BE631782A - - Google Patents

Description

       

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  "Ï4.oc.,. <: F ,, 1: .a. ',; i1 Dr .... ;;' 1. ', *' C 11 -U" .-
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 The present invention and relates to a process for continuously casting metal and more potatoes per hour ()! "It is a process for the continuous production of copper and more generally of low oxygen content of culvro.



  As a whole, the present invention comprises. in a process for casting uetal into a continuous into which
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 molten metal is introduced into one end of a flow
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 with open ends and in which the metal cast and rotated from the other end of the socket, the performance consisting of
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 to introduce hydrogen or a gas mixture containing

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 There is about 40% by volume of naked hydrogen in the vicinity of the area of the protein of the aoule in which ooamonce the 1011d111-
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 cation of the molten metal introduced during the
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 casting To obtain ltol "best results,

   and SUI hydro- gdnd this continuously introduced into the aforementioned area of the mold * The present invention therefore had particularly advantageous continuous casting processes in which 1. molten metal this introduced into the cooled area of the vertical mold with open ends and into where the rate of introduction of the metal in 1'u010n with respect to the rate of removal. vopúnt of the cast metal is such that it maintains a surface
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 free from the mold wall in the cooling area of
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 this mold, citing part of the wall of the mold located
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 a cooling element which extends above the level of the metal contained in said mold.

   In pro tele
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 As a result of casting, the molten metal begins to solidify at the right side of the tetai rdnioque in the Mule; and by way of the prior invention, the hy-trogttnd gas is introduced up to the onno of the wall of the stream in which and finds the molecule of molten metal. an important advantage of the present invention resides in the fact that it has made it possible to design a product which quoted 8p6c1: \ lc ..) nt copper and copper base alloys, and particularly low copper *.
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 oxygen content, can be continuously cast successfully
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 both during longer head laps and at higher speeds, but with these mild advantages, than was possible prior to the present invention.

   More,
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 the castings obtained by the process of the present invention have, in a uniform manner, excellent characteristics.
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 surface characteristics, which is an advantage auppld6nta1r.

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 of the present process. Another important advantage of the present invention is that it has made it possible to design a latch process where low oxygen copper can be continuously cast for longer laps of time and at higher speeds. larger than hitherto possible while at the same time producing a non-porous casting with a uniform surface and a specific gravity greater than 8.85 easily produced a low-oxygen furnace d 'a density greater than 8,

  9 and a density which is for all practical purposes substantially that of the theoretical specific gravity of copper. The advantages of the present invention and others will become readily understood by reading the description which will be made thereof.



   In the practice of the present invention, such introduction of this hydrogenated gas can be effected in any suitable manner. For example, the gas can be introduced into the target zone by bringing it as is into said region from an external source or by releasing this gas into said zone in any other suitable manner, from any suitable source, by for example by "in situ" decomposition of a suitable gas which produces hydrogen.



  To obtain the best results in casting processes in which the metal meniscus is located in the cooling zone of the mold, the hydrogen gas is introduced by bringing it as it is from an external source to the mold. mold, in the vicinity of the zone of the wall of the mold where the molten metal arrives comes into contact with the cooled wall of said mold. : For example, hydrogenated gas can be introduced into the mold cavity above the
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 level of the metal enclosed in this mold \ 1 ";

  ,, '2 ro' c, c, ua r - r-

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 drilled arranged above the mold cavity, at a level higher than that of the metal contained in this mold or else from openings made in the flow chamber, above and in the vicinity of the level of metal intended to be maintained in the mold during the casting process; or by diffusion through the wall of the mold at the point where the latter is formed by a sufficiently porous material, such as for example graphita The most efficient use of hydroième occurs when this gas is introduced by diffusion to through the wall of the mold.



   According to another important general means of the present invention, the hydrogenated gas is introduced into the area of the wall of the aforementioned mold in controlled amounts.



  This control is carried out in the easiest and most advantageous manner by adjusting the quantity of gas introduced to obtain a surface of a desired character on the casting, as can be seen on it as it goes. that it comes out of the mold. In general, when increasing amounts of hydrogenated gas are introduced, the appearance of an irregular network of irregularities on the surface of the emerging casting indicates that one is approaching a surplus. of the gas introduced, and an irregular network of irregularities over most of the surface of the outgoing casting indicates a harmful excess of gas introduced.

     The appearance of an irregular arrangement of irregularities having the appearance of folds or beads perceptible to the touch are characteristic of this irregular distribution on the surface of the casting. On the other hand, if the decreasing amounts of hydrogenated gas are introduced, the appearance of small visible surface friction marks on the casting as it comes out indicates that the introduction

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 tion of hydro gas ± 4n <$ approach of very small quantities qt a strong mU / rt-nct produces grivurt: 3 i rifia dtr.o la r.1èct) touleus indicates who was used trot- qjj-. nttt1 * too low 4a e, iz.

   Confor, .é; htnt k co qui v.tr.t dl: 4-tr # 1: 4ti: {:! Q6, a fioyfen ftn'r'11 and the ï-rs'.nte invention consisted of controlling introductita from ear. hydra <; yn until a sony of the J: 'tro! from aoule prc1t 'à une illtirq en d6blt lnft.'rïùur to ovlui to which a diopooltion 1rr6Gl1tr of Irré- f, Ular1tt5a occurs on the rjeurv part of the urtace of the smallest casting tri train to exit and eur1Qur & c << him to which deep -.irquu5 ru grVH.x'90 <sur producing dïma the species flowed when it comes out of the flow.



  We used a lot before the recent invention of my color process '"'.) Utl1icnt W1 ::: ow.1J vurt1c :: ll or. Lu level of! R.t3.1 in fualin fmf's? '? d'mu 10 soûle 6ot F.:l1n'tl:n ïin duooouo of the p'M 3uj.vrieur <* dô la. znnv rufrolliu du.dit <o'jlu tt üù 10 nivy.u du: 9aiequ <. ' do n4tntl .n fusion 4 ': <nM 1-t zerv rd'l'Oid1! J utt d 1ilac J according to a r.iweu-.4.nt da v: -tît vlvr t v-ttic-.lr yp. t -irol du isouluf during lu, r ') C'zC8':. l.! J df,;: coulv C 'p'sut obt << tp such a deplc-nt de- j-enisque jat all dë' .m <.... st nr '& t "Rt! # * s,: $ king'. "'1'1 ..... t! # *' T - ui ïnfr :, jur txtj.Ji;; r'y '-' 14: 1 hri.t's3. Dvo cts d * un;. oul tn or, r.1czx again by vsn ï'.ouvt: state of r;: onto-ut ... h'l10S (;

   drunk. î> uR0 lu r: ... tlloU4 "ï, orfe d * sation de- tue Irocunoue d coulé # nn rtclv dru z hydrne6n <dana le. sono of the wall of the socket on the \ '1uQllQ at d 'jlnoe lo s <* îîisquai so as to obtain duo r1 (.t.0 or ondu- lationo un1torudr.únt osrncdee on the oirlace of the 1èco
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 casting when it comes out.
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 A hydrogenated gas that enhances any amount

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 iit # tï'fcjrôï'Otfîno. could be used in the riloo in work 4th In Ilivurtlon provided that or and you hell: '1o more about 40 µ ± of hydrogen on vnlwc. From the prfrcnc, the gas is in "v. U! R-oi 1; \, One volur, o of hydrogen and better still, 0 * 11 iî, * t the hy1rotn ... ot.moibh : ", mt pure, co .... '1 $ we can in o <.n7 dKe i'idustrA.

   Li oonetintrutlon of the hydrogen dittti 1 -.s jr cit # tiur the quantity of gaa used Ea t; ';': 1 ("\ l, liCur obtain Ite ::. Ü111I; #urs retiultate, loraquu on 4iuimîii Xt \ concQntr: \ t1on dthydrog? Jn (l in gas, the q, \ vînt1tt. Du cr7. Ut1110ú nU {ß..cnteo ot vieu-voran, The quantity of ena ut'l.Ut, r! Oot function auaai.of the way in which the ect gas introduced inna the r (. @ '1on of the wall of the flow.

   In the rroecr'jovHî dtx poulwy in which the r.4tal n1oque is found to say the are of rutroidie3enunt of the coulu pcaâunt the coulda of the r.itt. * Ilf and oh the hydrogen gas is introduced until ' at the c <\ v1 tt5 of Rioulu drmo space 01 tu4 above the rt'-tal ue finding dnna lu r-oulu using a b "\ guo pl.:r1'o't;C cit'c au-daesuo du .ourle, lu rfmdt:

  .t! nt of this mode of induction colt due to the dilution, either of the combustion or of the eve duux is so low that this dJfft..11. ? & '* a use of pure hydrogen, to introduce 1' t the day o1.tn1r the diopoultion iti * f, UJfcïv 3uor..trntiQnni '* v of ifrgultrita 1' \ 8urrrlO di la ceiulee a tr, , iln to exit However, one easily obtains co S ... mc of surface n using such rrncessue do when the giz and introduces ear dos 1 =, Ièrue in the. rurnî of the ground # naked neighbor! of metal, and by t1o \ !. 1 i r (:. ißnt loroque lu eaz y is diffund through the wall
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 sank.
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  In the Ctiao in work of the present invention, it is noted that the speed of nouldu is a function of the

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 shape of the cross-section and size of the casting which it is desired to produce, the presence or absence of conical parts in the cooling zone
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 of the mold as well as of the shape of the movement of vuetwi, nt of the meniscus of Metal or the rate of solidification of the metal
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 in the cooling zones, as well as the thermal conduc- tivity of the metal being cast, as well as the total heat removal capacity of the cast.

   In general * the reciprocating rate is increased with the cut-off speed (that is to say the net rate of extraction of the casting from the mold) and vice versa * the presence of a convergent taper on the wall of the mold delimiting the cavity of the mold increases the heat dissipation capacity of the
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 mold and allows the use of higher casting speed than would otherwise be possible. On the other hand, the casting speed decreases when the smallest dimension
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 of the cross section of the casting at ± C4.nte.



  The present invention can be implemented in
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 any continuous casting process utilizing any conventional type of continuous casting mold made from any conventional material. However, it is extremely advantageous when casting copper at low
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 oxygen content in a mold in which the metal. is cast against a graphite surface, and especially a conical graphite surface, by a process in which a 11br: a hem of the mold wall, II1Ji101o.1 \ J is included in the cooling zone of the roller. ; .²r, .t;

   îorcquy one uses: v a layer of a partial light a = .â.4 on lu (, 1U "ÚtQO of the metal not found in the mold pvmh \ nt 1't) 15: l ';) t1n of
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 casting, and p: \ rt1culièrQont loraqua the inJUu * d% .t-û .vl which is found in the: .r.Ot.1ltt laying 00 a:, <.;.: it 6 '.' '' '1 r -.1. "

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 back and forth with respect to the wall of the roll during the casting of the metal in this mold.

   The term "low oxygen copper" is used herein to denote copper containing less than 0.015% oxygen and this term includes oxygen-free copper and copper which has been deoxidized with a deoxidizing agent. such as for example calcium from lithiua, boron or phosphorus
By carrying out experiments of continuously casting low oxygen copper against a graphite surface, in a vertical mold, using a process in which, during casting, the metal meniscus was located in the section mold cooling,

   the reciprocation of the meniscus relative to the wall of the mold was used and a protective layer of a solid particulate covering material was retained at the top of the metal enclosed in this mold, and it was found that, when the introduction of the hydrogenated gas is regulated so as to give a uniformly corrugated surface on the outgoing casting and then increased amounts of gas have been introduced, the corrugations become increasingly coarse to a point where a further increase in the quantity of gas introduced destroys the surface with regular undulations to transform it into irregular undulations,

   in that said corrugations begin to scatter or that an irregular network of surface imperfections having apparent folds arranged at irregular angles begins to appear on the casting.

   As a result, this surface deterioration increases until the greater part of the surface of the casting in the process of coming out is affected by this defect} it has been observed that, when this defect appears, we reduce quickly-

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 The rate of introduction of the gas ,, the possibility of the casting breaking in the flow is avoided. * On the other hand, when decreasing amounts of gas are introduced, the corrugations gradually become smaller and smaller
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 until we reach a point or the area of 1 <.

   cast part becomes smooth cosae of glass after which from blue trac * 3 visible surface scratches start gradually appearing on the cast part * in the process of
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 exit after which follows the gradual appearance of small traces of friction visible on the surface which are due to a slight adhesion of the casting in the raoule.
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  Insulting, usually within an hour, and usually after 15 to 30 minutes, the adhesion becomes and severe as the pouring of mta3. is interrupted due to the breakage of the casting in the mold, which breakage is caused by the deep engravings of the casting lying
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 in 1 * mold.

   It has been observed that and the rate of introduction of gas is increased after the appearance of the smooth surface such as glass or of small visible surface irregularities or small visible traces of surface friction, the risk of rupture of the surface is avoided. the casting. Accordingly, when such a low oxygen content copper casting is carried out, the rate of introduction of the hydrogen gas is.
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 controlled at a rate lower than that at which it produced an irregular arrangement of irregularities over the greater part of the casting,

   and greater than that at which the rupture of the deep scuff firing casting occurs. Preferably, the introduction of the gas is regulated at a rate lower than that at which the provision
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 Irregular the aforementioned cotsaence to be produced and a look superior to that at which deep engravings .. occur.

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 1tlt.

   more previously above the rate at which small visible traces of the surface prndule at the
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 surface of the casting being released and, so
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 ua much more preferable, above the pace at
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 which the surface of the casting @ is smooth as
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 In the best mode of operation, the input of the element is adjusted so as to obtain two uniformly applied surface waves on the surface during the exit of the casting. If we want to obtain the results $ read 1nt1111curil. the gas is introduced at a rate sufficient to mt'1ntur.1r deo undulations of surface un1fl ') mmunt eapa- C08 on the surface of the casting in the course of .outlining the entire casting process.
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  Give the nail on the work of the present invention
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 for low oxygen copper casting, no limit was found to the torp period during which
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 the casting process could not be carried out continuously, even
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 Using the exceptionally experienced DM casting speeds in the casting of low oxygen copper, consistent with the present invention, the highest values of copper have been obtained. casting with * tomes in the-
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 which the smallest linear dimension of tranever section
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 sale was less than about 127 nos.

   So, for example, deoxidized phosphorous copper reinforcing less z
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 of oxygen was easily cast into billets of 76.2 mm
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 Inertbtre by continuously extracting the casting from the mold due to speeds greater than 73.66 o. per minute, up to 162.56 est, per minute and even higher, Such sustained speeds can be increased up to
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 six times those that can be obtained one not using los general means of the precept invention. Furthermore. the

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 Surface and interior characteristics of the cast bale were of high quality and uniform throughout the production.

   Smooth results can be obtained with polygonal shapes, such as cakes of rectangular cross-section in which the smallest linear dimension, i.e. the thickness, is less
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 to about 127 mm. We obtain ccapsyabica speeds with other shapes and dimensions and with other similarities of casting of the metal, taking into account the di.Laa # tna of the shape and the thermal conductivity.

   In practice of the present invention, using such sustained and high speeds of aaza. ,, the smallest linear dimension of section tra1Qvorcala lot shape of the casting (1 thickness, in the case of C ! tQntix and similar shapes and the diameter, in the case of circular shapes, such as billets) is about 50mm up to about 127mm.
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  In carrying out the present invention, numerous experiments have been carried out whereby attempts have been made to substitute other gases for the hydrogenated gas of the present invention. For example, attempts have been made to substitute other gases such as, for example, nitrogen, helium, carbon monoxide, air and carbon dioxide. No gas or gas mixture other than the hydrogen mixture of the present invention could be found having an effect.
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 advantageous over the period of operation or the casting viteuU8.

   Thus the use of hydrogen gas over about 40 vol% by volume is unique and of essential importance in the process of the preceding invention.
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 It is impossible to explain the or the? ric..3

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 of the success obtained grade in the process of the present invention. Normally, when continuously casting metals, and particularly copper, the proclamation or use of hydrogen is avoided at all costs, since its detrimental effect on the physical properties of the metal is well known. .



  However, in the process of the present invention, the hydrogen possesses the advantageous effects described herein. In addition, and as far as the Applicant can know, hydrogen has no discernible effect on the composition of the metal during casting. Thus, for example, when pouring copper containing up to 0.015% oxygen) no noticeable reduction in the oxygen content of the cast copper could be observed. Although the Applicant does not wish to be bound by a particular theory, it is possible that the hydrogen can affect the superficial tension in the wall zone of the mold in question, and produce the advantages obtained in the practice of the process. present invention.



   The present invention has also been represented in the accompanying drawing and by describing a certain number of examples.



  It goes without saying, however, that the drawing and the examples are given purely by way of illustration and not by way of limitation; in this drawing the fief 1 is a schematic view in side elevation and in partial section of a casting system utilizing the preferred method of introducing hydrogenated gas of the present invention into the mold; fig. 2 is a schematic sectional elevation of the mold shown in FIG. l, taken according to II-II of FIG.



  3, fig. 3 is a half-section in plan taken along III-III of fig 2, one half of the mold not having been

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 represented *** their do not overload the drawing} lit fies 4 is a wchatique view of part of the flow and the siphon roir4oçnt4o on the fige 1 and l11uatro the solidification of the 6tal in the mold. fig 5 and a colon V-V view of tic # 2; t1g. 6 .and a sabbatical rise and casting # countering a variant of the method * of introducing hydrogen gas into the mold; fig 7 is a view required * depule the 1ftt .. laughing * part of the roprdoent4 ring. on fig 6;

   fies a is a schematic sectional elevation showing another YAr1nnt. of a mode of introduction in the mold of the pz of the prl'tlnte invent the fig 9 is a view taken in IX-XX of the fig 8.



  In fige 10 is a sketch representing the surface of a COUI40 ribea produced according to the rda11Gtion rcilleur of the invention, the fige It is a side elevation * agran41..t in color <$ still representing the Illu4tr4o surface on the lees . 10, In exaolno.nt astintenant the drawing we see that the fig 1 illustrates a 1utè = u casting that the Request ....... 1; 1 & 0 preferable, at the present time, for the continuous casting of copper low in #in oXY6ne. A melting furnace (not rllprdeont4) supplies a furnace 10 for raintion of the cdtvJ. molten to flow. The furnace 10 feeds a ladle 11 which feeds the siphon 12.

   The latter feeds the Mold 13 which is mounted on the platform 14 which is mounted on a carriage 159 for Ion QOUV8f.vnt of rr.onto-e't-bt11sse. the casting 17 ce removed from the mold by a drive con1C1e

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 1 \\ JtO olüut'l1quti 18 ut this sectioned into a section of the lor./Ut '.n ddD1r' "l% r un 1.cnlQt .... d .." oUnnnCiln..nt ol / \ 081quI. co, 11tI the one which is illustrated, pnr a cut-off box 19.



  Ce., Ctmiu ... w c1 '}. Go1qu a 4t4 disclosed in US Pat. No. 2,291,204 of July 28, 1942.



  Before 8aÙr ai f.dounie4. 4'Qntratnúont 16 hi .. la ribct) coul4y .ut travurer a cbwbr. 20 which can be fitted with an appropriate seal 21. The carriage 15 has to be moved hor1zontolct: umt our bearing tracks 16 removed a rdeorvoir 20 to purco "early the installation of -4noulon 44 different form or development, or to give an ocobo to a fixed work bike (not shown. eentéo) can be lit from either side of the rolling path: nt 16 ot at level, on which the worker can. lu move pundftnt the, Z'nCes3uo of casting. the furnace 10 ï't? ïrantd can in addition to a vertical furnace tt. ir.'luctton h bnou4I frequi> nc i being able to turn around a horizontal axis and studded with a nozzle pourer 25.

   It can receive cât & l a fuolon jar it. of a trough or uni * yache (not re; r "4, Jntdu) from a suitable melting furnace. The gQncnt and the funct1onnunt of the ladle * 11 and the eiphon 12 rulréauntde in fig 1 have been described in the Canadian Bravât No. 640,600 of 1 1 1962 of the Drjro9ae.

   Ladle and siphon are preferred coma * acoRies.o de ver8e6nt for high speed castings, and port1cul1rOQont for lu * high speed castings of shapes
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 of which the smallest linear dimension of cross section
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 oat less than 127 sm, although, if desired, another installment screen could be used, especially for
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 low casting speeds or for heavy rumblings.

   
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 General ilaeencoment and operation code of the mold 13

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 illustrated in figs 2 and 3, have been described siuset in the aforementioned Canadian patent, by the fact that the preferred mold 13
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 has at the corners two cooling zones in the first of which the (metal in the process of casting is cooled only-
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 contact with the cooled walls of the mold and then by contact with the cooled wall of the mold and with water or other cooling fluid,; ': is in a second zone, and preferably , also, uiqucnt by direct contact with the cooling fluid in uaa troiei :: the 1st cone.



  In addition, the mold wall delimiting the casting cavity is preferably conical and converges towards the extract * of the mold from which the casting comes out, and the second cooling sound system.
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 is fitted with nozzles intended for the cooling liquid, against the central part during the exit, at an angle such, with respect to these, that it produces a venturi action , as described in the aforementioned Canadian patent.



   As shown in Figs 1 and 4, the pouring bag 11 may include an enlarged bowl 25 constituting a reservoir of molten metal and a trough 27 supporting the
 EMI15.5
 siphon 2. The pocket also has a b3rrso 23 their dirt. The pocket 11 is supported by a 4w;,. Nàaa which allows said pocket to be inclined for luck at the level of the tank with respect to the siphon; we raise and lower the pocket
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 whole without tilting it, then the entire pocket is rotated from a position (shown on the law freeze 1 4t 4 where the siphon 12 is on the flow 13 * jt: ':': 1 t at.% Lt, .g the coi t10n where it is located above a pot b slag (.-on reer "zn- té) located along the mold.
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  Dansa the supporting tBconiaae do 1: 1 .tG h which Ci.; T; shown on tig. 1, we predicted taj cU - ù> 5} C; - k 3

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 the lower end of which is fixed; the cylinder 31 comprises a piston connected to the carriage 32 of the pedestal. Operation of the lift cylinder 31 raises and lowers the entire pedestal carriage 34 as a unit. The pedestal 32 supports a curvilinear guide path 33 on which the pocket carriage 34 is movably mounted. The curvilinear raceway 33 is drawn along an arc of a circle, the center of which is at the center of the bowl 42 of the siphon.



   The pocket carriage 34 supports rollers 35 which move on the curvilinear guide 33. An inclination cylinder 36 is connected to a cross member 37 attached to the pedestal 32, and a piston is connected to the pocket carriage 34. The carriage 34 of the pedestal 32 can rotate about the vertical axis of the elevator cylinder 31 to allow the operator to rotate the pocket 11 in a horizontal plane.



   Operation of the elevator cylinder 31 raises and lowers the pocket 11 without tilting it. Actuation of the tilt cylinder 36 moves the pocket carriage 34 on the curvilinear raceway 33 and thereby tilts the pocket 11 in a vertical plane around the center of the siphon bowl 42; this inclination can be given in any position of the pocket 11 in its pivoting arc around the vertical axis of the lifting cylinder 31, for any elevation of the carriage 34 from the pedestal 32.



   It goes without saying that when the cup 42 is in coincidence with the mold cavity, when the lifting cylinder 31 reaches its extreme lowering position, the cup 42 is automatically located at the proper level inside the mold 13, which whatever the angle of inclination of the pocket 11 ..

   Correct positioning of the bowl 42 in the mold means that this bowl is completely submerged

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 in the * molten forestay when it occupies its position
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 normal about '8 m below the aocaet of the moult (tll.

   4) All of the tilting cylinder 36 acts to tilt the ladle 11, either direction of which acts to change the metal level of the ladle *
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 and, the carriage 34 as finding at and lowest position, does not change the elevation of the bowl 42 deputu or suitable position in 1 Z0.4100 Thus the bowl 42 is at its ooa- vunablt position in the mold, we ladle 119 can be changed to level 4t either by tilting said ladle, or by adding metal or removing it.

   We use the cn = ass of the level of the metal in the pocket to control the flow of the natal in the siphon 12. the pocket can be tilted backwards (that is to say the carriage 34 lowered) suftteo = In order to stop the flow in the siphon * in order to prevent loss or cessation of suction during an easy en route operation, the bowl 42 was provided with an overflow device.

   Lug shown in fig 4, the bowl 42 has a lower opening of
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 discharge provided with a washer or fitting 53 'in It4atlte, The lower end of the tube 40 of the siphon has three notches 54 circumferential and equally distributed and three
 EMI17.4
 corresponding tabs 55 to which the overflow bowl 42 is bent, constituting three overflow openings 56 in the form of a bowl.

   Therefore, provision has been made for the siphon to discharge molten metal through,. the liver, the lower stdatite opening 53 and the three bowl-shaped overflow openings 56. the siphon tube 40 of the siphon 12 is preferably made of stainless steel, with an intermediate curved part,

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   confis represented.
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 They melt the metal 101141t1 'in the event of accidental solidification, the siphon tube 40 can be fitted with a screen 43 (Fig. 4).

   The screen is section
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 tranovornale n U. has the greater part of and length and follows the curvilinear part of the tube do, phan. the screen is suitably fixed to the siphon tube at a distance therefrom and * and fitted in the gasket 46 of the wall of the
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 the ladle or the siphon crosses the wall, in order to fill the door with liquid metal when molten metal is poured
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 in the siphon # Moreover, the screen is provided with a baffle 47 which forms the tranoveroale section of the screen * Itextrécit4 before the screen 43 has a vertical front wall 499 which comes out of a proton ± t! t1 'Tubular acnt 50.

   The front wall 49 and the tubular extension may have a series of openings 51 and the lower end of the tubular extension.
 EMI18.5
 The first one can be compressed around the siphon tube 40 to provide a narrowed passage 52, or a series of such narrowed ones to aid in the fusion of a slow siphon which solidifies.
 EMI18.6
 



  As shown in fig. !, we see that the mold 13 is supported by a frame 14 oscillating 1 vertically thanks to a reciprocating mechanism. A suitable motor (not shown, pouçhe paa overload the drawing), is mounted on the carriage 15 which moves the connecting rod 61 to and fro. The connecting rod 61 is articulated to a series of angled levers 62 on one side. of the frame 14. A series of angled levers 63 is articulated to the carriage on the other side of the frame 14.



    Rods 64 and 65 articulate the bent levers 62 and 63 to the oscillating frame 14. A rod 66 connects the bent levers 62 ot 63. Several guide columns 67 are supported

 <Desc / Clms Page number 19>

 on the carriage 15 and come to slide * on the guides of the frame 14 to allow the back-and-forth movement
 EMI19.1
 comes vertical from the mold in a straight vertical tensiblemont line. The appropriate means can be provided to vary the stroke and the frequency of the vertical reciprocation of the mold. For example, to vary the stroke, the motor may have an elbow arm of adjustable length. To do
 EMI19.2
 vary the frequency, the speed of the motor can be varied.



   As shown in fig. 2 and 3, cast 13 is a composite mold. A metal block 79 provided with a removable sleeve 94 in graphite, is mounted on a manifold
 EMI19.3
 lower 70, annular in shape, thanks to an infriewf ring 72 which is bolted to the manifold in,. The collseteur 70 rests on suitable cross members forming part of the
 EMI19.4
 platform 14, which is mounted on a carriage 5 so as to be able to be driven by a back-and-forth movement. sleeve 94 may be made from any suitable Industrial grade graphite and machined to the desired shape.

   Preferably, the inner surface of the casting is machined so as to have a cct: rq ,, .. aat council towards the bottom of the sleeve, although the curracu 00, then, if desired, be a cylinder. pxtfeit, in order to obtain; a heat transmission the sxr ch <m ± 4 is adjusted with wedge in the block 79: the surfaces in contact are cylindrical and machined with precision so as to obtain a solid against solid contact between the tu-achoa and the block, without there being at their do oouc-ho interface that would generate an excellent;

   heat transfer*
 EMI19.5
 Preferably when it comes to J ::: '1,' 1 ", .. 1 c., R '[to the casting of formoa rO1deo, by t..t .., s.' 3 .. > i 1.1 ... t \ .a 4 * 1

 <Desc / Clms Page number 20>

 In circular cross section, the sleeve 94 is oversized with respect to the block 79, and is assembled therein by forcing it axially into the block. Also preferably, the compression fit between the assembled sleeve and the block should be strong enough to provide "solid to solid" and fluid-free contact at operating temperatures.



   If desired, the sleeve 94 can be omitted and the block 79 can be formed integrally, the molding surface 80 being machined directly into the block; the Applicant considers that this one-piece structure is preferable for molds intended for casting shapes, such as cakes whose cross section is square or rectangular, or else for other polygonal shapes.



   The shape of the manifold 70 is in general conformity with that of the block 79. At its upper and inner corner, the manifold 70 is provided with an extension rim 81 facing towards the interior of the mold and has a passage. inlet 82 provided with a flange to be connected with a pipe (not shown) for supplying cold water to the manifold.



   Additional inlet passages located at equidistant points along the outer periphery of the manifold, if desired, can be provided for the large amounts of water which are supplied to the mold.



   The manifold 70 supplies water to the main cooling tubes 83 arranged in passages 96 which are bored into the block 79 and at five levels of water spray. For this purpose, the collector has a series of upper openings 84, a series of lower openings 85; its rim 81 has a series of drilled passages 86; the rim has openings 78 to allow passage

 <Desc / Clms Page number 21>

 the main cooling tubes 83.
 EMI21.1
 



  In order to cover the sprayers from the top or the next level, block 79 is provided with a series of horizontal passages arranged in the radial direction, ronter-
 EMI21.2
 mant of transverse tubas 68, each of which has an end with a nozzle ti9 having a downwardly oriented discharge passage tit arranged at an internal angle of about 302 to the vertical and of preflrenos of about 201 to the vertical.

   Ls passages 88 connect to elbows 90 which are connected to connectors 91 connected to the upper openings 84 formed in the manifold 70. the inner face of the lower part of the sleeve 94 has clearance openings below the die nozzles. - load 89 constituting in fact due ribs or vertical projections
 EMI21.3
 wedges 92, which are ready to support the casting as the water sprays are directed between the ribs onto the surface of said casting before they leave the mold. when high casting speeds are used, this results in cooling of the surface of the casting below its plasticity guarantee while it is thus supported.



   The second water spray level is formed by nozzle openings 87 pierced in the rim 81 and in communication with the passages 86 of the manifold.



  The axes of the nozzle openings 87 can also be
 EMI21.4
 an angle which is less than about 30 ° in the vertical direction, this angle preferably being about 20 ". The third, fourth and fifth levels of spray nozzles
 EMI21.5
 verisation are formed by openings 103, 104 and 105 located in the refrigeration tubes 18aocont 83 and in the * return bends 93.

   All these spray openings

 <Desc / Clms Page number 22>

   direct water against the emerging casting. in the directions indicated by arrows * The return bends * 93 connect the lower openings * 85 with the inner tubes 83,
In accordance with the embodiment of the present invention which the Applicant considers to be much preferable, the mold 13 is also provided with devices for diffusing the hydrogenated gas of the present invention through the graphite sleeves 94 to introduce the gas to. to the area of the wall 80 of the mold where solidification of the introduced metal begins to occur during the casting process.

   As shown in Figs. 2, 4 and 5, the outer surface of the liner 94 is provided with a plurality of machined horizontal grooves 110-114 extending around the outer surface of said liner. These grooves may have a V-profile and are suitably spaced from each other, preferably a distance of about 12mm. The horizontal grooves are joined by a plurality of machined vertical grooves 115 disposed around the perimeter of the outer surface of the sleeve 94 and impart an embossed appearance to the sleeve.

   These vertical grooves can also have a V-profile, and the preferable spacing is also about 12mm. The hydrogen gas of the present invention from an external source (not shown, * is supplied through tube 120 preferably to the highest horizontal ring 110, through at least one. passage 121 machined in bloo 79, and preferably by at least three of these passages distributed equidistantly around the periphery of the periphery of block 79.

   The gas thus supplied to the upper groove or groove flows around said groove to the other grooves, from where it

 <Desc / Clms Page number 23>

 
 EMI23.1
 is distributed by diffusion through the pores of the graphite to the area of the inner surface of the liner which is gripped by the grooves;

   such diffusion occurs conducted with light pressure - for example mono pressure *
 EMI23.2
 metric as low as 0.035 ka / c & 2 - or OQ 'less * For best results in and mode of gas introduction, a sufficient number of horizontal grooves are used to provide coarse support to the mold wall region at which the metal introduces cosacooe to solidify during the casting process. Good it
 EMI23.3
 molds the entire length of the pig 94 this cold and, as shown in Fig. 4, the molten metal introduced begins to solidify at the Ón1cqUg.

   Covse roper4- sente on figt 49 a sufficient number of horizontal grooves are used, preferably at least five to allow
 EMI23.4
 the reciprocating motion of the meniscus ut uuu1 to allow for a change in the average working level of the metal in the mold.



   We represent eur figs 6 to 9 duo variant * of the mode of introduction of the hydrogenated gas of the present invention.



  As shown in Figs. 6 and 7, the gas can be tntro-
 EMI23.5
 down to the area of the flow wall at which the solidification of the introduced metal commtlnoe from a source (not shown) to a bagua 125, from which it is discharged into the mold cavity , cu-deoaua of the metal therein, through a series of perforations 126, oriented downwards and distensions ap-
 EMI23.6
 properties, for example of 0 # 254 ffisa of d.â 'r ,, v iq6 & at regular intervals around the bazliu t, of grfirz this # dietantoe of about 12 # 5 mô ..

   Dsna ust <v? I! Nt9, 1-9 Liz can be Introduced, like rdprc4arts zur 1.fis 8 and 9, in

 <Desc / Clms Page number 24>

   feeding it from an external source through a passage 130 drilled in the block 79 to an annular channel 131 which is machined on the outer face of the sleeve 94, from which it is discharged into the mold cavity, above of the metal therein, through apertures 132 facing downwards and of suitable dimensions, for example 0.254 mm in diameter, which have been drilled in the sleeve and which are spaced at regular intervals around the perimeter. phase of said sleeve and preferably at intervals of
 EMI24.1
 12.5 mm approximately.

   when starting up the casting system shown in fig 1, using a conventional starter bar or bar, of appropriate length, and the cross section of which has the dimensions and shape matching those of the mold cavity delimited by the surface 80 of the mold and, preferably, also comprising a conventional threaded end of small dimensions at its upper part.

   The upper part of the starter bar is introduced into the bottom of the mold a sufficient distance to cover the ribs 92 of the sleeve 94, so that the lower end of the bar extends below the extraction rollers 18 , so that when the initial molten metal is brought into the mold, it solidifies around the threaded end and the solidified product is pulled down and out of the mold by the rollers 18.



   Then the siphon 12 is primed. When the siphon is primed, it is first heated at least to the red number and, preferably, to the melting point of the metal being cast, with a torch. The pocket 11 which supports the siphon thus heated is then tilted into a position where it is located above a slag tank

 <Desc / Clms Page number 25>

 
 EMI25.1
 and the pocket which, in the interval of time @ a 4td fills with Letal seen fusion, depresses the furnace 10 # is tilted so that it wants to move forward for 0 .:

  . unIr the level of the fuel cell = finding you whose pocket is at a level around that of the highest part of 1 part of the siphon tube 40 # the bitch 47 surviving to retain the molten metal, 09 which produces a copious 4Qoulont of = 4t1 in fusion by the siphon tube 40 and through the orifice lnt6rlC1U1 'S) trump quo by the * nrilleun .upAr1vuro 56 c4ungde dune the cuvette 42. j Zn d1r.¯n81on of the or1f10' 53 4no 4 in the cuvette port .ntr. 1.a 8urtaoul ut11 .. 4. or1f1co 5 'and 4. Leo-
 EMI25.2
 port between the * working surfaces of the orifice 53 and the etc-
 EMI25.3
 tion of the siphon tube 40 is such that it establishes sufficient colonHw de; roooioa in the bowl 42 to maintain 3.

    n1vuu du: 'tn1 * 4 fusion and finding in 1- bowl 42 au-duoeuo of l' .. tr4w1t 'of the siphon tub * during a # orças * Low urfMwa useful cotbinds of the orttleus of too plain 56 and of the 'internal orifice 53 must be fltrs 8upjr1eure,. the effective surface of the cross section of the siphon tube 40, so as to obtain in and tube 40 a denuleuunt and a v1 t.,. 88 r.nx1r .WJ, in order to purge 194 cage
 EMI25.4
 If the orifice 53 is too small.

   the speed in the tube
 EMI25.5
 siphon will be too weak, and which prottr3 a separation
 EMI25.6
 gas at the upper part of the curvilinear part * of the tubs
 EMI25.7
 of the siphon and a loss of the action of 8ipMM4S8 or even a possible request * of the metal in the siphon tube It goes without saying that the volume "useful surface" applies to the zone or surface which co-associates the flow in the siphon tubes. various parts of the siphon, namely the siphon tube 40 # the discharge port 53 and
 EMI25.8
 the overflow holes 56.
 EMI25.9
 For example, in a siphon intended to supply

 <Desc / Clms Page number 26>

 
 EMI26.1
 a billet 4iulo do 76.2 odd, the 41t; undlcm of orifice 53 was worse wup'îrieure 80% of the usable surface
 EMI26.2
 siphon tube 40.

   It has been found that the best ratio
 EMI26.3
 of will work was between 30 and 60 96. The useful surface of the overflow holes 56 was not less than 50 # of the useful surface of the siphon tube, To obtain loo rt1 (tult.Ht. 1 ... .. ". lllfura, la ana .... de aurtac .. utilua d l1 orifice 53 t due nritleo. of overflow 56 must be pr., where <\ uu c the other .. useful of the tube siphon 40 (not 1. '11 \' of 60!) v or m8rnut preferably # aup4ribure to said .ur1'Q (ltI.



  It is easy to see that, with the discharge port 53 being too small, the flow passing through the olphon will not be fast enough to discharge the oroprieon gas out of the siphon tuba. The tronsvorsal section of the siphon tube, at the top of its bend, should be very small so that the metal flow velocity at this point is high to prevent the ori8onnda gases from reeabolving. On the other hand, there must be
 EMI26.4
 provides sufficient flow through the overflow holes 56 to seal the end of the siphon duct, and
 EMI26.5
 rticu11brèunt when the molten metal does not come to wet the table of the siphon duct. the function of the screen 43 and due
 EMI26.6
 overflow 51 and 52 is to melt again a siphon tube
 EMI26.7
 40 or the Metal has solidified.

   Due to an error in preheating leading to solidification, or in the case of a foreign body getting lodged in the siphon tube, the flow of copper during the ignition may stop before than
 EMI26.8
 we could have produced the maximum flow of metal If this
 EMI26.9
 state produced, the pocket is tilted to a per-

 <Desc / Clms Page number 27>

 allowing molten metal to flow over the baffle
47 and around the siphon tube.



   Solidification can also occur between the screen 43 and the tube 40, and a gradual melting must be carried out to remelt this metal. This is achieved by allowing the molten metal to overflow over the front wall 49 of the screen 43 and to flow successively from the openings 51 and 52 made in the front part of the screen. The solidified metal is remelted very quickly and, within minutes, any solidified area of the siphon tube is remelted, recreating the flow conditions.



   After the siphon has been primed, the cooling water is circulated in the mold 13, causing it to flow through it in the direction indicated by the arrows visible in FIG. 2, and discharging it through orifices 89, 87, 103, 104 and 105 into tank 20.

   Thereafter, the inclination of the ladle 1 'is reduced in order to reduce the priming flow of the metal to a volume more suitable at the start of the casting operation, and usually to a value which is not. is not less than about half the flow which is to be used in the casting operation, such flow generally being indicated by a drip passage. intermittent, or extremely weak, through the upper ports 56 while full flow flow, from the lower port 53, continued to occur.

   So, without having to change the angle of inclination of the pocket, the molten metal continuing to flow into the siphon, the pocket is rotated as quickly as possible until it comes to face mold 13, then we tag the pocket until

 <Desc / Clms Page number 28>

 that the end of the bowl 42 is in its normal operating position in the mold.



   If we have to use a back and forth movement of the mold, we start this back and forth movement after the siphon has been rotated so that it comes opposite the mold, and . that the latter is partially filled. When the metal covers the cup 42 and has reached its normal operating level, usually about 38 millimeters below the top of the mold and generally no higher than about 12 millimeters below. from the upper part of the mold 13, the operator starts the discharge rollers 18 to extract the starting bar at a reduced initial speed chosen beforehand;

   the reduced priming flow of metal in the siphon automatically adjusts to the pre-selected initial speed when the bowl 42 is completely submerged in the molten metal. When the operator is ready, he increases the rate of lowering of the starting bar to full speed and, at the same time, raises the level of the liquid in the bag 11, in order to give a sufficient pressure column. to bring the metal up to speed.



   When the level of the metal in the mold has reached its normal operating level therein, the introduction of the hydrogenated gas of the present invention is preferably started and continued during the casting process, this gas being introduced at a rate. sufficient speed during the process to produce the kind of pre-emptive surface depicted on the exiting casting.

   In addition, in cases where a covering of solid matter is used, it is placed in the mold on the upper part of the metal which therein contained when the latter has reached

 <Desc / Clms Page number 29>

 
 EMI29.1
 its normal operating level $ When the 1'80I) U "" ... o 'consists of discrete * particle * @ OOM! C shown on the ± le. 49 one addition of t * rap m tenpa, during the precossue of casting, a sufficient quantity 8Uppld & .lento.1ro of:

  et.lra do this kind to provide the metal and maintain there a protective cover of important thickness which is generally not able * Inside about 3 U11J, - btrooo Orâco with the great capacity d8dlic4 = tinn of heat qit dnnao a flow of the typa represented on the t1l. 2 and #
 EMI29.2
 with the * high casting speeds * that it is possible to
 EMI29.3
 .utwn1r r4ce to the mine implementation of leu present invention, the cast part * 1't which comes out of the mold this chauttit red
 EMI29.4
 and is quickly cooled by the sprayer series
 EMI29.5
 of water under prueston 89, 87, and 103 - 105 and the large volume of water collected in tank 20.

   This water is discharged at any desired level 00: - "": 0 for example, to a suitable drain line 57, and can be circulated by a circulation and pumping system. by the intur.7.éd1a.1ra of a rQtrnid11'eur device to bring it back to the water collector 70 which is located on the roll 1 '. t'1ntvn81t4 of the rwtr1418.wuunt of the mold 13 is groom 41wv4o than 6c: e at the high casting speeds * which can be sustained and which can be obtained by the present Invention the molten octal is 8011di .:

  ! '"pl'o.tique-
 EMI29.6
 mount as soon as it touches the wall of the flow by making
 EMI29.7
 that the rim of the envelope of the crater 101 (fig. 4) extends anl1blOQQnt to the free surface 24.
 EMI29.8
 In the implementation of the present invention,
 EMI29.9
 by using a coula equipped with sprayers in = * described, it is uxtr3em.nt advantageous that the nozzles work
 EMI29.10
 with such a high speed and in the tangential direction

 <Desc / Clms Page number 30>

 
 EMI30.1
 It is appropriate that the cooling be effected by heating up the water and not by producing appreciable quantities * of steam * The use of low speed spray rulers in the upper position would have the effect of creating steam at a sufficient temperature so that Ait seeps through the top of the stream,

   between the casting and the
 EMI30.2
 mold wall. This produces faults = * shallow * do
 EMI30.3
 surface of the billet if the vapor reaches the surface in progress says solidification. This is why one uses fols a prwsoion and a reotin creating a downward rotating action which suppresses this etfot. So pr4tdr.nc., When the present invention is implemented with sprayers operating in such a way as to ensure this vanturi action, the flow presents a cnnlc1t4 and the Duoandoresse considers it much preferable to operate in a torus cone. , cosmo we will describe it by cooking. It is also considered rrZf4rablo that the direction of the nozzles 69 and 87 of the plum tree and of the lower levels is sufficient to give a gln, r31e action of the venturi.
 EMI30.4
 



  It will be noted that the sprayers 69 of the level
 EMI30.5
 8u.6r1úU1 "'exert cooling while the ribs
 EMI30.6
 92 of wall are still available to be in contact with
 EMI30.7
 the shell of the crater and support it * It will do * ni that k8.?c when the withdrawal of the casting, due to its rotr1d1aooont. fact will tend the casting to lose contact with the norvuruu 92p these still carry sell- enr - .. # \ lnt on the casting to evacuate imper quantities. heat aunts. Thus, to the area bounded by the ner-
 EMI30.8
 vurea 92, the heat is evacuated out of the casting by
 EMI30.9
 contact with the liver a liquid medium and a solid medium.



  In autro. dulls the contact cooling area

 <Desc / Clms Page number 31>

 with a solid medium overflows on the cooling zone by a liquid medium.



   Preferably, in the embodiment of the present invention, the mold, as shown in FIG. 2, should be tapered, especially when using a high casting speed and especially when casting low oxygen copper at high speed.



  When a taper is used, it can be either of the type called "natural" or of the type called "forced".



   Using a "natural" taper, the interior surface 80 of the mold 13 is designed to follow the shrinkage of the casting as it passes through the mold, and this tight enough for any speed. particular linear log. By virtue of this arrangement, a low linear coulde rate which produces a well-cooled cross section in the casting allows a more pronounced mold taper to be used than a rapid linear casting rate in which the shaped part exits the mold at a low rate. higher temperature.

     When using natural taper, it is extremely advantageous that there is a small clearance between the log and the wall of the mold, but defined over the major part of the contact length, in this type of mold.



   Higher taper speeds can be achieved by using a "forced" taper, and it is for this reason that forced taper operation is preferred. In forced taper operation, a linear speed is used. casting which, compared to the value of
 EMI31.1
 The shape of the mold is such that on the product there is the conicity of shrinkage resulting from the solidification and the ru- coldiscoment of the plecia colt clamps '' tro 1!.

 <Desc / Clms Page number 32>

 fuck the mold,

   so as to produce a plastic deformation of the very hot tube constituted by the crater shell 101 enclosing the liquid core 102, as shown in FIG. 4, There is some sense that such a forced taper operation is similar to wire drawing, This operation necessitates the creation of an elongated and deep V-shaped crater envelope which extends into the monk's mold as far as the taper of the mold, with a strong but plastic shell wall surrounding a soft liquid center, this combination being easily deformed by stretching through the tapered mold.

   Such conditions are easily achieved in a forced taper operation due to the improved contact between the shell 101 and the wall 80 of the mold, thereby improving the rate of heat removal from the mold so much. envelope up to the mold wall which the envelope wall solidifies so as to be strong enough and thick enough to resist breaking when using high operating speeds which create the deep V.



   To obtain the maximum effect over the entire working length of the mold in a forced taper operation, the angle of taper of the mold at each level of the mold should be more pronounced than that of the corresponding natural withdrawal taper of the casting which is produced only by solidification and cooling of the casting at this level.

   In practice, the Application has found that a taper of a mold shape extending the full length of the mold, as shown by the taper of surface 80 to sleeve 94 (Fig. 4), will work. satisfactorily * Such a taper has

 <Desc / Clms Page number 33>

 
 EMI33.1
 the advantage of ensuring the correct taper angle on the part of the mold wall which surrounds the free surface of the molten plate, regardless of the variation in the level of
 EMI33.2
 this surface, oe which portwt to obtain a good contact between the wall of the mold and the envelope of the crater, even at its point of formation.
 EMI33.3
 when using a back and forth motion # and more part1culi'rom.nt when moving the dt st ..sn1.quo back and forth;

  JMk, î * one of yourre4tueuzent of the mold $ we get from pr4t'r.na.'ō, there are back and forth one doing .. j 10, t '<' "\ - come and go vrrti.w , please a vertical mold on the casting, as shown on rod 1. In such a process
 EMI33.4
 au @ $ the amplitude as well as the frequency of the back-and-forth movement of the mold depend on the cast cross section, the value of the taper and the casting rate * In general, the greater the casting speed is higher, the higher the reciprocating frequencies * In addition,

     it has generally been observed that the ratio of the reciprocating frequency (expressed in cycles per minute) and the casting speed by
 EMI33.5
 minute (expr1 = 6th ta ca) should be at least eight to one. From pr6t4runc. the ratio should be between ten to one and fourteenth to one, and at the present time, a ratio of about eleven to one is considered ideal cosao, especially in low oxygen copper.

   Higher ratios can also be used although the advantages gained by using higher ratios will not be.
 EMI33.6
 general = unt interesting due to the additional wear of the reciprocating mechanism. For example # when we use a ratio of Il f '-1 :; 220 periods or cycles per minute are used for a linear flow rate of 50.8 cm at
 EMI33.7
 the minute or e 44f. y3âaa é -1 \ 1t. for a vitersa.-ll \: 4

 <Desc / Clms Page number 34>

 
 EMI34.1
 l1n1r. 1 m cast, OS per minute * It is generally preferred to use a short stroke because this avoids having to exaggerate the clearance between the cast and the casting towards the lower part of the casting.

   Preferably the race
 EMI34.2
 was about 3ol m to 399 ost this last short 'both col- which and far from the distance pods the most advantageous.



  The ulpru801on "runs *" or * cycle ,, of a mold an1r of a vertical reciprocating #open * and requests * in the ** ne of the move to go and turn coaplot of the taoulw d <tpui 'o bnfep pan to the next low poultion *? a preferred. the d4plnc @ u nt aat a simple harmonic varying from zero velocity at the * upper ends * and Lower until a vitue and mnxicua between the upper ends * ut 1nfrluur. of the displacement *
When, in a casting system such as that which has been shown in FIG. 1, a vertical back-and-forth movement of the flow is used in conjunction with a covering of a solid particulate material, pod shown in Fig. 4.

   it is advantageous that the maximum instantaneous speed of the casting vera la baa is greater than the uniform downward linear speed of the casting, in order to obtain a slight adjustment between the taper of the mold and the taper of the mold.
 EMI34.3
 casting had, therefore, to persist that a controlled amount of the covered 23 unit advanced down the wall of the mold between the ball and the cast product *
To obtain the best results in the implementation of the present invention applied to casting processes in which a covering is used at the top of the metal present in the raoule,

     the covering is a particulate matter, preferably a material which flows easily, especially under the conditions observed.

 <Desc / Clms Page number 35>

 of the casting. To achieve the best results when casting low oxygen copper against a graphite mold wall, layer 23 is a layer of discrete particles of carbon-containing material, eg flake graphite, carbon black, powdered anthracite. fine carbon particles, etc. or mixtures of said products.

   The Applicant considers it preferable to use fine carbon particles with a bead strength, obtained by instantaneous distillation of a liquid petroleum product, such as, for example, distillation residues and which is known under the name of porlea Kicronex.



   We find that a mixture of flaked graphite and Microex porla, especially a mixture containing about 25% by weight of Miconex beads, is highly preferable when casting low oxygen copper. Preferably, such particulate covering material is used in an amount sufficient to maintain a protective covering of 12.5 mm to 26 mm in thickness at the top of the metal in the mold 13. It is possible to use the coating. covering material as an introductory agent for the hydrogen gas of the present invention.

   For example, when the absorption characteristics of the covering material are sufficient, it is possible to treat this material in an appropriate manner outside the mold, such as for example with an ad hoc gas, to releasably produce the hydrogenated gas of the present invention, and then adding the covering material to and removing from the mold at a rate sufficient to release therein, under the temperature conditions therein.
 EMI35.1
 reign, the hydrogenated gas of the prdgbnte invention in qur: lt1 ... sufficient to ensure the reaultntç fn'oa out (,! fo1t

 <Desc / Clms Page number 36>

 this process is difficult to carry out and is not the one preferred by the Applicant.



   In practicing the present invention, it is advantageous that the temperature of the molten metal introduced into the mold is maintained as close as possible to the solidification point of the metal, given that excess overheating. -as it repeats itself into the molten metal - increases the heat removal load demanded of the mold and results in lower casting speeds than would otherwise be possible in a mold given.

   In general, the temperature of the molten metal introduced into the mold is preferably less than about 111 sec above the solidification point of the metal. If the best results are to be obtained in casting low grade copper. oxygen, at casting speeds exceeding about 73.66 cm per minute, the temperature of the metal introduced should be less than about 117780, preferably less than about 11490 and more preferably should be between about 1099 C to 1132 C a temperature of around 1121 @ is currently considered ideal.



   The present invention will be described even more completely by means of the examples which follow.



    Example
Deoxidized phosphorous copper having a total oxygen content of less than 0.015% was cast in 76.2 mm diameter billets in the casting system shown in Fig 1 and using the mold shown in Figs. 2 and 3 ,. except that the mold did not include a device for introducing the gas of the present invention and that no gas was used. sleeve 94 was machined from

 <Desc / Clms Page number 37>

 
 EMI37.1
 of an industrial graphite block and had sufficient aurd1lAcuw! .oo so that, when introduced into copper block 79, it received sufficient o1pr8.alD to ensure excellent contact between the canohon and the ohoQi8e d <M! <The conditions of the casting * The! 1DOhoD also had a cord. conversant <uniform 4th 0.177 4i .:

   per length of 2594 un da 0.1 \ & 1-01 have any * li length of # surface tat4- r1uur. 80 # in order to produce a rolling 1 contettf trl6t des bl11., '\ E. for utility speed. In toap6raturw copper fitted in 7 * <6C'ul <& 4% 4 aa1ntonue. about 1 t 21 to. The level * of the copper aa found in the voule was tatatmu au- diecoue du tooawt de la ouvatt * 42 th about 38 m from the upper part of the base, but one that They stinks left <t '<lift until a lower level z, 12.7 <aa the party * eup4r1eur. noulo.

   The flow was mined, filled with an r-, f1.Mc8 of flake graphite * and Kicronoi pearls above the level of the metal which was there; the = d.ltu1go contained at the corners 25% by weight of pearls Hic roc ex To ensure the rourrwrort of VQ-.t..v1nt of the flow, we used a court ** do 3,9 ea> # and the ratio of the frequency of ra- t..virat (.zpr1b 'had cycles per minute) and the speed of casting (oxprizé .0 and,. the fcinuto) was from Il to! # Lu retrnidiI8Qnt produced therefore the t ule compared to the utillodu petta1t pouring speed to keep a crater in volume V (crater 102 of fig 4) of the molten stick in the mold, this crater is rotated 4a4t below the lower part of the -a 94 # cor.;: t represented-
 EMI37.2
 felt on the freeze 4.

   To cool the flow, water from
 EMI37.3
 cooling to 2696720 was introduced into colloo- tower 82, and circulated in the socket at the rate of 2.ZTl, 2
 EMI37.4
 liter @ per minute.
 EMI37.5
 At the start of the casting process we introduced

 <Desc / Clms Page number 38>

 
 EMI38.1
 a classic b <rre do d6.rro .. in mold 13, on = gold. cd lo siphon 1, Mit on route the water circulation in the mold # a:

  r.n4 the siphon in position do dv "rset.1..nt. starts the new vertical vt-vivat of the drain, added the entire carbon cover when the upper part of the nozzle 42 was covered with metal, then the casting speed was increased to the operating speed.
 EMI38.2
 ment # all coaae it has been described before.
Initially, a running speed of 102.8 cm per minute was used. the billet coming out of the mold
 EMI38.3
 at the beginning of the production you showed the surface of the 146ères wrinkles or undulations mitis un1tor.'nc1:

  unt spnedons As tt zut ivoured by the continuation of the production fire, the surface of the billet a train of leaving at o ')! 3nenc4 t 49 degra. dvrt is davonua first smooth cocase of the glass after which of small traces of visible friction have co = tw. 4 to appear on the surface and were followed * by back small engravings or visible mrquea, and then the billet has cO =. ::

  lonc4 to adhere to the casting in such a way that at the end of the first hour of operation, we could not continue the casting process *
Subsequently, many tests were carried out to try to extend the period of operation and to conserve
 EMI38.4
 un1torc680nt undulations spaced apart on the surface of the casting.

   In the course of these experiments, the operating conditions were modified to use higher temperatures ot lower for the metal introduced into the slack, and a higher and lower proportion of phosphorus in the copper, ratios of va- and -Comes and higher and lower casting speed, different levels of metal in the casting or changes in the level of the

 <Desc / Clms Page number 39>

 metal during the casting process, greater or lesser height of the carbon overlap on the metal, as well as various carbon overlays of different composition, increased or smaller taper or no taper at all,

   as well as lower and higher casting speeds * None of the said operating conditions or their combinations have been found * to give full success
Example II
The process and operating conditions described in Example I for an operating speed of 102.8 com per minute were repeated, water! that in this case, hydrogenated gas was used in accordance with the present invention.

   The mold 13 was provided with the gas introduction devices illustrated in FIGS. 2, 4 and 5. As shown by the dimensions given in FIG. 4, the upper horizontal groove 110 was 12.7 mm from the upper part of the mold and the horizontal grooves 111-114 were located below this upper part at 12.7 mm mounting spaces, the groove the lowest 114 was located 63.3 mm from the top of the mold.

   The vertical grooves 115 extending from the horizontal grooves 110-114 were spaced around the perimeter of the outer periphery of the sleeve 94 at 12.7mm lengths. The groge 110 had a width of 3.17 mm and a depth of 0.762 mm. The grogas 111 to 114 had a depth and a width of 0.762 mm.



   After the primed siphon 12 has been in the operating position in the mold and the introduced metal has
 EMI39.1
 covered the cup 42, added l.ca do tAuttiro do cover containing carbon and c c. ", n: é h iî-trodul-

 <Desc / Clms Page number 40>

 re hydrogenated gas. Subsequently, the casting speed was increased to the operating speed of 101.6 cm per minute. During the casting process, the level of the metal in the mold was maintained approximately 38mm below the top of the mold and the mold space above the metal was kept filled with cover material. carbon based. As in Example I, the ratio of the reciprocating frequency and the casting speed was 11 to 1 and the stroke was 3.9 mm.



  The gas was industrially pure hydrogen and was introduced continuously into the mold during the casting operation at the rate of 315 cm3 per minute, measured under standard conditions of ambient temperature and pressure, this total flow being divided roughly evenly by the three passages 121 arranged at equal distances around the perimeter of block 79.



     The fabrication pass was continued uninterrupted for 22 hours, at which time this pass was only interrupted due to the exhaustion of the available quantity of molten metal; the continuously produced billet was cut into appropriate sections by the tang 19 as it passed below the extraction girths 18. The entire surface of the continuously cast billet had the uniformly spaced wrinkles 1 ' encircling, as shown in Figs, 10 and 11. Fig. 10 is a scale drawing illustrating the appearance of the surface of billets when viewed with the naked eye.

   As shown in the enlarged view of FIG. 11, the corrugations or wrinkles had a recessed portion 140 and a relatively flat bearing or portion 141. By examining the billetto, it was found that the length (taken on the vertical of each bearing portion

 <Desc / Clms Page number 41>

 
 EMI41.1
 141) bound about four times that of the adjacent hollow part and that it * produced about 11 portdeo by 25 # 4 Ma of cast length. The specific gravity of the casting was 8.92.

   It was found that the interior of the cast piece had no discernible void portion or had a conxided grain structure through the radial sound hearing substantially up to the center of the ball. found that the billet ria did not include do poroo1tÓ. or rutuseureu at the center the * section cut from billets were used to produce the tube * in the conventional manner by hot isandrlnngc and cold drawing to the finished dimensions - tion # and this resulted in the production of superior quality tubing which satisfied the new S4V'rQ8 which are required for the tubes used in air conditioners as well as for even more severe standards than the 'on r4clw ::

  e for the production of tubes 1 = india to allocate
 EMI41.2
 During a large number of manufacturing passes *
 EMI41.3
 following operations performed under 38 operating conditions, it was found that the results * could reproduce this exact.mont for all purposes. No greater limit than the casting period was found, and in each case the casting * was only stopped when the available molten metal supply was exhausted.
 EMI41.4
 wavy face and Interior features were the
 EMI41.5
 mbiws quo those which were obtained in the preailre pusse
 EMI41.6
 of manufacture described in the present example, it was found
 EMI41.7
 The specific gravity was 8992-8.93.

   In later manufacturing paeoea executed in m4m # a
 EMI41.8
 condition., jump as the ratio of the frequency of movement

 <Desc / Clms Page number 42>

 
 EMI42.1
 of the \ "\" 'fJt ... v1nt ut of the casting speed a varies from 6 to up to 14 1! 1 and more it was found that the results * were evnQ1blucunt read E: 8 & Me, except that the number of staves was 141 by 25.4 sa of ior, -uur dg the corresponding cast was made in the ratio used: 3l. e that 3a .trg, ur must portait "U6- ..:

  ... utu1.t when the ratio was decreasing, and vice versa * Thus, lQr04uton reduced this ratio to 8 to 1 There occurred 6 port {IJG I) 'ir 2504 or of the length do in piece coul 5 t 1. laws carried out in a corresponding manner * (even though the ratio was increased to 14 to!, We observed the pra + nca of 14 narrow stavesaa corruspondiintc by bzz 'ce dQ length said the casting, r; J; \.! .. t'1 m procusaun used for example XI i was repeated using a ratio of the reciprocating frequency and the casting v1tUQOû of 11 k 1.

   After the aa reached the operating speed of 101.6 cm / min, the casting was continued for 2 hours while introducing pure hydrogen gas into the mold at the rate of 315 cc, at the minute. this;, - I describe for the deluxe & ple II, to produce the regular and un1tormoa undulations spaced apart on the surface of the billet,
 EMI42.2
 the rate of introduction of hydrogen was then reduced.
 EMI42.3
 We noticed that, as we gradually decreased
 EMI42.4
 the introduction rate, the surface of the outgoing casting
 EMI42.5
 of the pard mold, 3t of the. qu.'111tG in a gradual and progressive manner.

   In this loss of quality, the corrugations on the surface of the billet in the exit yard became lighter.
 EMI42.6
 managed and less pronounced until they disappear completely, and, for a rate of introduction of gas into
 EMI42.7
 the 25 cm3 mold at the c1nu4 .. the surface being released has become smooth coaue du voere.

   By continuing to decrease

 <Desc / Clms Page number 43>

 the rate of introduction of the gas, small visible scratches on the surface, began to appear on the casting in the course of exit * the traces were small eroded areas which were in successive alignment, as a whole, with the axis of the billet during exit,

       these abrasion marks aligned as a whole occurring at irregular intervals around the periphery of the casting. After the appearance of the traces of abrasion, small, shallow, but visible, surface erosions were observed, produced by a slight adhesion of the casting in the mold and which began to appear on the surface as it came out of the mold. said casting.

     Then, the erosions became progressively deeper, and 30 minutes after the initial appearance of the small traces of erosion, the adhesion became so strong that the flow of the metal was interrupted due to deep tears in the billet in the mold which eventually produced its rupture in the mold * As was the case with the traces of erosion, the shallow and deep engravings were lined up in succession, with some spacing,

   with the longitudinal axis of the billet and these aligned tears occurred at irregular intervals around the periphery of the billet.



   The sleeve 94, which was endoxmaged due to the rupture of the billet, was replaced and the manufacturing pass was started again as before, but in this case, the rate of introduction of the gas juw 'was reduced. that the surface of the billet running from the desine outlet connected to the glass and then the rate of gas induction has not been further reduced. An hour after the curace of the billiate
 EMI43.1
 in the run out had become 3: 3. v du V ..... 'j.') 1 1, l ï

 <Desc / Clms Page number 44>

 casting was stopped as before, due to the rupture of the billet.



   The sleeve 94 was again replaced and the fabrication pass was repeated as before. In this case, after the surface of the current billet started to become as smooth as glass, the rate of gas introduction was increased to 315 cm3 per minute, the rate used at the start of the process. the pass, and the evenly spaced normal corrugation quickly returned to the surface of the casting being released. The rate of introduction of the gas was then reduced until the appearance of small superficial erosions on the surface of the casting. At this time, the rate of introduction of the gas was increased up to 315 cm3 by minute, which had the effect of rapidly bringing back the normal corrugated surface.

   Then, the rate of introduction of the gas was reduced until the appearance of small visible engravings, after which the rate of introduction of 315 cm3 per minute was resumed. Again, normal ripples promptly reproduced on the surface of the casting. During additional manufacturing passes, this reduction and increase in the rate of gas introduction was repeated many times without damaging the wall 80 of the mold (Fig. 2).

   In each case, the surface of the billet being exited deteriorated as described and the damaged surface was quickly reduced to a surface of evenly spaced corrugations as the rate of gas introduction took hold. been swept from that which had been used originally in the said pass.



   An attempt was then made to obtain the appearance of a uniformly wavy surface again after deep tears had occurred in the casting. The pace

 <Desc / Clms Page number 45>

 introduction of the gas had been reduced enough to produce deep tears and was reduced to the rate of 315 cme per minute before the rupture of the cast part occurred @. In a minimal number of tests, we have reunited to have the corrugated surface again on the surface of the casting * by increasing the rate of introduction of these to 315 cm3 per minute.

   However, in most of the * tests the ateremce of the deeply torn billet so marked the wall 60 of the mold that the normal corrugation could not be obtained again * and had to be stopped. casting due to the rupture of the billet in the mold within an hour having auivi the return to the gas introduction rate of 315 cm3 per minute.



   Sleeve 94 was replaced again and the manufacturing break was started and continued as before for 2 hours using the gas feed rate of 315 cc per minute. Then, the rate of introduction of the gas was constantly increased.

   It was observed that with the increase in the feed rate the surface of the corrugations on the exiting casting became increasingly coarser until, for a feed rate of gas of 850 cm3 per minute, the ripple produced on the casting as it came out began to disperse and take on an irregular arrangement of surface imperfections which was perceptible to the touch and which had the appearance of plia arranged at irregular angles.

   By further increasing the rate of gas introduction, this Irregular pattern was increased until, for a rate of gas introduction of 1320 cc per minute, this irregular pattern affected most of the time. the surface of the cast part ** We have

 <Desc / Clms Page number 46>

 slares further increased the rate of gas introduction.

   In the 5 minutes which followed the casting was stopped * due to the rupture of the billet in the mold * Its repeating this production pass after replacing the Sleeve 94 and after having restarted the system as before * we have noted that it was necessary to introduce higher rates of introduction of the day gas to produce the appearance of the over-regular arrangement on the sufface of the part and for this slide to occur over the major * part of the surface, using better reforidiesent conditions in the mold.

   this more powerful roforidly had been obtained in this case by lowering the temperature of the cooling water supply,
In another manufacturing run, sleeve 94 was replaced, the apparatus turned on and operated for the 2 hour period as before.



  Subsequently, the rate of gas introduction was again continuously increased and the evenly spaced corrugations on the surface of the exiting casting deteriorated as before. However, when most of the surface was reached by the aforementioned surface irregularities, the rate of introduction of the gas was quickly reduced to 315 cm3 per minute originally used, which brought back the normal undulations. - = the surface areas evenly spaced on the casting being released, In the course * of additional production *,

   this increase vt this reduction in the rate of introduction of ga was repeated many times and the same results were obtained. Subsequently, during other manufacturing paunchies, the rate of gas introduction was adjusted so as to produce the disposition at will.

 <Desc / Clms Page number 47>

 the previously cited irregularity of irregularities, glass-smooth surface, small viable surface erosions and tears, checkerboard arrangements, as well as evenly spaced corrugations on the surface of the emerging casting.



   Additional fabric passes were made at speeds ranging from 76.2 cm per minute up to 162.56 cm per minute; at the highest speed, the heat removal required for the mold was close to the maximum heat removal or removal capacity of the mold used.

   The ratio of the reciprocating frequency and the casting speed was varied from 8 to 1 to 14 to 1 during these runs. No limitation was found to the lapa of time during which the casting process could be carried out continuously at these speeds and it was found that the rate of gas introduction could be regulated so as to produce. at will the evenly spaced corrugation, the irregular arrangement of irregularities, as well as the glass-smooth surface, as well as small erosions or tears on the surface of the billet.

   In addition, it has been found that when the rate of gas introduction is adjusted to produce the normal corrugations evenly spaced across the surface of the casting at a given speed, the speed can subsequently be varied over a range. comparatively wide range without having to carry out other adjustments of the rate of introduction of the gas while preserving this kind of surface on the casting the Dammderse supposed that a pronounced taper reduces or prevents the port of hydrogen in the reduced pressure zone located at the bottom! of the mold and which is created there because of the belly effect given by the nozzles 89 and 87.

 <Desc / Clms Page number 48>

 
 EMI48.1
 J11xeplt U
The process of Example II was repeated,

   but in this case, the mold was provided with the devices shown in figs 8 and 9 for the introduction of the hydrogenated gas, using apertures 132 which had a diameter of 0.25 mm to 0.30 mm. found that the rate of introduction of the gas could be adjusted to produce at will the irregular arrangement of the irregularities, as well as the smooth surface like glass, the faint visible traces of surface erosion, or else surface tears and also the corrugated surface with uniform spacing which is normal on the outgoing castings.



   Example v
The procedure of Example II was repeated using the devices illustrated in Figs. 6 and 7 for the introduction of gas; the perforations 126, facing down, had a diameter of 0.25 mm. Since the mold was not protected from outside air, gas combustion occurred at the top of the mold. It has been found that the rate of gas introduction can be controlled to produce visible surface scuffs and tears as desired, as well as evenly spaced corrugations on the surface of the casting.



  However, it was not possible to introduce the gas at a sufficiently high rate to produce the irregular arrangement of irregularities on the billet being taken out. the Applicant assumes that this impossibility was due to the effect of dilution of the combustion products and / or of the air.
 EMI48.2
 



  E: 1type YI The process of Example II was repeated using

 <Desc / Clms Page number 49>

   state the to-and-fro and speed ratio
 EMI49.1
 casting d. 11. 1. After the operating speed of 10196 cm per minute had been reached, casting was continued for 2 hvuruo # while introducing 1 industrially pure hydrogen gas into the mold, as described in the example. II, in order to produce the normal uniformly spaced corrugation on the supercar of the billet, as previously described * Next * the hydrogen gas introduced was pr4grsrr- level diluted with nitrogen gas.

   As a result of the decrease in concentration of hydrogen in the a4lM; w gas, there was no apparent change in the character of the wavy surface until. that the concentration of hydrogen in the gas has been reduced to about 79% by volume. After which the ripples became * proressi- vemet monk pronounced When the concentration of hydrogen
 EMI49.2
 When the gas reached about btw in flight., the billet surface had the liana-like appearance of glass which, as noted in Example III, preceded deep tears and final breakage of the part casting in the moula,

   and it has not been possible to improve the surface of the billet in the course of exit by increasing the rate of introduction of the gas thus diluted. The manufacturing procedure was repeated using helium as the diluent gas and the best results were obtained. The results obtained with these manufacturing runs illustrate the critical importance of the concentration of hydrogen due to the gas introduced in the practice of the present invention.



   Example VII
The procedure set forth for Example II was repeated, using a ratio of 11 to 1, for the ratio of the reciprocating speed and the casting speed *. After

 <Desc / Clms Page number 50>

 avior reaches the casting speed of 101.6 cm per minute the casting is continued for 3 hours tnut by Introducing the pure industrial hycrogen gas into the mold at the rate of 315 cm3 per minute, to produce the corrugations uniformly entwined on the surface of the outgoing casting, as described for Example II * Next,

     an equal flow of industrial pure carbon monoxide was substituted for the industrially pure hydrogen. Within the 15 minutes which had elapsed, the introduction of the gnzuux carbon monoxide had to be ceased due to the rapid deterioration of the surface of the billet and the introduction of pure hydrogen was immediately recommenced at the rate of. 315 cc per minute to make the normal wavy surface of the casting reappear. The process was repeated with variations in the casting conditions, as described for Example I, using various rates of carbon monoxide introduction in an attempt to extend the casting period. operation.

   In all these tests, it was necessary to cease the introduction of carbon monoxide within 15 minutes due to the deterioration of the curface of the bil- luttu and no adjustment of the conditions could be found. operation or gas introduction rates which could have allowed the carbon monoxide gas to maintain the evenly spaced corrugations of the surface of the casting given by the use of the hydrogenated gas of the present invention.



     The process just described was repeated by using, instead of hydrogen, various gases, such as, for example, nitrogen, helium, air, carbon dioxide, steam, etc. and mixtures of these gases.



  In all cases, we had to stop the introduction of gas

 <Desc / Clms Page number 51>

 substituted after a period of time comprised between 15 minutes and 1 1/2 hours and no operating setting could be found which would allow a substituted gas to maintain the corrugations uniformly spaced on the aurfaoe of the cast part. when the above test was carried out with steam, it was found that the steam condensed in the passage 121 and in the grooves 110 to II, *;

  . This is why the steam was introduced using the introduction devices shown in figs 6 and 7. The introduction of steam had to be stopped within 15 minutes due to the risk of explosion from the steam. Codnation of Steam Against the Cold Walls of the Mold * The results of the aforementioned manufacturing runs of this example further illustrate the exceptional and critical importance of the hydrogenated gas of the present invention.



   Example VIII
The procedure of Example II was repeated using the 11 to 1 ratio of the back-and-forth frequency and the casting rate. After reaching the operating speed of 40 inches per minute, the casting process was continued for 2 hours, while the pure hydrogen gas was fed into the mold at the rate of 315 cc per minute, as described. in example II, to produce the billet surface which was described in liedit exmep, Then the level of the metal in the mold was raised and lowered, from the norsal level do 38 mm from
 EMI51.1
 the upper part of the mold. f) .. rJ n: 1.vù: .u-:

   1 * .: 3. "1. = b, produced a larger surface brocaièrvrac, 4it r .wx" .. of the bil1tto being released, the effect being whatever we have * .. "1 ! \ "1 eugmontant the introductory pace of c-5 f" 1 r * '- n! Ïr .., 1

 <Desc / Clms Page number 52>

 38 mm from the top of the mold. The lowering of the level below the normal level produced a progressive weakening of the undulations of the surface; the effect produced was that which the reduction in the rate of introduction of the gas would have produced.

   When the level of the Batai has been lowered to the lower limit of the effective diffusion zone of hydrogen in the mold and below this lower limit (this lower limit occurring below the level of the throat 113 and above from that of the groove 114 of the mold shown in fig 4), the effect was the same as that which had been obtained when no hydrogen was introduced into the mold. These results further illustrate the critical importance of introducing the hydrogenated gas of the present invention to the area of the mold wall where solidification of the introduced metal begins.



   It goes without saying that the description which has just been given was purely illustrative and non-limiting and that it is possible to add various variants and modifications thereto without departing from the general scope of the present invention,


    

Claims (1)

CLAIMS 1- Process for continuously casting a metal, consisting of introducing molten metal into one end of a mold with open ends and extracting the cast metal from the other end of the mold, a characteristic process in that one introduces a gas containing more than about 40% by volume of hydrogen in the vicinity of the area of the mold wall where the solidification of the metal introduced during the casting process begins. 2 - Method according to claim 1, oarao- terized in that the molten metal this introduced into the upper part of a vertical mold has open ends comprising a cooling section and that the level of the metal enclosed in the mold is kept below the top of the cooling section. 3 - Process according to claim 2, characterized in that the metal meniscus located in the cooling section is made to move back and forth in the vertical direction in relation to the wall of the aforementioned cooling section. 4 - Process according to any one of the preceding claims in which molten copper with a low oxygen content is introduced into the mold, a process characterized by the fact that a covering of particulate matter is maintained at the same time. the solid state on the upper part of the metal in the mold. 5 - Process according to any one of the preceding claims, characterized in that the introduction of the gas is regulated at a rate below that at <Desc / Clms Page number 54> whereby an irregular arrangement of irregularities occurs over most of the casting surface exiting the mold and at a rate greater than that at which deep tears appear on the emerging casting. 6 - Proceeds comforts * to claim 5, charac- terized for the fact that the gas is introduced into the mold at a rate lower than that at which an irregular arrangement of irregularities begins to appear on the surface of the casting being released from the mold, and superior to the intoduditon pace at which small visible surface tears appear on the surface of said casting. 7 - Process according to claim 5, charac- terized in that the gas * is introduced at a rate greater than that at which small visible scratches appear on the surface of said casting. 8 - Process according to claim 5, charac- terized in that the gas is introduced at a rate above which the surface of the aforementioned casting * and coconut. glass. 9 - A method according to claim 5, charac- terized in that the introduction of hydrogenated gas takes place at a rate sufficient to maintain regular and uniformly spaced corrugations on the surface of the casting, giving rise to the casting process. . 10 - Process conforms to any of the preceding claims, characterized in that the gas contains at least 75% hydrogen by volume. 11- Method according to any one of the preceding claims, characterized in that the gas <Desc / Clms Page number 55> is substantially pure hydrogen gas. 12 - A method according to claim 3, characterized in that the gas is introduced into the metal meniscus enclosed in the mold by diffusion through the cooling section of said mold. 13 - Process according to claim 4, charac- terized by the fact that the gas is introduced into the metal meniscus contained in the mold by sending this gas into the mold cavity above the metal in this mode. , by openings made in the opening of the wall of the mold into the mold cavity above the level of the metal meniscus therein. 14 - Process according to claim 4, characterized in that the gas is introduced into the metal meniscus enclosed in the mold by bringing a plurality of streams of gas oriented downwards and not delimited into the cavity. of the mold, above the metal enclosed in said mold,