cation wherein a moving chill surface iQ diBcontinuous to
intermittently form ~eparate sections or lengths in~tead o~
... . . .
being continuous as in all of the hereinbefore described casting
. :,. ~ .. '. .
apparatus. A~ here shown, there is a casting roll designated ~;
generally as 230 on a shaft designated generally as 231 and
which is driven in the dlrection of the arrow shown in Figure
19 by driving means, not shown. The roll 230 has a chill
. . ~ , .
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1~89~3
sur~ace 232 extending ~round the greater portion of its
per~phery. Th~s chill suriace ~urrounds and ~orm~, in part,
a water cooling space 233. There 18 a recess 234 formed
acro~s the ~ace Or the roll ~ormlng a gap in the chill suriace
o~ a relatively ie~ degrees o~ arc around the periphery of the
roll. In this reces~ there is an insert or segment 235 of
lcw heat conductivity, being iormed mainly o~ a refractory,
and its surface i~ ilush with the chill sur~ace and concentrlc
with the axi~ of rotation of the roll. It may have heater
elements embedded therein, as indic~ted at 236, to a~sure oi
its being hot enough to prevent the molten ~etal fro~
solldifying thereon.
The shaft 231 for the roll comprises an inner
tubular passage 231a connected with a supply of cooling water,
not shown, and ~hich i8 ~urrounded by a concentric tube 231b
forming a cooling water discharge duct, as ~ndieated by the
arrow at 231e in Figure 20. Radial pas~age means 231d pro-
vide for the ~low o~ water from the central passage to the
peripheral water eooling ~paee 233 and passage means 231e
provide an outlet irom the opposite limit oi said spaee
arcuately iroa the inlet and diseharging it to tube 231b.
There is a refractory shoe 237 loeated against, or
very close to, the upper left quadrant oi the roll 230 with a
central passage 238 through ports 239 through ~hich molten
metal is supplied to the cavity or pocket 240 formed between
the ~hooand the periphery of the roll. This cavity or poc~et
open~ upwardly in the direction of rotation of the roll which,
as here sho~n, is cloek~i~e and retains a pool of molten ~etal
against that portion oi the periphery oi the roll which at any
moment is submerged beneath the said pool. As the roll rotates,
, ~.
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~, r.
lO~gl73
~ thin l~yer of met~l ~olidiIies on the water-cooled suriace
and Iresh metal is continuou~ly supplied through pa~sage 238
and ports 239 as metal ln the pool i~ removed. llhen the
reiractory ~egment moves beneath the pool oi molten metal,
none of it solidiries against said sur~ace. Belo~ the ~ur-
face OI the roll 230 there may be a trough or pan 232a for
holding a release compound into which surface 232 oi the roll
dips to enable the castine to be more easllr stripped from the
~auri'ace oi' the rollO ~ ~imilar result may be achieved, OI
course, by operating ~he chill sur~ace continuously bu* ~ ;
periodically cutting oi'f the supply of molten metal to the
pool.
Above the roll there is a track ~tructure cc~prising
a center section 240 along which a supporting table or plate
241 moves ~rom leit to right Iirst over the roll 230 generally ;
tangent thereto. The solidiiying layer oi metal on roll 230 .
is stripped ~rall the drum with the aid o~ stripper 242, and
held against the undersur~ace of the plate magnetically or ~
si~ply by the counterpressure exerted by a weighted or spring- ;
biased counterpre~sure roller 243, and subsequently by the
pairs oi pres~ure rolls 244 and 245. A~ter the initlal pass -~
oi the plate over the roll 230, subsequent layers will be sup~
plled, each against the preceding one until a slab of the
required thickness ha~ been produced.
The track structure has a run-out end section 246 to
. ~ . .
the right of the center section 240 onto which the plate 241
travels between pairs of rollers 245, then elevated to travel `~-
in the reverse dlrection between pair~ oi rollers 247 and
~urther bet~een rolls 247a, on track section 248 and lowered ~-
to repeat a pal3s over the top of the casting roll ~here a
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1()~9173
~econd and, ln a ~imilar cycle, succeedlng larers are pres~ure
iused to the prev~ously applied layer until the ~lab has
attalned the requlred thickness.
Each cycle starts with the right end of plate 241 in
line with a vertical line oi centers extending ~rom roll 230
to counterpressure rollers 243. It will be noted that there is
a heat insulating slab 241a therein, set back ~rom the leading
edge of the plate. Also, at the start of the cycle, the
heated segment i8 immersed under the molten metal in the
cavity 240.
As the rotation o~ the roll 230 atarts, the plate
241 begins moving toward the right, and as the leadlng edge
of the solidified layer on the water-cooled area o~ the roll
230 is lifted o~i roll 230, it is pre~sed between roll 230 and
the leading end of the insert 241a. When the roll 230 has -~
co~pleted one conplete revolution and the refractory segment ~-
is again in the "start" position, the plate 241, ~hicb is now ~
supported on track section 246, ~ill be raised by liiting the ~ ~ -
track section and placed pa~sed over the casting roll but at an
elevated level above it to the left onto elevated track sec-
tion 248, ~hich is then lowered and the plate moved toward the
right to its "start" position,
Thi~ is but one ~ay in ~hich individual sections are ~ ;
formed and layered without any cutting of a continuous ~trip.
Of course, the apparatus of Figures 16 to 18 could be used by ~ - ~
feeding the successive individually cast pieces down the ~ ~ -
e lo~ure 220 o~ Figure 16, but no ~hear ~ould be required. ~ -
~ith such an arrangement, a separately cast length could be
layered on eaeh pass o~ the table beneath rolls 217 and 217a ~-
or with each pass in one direction only, Various other
,'.' ~ ~ ''~'
., :
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1~)89173
apparatus, as herein dlsclosed, may be used ~or layering the
successive length~. Blllets may be changed ln length by
increa~lng the heated segment of the ca~ting roll and decreaslng
the length o~ the chill sur~ace, sub~tltuting one roll ~or
another.
Al~o, in the ~oregoing de~cription, any apparatus
or procedure illustrated in any o~ the ~igure~ may, where
relevant, be used with or ~ubstituted ~or a part having a llke
~unction in any other ~igure, such as for exa~ple, a chilled
roll as shown in Figures 1 and 2, may be substituted ~or an
endless belt casting unit or vice versa and elements or means
or ~teps shown in one ~odi~ication may be used ~here applicable ~ -~
in other modi~ications.
In each o~ the several appæratus e~bodiments and
~ethods herein ~hounand described, there i8 a single or primary
castlng unit, operating continuously or inter~ittently, capable
o~ provlding all of the piece~ or layers required to produce a
,~.
complete billet, whereas, in ~y earlier filed application, a `~
minimum o~ two casting units, one ior formlng an under-layer and
one ~or ~orming an over-layer, are required and for each addi~
tional layer another casting unit is neces~ary. This casting
unlt o~ this invention may ~orm individual pieces directly or
include means ~or continuou~ly ~orming a casting with shearing
- means ~or dividing the casting as ~ormed into separate pieces
; or layers. Also in the present application successlvely ~ormed
pieces are stacked at a temperature where the last layer will
pressure weld to a previously ~ormed layer so that a p~s
through a ~ingle pressure unit, which, however, may co~prise
successive step~, as in Figures 8 and 9, where pressurs plates
e~ect an initial ~u~ion which may be improved by subsequently
,~
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.. . . . .
1089173
rolling the assembled slab. In my sald copending application
thera are required to be ~eparate roll ~tand~ for each added
layer, The pre~ent inventlon also provides a production llne
in which one stacking unit or operation takes care o~ stacklng
all of the pleces ~rom a ~lngle casting unit. Thls, however,
does not exclude a method or apparatus as disclosed ln Figure
7, ior example, where two casting unlts may ~upply layers to
the same stacking and pressing rolls ~uccessively or by inter- -
lea~ing strands fro~ t~o casting unit~ where a thlcker blllet
is to be ~ormed than can be produced econo~lcally on a single ~-
casting unit, or where, as disclo~ed in Figures 12-14, a ~ -
single pre~sure roll unit 140 accepts indivldual pieces to
$orm successive layers of a billet cast in castine unit 145
and line 150 and ~hich, at the same time, accept~ ~tacked and
initially welded pieces irom line lSl and provides a second
pres~ure rolling pass ~or finishing slabs assembled on
stacking units 170 and 170'.
The term "casting unlt," as herein used and unless
othor~ise stated, comprises either n arrangement ~herein the `~ ;
casting roll delivers individually formed ~eparate layers or
pieces or where it delivers a single strand that is sheared to
produce separate layer~ or pieces while the pieces are still
hot enough, either as sheared or-with added heat to be pres~
sure welded to the con~ronting surface of a previously formed
layer. The terms "stacking unit" or "layering unit" include
apparatu~ where the cast pieces or layers are brought together -~
in superimpo~ed relation and face to iace contact, and the ter~
"pressure ~lding unit" ~or applying pres3ure, either by rolls
or opposed pres~ platens or the like, may, in many cases, be
also a part of the stacking or layerlng operation The term
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.. ~, ........ . .. . .
, . ~ . . . . . ............................... ..,, - . . . ~ . , . . ~
1089173 ~
"pre~sure welding unlt" may al~o de~ine an arrangement a~
shown, for example, ln Figure 13 ~here an initial pres~ure i8
applied in press 170-171 or 170'-171' and final con~olidation
is e~fected in roll stand 140. Also it includes apparatu~ a~
disclosed in this ~igure where a slitting roll, as 62 in
Figure 7, would divide the strand length~i~e into t~o piece~,
one of which would be moved o~er top o~ the other and initially
pressed together in unit 170-172 to then be discharged onto
bed-plate 160 to await the discharge of a second pair to be
then passed through rolls 140, Alternately a pair of two may
first be fused together in pres~ 170-172 and then moved
through roll~ 140 to receive a second pa~r ~ro~ pres~ 170'-172'
and then returned to the first position and thus alternated
until a piece of the required thickness had been completed. :~
It may be iurther noted that the terms "billet" and
"slab" a~ used herein to designate the composite body produced
as herein described are not strictly limited to bodies in~ended
to be converted to a finished product by reheating, but i~
intended primarily to indicate shape, as a billet primarily
ind~cates a shape which i# thicker and more nearly of square
section while slab refers to a product the width of which 18
much greater than the thickness. Each term, however, i8 used
in the sense o$ a semi~inished product intended to be sub-
~equently converted to a finl~hed product by further wor~ing,
hot or cold.
In addition, or in lieu o~, the means herein
illustrated for supplying heat to the piece~ as they move
bet~een the casting unlt and the pressure welding unit, torches, :
inductive heating means, etc. may ~e located at the bight where
pre~ure rolls engage the layer or layers to supply heat
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, .
1()89173
locally to a~sure adequate pre~ure weldlng of the layers, but
~or clarity oi illustration and the small ~cale of the drawings,
have not been ~ho~n.
Typically, each cast layer in a billet or 31ab will
be o~ the ~ame thlckness and this thicknes~ uill be in the
range o~ perhaps 2 mm. to about 5 mm., but may be thinner or
sllghtly thlcker. The invention will doubtles~ ilnd applica-
tlon principally ln smaller ~hop~ and in specialty ~teel
production, but thi~ ls not necessarily the case.
It i8 al80 well kno~n to metallurgi~ts that, in
processes such a~ this ~here intercrystalline dif~uslon take~
place, time and temperature are signiiicant variables, 90 that
in some ca~es it may be desirable to retain the pre~ure ~elded ~;
product at elevated temperature in the nonoxldizing atmosphere
to take adhntage o~ these factors before e~posing the product
to ambient temperature.
;.
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:
