US927371A - Process of making clad-metal articles. - Google Patents

Description

J. F. MONNOT. PROCESS OF MAKING GLAD METAL ARTICLES.

APPLICATION FILLED JUNE 13,1908.

Patented July 6, 1909.

, 3% i m Q Inventor:

v Attyd M. M T. m 4

UNITED STATES PATENT OFFICE. JOHN nnoimor, on NEW YORK, N. Y., ASSIGNOR DUPLEX METALS GOMPANYQOF New YORK, N. Y., A CORPORATION OF NEW YORK.

rnlocnss'or name emu-urn. an'rrcnns.

Specification of Letten Patent.

Patented Jul 6, 1909.

Application filed June 18, 1908. Serial No. 438,896.

face of themetal which is to form the cover- 7 To all whom it may concern:

Be it known that I, JOHN F. Mormo'r, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Process of Making Clad-Metal Articles; and'I do hereby declare the following to be a full, clear, and exact descri tion of the same, suchas will enable others s illed in the art to which it appertains to make and use the same.

My invention relates to a process of making clad metals; by which term is meant bodies comprising a core or base of one metal (iron or steel for instance) having united thereto, and preferably inseparably united or-welded thereto, a substantial layer or coating of metal, usually an unlike metal, (for instance, copper, silver, gold, aluminum, brass, bronze, aluminum bronze, etc).

' particular, my invention comprises a process of making clad metal ingots; which ingots,

when formed, may be rolled, pressed, hammered, or otherwise extended down to rods, sheets,"bars, strips, wire and other commerf cial ordesired forms.

In various prior patents and applications for patents, :for example, Patents Nos.

851,993, 853,716, and applications Sr. Nos, 281,680, 391,673, and 400,843, I haveillus-'- trated and described processes and apps ratus for producing cla metal bodies or ingots such as referred to, andcomprising various pairs of unlike metals such as referred to inseparably weldeddogether, such' pro c--, based on a discoverysmade by me, Q

, pper and silver for exam 'le, which donot form-a peresses being A to the eii'ect that various meta manent aor wel -like union with iron or' steel when cast against aniron orsteel surface at ordinary castipi temperatures, do form {get- ;1 raised a" :manent weld e unions when much higher temperature (termed by me, for the sake of a name, the supermolten temperature) and contacted with the iron or stee surface. The said patents and applicationsdisclosemethods of and ,means for contaotinga solid base of one metal, steel for .examplefwith molten metal of an unlike nature, copper for example, under such conditions .of tem erature and physical contact that union wil take place.

A processinvolvin the casting of the core or base, metal, whi 1 is usualb relatively large in amount inside of or against the sun-1;

, forth in ing or coating of the in ot or other article to be produced and whlch is usually relatively small in amount-for example, a process involving the castin of a steel core -or base inside of a copper s ell-has numerous advantages from a practical pointof view. In such a process, ingots ofany desired size may be produced; the apparatus required is pro ortionately less expensive and more covering .of the surface with the molten oxidation :of the metal and of preventin I surface of the cast meta as well as other difiiculties which might be mentioned, have militated against the use of any such process, however. To produce, a metallic union between two metals it is-necessary that such 111161 1318 shall come into contact with clean,

trul metallic surfaces, free of infusible 01ml; or impurities, along the line of intended union.- It has been difiicult, furthermore, to prevent the cast -steel core from pullin away from the solid coatlng, durlng the so 'dification and shrinkin of the cast core. And in 'unitinga molten 'gh-mjeltmg core metal with ,a sohdloWer-mel-tmg coating metal, there has been extreme probability that the'coa-ting metal will be contaminated to a considerab e extent by the core or ,base metal, owing topartlal iuslon of ,the coating -metal'and consequent mingling of ,the two metals; Such contamination is exceedingly objectionable in ,manywcases'; for examp e, in the making of metal for electrical .conductors.

The :method of casting metal ingots set my application Sr. No. 391,674, 1nvolvm the passing of .the molten metal throu a layer of molten :Wl ing matena, such use suitable flux, an the retarded cooling ofn large body of molten metal at oxidation e y handled, little manipulation is necesthe top of the ingot, so that this body will remain fluid after the main portion of the ingot has set and will flow down to fill any pipes or the like which may form, and Will also exert a certain amount of fluid pressure to solidify the metal, overcomes these difficulties, and makes it possible to cast a steel core inside of a copper shell, and to obtain a dense, solid core; and the same layer of wiping material through which the metal for this core is cast, also serves to remove any layer of oxid or other contamination on the surface of the said shell, besides preventing contact of the air with the portion of the solid metal immediately above the molten metal andv necessarily heated to a high temperature. This layer of wiping material further removes entrained and occluded gases, oxid impurities, etc. from the moltenmetal, preventing the formation of bubbles, blow-holes or blebs where the cast metal core contactswith the said coating metal and allowing a full-area contact between truly metallic surfaces of the two metals. It is extremely important, in the making of clad metal articles intended to be extended or worked, to avoid any such flaws at the surface of union, as any such flaws, if formed, extend greatly during the subsequent working and extension of the clad metal, producing what may prove to be serious defects in the final product. For example, in the case of clad metal ship plates, consisting of a steel base or back and a co per, brass, bronze, Tobin bronze, or li e coating, a bubble or blow-hole at the line of union in the large ingot, may in the final plate form a lineal flaw or pore which will admit sea-water to the steel back, permitting galvanic action between the metals of the back and of the coating, which will result in the weakening and finally in the perforation of the plate. asting the molten steel through wiping material, as described, avoids the presence of the gas to which such bubbles or blow-holes are due, ermitting the two metals to come into abso ute metallic contact at all meeting oints. This method of casting through mo ten wiping material also makes possible the casting of the metal of the said shell or coating itself, immediately in advance of the casting of the metal of the core or base. Heretofore this has not been practicable, because cast copper or like metal usually contains numerous internal flaws, blow-holes, etc. which make it necessary to roll -or otherwise work it before it can be used as such a-coating or shell. But metal east through wiping material is practically free from such internal flaws. 1

The preferred method of carrying out my present process, therefore, supposing the article to be produced to be an ingot composed of a steel core and a copper or other non-ferrous coating, comprises casting the metal for this coating in a suitable mold containing a collapsibleorotherwisc removable core adapted to form inside the coating a space sullicient for the cast core, such casting being done through a layer of molten wiping material; in removing the said collapsible core as soon as the metal for said coating has set, and in then casting into the space from which such core was removed, the molten steel to form the core of the ingot, such casting being also done through a layer of molten wiping material. And preferably, to cause rapid shrinking of the coating, so that there can be no separation of the cast core from it, I chill the mold as soon as, or soon after, the core has been cast. This chilling is further advantageous in many cases, because copper and many other metals are softer, closergraincd, and altogether better if cooled quickly from the molten state. This chilling also obviates fusion of the coating metal and consequent mingling of the two metals, with consequent impairment of quality of the metal of the coating.

In the accompanying drawing I illustrate apparatus for carrying out my said process, and the manner of carrying it out.

Figure 1 shows a central vertical section of one form of mold which may be used, and with one form of collapsible core which may be used in place in said mold; also a layer of molten metal for the coatin in the annular space between the core and sides of the mold, and a layer of molten wi ing material above such molten metal. .ig. 2 shows a similar section (except that the section is not taken through the two "runners, as is the section of Fig. 1) of the mold after the shell for the coating has been cast and solidified, and after the collapsible core has been removed and the runner for pouring the metal for the ingot core has been put in lace. Fig. 3 shows a horizontal section of t e mold and collapsible core, on the line aca: of Fig. 1..

In the drawings, 1 designates an ingot mold, which in most cases may be of iron;

and 2 designates a collapsible core of the size v required to give the desired size of cast core in the final ingot.

3, 3, designate inclined runners on opposite sides of the mold, through which molten metal for the coating may be poured into the mold from two sides at once. v

4 designates a cooling jacket with which the mold may be provided, and which is provided with means for introducing into it or four side-pieces 7. The mo d l has at its 'dra t in the mold.

a suitab mixture or wash, to prevent the molten metal bottom a shallow recess 8 in which the lower end of the core may be stepfpgig saidlrfipess o to 0 its serving to center the core an sections together at the bottom; and at its upper end the core has a clamp 9 which serves to hold its sections together.

10, Fig. 2, designates a runner of refractory material which is applied to the mold after the shell for the coating has been cast and when the metal for the ingot core is to be cast.

The mold 1 is preferably formed of a lurality of sections secured together, w 'ch pur ose I have shown clamping rings 11 and We ges 12. The mold shown is made in two sections, so that it will part to permit re.

moval of the cast ingot. A mold made in a meter number of sections will serve as we 1, or even better. It is desirable to avoid employing a mold with material draft, so that the coating may be of substantiallythe same thickness, and the cast core of substantially the same diameter, at the to as at the bottom; and employing a mold w 'ch parts lon 'tudinally make t possible to avoid The method of carryin been clam ed together, as shown in Figs. 1 and 2, and the collapsible core 2 being in lace as indicated in Figs. 1 and 3, and the inside of the mold and the surfaceof the core 2 havin preferably been given a coatinglof dc substance, for example a grap 'te clingin to them, molten metal, copper for examp e,is poured into the annular space between the core 2 and the sides of the mold through a layer 13 of molten wiping material previously introduced, the metal being preferably introduced from a pluralit of points simultaneously so that it will iii the mold quickly. In descending throu h of wi ing'material, which should be of substantlal thicluiess, the molten metal is freed of adhering, absorbed and entrained .moisture and gases so that theseveral drops or bodies of'sucli metal meet beneath the ayer with clean, readily coalescmg surfaces form ing a sound and perfect casting. And as the;

molten wiping material rises above theaccu mulating molten metal, it similarly wip th surfaces of mold and core, permitting the, Cast-1 ing to take an accurate shape and have a good surface, free of blebs, pitholes, etc. The molten copper is poured 1n until it; about reaches the top of the jacket 4, andthen the pouring is stopped,-and the molten metal is.

permitted to solidify. To hasten solidifica tion, cooling water or other coolingfluldmay be introduced into or circulated through the jacket 4, though in general cooling will not out the process is. as follows: The parts 0 the mold havingthe layer be necessary at this point. As soon as the molten metal, which now forms a shell 14, has set and while it is still redhot or hotter, the'collapsible core 2 is removed, the layer of wiping material now flowing down to the bottom of the central space 15 from which the core'2 was removed, the runner 10 is put wiping material, which rises as the steel fills the central space 15. Steel is so poured in molten wiping material then forming over the top of the molten metal a protective covering of relatively low heat conductivity; and since the runner 10 is also of a material of metalin the runner is relatively slow. As soon as the mold has been filled as described water or'other suitable cooling fluid is admitted to or circulated through a cooling jacket 4, so preventin the copper shell from melting and chilling to contract with the cast steel inside it. As the copper shell coolsit will in turn cool the adjacent portion of the cast steel core, causing the metal below the runner to cool more rapidly than the-metal within the runner, the lattermetal remaining liquid until the metal below has fullyset. Any pipes or the like which may form during the solidifica tion of the cast core are filled by dow'nflow of metal from the runner; and the fluid ressure exerted by the metal in this runnera ohelps to insure good density of the cast metal. Preferably the ingot so cast is removed from diately worked, by rolling or otherwise; or it may be subjected to pressure while still fluid ods of pressure-casting.

W1 oxi and like impurities, entrained and oc-' cluded gases, and insures a particularly good in the mold is at alltimes covered by anair excludinglayer ofwiping material. .difierent wipinginateria s may be used; one

.solid t e mold, if desired.

wouldbe an obvious modificatign of the process above describedto cast the steel core within mold 1, remove the said sectional mold when the steel core is solid, andthen cast molten coating metal, through wiping the shell and causing it the mold as soon as practicableandis immein the mold, according to well-known moth-V The casting of both metals through molten I V ing material as described removes all Var ous in place, and molten steel for the core'is poured into this central space, through the until space 15 is full and the runner 10 is also partly filled with the molten metal, the

low heat conductivity, cooling of the molten quality of metal, if the process .is carried on properly. Oxidation of the metal during the "casting, is precluded, since the molten metal. 11s

suitable material being a mixture d sodium 'orgotassium silicate, bore]: and boracic acid. v f' course my process'described aboveisj not to the production ofthe 811811111; bycasting as described the shell 14 may V produced in an suitable manner, and ladced n it 1 first, within a sectional mold contained the ingot as described.

1 holes and the like.

material, into the space between said core and the sides of mold 1; afterward working It may be that the steel, when it first contacts with the solid cop er, produces actual or incipient fusion of t 1e copper on the extreme surface; such fusion, if it occurs, facilitating the formation of a union between the two metals. But the cooling of the copper shell as described prevents any materia fusion such as will result in material contamination of the copper by the metal of the core.

If desired or required, after theremoval of the collapsible core from the mold, after casting the annular body 14, additional flux or wiping material may be poured into the interior of such annular body to completely fill it, so absolutely protecting its surfaces from oxidation andremovin any trace of oxid which may have been already formed, so that an absolutely clean surface of the metal is exposed when the molten steel displaces this flux or wiping material.

I do not limit the rocess to top pouring, but'may pour throug the bottom of the ingot mold, as is common in steel practice, if desired.

It is obvious that the same process above described is equally ap licable to the formation of objects in wine 1 neither metal completely surrounds the other; for example, ob]ects in whichone body of metal abuts against, without surrounding, the other; in such case the mold used will have a removable filling piece, corres onding to the collapsible core 2, which will fill that portion of the mold which is to be occupied by the body of metal cast last; and the body of metal first cast will be cast into the remaining ortion of the mold, and after it has solidi ed the said filling piece will be removed and the other body of molten metal cast.

Instead of first casting a cop er or like metal body, permitting it to so idify, and then casting molten steel against the surface of the solidified copper or other metal,,I may cast the steel and the non-ferrous metal practically simultaneously, by lacing a suitable separator in the mold and casting the one metal on one side of the se arator and the other metal on the other side of the separator; casting both metals through molten wiping material, as already described, so as to obtain dense, sound metal free from blow- Thus, in the making of a copper-steel round ingot, I may lace a steel tu e of suitable size in the mo (1, and cast copper, through flux, either inside or outside the tube, according as the copper is desired either on the inside or outside of the finished product, casting the steel on the opposite side of the tube, casting through flux or wiping material in both cases. And in making fiat or square ingots the same method may be employed, a suitable separator being placed in the mold to keep the two metals separate during the pouring. In casting by this method, both metals will weld to the separator, and so will in effect be welded to the ingot may be rolled, without reheating,

immediately after the steel has solidified and while it is still at a much higher temperature than the copper or other coating metal. Rolling clad metal ingots produced by casting the copper or the like about the steel, presents certain practical disadvantages, owing to the fact that the ingot must be rolled at a temperature at which the copper or like metal issolid, which is not necessarily the best working temperature for the particular steel em loyed; and after the ingot is once produce it can be heated only from the outside, that is to say, through the copper or like metal, so that on such reheating its interior temperature cannot be higher, initially, than its exterior temperature. But when the ingot, produced as described herein, is rolled without reheating, the steel may be at a much higher temperature than the copper, first because it solidifies at a higher temperature, the copper being kept at a lower temperature in the mold bythe cooling means described, and then when the ingot is removed from the mold and rolled, radiation of heat to the air and the higher heat conductivity of the copper will keep the temperature of such copper materially lower than that of the steel inside. For this reason the ingot so produced is much easier to work by rolling or otherwise, and no reheating before rolling is required.

What I claim is 1. A process of making clad metal objects which comprises forming a compound ingot by casting molten metal of relatively high melting point through a layer of molten wiping materialin an ingot mold and against the surface of a solid body of metal of lower melting point and causing it to solidify thereagainst.

2. A process of making clad metal objects which comprises casting molten metal of relatively high'melting point through a layer of molten wiping material against the surface ofa solid body of metal of lower melting point andcausinglit to solidify thereagainst,

and abstracting eat from the solid metal during contact with such molten metal.

3. A process of making clad metal objects which comprises forming a compound in ct by casting molten metal of'relatively high melting point throu h a la er of molten wiping material into t e interior of an annular body of metal of lower melting point, and causing'it to solidify against the surface of such annular'body.

4. A process of making clad metal objects which com rises casting molten metal of ing material into contact with a solid bo y I ferrous metal hr'ough rial into the interior of an annular of metal consisting in whole or in greater part of non-ferrous metal, and permitting the molten metal to solidify against such body. 6. Aprocess of forming clad metal objects which consists in casting a molten body of a layer .of molten wiping material 'into contact with a solid body of er and permittingthe molten meta to co 'soii ify against suchhody. 7 A process ofform'ing clad metal objects which consists in casting a molten body-50f ferrous metal through a layer of molten wiping material into contact with a solid body of metal consisting in whole or in greater part of non-ferrous metal, and permitting the molten metal to solidify against such surface and abstracting heat from such solid metal during contact thereof with the molten metal.

8. A process of forming clad metal objects which consists in castinga molten bed of ferrous metal through a layer of mo tan with a solid wiping material into contact V p the molten body of'co er and permitt' metal to so idify againstj'suchody and abstracting heat contact 'thereof with the molten metal.

9. A process of forming-clad metal objects which consists in casting molten ferrous" ing material metal through a layer of'wi ody of metal into the interior of an annular consisting 'in whole or greater part of nonmolten face of the body ferrous metal andpermitting such metal to solidify ainst such body. 7 10. A process 9 forming clad metalobs jects which conslsts'in casting molten ferrous metal through a layer of wiping mateco er and 'ermitt' such molten metal to SOEE P ft ify against suc ody.

11. A process of forming clad metal objects which consists in casting molten ferrous metal through a layer of wi in material into the interior of an annular bofy of metal consisting in whole or greater part of nonferrous metal and permitting such molten metal to solidify against such body, and

jects which consists from such solid metal during ody of abstracting heat from such annular body during contact thereof with the molten metal.

12. A process of forming clad metal ob: jects which consists in casting molten ferrous metal through a layer of wipin mate rial into the interior of an annular ody of copper and permittin to solidifv against suc body, and abstracting heat from such annular body during contact thereof with the molten metal.

13. A process of forming clad metal obin contacting with the surface of a solid body of metal a layer of molten flux comprising oxid-dissolving material, casting through such layer of flux into contact with the surface of such metal, a body of molten metal of higher melting point and by the progressive rise of the layer of flux removing oxid'from the surface of the solid metal and exposing a clean surface of such metal to contact with the molten metal, and permitting the molten metal to solidify against such surface. v

14. A process of forming cladmetal objects which consists in contacting with the surface of a solid body of metal a layer of molten flux comprising oxid-dissolving material, casting into contact with such surface. a body] of molten metaland causing the molten metal so cast to raise the layer of flux and thereby to ex ose progressively a clean surface of the so id metal to contact with the. molten metal,- and permitting the molten metal to solidify against such surface.

15. A process of forming clad metal objects which consists in contacting with the inner surface of an annular body of metal a layer of molten flux comprising oxid-dissolv ing material, casting into the space within said annular body a body of molten metal andcausing the molten metal socast to raise the-layer of flux and thereby to expose progressively a clean surface of the so 'd metal to contact with the molten metal, and permitting the molten metal to solidify against such surface.

such molten metal 16. A process of forming clad metal objects which comprises casting a bodv of mol ten; metal and permitting it to solidify, producing a substantial layer of flux next a sur so formed and while sa d :body is hot casting into contact with its said surface through said layer another body of molten metal and causing such metal to displace saidilux, and ermitting such second ody of molten meta to solidify against such surface.

17. A recess of forming clad metal obpermitting it to solidify,

jects whlch com rises casting a body of molten metal an producing a substantial layer of flux next a] surface of the body so formed and while said body is hot casting into contact with its said' surface through said layer another body of molten metal and causing such metal to dis place said flux, permitting such second body of molten metal to solidify against such surface, and abstracting heat from such first body of metal during contact thereof with said second body of molten metal.

18. A process of forming clad metal objects which comprises casting a body of molten metal through a layer of wiping material, and permitting the metal to solidify, and While said body is hoteasting into contact with a surface of it, through a layer of wiping material, another body of molten metal, and permitting such second body of molten metal to solidify against such surface.

19. A process of forming clad metal obj ects which comprises casting a body of molten metal through a layer of wiping material, and permitting the metal to solidify, and while said body is hot casting into contact with a surface of it, through a layer of wiping material, another body of molten metal, permitting such second body of molten metal to solidify against such surface, and abstracting heat from such first body of metal, during contact thereof with said second body of molten metal.

20. A process of forming clad metal 0bj cots which comprises casting a body of molten metal through a layer of wiping material, and permitting the metal to solidify, protecting a surface of such body from oxidation With molten flux and while said body is hot casting into contact with such surface,

through flux, another body of molten metal, and permitting such second body of molten meta to solidify against such surface.

21. A process of formingclad-metal objects which comprises casting a body of molten metal and permitting the metal so cast to solidify while protecting such metal against oxidation, casting into contact with the surface of the body so produced another body of molten metal under conditions precluding oxidation and permitting it to solidify against the surface of said first body, and abstracting heat from said firstbody of metal at such rate as to permit refusion of only a thin layer thereof adjacent the second body of metal, thereby insuring molecular contact of the two metals and avoiding material mixing thereof.

22. A process of working, by rolling, pressing, hammering or the like, clad metal bodies, which consists in maintaining the core, of metal of higher melting point, at a temperature higher than that of the coating, of metal of lower melting point, and working same by rolling, pressing, hammeringor the like while maintaining a temperature differ-- ential between the two metals.

23. A process of forming compound metal objects which comprises placing a separator in a suitable mold and casting different kinds or grades of metal, through molten wiping material, on opposite sides of said separator,

causing the two metals in solidifying to weld to the separator and so to each other.

In testimony whereof I afiix my signature, in the presence of two witnesses.

JOll N 3 MO NOT. Witnesses:

H. M. MARBLE, K. G. LE ARI).

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