US2832700A - Non-oxidising heating of metal articles or blanks - Google Patents

Non-oxidising heating of metal articles or blanks Download PDF

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Publication number
US2832700A
US2832700A US427771A US42777154A US2832700A US 2832700 A US2832700 A US 2832700A US 427771 A US427771 A US 427771A US 42777154 A US42777154 A US 42777154A US 2832700 A US2832700 A US 2832700A
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United States
Prior art keywords
workpieces
bath
furnace
heating
blanks
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Expired - Lifetime
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US427771A
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English (en)
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Balestra Osvaldo
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/0031—Rotary furnaces with horizontal or slightly inclined axis
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/44—Methods of heating in heat-treatment baths
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/44—Methods of heating in heat-treatment baths
    • C21D1/46—Salt baths
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/52—Methods of heating with flames
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
    • C21D1/70—Temporary coatings or embedding materials applied before or during heat treatment while heating or quenching
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor

Definitions

  • This invention relates to a method and means by which metal articles or blanks may be heated to the desired high temperatures without surface oxidation in furnaces which are conventionally fired.
  • the improved method consists in coating the metal articles, e. g. blanks or billets, at least within the range 'of temperatures liable to give rise to oxidation, with a film of protective molten material, preferably glass.
  • This film extends over the whole surface of the workpieces and prevents direct contact thereof with the surrounding atmosphere, which cannot therefore oxidize the metal surface.
  • the film preserves the metal against oxidation during the whole pre-heating period and the short period dur ing which the articles are conveyed to the pressing or rolling machinery for hot working.
  • the film further affords protection against decarbonising of the metal articles during pro-heating.
  • Pre-heating carried out according to my improved method not only avoids oxidation of the surface of metallic articles so treated, but also eliminates any previously formed oxide film on the surface thereof.
  • the molten .glass efiects a hot pickling of the metal by absorbing iron oxide therefrom.
  • iron oxide itself may be added to the glass in order to modify its melting properties, and suit it to a wide range of working temperatures. It is thus possible to obtain glasses which are fluid at temperatures below 1000" C.
  • the protective film is applied to the workpieces by imparting a relative movement to a furnace having a layer of molten material such as glass therein and to the metal articles or blanks contained in the furnace. This may be achieved by imparting a motion to the furnace or to the articles contained therein or to both.
  • the furnace is of tubular form and is adapted to rotate or oscillate about its own axis.
  • a number of spaced lugs are arranged within the furnace and are formed at their central region with seats substantially aligned with the furnace axis for the introduction and removal of the workpieces in an axial direction.
  • the furnace is so positioned that the lugs occupy the lower portion of the furnace chamber and the bath is located between the lugs; during the preheating operation itself, as a result of an angular displacement imparted to the furnace, the lugs are moved laterally, leaving the workpieces in the bath which of course remain in the lower portion of the furnace.
  • Figure l is a longitudinal section of a furnace according to the invention.
  • Figures 2 and 3 are cross sectional views'of the furnace in the positions for introduction and removal of the workpieces, and for the heating thereof, respectively;
  • Figure 4 shows a modification of Figure 1
  • Figures 5 and 6 are cross sectional views of the furnace shown in Figure 4- on lines V--V and VI- VI of Figure 4, respectively;
  • Figure 7 shows a further modification of Figure 1.
  • the furnace l is of cylindrical drum shape having at its ends axial openings 2, 3 for the passage of the heating gases and for the introduction and removal of the workpieces.
  • a burner R is located in front of the opening 2 as a source of heat.
  • the furnace is carried by rollers 4 through which it is rotatable about its axis.
  • a number of cross partition lugs 5 having each ap proximately the shape of a circular segment are arranged within the furnace and are formed with a concave seat 6, substantially aligned with the furnace axis for supporting the work-pieces P as they are introduced into and removed from the furnace.
  • the lugs are provided laterally of the seat 6 with gradients 7 having inclinations varying gradually and by sets along the furnace axis.
  • the lugs are suitably spaced so as to contain between them the bath B of a material adapted to prevent oxidation of the workpieces, for example molten glass.
  • the furnace Upon introduction of the workpieces P onto the seats 6, the furnace is rotated through half a turn in the direction of the arrow P (Fig. 2) until it takes the position shown in Figure 3 with the lugs displaced to one side. As a result of this rotation the workpieces roll off one side of the lugs into the underlying bath B.
  • the workpieces may be submerged in the bath during the whole heating period, so that they are fully protected against oxidation. Should the workpieces be only partly immersed into the bath, they may nevertheless be protected by causing them to roll in the bath by effect of angular oscillations imparted to the furnace so as to form on said workpieces a protective film of molten glass.
  • the furnace On completion of heating the furnace is returned to its initial position and the workpieces are gradually collected by the inclined sides 7 of the lugs and returnedto their central seats 6. As so collected they are coated by a molten glass film which further protects them also during removal and transport of the workpieces to the machine for the hot working step.
  • bustion chamber of the furnace encloses at its ends two the furnace in the position shown in Figures 4 and 5,
  • furnace comprises one ing 5 only at the discharge opening 2, and is free from lugs at the opposite end, the workpieces being charged by directly introducing them into the bath B through the charging opening 3.
  • the process according to this invention is particularly advantageous when the workpieces are to be heated to temperatures over 1000 C. It can be employed solely within the range of temperatures at which oxidation takes place, in which case the workpieces are preheated within the lower temperature range in a conventional manner.
  • furnaces in which the workpieces are situated in one row only, it is understood that the invention comprehends the use of furnaces of a size suitable to receive a plurality of rows of workpieces side by side.
  • the method of heating metallic workpieces which comprises partly immersing said workpieces in a molten glass, exposing the surface of said molten glass to high temperatures, and systematically altering the portion of the surface of said workpieces immersed in said molten glass.
  • the method of protecting metallic workpieces from oxidation during heating preparatory to hot working which comprises partly immersing said workpieces in a bath of molten glass of depth less than the height of said workpieces as placed in said bath, exposing the surface of said bath to high temperatures, and successively changing the a portions of the surface of said workpieces immersed in said bath.
  • the method of heating steel workpieces of substantially cylindrical shape which comprises partly immersing said workpieces in a bath of molten glass, exposing said bath to a flow of high temperature gases, and effecting rotation of said workpieces about their cylindrical axes relative to the surface of said bath, whereby the portion of the surface of said workpieces submerged in said bath is changed with said rotation and the cylindrical surfaces of said workpieces are completely and continuously coated with molten glass.
  • the method of heating a metallic workpiece preparatory to hot working thereof which comprises bringing said workpiece into contact with a bath of molten glass, passing a current of hot gases over said bath, effecting relative motion of said workpiece and bath to coat said workpiece with an adherent layer of molten glass and to renew saidlayer from-said bath, and causing a portion of said coated workpiece to emerge from said bath into said current.
  • the method of heating metallic workpieces preparatory to hot working thereof which comprises bringing said workpieces successively into contact with a path of molten glass, passing a current of hot gases over said bath, eflFecting relative motion of said workpieces and bath to coat said workpieces in contact with said bath with an adherent layer of molten glass and to renew said layer from said bath, causing a portion of said coated workpieces to emerge from said bath into said current of hot gases, translating said workpieces successively through said bath from an entrance to an exit point thereof, removing from said path portions thereof exhausted from contact with said workpieces, and replacing said removed portions with fresh glass.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Surface Treatment Of Glass (AREA)
  • Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
  • Coating With Molten Metal (AREA)
US427771A 1953-11-13 1954-05-04 Non-oxidising heating of metal articles or blanks Expired - Lifetime US2832700A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT327376X 1953-11-13
IT200354X 1954-03-20

Publications (1)

Publication Number Publication Date
US2832700A true US2832700A (en) 1958-04-29

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ID=26327377

Family Applications (1)

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US427771A Expired - Lifetime US2832700A (en) 1953-11-13 1954-05-04 Non-oxidising heating of metal articles or blanks

Country Status (11)

Country Link
US (1) US2832700A (zh)
BE (1) BE533254A (zh)
CA (1) CA540098A (zh)
CH (1) CH327376A (zh)
DE (1) DE1075651B (zh)
FR (1) FR1106448A (zh)
GB (1) GB768855A (zh)
IT (3) IT505391A (zh)
LU (1) LU33204A1 (zh)
NO (1) NO91951A (zh)
SE (1) SE170972C1 (zh)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001508A (en) * 1958-08-13 1961-09-26 Ernest F Elliott Molten material coating furnace
US3080649A (en) * 1959-06-10 1963-03-12 Ernest F Elliott Continuous process of hot-forming metal
US4177088A (en) * 1977-03-02 1979-12-04 Pont-A-Mousson S.A. Process and installation for heat treating spheroidal or lamellar graphite cast iron pipes
DE3029293A1 (de) * 1979-08-03 1981-02-26 Pont A Mousson Verfahren und vorrichtung zur handhabung und waermebehandlung von roehren aus gusseisen oder rohren aus stahl

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1150699B (de) * 1960-09-29 1963-06-27 Osvaldo Balestra Ofen zum oxydationsfreien Erhitzen von mit einer Schutzschicht versehenen Eisenteilen

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US376421A (en) * 1888-01-10 Edwin d
US862285A (en) * 1906-12-14 1907-08-06 Charles R Schmidt Method of enameling.
US1452635A (en) * 1918-06-10 1923-04-24 Berninghaus Eugene Method of enameling
US1916569A (en) * 1930-07-14 1933-07-04 Haller Carl Rotating furnace
US1919136A (en) * 1933-02-15 1933-07-18 Smith Lloyd Raymond Enameled metal articles and method of producing them
US2009165A (en) * 1932-09-20 1935-07-23 Cross Richard Watson Process and mixture for hardening steel
US2135934A (en) * 1937-12-17 1938-11-08 Buffalo Bolt Company Rotary furnace
US2235825A (en) * 1937-09-23 1941-03-25 Buffalo Bolt Company Method of pickling and liming ferrous articles
US2628173A (en) * 1947-10-30 1953-02-10 Koppers Co Inc Method of coating metal articles with bituminous materials

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT89949B (de) * 1920-09-15 1922-11-10 Topf J A & Soehne Trockenvorrichtung.
DE600401C (de) * 1932-01-13 1934-07-21 Polte Fa Vorrichtung zum Hindurchleiten einseitig offener Hohlkoerper durch die vordere Absperrvorlage von Blankgluehoefen
US2182616A (en) * 1938-07-09 1939-12-05 American Electric Furnace Comp Apparatus for continuous heating and cooling of metals

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US376421A (en) * 1888-01-10 Edwin d
US862285A (en) * 1906-12-14 1907-08-06 Charles R Schmidt Method of enameling.
US1452635A (en) * 1918-06-10 1923-04-24 Berninghaus Eugene Method of enameling
US1916569A (en) * 1930-07-14 1933-07-04 Haller Carl Rotating furnace
US2009165A (en) * 1932-09-20 1935-07-23 Cross Richard Watson Process and mixture for hardening steel
US1919136A (en) * 1933-02-15 1933-07-18 Smith Lloyd Raymond Enameled metal articles and method of producing them
US2235825A (en) * 1937-09-23 1941-03-25 Buffalo Bolt Company Method of pickling and liming ferrous articles
US2135934A (en) * 1937-12-17 1938-11-08 Buffalo Bolt Company Rotary furnace
US2628173A (en) * 1947-10-30 1953-02-10 Koppers Co Inc Method of coating metal articles with bituminous materials

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3001508A (en) * 1958-08-13 1961-09-26 Ernest F Elliott Molten material coating furnace
US3080649A (en) * 1959-06-10 1963-03-12 Ernest F Elliott Continuous process of hot-forming metal
US4177088A (en) * 1977-03-02 1979-12-04 Pont-A-Mousson S.A. Process and installation for heat treating spheroidal or lamellar graphite cast iron pipes
DE3029293A1 (de) * 1979-08-03 1981-02-26 Pont A Mousson Verfahren und vorrichtung zur handhabung und waermebehandlung von roehren aus gusseisen oder rohren aus stahl
US4353531A (en) * 1979-08-03 1982-10-12 Pont-A-Mousson S.A. Process and installation for the handling and heat treatment of cast iron or steel pipes and tubes

Also Published As

Publication number Publication date
CH327376A (it) 1958-01-31
GB768855A (en) 1957-02-20
IT505391A (zh)
CA540098A (en) 1957-04-30
SE170972C1 (zh) 1960-04-05
IT524900A (zh)
BE533254A (zh)
FR1106448A (fr) 1955-12-19
IT524856A (zh)
DE1075651B (de) 1960-02-18
NO91951A (zh)
LU33204A1 (zh)

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