US2740177A - Continuous metal casting process - Google Patents

Continuous metal casting process Download PDF

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US2740177A
US2740177A US369292A US36929253A US2740177A US 2740177 A US2740177 A US 2740177A US 369292 A US369292 A US 369292A US 36929253 A US36929253 A US 36929253A US 2740177 A US2740177 A US 2740177A
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mold
metal
casting
shell
zone
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Jr John S Smart
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American Smelting and Refining Co
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American Smelting and Refining Co
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Priority to DE19541408397 priority patent/DE1408397A1/de
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
    • B22D11/1241—Accessories for subsequent treating or working cast stock in situ for cooling by transporting the cast stock through a liquid medium bath or a fluidized bed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/14—Plants for continuous casting
    • B22D11/141—Plants for continuous casting for vertical casting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/14—Plants for continuous casting
    • B22D11/147—Multi-strand plants

Definitions

  • the castings from 4such prior Yprocesses have been characterized in varyingfdegreeby certain surface defects and internal faults.
  • the surface defects in the castings from such prior processes may take the form of a plurality of small lateral ⁇ surface cracks, wrinkles,v crumpled areas which are usually-composed of minute longitudinal gouges confined to an area or zone; or rough, shaggy surfaces.
  • the surface cracks may oe so severerthat thecasting rnaybreak in the mold.
  • the surface may become so rough and shaggy, due to bleeding ofthe lower freez-V ing constituents, ⁇ that the y'casting mayA become jammed in the mold and may be broken during the withdrawal from the mold.
  • dissolved gases released from the molten metal during the freezing may become entrapped in the interior of the castingand cause internal faults.
  • Such entrapment generally results in a porous internal condition usually evidenced by small wide-generally ranging from visuall to microscopic in size, and'mayause brittleness in the casting or loweringbf tensile strength.
  • the entrapment -of the gases may result in relativelyvlarge'interior voids,tand this condition may become s severe as to cause a'con tinuous channel in or adjacent Ythe center of the casting..
  • the invention comprehends introducing molten metal intol one end of an'open-ended mold having an un cooled sectionk and a chill section .ofhigh thermal conductivity dividing the moldrinto an uncooled zoneanda chill zone which is in substantially fixed relationshipr and immediately adjacent to theuncooled zone, with eachy of the zones surrounding the metal contained Vin their re.- spective portions of the mold.
  • the temperature of the inside surface of the uncooled zone is maintained above the melting-point of the metal and the temperature of the inside surface of the chill zone is kept below the freezing point of the metal in that zone.
  • rl'he molten metal is introduced into'the end'of the mold containing the uncooled zone at a rate which, in' relation to the rate of metal withdrawal from' the lmold,'is sucient to maintain molten,A non-turbulent meta-lin the mold-beyond that 'plane in ⁇ theuncoo1ed :zone'which lies 2.. nearest the chill zone, and which passes through ⁇ the entire cross-section of -the mold intersecting the molds longitudinal axis and in which themetal .remains entirely molten during the process.
  • the metal in the moldis maintained stationary with respect to the mold (i. e.
  • -no metal is withdrawnfrom the mold.) until at least the outer surface ofthe metal in the chill vzone extending-sub? stantially to said plane, is frozen into a shell of suilicient thickness and strengthA to permit .intermittent withdrawal of the .shell fromthemoldlwithout rupture of the shell.
  • the formationtofthe shell, at least .a'major por,- tion .of the ⁇ sensible andnlatent heat requiredtofreeze the metal constituting .the shell is .rapidly withdrawnsube stantially laterally from the metal .through the. surface of the chill zone due .to thehigh thermal conductivity of the wallsof-.the mold in the chill zone.
  • the .frozen shell and anyunfrozen metal encompassed thereby are withdrawn intermittentlywith respect to the moldfrom that end of the mold which contains the chilly sectionby intermittently withdrawing the castingtherefrom.
  • the rate ⁇ and period ofthe intermittent withdrawal of the casting is such that ⁇ a major portion of the shell of the with ⁇ drawn casting is ⁇ formed within themold while the-casting is stationary with respect thereto.
  • the periods ,be-v tween vwithdrawalperiods are also such that .themetal remains entirely molteninthe.intersecting plane inthe uncooled zone.
  • low melting constituents especially those which yinthel solid state are-harderthanthe bodyof the casting, cause' a rough, shaggysurfacefonvthe-casting'and may-proceed to suchan extent as tojam inthe mold.
  • l ln such an event; lthe casting may break due tothe tension required to with-zl drawit, orthe mold :may'break if it is constructedof a fairly brittle material such-as graphite.
  • Rapid cooling to such temperature quickly freezes the metal in the interdendritic channels to produce a shell which is impervious to the low melting constituents before the latter material can vbleed to the outer surface of the shell. Thereafter the outer surface of the shell is maintained below this temperature during the freezing of any remaining molten metal encompassed by the shell.
  • the mold is preferably vertically disposed, with the uncooled zone in the upper portion and the chill zone in the lower portion of the mold.
  • the most preferred procedure is to practice the process with a stationary mold and to withdraw the casting intermittently from the stationary mold.
  • the rate and period of the metal withdrawal from the mold is such that substantially all of the shell of the withdrawn metal is formed Within the mold ⁇ while the metal is stationary with respect thereto.
  • the linear length of the withdrawal stroke preferably is not in excess of about 2". Withdrawal strokes not in excess of about l" are the more preferred, with withdrawal strokes not in excess of about 1/z as the most preferred.
  • the rate of withdrawal during the withdrawal stroke is as'high as possible.
  • the mold be vertically disposed with the uncooled zone above the chill zone to allow the released gas to escape upwardly and away -from the freezing metal.
  • the mold is held stationary, i. e., stationary with respect to the earth, and the metal is withdrawn intermittently from the mold.
  • the linear length of the Withdrawal stroke is not in excess of about 2 and that the period between any two adiacent withdrawal strokes, during which time the metal within the mold is stationary with respect thereto, is such that no metal in a molten state exists below the physical intersection between the uncooled section and the chill section at a distance which is greater than the largest lateral cross-sectional dimension of the mold cavity, and that molten metal only exists above the referred-to plane which intersects the longitudinal axis of the uncooled zone.
  • the withdrawal stroke does not exceed one linear inch and for best results the stroke is not in excess of about 1/2.
  • the molten metal may be introduced into the mold in any desired manner.
  • the mold may be iixedly attached to the bottom of a molten metal holding furnace with the metal flowing directly into the mold so that a column of metal extends from the bottom of the casting to the top of the liquid metal in the holding furnace.
  • Such introduction of the metal into the mold causes no turbulence in the molten metal in the mold.
  • the metal has no free surface in the mold.
  • a free metal surface in the mold may also be practiced.
  • the metal may be led into the mold by a pipe or other conduit which terminates within the mold at, above orybelow the surface of the molten metal therein; or the metal may be introduced as a free falling stream.
  • a free metal surface in the mold is preferred for casting shapes having a relatively large cross-sectional area, and especially solid shapes in which the smallest dimension of the cross-sectional area is greater lthan about 3".
  • the turbulence of the metal entering the mold may extend to the freezing metal and cause irregularities such as wrinkles, ripples, cold shuts and the like to be frozen into the surface of the casting.
  • turbulent motion is to be avoided inV this region, it should be noted that nonturbulent motion may exist and may in some instances be desirable.
  • the process may be practiced in connection with any ferrous or non-ferrous metal or alloy, and such material may be cast in any solid or hollow, circular or polygonal shape.
  • the process of the invention is most effective in connection with the casting of copper and copper base alloys such as, for example, tough pitch copper, low oxygen coppers including oxygen-free copper and phosphorous deoxidized copper, brasses, bronzes and the like.
  • alloys include metallic mixtures in which the components are completely miscible in each other in the molten phase, as well as metal mixtures which are not miscible in this phase.
  • the mold may be fabricated of any suitable material, and different materials may be used in any one mold.
  • Material of high thermal conductivity is used to fabricate the chill section.
  • thesurface of the uncooled section or this entire section is composed of a material which is, or is substantially, not wet or dissolved by the,
  • moltenV metal In general, graphite molds are preferred, especially in the casting of copper or copper base alloys containing tin, although molds of a suitable metal may also be used.
  • a free metal surface in a graphiteV mold the exposed interior and exteriorwalls of the uncooled section of the mold may be protected by a ceramic or replaceable graphite insert for this section.
  • this section may be protected by an inert or reducing material such as nitrogen, carbon monoxide or other reducing gas, powdered magnesia, powdered graphite, charcoal, coal, orcoke breeze Y and the like.
  • thev chill section may be Y composed of a metal, especially copper, and theiuncooled section of graphite or a ceramic material.
  • the chillV zone may be established by a jacket surrounding the chill section of the ⁇ mold through which Water or ani other fluid coolant may be circulated.
  • the high thermal conductivity of the chill section thus affords rapid lateral extraction of heat from the metal in this portion of the mold.
  • the mold is characterized in operation by cold walls in the chill section and a sharply increasing temperature gradient in the mold wall just above this section in the uncooled section.
  • Fig.; 1 isanfexaggerated 'view partly vin'.ver5ti tal:seet-ionf. illustrating a. preferred:-metliod anda apparat-'usifor com ⁇ ducting the fprocessot 'theii'lventiion tofcastzsmall shapes
  • Fig. 3- is.' a fvertical section'. through" a fmoldf and; I. illuse trates a l modified: method and mold :f-for) casting t small: shapes; ⁇
  • Figui is atop view of Figg along thefline 4?-4 in the. directionl of the arrows;
  • iis; ⁇ an enlarged .-vertical.sectionI of t a mold illus tratingttheevarious Icondi-tionsrexistinggin the'moldduringf thef practiceeof the processi 6. is. a i horizon-tal ⁇ crossssection off the --mold or- Fig. 1.
  • Figs.. 7 and 8 are -similar to -Figafandzshcwf m'oldssot different cross-'sectional j shapesrc c Fig. 9 :is .a specimen casting;.displaying-surfacefcracks.i
  • Fig. .10 isa specimen-casting simi-lar incomposition to. that fof Fig., 9 but producedin -accordancewith jthepresent process.
  • Fig.:12 isfa specimen .oan .alloyof-J composition .simi-.- lar to that or" Fig. 1l but castin ⁇ accordancewiththe pres-.- ent v invention. 4
  • Fig.. 13 vis a Yspecimen of metal ⁇ displaying-gas. entrapz-.L ment. ⁇ pl1enon1ena.
  • Fig.. 14 is -aspecimen castingfsimila'r incomposition to.. thatof ⁇ Fig.- 13 but cast infaccordance withlthe, present. process.-
  • Fig.15 is-a disc4 which. was-:cut fronrthespecimensof.
  • Fig. 16-' is .a disc. similarA to ⁇ Fig.; 15but specimen of Fig; 14.
  • FIG. .l there. is showna. general assembly of a molten. metal ⁇ -holdi'1:lg..v furnace;V 1,1 mold 2 and intermittentv withdrawing. means-indicated; generally by the .numeral 3. for. withdrawingrcastingd: fromuthe mold.
  • the rnold-2 v extendsthroughthe bote torn of the furnace 1 and in contactwith Vthem'olten.metal 5 therein.
  • the mold is iixedlyjattached to. thebottomof the-furnace .by means ofthreads 6which engagemating threads 7 in the furnace bottom.
  • Thelower section ofi the-mold is surrounded by water jacket8 whichlprefe'rr ably is iixedly attached thereto.
  • Wateror otherfcoola'nt is circulated through thejacket in any .desired'rnannerl
  • the water jacket establishes in themolclanuneooled.'v zone 9 and a chill zonelt). The latter zoneextends yertically upward beyond the upper edge of the jacket 8 to the line C-C.
  • the exact locationof-.thisline and of the plane passing through it isdeterminedhythe thermal conductivity of the mold materialgthe thermal -conduc ⁇ tivity of the metal being cast, the sensible and latent heat of the metal tovbe cast, the cooligcapacity of thejacket 8 in relation to the cross-sectional' dimensions of "the mold, the period during which the metal is stationary in the mold and the rate and/period of the withdrawal stroken dtu'ingfthe intern'littentv withdrawal.
  • the plane passing ⁇ through lin-e C-C' is the lowest plane. inwhich the metal.. ⁇ remains entirely molten duringthe process.'
  • WitlnirawalV means whichgincluderolls llt-jat: ⁇ least'one of which; as'shown', may be drivenby.electricsv motor 12;.by. means ⁇ ofqbelt 13. OperativelyL connected 1to1' cut. from ⁇ the themotor 4121s startinigandstoppngswitchnlltttorfoperate- 75":
  • TheV 'means-3. may .also include' any suitable lbraking means suchias is AillustratedI bythe shoe15 ⁇ which engagesithe brake drum leon-.the roll 111.' The lshoemay-beoperatively connected :by .levers 17 andi to-switch .14 :so as to brake and quicklystopthe wheels' when 'the motor-121 is tu1ned..lotl.
  • The-switch 14 mayxbe manually.
  • Fig.2 ⁇ shows a graphitemoldin'which the process mayibe conducted with afree metal surfaceinthe'mold, ⁇ preferably for casting large-shapes; Asislrown, thernold 2r providedwith water jacket'Sis supported 'by legsitwhich 21 which may, iny turn, ⁇ 5
  • any suitable tilting furnace may be used. As illustrated, the furnace may bepivotahly mounted on support 27 and may be tilted -as desired byhydraulic jack 28 suit-v ⁇ ably'. attached to the furnace at 29.
  • the launderZS likev wiser may Dbe mounted on pivots .30* toadjustfthehei'ght which f height .preferably .isasA short as-possibiet Y in operation, thefu-rnace 24-is tilted to deliverfmolten ⁇ metal at a rate which, in relation to the rate of withdrawal.
  • the casting. f4' may be vwithdrawn intermittently-from the mold by. rollsl l in the same manner as' described in Fig. vl. In passing to the rolls l1. thecasting may pass through vwater tankZ- which may beprovided witha suitable seal 33, such as a rubber; gasket.” Suitable severingmechanism (not shown) vmay blused ⁇ in the'amnaratus of.Figs. l and 2 below thero-lls 11 to sever the castiuginto-v any desired length. Also, in startingeither type'off'ap'pa ⁇ v ratus-.a solid bar. may-be placed-in the rollsll' 'sofas-*tol extend up into the mold. After the initially vintroducedmetal has been frozen, the starting harl is withdrawn.
  • The:k apparatus large shapes4 and inasmuch as the illustratediu Fig. i2 isffusefulin casting .particularly for ycasting shapes of "copper air.
  • a pool of metal of sufcient depth to establish the desired nonturbulence includes one in which a portion of the metal is replaced by a protective layer of solid material.
  • this section may be protected by a wall 3S surrounding this portion cf thc mold. A space 36 between such a wall ⁇ and the mold may also be filled with the protective material.
  • the uncooled section of the mold may contain a ceramic or a replaceable graphite insert protecting the inner or both the inner and outer surfaces of this section of the mold.
  • the chill section also may be fabricated of a metal such as copper and the uncooled section of the mold, as well as the launder 25 and the space in furnace 24, may be protected by an inert or reducing gas.
  • Fig. 2 affords good insulation and assures the maintenance of a temperature in the uncooled zone of the mold, which is above the melting point of the metal being cast. This is especially advantageous where the uncooled section of the mold is fabricated of a material of high thermal conductivity such as graphite. Heat, if and when necessary, may also be applied to this section of the mold.
  • the mold itself may be reciprocated so as to withdraw the casting inter mittently with respect to the mold.
  • the mold itself may be reciprocated so as to withdraw the casting inter mittently with respect to the mold.
  • the casting may be lowered continuously with respect to a point in space and while being so lowered the mold may be lowered at the same speed as the casting during the period in which the metal is stationary with respect to the mold.
  • the mold then is moved upwardly at the same or a dierent speed as the downward speed of the casting during the intermittent periods in which the metal is withdrawn from the mold. ln such a procedure, as well as that described inFigs. l and 2, the relative motion between the mold and the casting during the intermittent withdrawal periods preferably is as rapid as practicable. Also at the end of the withdrawal stroke the relative motion is stopped as rapidly as possible with a minimum of coasting.
  • mittent removal of the present process permits net withdrawal rates which are 20 to 30% greater than those possible with a process in which the casting is continuously withdrawn with respect to the mold. At the same time, all the enhanced surface and interior characteristics of the process are obtained.
  • the stationary period between any two adjacent withdrawal periods is of such duration as to form a shell of suticient strength and thickness to withstand withdrawal of the casting without rupture. This condition is evidenced by the smooth appearance of the surface of the casting'emerging from the mold, and in practice this period may be adjusted as required to obtain such surface characteristics. tends substantially to the plane C-C' in Fig. 5.
  • a length of casting corresponding generally to the linear length of line C-D in Fig. 5 is withdrawn and the cycle is repeated.
  • the rate of withdrawal is such that a major portion and preferably substantially all of the outersurface of the withdrawn casting is formed as shell 37 while the metal is stationary in the mold.
  • the stationary period may be just suihciently long to form a shell of required thickness to permit withdrawal which, lin the case of alloys of non-eutectic and non peritectic composition, is also of sufn'cient duration to cool rapidly at least the outer surface portion of the shell to a temperature below the temperature of the lowest freezing component of the alloy which in the solid state is harder than the matrix of the casting.
  • molten metal may exist in the interior of the casting to any desired depth below the edge of the chill section.
  • the lowest levell at which molten metal may exist in the interior of the casting with such a procedure will depend, among other factors, upon the size of the casting, the over-all length of the water jacket 8, the amount and extentnof cooling below the plane passing through points D-D in the mold, and the duration of the stationary period.
  • the linear length of the withdrawal stroke is affected by the speed of withdrawal and especially the starting and stopping phases of this step, depending upon the mass of the casting.
  • the withdrawal stroke preferably is not in excess of about 2" in length. Very good results are obtained with withdrawal strokes not in excess of about 1", and best results with withdrawal strokes not in excess of about l.
  • the stationary period preferably is Vsufliciently long so that no molten metal exists in the casting below the intersection of the uncooled and the chill sections of the mold at a distance which is greaterthan the largest horizontal dimension of t the mold cavity. This is illustrated in Fig. l by the point E" below which no molten metal exists.
  • the length of the line 38 extending from the top edge 39 of the water jacket 8 to the point E is not greater than the largest horizontal dimension of the mold cavity.
  • This latter dimension is illustrated in Fig. 6 by the internal diameter 40 in the case of a mold cavity which is circular in crosssection.
  • This dimension is 42 in the case of a rectangular mold cavity shown in Fig. 7 and bythe line ⁇ 43 in Fig. 8 in the case of a mold having amandrel44 for the casting of hollow shapes.
  • FIGs 1 :and 2,2 a .fmold.:. 15 havingaiplurality of mold cavities may be used; especially inithe'casting of small'shapes; ⁇ Such ralternativeconstrucei tion is iillustrated in'Figs. 3fand 4*in.'.which"the'mold. 2 is:provided with a 4plurality of cavities'45g46 'and4'7fwith ⁇ f thechill zone being establish'edfby'a1singlewater.jacket48.
  • Example I Commercially pure copperwaszcasttin apparatus :simiei Y lartto'th'atshown in Fig. 1 'exceptrth'atitheacastingzwas withdrawn continuously from vthe moldat'a constant rates of 19% inches per minute; A ⁇ .solid cylindrical :castings-3 a inches in diameter was produced. Circulating iwater was". used'in the water jacket 8'surrounding1hel graphiteimold. 35 2; Fig. 9 is a photolithograph offa'sectionof the :casting: thusproduced. It will be'noted that 'the surface'containsa plurality of horizontal cracks'.v
  • Exampler II The procedure Aof Example I wasAl repeated zexcept thatv a-s0lid, cylindrical casting4 inches.in-diameterfwasproe quizd and the casting was withdrawn intermittently from: the stationary mold 2.
  • the intermittent withdrawal :periods were 3 seconds in duration, durin'geachfoffwhichthe linear length of'casting withdrzufvnzwas. ⁇ 1/sof'.an.'.'inch.
  • Each stationary period between vadjacentxwithdr'awal: peri-pV odsl was 1 second in. duration.I Figs.10Iis-aphotolithoav graphtofthe casting thus produced. It;will befnotedthat the4 surface vof the casting ⁇ is :smoothnand free fof; surface cracks.
  • Example I wasfrepeated-.to produce: a tubeof an alloy composedof 88%:copper, 10%.tin.v and 2% zinc.
  • the tube produced wasl%2,-inches inout- 55 side diameter and1/2 inch'in its inside .diarneter..
  • Thef. graphite mold had the cross-section of .thatillustrated in Fig. 8.
  • the water jacket surroundedftheoutside-.surfacef of the mold 2 inthe chill scctionand. no water was'scircul lated through the'mandrel 44-. ⁇
  • The-tube was continufy 60' ously withdrawn from the stationary mold at a constantv rate ⁇ of.ll% inches per minute. Thesurfaceoffthe.
  • Example-I V The procedure of Example I was repeatedexcept-v that aY solid,V cylindricalv ⁇ casting 1%1"A inches: in' diameter: 'was produced fromv analloyisir'nilarto thatfoffEXampllII" containing; 90 ⁇ % ⁇ " copper-"and 10%? Inftheepresentl 751y ously withdrawn from the mold atithe zcastingawas withdrawn intermitexample, however, tently( from .the stationarymold. The. intermittent withdrawal periods were2 "seconds-in duration; and yduringwell below the freezing temperature ofthe lowest'freezf ing constituent in the alloy.-v The -surface of the casting thus produced isshown in Fig. 12. It will .be noted that it s free of the rough, shaggy'exudationsV foundin Fig. ll.v
  • Example.y VI The procedure-of Examplel composed of 90% copperand'10%t mold.
  • the intermittent withdrawal periodsl were 3 seconds in duration, and during each such period 0.35 Alinear inches of casting stationary period secondV in duration.
  • Example VII rod stock 1% inches in diameter analyzing 98% 2% tin and 0.25%
  • the -rod was lcontinuthe rate of 51/2 inches perminute.
  • the Asurface ⁇ ofthe rod had 'the roughand shaggy surface illustratedinfl-iig.v 1l.
  • Example VIII Thexsame :size and'composition of rod as thatset forth inEXampleVIIwas made nlaccordance with the present invention .in apparatusxof..thetypexil1ustrated in Fig. l
  • Example IX The procedure of Example VII was repeated to produce rodV stock l/s inches in diameter and analyzing 84% copper, tin, 295% lead and Bti/2% nickel. The rod was withdrawn continuously from the stationary mold at a constant rate of 51/2 inches per minute. The produced rod has a surface which was even more rough and shaggy than that of Example Vll.
  • Example X The same size and composition of rod as that of Example iX was made in accordance with the present invention using apparatus of the type illustrated in Fig. l and which was equipped with a graphite mold.
  • the casting was withdrawn intermittently from the stationary mold using Withdrawal periods of three seconds duration. In each withdrawal period 0.465 linear inches of rod were withdrawn from the mold; this rate amounting to a net withdrawal speed of '7 inches per minute.
  • the stationary periods were l second in duration.
  • the outersurface of the shell of the rod formed in the mold was rapidly reduced during the stationary periods to a temperature well below the freezing point of the tinrich constituents of the alloy but not below the freezing point of the lead-rich constituents.
  • the casting had an exceptionally smooth, even surface of the type illustrated in Fig. l2.
  • the present invention provides a continuous method of casting ailoys of non-eutcctic and non-peritectic composition to eliminate the rough surface caused by low melting components which in the solid state are harder than the body of the casting and which in prior processes bleed to and freeze on the surface of the casting.
  • the invention also provides a method for casting metals and alloys so as to reduce or eliminate surface cracks. ln addition, it provides a step for eliminating surface imperfections caused by turbulence in the molten metal irnrnediately before freezing, such as is encountered with molds having a free metal surface into which molten metal is introduced as a free falling stream.
  • the invention further provides a process in which castings are produced which have enhanced surface characteristics and at the same time improved internal characteristics by eliminating or reducing internal faults due to entrapment of gases which are released by the molten metal as it freezes.
  • a continuous metal casting process comprising introducing molten metal into one end of an open-ended mold having an uncooled section and a fixed cooled section of high thermal conductivity dividing the mold into an uncooled zone and a chill zone immediately adjacent to said uncooled zone with each of said zones surrounding the metal contained therein, continuously maintaining the temperature of the inside surface of said uncooled zone above the melting point and the temperature of the inside surface of said chill zone below the freezing point of the metal contained in the respective zones, said molten metal being introduced into the end of the mold containing the uncooled zone at a rate which in relation to the rate of cast metal withdrawn from the mold is suiicient to maintain molten and non-turbulent metal in the uncooled zone of thc mold in the vicinity of a plane which intersects saidY zones and in which plane the metal remains entirely molten, maintaining the metal stationary with respect to the mold in the chill zone until at least the outersurface of the metal extending substantially to said plane is frozen into a shello'f suicient thickness and strength to overcome the surface friction forces between
  • a continuous metal casting process comprising introducing molten metal into one end of an open-ended mold having an uncooled section and a fixed cooled section of high thermal conductivity dividing the mold into an uncooled zone and a chill zone immediately adjacent to said uncooled zone with each of said zones surrounding the metal contained therein, continuously maintaining the temperature of the inside surface of said uncooled zone above the melting point and the temperature of the-inside surface of said chill zone below the freezing point of the metal contained in the respective zones, said molten metal being introduced into the endof the mold containing the uncooled zone at a rate-which in relation to the rate of cast metal withdrawn from the mold is .suicient to maintain molten and non-turbu lent metal in the uncooled zone of the mold inthe vicinity of a plane which intersects said zones and in which plane ⁇ the metal'remains entirely molten, rnain-.v taining the metal stationarywith respect to the mold;
  • a process according to claim 2 in which a free falling stream of molten metal is introduced into the top of a vertically disposed mold having said uncooled zone in the upper portion and said chill zone in the lower portion thereof, and in which there is maintained in the uncooled zonea pool of molten metal of sufcient depth to dampen the turbulence caused by the incoming stream of metal and to establish non-turbulent metal in said vicinity of said plane.

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US369292A 1953-07-21 1953-07-21 Continuous metal casting process Expired - Lifetime US2740177A (en)

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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2955333A (en) * 1957-04-11 1960-10-11 Ici Ltd Electric arc furnaces
US3278999A (en) * 1964-02-04 1966-10-18 Mesta Machine Co Apparatus for continuous casting of metals
US3354936A (en) * 1965-05-26 1967-11-28 Anaconda American Brass Co Continuous casting process
US3375107A (en) * 1965-10-11 1968-03-26 American Smelting Refining Copper base alloy and method for its manufacture
US3415306A (en) * 1964-07-23 1968-12-10 Olsson Erik Allan Method of continuous casting without applying tension to the strand
US3638715A (en) * 1969-02-27 1972-02-01 Schloemann Ag Method for the continuous casting of tubes
US3752216A (en) * 1969-05-14 1973-08-14 Sandel Ind Inc Apparatus for homogeneous refining and continuously casting metals and alloys
US3797555A (en) * 1971-09-30 1974-03-19 Noranda Mines Ltd Method for continuous casting of metal strips
US3834446A (en) * 1972-04-10 1974-09-10 B Medovar Mould for electroslag remelting of metals
US3916985A (en) * 1971-09-30 1975-11-04 Noranda Mines Ltd Apparatus for continuous casting of metal strips
US4674559A (en) * 1985-01-28 1987-06-23 Inresa Schultheiss Gmbh Continuous caster
US4736789A (en) * 1978-07-28 1988-04-12 Kennecott Corporation Apparatus and method for continuous casting of metallic strands at exceptionally high speeds using an oscillating mold assembly
US4899801A (en) * 1986-06-10 1990-02-13 Asaba Co., Ltd. Method for continuous casting of metal and an apparatus therefor
US5116027A (en) * 1989-05-03 1992-05-26 British Steel Plc Apparatus for controlling teeming streams
US20180250736A1 (en) * 2015-09-16 2018-09-06 Posco Vertical semi-continuous casting equipment and vertical semi-continuous casting method

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2128943A (en) * 1936-04-01 1938-09-06 American Rolling Mill Co Formation of encased structures by direct casting
US2136394A (en) * 1935-06-29 1938-11-15 Frank F Poland Casting metal
US2195809A (en) * 1936-06-22 1940-04-02 American Smelting Refining Continuous casting
US2225416A (en) * 1937-05-08 1940-12-17 Junghans Siegfried Continuous casting process
US2242350A (en) * 1938-10-06 1941-05-20 Continuous Casting Corp Continuous casting of metal shapes
GB598385A (en) * 1944-07-10 1948-02-17 Rossi Irving Improvements in processes and apparatus for the continuous casting of metals
US2527545A (en) * 1947-05-02 1950-10-31 Norman P Goss Apparatus for continuous castings
US2667673A (en) * 1951-03-19 1954-02-02 Nat Lead Co Apparatus for casting metallic rod
US2682691A (en) * 1949-07-09 1954-07-06 Babcock & Wilcox Co Continuous casting process and apparatus

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2136394A (en) * 1935-06-29 1938-11-15 Frank F Poland Casting metal
US2128943A (en) * 1936-04-01 1938-09-06 American Rolling Mill Co Formation of encased structures by direct casting
US2195809A (en) * 1936-06-22 1940-04-02 American Smelting Refining Continuous casting
US2225416A (en) * 1937-05-08 1940-12-17 Junghans Siegfried Continuous casting process
US2242350A (en) * 1938-10-06 1941-05-20 Continuous Casting Corp Continuous casting of metal shapes
GB598385A (en) * 1944-07-10 1948-02-17 Rossi Irving Improvements in processes and apparatus for the continuous casting of metals
US2527545A (en) * 1947-05-02 1950-10-31 Norman P Goss Apparatus for continuous castings
US2682691A (en) * 1949-07-09 1954-07-06 Babcock & Wilcox Co Continuous casting process and apparatus
US2667673A (en) * 1951-03-19 1954-02-02 Nat Lead Co Apparatus for casting metallic rod

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2955333A (en) * 1957-04-11 1960-10-11 Ici Ltd Electric arc furnaces
US3278999A (en) * 1964-02-04 1966-10-18 Mesta Machine Co Apparatus for continuous casting of metals
US3415306A (en) * 1964-07-23 1968-12-10 Olsson Erik Allan Method of continuous casting without applying tension to the strand
US3354936A (en) * 1965-05-26 1967-11-28 Anaconda American Brass Co Continuous casting process
US3375107A (en) * 1965-10-11 1968-03-26 American Smelting Refining Copper base alloy and method for its manufacture
US3638715A (en) * 1969-02-27 1972-02-01 Schloemann Ag Method for the continuous casting of tubes
US3752216A (en) * 1969-05-14 1973-08-14 Sandel Ind Inc Apparatus for homogeneous refining and continuously casting metals and alloys
US3916985A (en) * 1971-09-30 1975-11-04 Noranda Mines Ltd Apparatus for continuous casting of metal strips
US3797555A (en) * 1971-09-30 1974-03-19 Noranda Mines Ltd Method for continuous casting of metal strips
US3834446A (en) * 1972-04-10 1974-09-10 B Medovar Mould for electroslag remelting of metals
US4736789A (en) * 1978-07-28 1988-04-12 Kennecott Corporation Apparatus and method for continuous casting of metallic strands at exceptionally high speeds using an oscillating mold assembly
US4674559A (en) * 1985-01-28 1987-06-23 Inresa Schultheiss Gmbh Continuous caster
US4899801A (en) * 1986-06-10 1990-02-13 Asaba Co., Ltd. Method for continuous casting of metal and an apparatus therefor
US5116027A (en) * 1989-05-03 1992-05-26 British Steel Plc Apparatus for controlling teeming streams
US20180250736A1 (en) * 2015-09-16 2018-09-06 Posco Vertical semi-continuous casting equipment and vertical semi-continuous casting method
US10913109B2 (en) * 2015-09-16 2021-02-09 Posco Vertical semi-continuous casting equipment and vertical semi-continuous casting method

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