US3540514A - Production of metal ingots,slabs and billets - Google Patents

Production of metal ingots,slabs and billets Download PDF

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Publication number
US3540514A
US3540514A US634120A US3540514DA US3540514A US 3540514 A US3540514 A US 3540514A US 634120 A US634120 A US 634120A US 3540514D A US3540514D A US 3540514DA US 3540514 A US3540514 A US 3540514A
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US
United States
Prior art keywords
mould
substance
metal
walls
volatilisable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US634120A
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English (en)
Inventor
Roderic Hugh Hammerton
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Foseco International Ltd
Original Assignee
Foseco International Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB2044466A external-priority patent/GB1153752A/en
Application filed by Foseco International Ltd filed Critical Foseco International Ltd
Application granted granted Critical
Publication of US3540514A publication Critical patent/US3540514A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
    • B22C1/02—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds characterised by additives for special purposes, e.g. indicators, breakdown additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C23/00—Tools; Devices not mentioned before for moulding
    • B22C23/02—Devices for coating moulds or cores

Definitions

  • PRODUCTION F METAL INGOTS, SLABS AND BILLETS This invention relates to the production of ingots by the method in which molten metal is poured into metal moulds and is particularly concerned with the production of ingots of steel or of slabs or billets of copper, nickel or alloys or either of these.
  • mould dressings or mould additives which reduce oxidation of the molten metal by their fluxing or reducing action and thus help to prevent the above defects.
  • slags with a melting point considerably lower than that of the metal being cast, which form a molten fluxing layer on the rising surface of cast metal
  • mould dressing including those based on tar, pitch, bitumen or heavy oil compositions.
  • Suitable compounds for the indicated purpose include carbocyclic hydrocarbons such as naphthalene, phenanthrene, anthracene, biphenylene, naphthacene, rubrene, pentacene, heptacene, pyrene, perylene and acenaphthene.
  • carbocyclic hydrocarbons such as naphthalene, phenanthrene, anthracene, biphenylene, naphthacene, rubrene, pentacene, heptacene, pyrene, perylene and acenaphthene.
  • Other suitable substances are phenolic compounds (e.g., resorcinol,
  • Nitrogenous compounds may also be used, e.g., anaphthylamine and the aminoanthraquinones.
  • the substance (1) may be any of those referred to above, the substance (2) may be for convenience a common inflammable solvent such as solvent naphtha, turpentine, white spirit or isopropyl alcohol.
  • the substance (3) may be, for example, a metal soap such as aluminium stearate, napthenate, octoate, or 2-ethyl hexoate, alkyl ammonium montmorillonite or silica gel.
  • a metal soap such as aluminium stearate, napthenate, octoate, or 2-ethyl hexoate, alkyl ammonium montmorillonite or silica gel.
  • a method for conditioning a mould for use in the production of ingots of steel or slabs or billets of copper, nickel or alloys of either which comprises, introducing into the mould a body of a volatilisable substance which will on heating cause a deposit of the substance and/or its decomposition products on the walls of the mould, the said body of volatilisable substance having associated there with a product of which the ingredients will react exothermically when fired, igniting the said exothermic product thereby to cause volatiisation of the volatilisable substance, and restricting access of oxygen to the interior of the mould thereby to prevent total combustion of said volatilisable substance.
  • the volatilisable substance may be a pure chemical compound or a mixture of compounds.
  • molten metal is poured into the thus conditioned mould.
  • the resulting cast metal has an improved surface as compared with cast metal obtained in a mould not so conditioned and it is believed that this is at least in part due to the fact that when the molten metal is poured into the mould, volatilisable substance on the wall of the mould is again volatilised at the mould/molten metal interface and such volatilisation causes oxide scum on the metal surface to be driven away from the mould walls.
  • any of the volatilisable substances hitherto proposed for the purpose may be used in the method of the present invention, e.g., pitch, or a carbocyclic compound as described in U.S. Pat. application Ser. No. 407,240 as a powder or tablet or a gel composition as described in U.S. Pat. application Ser. No. 473,816.
  • pitches e.g., pitch, or a carbocyclic compound as described in U.S. Pat. application Ser. No. 407,240 as a powder or tablet or a gel composition as described in U.S. Pat. application Ser. No. 473,816.
  • Examples, apart from pitch itself are the following:
  • Unit 1 Unit 2 Unit 3 External diameter (ins) 4% 4 5 2 External height (ins.) 3% 3% 3% Internal diameter (ins 3% 2% 1 Internal height (ins.) 3 3 2% Unit 1 will accommodate 5 /2 ounces of powdered pitch of 8 ounces of fused material. Unit 2 accommodates 4 ounces of powder and unit 3 one-third of an ounce of powder. The rate of application is recommended as:
  • a cup or layered product of appropriate size is ignited and lowered into an empty ingot mould, using a wire or other suitable support, and the mould mouth is immediately covered to prevent ingress of atmospheric oxygen, thus restricting the degree of combustion of the volatilisable material.
  • the exothermic composition does not depend upon an external source of oxygen for its reaction and the reaction is not inhibited by exclusion of the atmosphere. As the exothermic reaction proceeds. the heat liberated causes the volatilisable material to deposit on the mould walls, possibly with a minor amount of combustion products. After the exothermic composition has completely burned, the spent body is removed from the mould which is then ready to receive molten metal.
  • mould additives for the purpose described above which comprise a body of a volatilisable substance as aforesaid associated with an exothermic composition.
  • the exothermic composition may be an aluminothermic composition, and may be in the form ofa cup. adapted to contain the volatilisable substance within the cup-cavity.
  • the additive to the mould consists of a body of combustible porous material impregnated with an oxidising agent. and having a coating of a desired volatilisable substance thereon.
  • the combustible porous material and the oxidising agent being such that the combustion of the porous material is sustained by the oxidising agent even though air supply is restricted.
  • This additive is used in exactly the same manner as the additive described above, i.e., its combustion is hindered, but not wholly prevented, by limiting access of oxygen to the mould
  • the heat generated exothermically by the reaction of the oxidising agent with the porous support material serves to volatilise and in some cases also to decompose, the said volatilisable substance.
  • the porous support material may be, for example, paper or other matted cellulosic fibre.
  • the oxidising agent may be chosen from a large variety known per se but is preferably a nitrate or perchlorate, e.g., sodium nitrate.
  • the volatilisable substance may be any of those described above.
  • a product found to be of particular value for the indicated purpose is paper impregnated with sodium nitrate and coated with pitch. To use it, this product is simply ignited and dropped into the mould cavity where it smoulders and deposits pitch and/or decomposition products of pitch on the mould walls.
  • a further type of mould additive suitable for use in the process of the present invention is one in which the exothermic composition is in finely divided form dispersed throughout the body of volatilisable substance.
  • a suitable exothermic material is a finely divided combustible material impregnated with or in close contact with an oxidising agent such as sodium or potassium nitrate.
  • Suitable materials are cellulosic materials and expanded polystyrene. Sawdust impregnated with oxidising agent is the preferred material for economic reasons. volatilisable materials preferred in this type of additive are bitumens, pitches and tars.
  • the problem may be readily solved by packing the product in a readily combustible container itself comprising an oxidising agent, e.g., a paper bag impregnated with an alkali metal nitrate.
  • an oxidising agent e.g., a paper bag impregnated with an alkali metal nitrate.
  • the quantity of nitrate used to impregnate the sawdust or like material is selected such that the heat generated is enough to vapourise the bituminous material, but not wholly to carbonise it.
  • the amount of nitrate present is too low, the coating of bituminous material deposited on the walls will be too thick and this may lead to the generation of gas below the surface of the molten metal during teeming of the molten metal into the mould.
  • Particularly preferred products are those in which the ingredients are present in substantially the following proper tions, by weight:
  • Bituminous material3242% preferably 37%.
  • the optimum amount of additive needed may alternatively be calculated if the mould wall area is known. Generally, an application rate of about 140 gm/sq. metre of mould wall to be coated is found to give satisfactory results, when used in cold moulds (i.e., at about 50C.) having hot base plates. If the mould is hot as well as the base plate, then a higher application rate is generally necessary to ensure an adequate coating.
  • the process and additives of the present invention are simple to use and have the great advantage that they may be used on moulds at temperatures from 50 to 500C. If the temperature of the mould is greater than 500C., the deposited layer tends to be sooty and this is less desirable, as explained above. In addition, the method of the present invention produces a far more even coating on the inner mould walls then is normally obtained by manually operated spraying, painting or like processes.
  • volatilizable substance is selected from the group consisting of bituminous materials, carbocyclic chemical substances, mixtures of ester gum and formaldehyde resins and mixtures of camphor and naphthalene.
  • exothermic material is a body of combustible porous material impregnated with an oxidising agent.
  • oxidising agent is selected from the group consisting of nitrates and perchlorates.
  • finely divided exothermic material comprises finely divided cellulosic material impregnated with oxidising agent.
  • said combustible casing comprises a paper bag impregnated with oxidising ingot cast in the mould to which the coating is to be a plied.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Mold Materials And Core Materials (AREA)
US634120A 1966-05-09 1967-04-27 Production of metal ingots,slabs and billets Expired - Lifetime US3540514A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB2044466A GB1153752A (en) 1966-05-09 1966-05-09 Conditioning of Moulds for Metal Ingots, Slabs and Billets
GB2044366 1966-05-09

Publications (1)

Publication Number Publication Date
US3540514A true US3540514A (en) 1970-11-17

Family

ID=26254681

Family Applications (1)

Application Number Title Priority Date Filing Date
US634120A Expired - Lifetime US3540514A (en) 1966-05-09 1967-04-27 Production of metal ingots,slabs and billets

Country Status (4)

Country Link
US (1) US3540514A (2)
BE (1) BE698157A (2)
DE (1) DE1558116B1 (2)
SE (1) SE340338B (2)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3978908A (en) * 1975-01-06 1976-09-07 Research Corporation Method of die casting metals
US4005742A (en) * 1974-10-25 1977-02-01 United States Steel Corporation Method of restoring ingot mold stools and closed-bottom ingot mold
USRE29646E (en) * 1976-03-08 1978-05-30 United States Steel Corporation Method or restoring ingot mold stools and closed-bottom ingot mold

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1413013A (fr) * 1963-11-04 1965-10-01 Foseco Trading Ag Procédé de préparation de lingots d'acier ou de billettes de cuivre ou de nickel ou d'un alliage de ces métaux et produits pour la mise en oeuvre de ce procédé

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4005742A (en) * 1974-10-25 1977-02-01 United States Steel Corporation Method of restoring ingot mold stools and closed-bottom ingot mold
US3978908A (en) * 1975-01-06 1976-09-07 Research Corporation Method of die casting metals
USRE29646E (en) * 1976-03-08 1978-05-30 United States Steel Corporation Method or restoring ingot mold stools and closed-bottom ingot mold

Also Published As

Publication number Publication date
DE1558116B1 (de) 1970-01-29
SE340338B (2) 1971-11-15
BE698157A (2) 1967-10-16

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