US3553010A - Carbon or graphite formed body - Google Patents

Carbon or graphite formed body Download PDF

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US3553010A
US3553010A US747129A US3553010DA US3553010A US 3553010 A US3553010 A US 3553010A US 747129 A US747129 A US 747129A US 3553010D A US3553010D A US 3553010DA US 3553010 A US3553010 A US 3553010A
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layer
carbon
aluminum
graphite
comprised
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US747129A
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Ottmar Rubisch
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Sigri GmbH
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Sigri GmbH
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Priority claimed from DE19671671065 external-priority patent/DE1671065C3/en
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    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00Heating by electric discharge
    • H05B7/02Details
    • H05B7/06Electrodes
    • H05B7/08Electrodes non-consumable
    • H05B7/085Electrodes non-consumable mainly consisting of carbon
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/52Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/009After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/45Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
    • C04B41/52Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
    • C04B41/81Coating or impregnation
    • C04B41/89Coating or impregnation for obtaining at least two superposed coatings having different compositions
    • C04B41/90Coating or impregnation for obtaining at least two superposed coatings having different compositions at least one coating being a metal
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/02Pretreatment of the material to be coated, e.g. for coating on selected surface areas
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/04Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
    • C23C4/06Metallic material
    • C23C4/067Metallic material containing free particles of non-metal elements, e.g. carbon, silicon, boron, phosphorus or arsenic
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/18After-treatment
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B7/00Heating by electric discharge
    • H05B7/02Details
    • H05B7/12Arrangements for cooling, sealing or protecting electrodes
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474Uses not provided for elsewhere in C04B2111/00
    • C04B2111/0087Uses not provided for elsewhere in C04B2111/00 for metallurgical applications
    • C04B2111/00879Non-ferrous metallurgy
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/24Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24942Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
    • Y10T428/2495Thickness [relative or absolute]
    • Y10T428/24967Absolute thicknesses specified
    • Y10T428/24975No layer or component greater than 5 mils thick
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/30Self-sustaining carbon mass or layer with impregnant or other layer

Definitions

  • the primary layer is comprised of 90 to 100%, 3,553,010
  • This invention relates to a carbon or graphite formed particularly preferable to provide the primary layer with body, and m r p r y n rc el r ing a a layer thickness of 0.01 to 0.15 preferably p pg o protective layer which arrests oxidation, and which in- 0.1 rrrnm, and the comm a thickness 033i cludes a primary layer, applied. upon a carbon or graphite Winn, preferably ill to 0.3 mm.
  • coated bodies are heated above approximately 550 C., of Sodium, magnesium, Calcium, 13 aluminum, titathe components of the double layer react with each othernium, Zirconium, manganese, iron, carbon, nit ogen p to form a low melting, eutectic alloy which closes the phorus and oxygen, separately or in combination.
  • the pores formed by the flame injection
  • cover layer is'comprised of 85 to 100%, preferably 93 that silicon which is dissolved mainly in aluminum, reacts to 99.5%, aluminum and 0 to 15%, pref bly 0.5 to 7%, with the carbon of the fundamental body forming silicon sodium, magnesium, boron, silicon, phosphorus, oxygen, carbide when the operational temperature of the procopper, zinc, lead, titanium, zirconium, chromium, mantected parts exceeds about 550 C. which leads to a tearg fi, irOXl, Cobalt and nickel, lfi y in flflfree and solid bond between the protective layer to the tion. carbon part. This bond is resistant to temperature changes.
  • Carbon or graphite bodies provided with such coatings have shown a long lasting excellent stability with respect
  • My invention relates to a carbon or graphite formed to oxidation, at approximately 1700 C., due to the aforebody, and more particularly an arc electrode having a described alloying effect.
  • the protective effect of the double layer "eludes a primary layer, applied upon a carbon or graphite upon the body can be increased by an additional melting formed. body, and a metallic cover layer, comprised essenof the already applied coating. This melting is carried out tially of aluminum, over the primary layer.
  • Carbon or graphite formed bodies are very widely used burner.
  • the subsequent melting of the protective layers I in chemical and metallurgical arts because of their excelre ult in an elimination of the pores and in a chemical ⁇ X J lent mechanical and thermal qualities. Frequently, howanchoring, which leads to a considerable improvement of ,1 ,yever. the burning err, which occurs in these materials at the protection againstburning olf.
  • the base layer may be a carbide layer, e.g. a a current supply and the are, are in a fluid or even in a silicon carbide layer, while the cover layer may either plastic state, so that no voltages whatsoever can be proconstitute a layer of an oxide mixture or a metal or siliduced in the coating layer through the dilferent expan- .cide layer. But even these layers do not yet afford an adesions of the coating layer and the fundamental body.
  • tween 600 and 1200 (3., preferably 700 to i000" (3.,
  • the Present invention, lhefefofa has 85 an j t rfform melting eutectics and to measure the current load such that the melting point of the eutectic is at least obtained on the electrode surface.
  • EXAMPLE 1 A graphite electrode with a diameter of 450 mm. and a length of 2000 mm. is left to rotate at about 50 revolutions per minute, following the customary, accurately scaled turning oft", in a rotating lathe.
  • Two tlame injection elec rodes arranged in sequence at a distance of 200 mm., uniformly coat the electrode surface (injection dis tance 100 mm.), first with an 0.05 mm. thick. primary layer of 98.5% silicon+0.8% Fe+0.5% Al+0.2% Ca and thereafter with an 0.15 mm. thick cover layer of 99% Al+0.7% Mg+0.3% Si.
  • electrodes coated in this manner result in a graphite saving of 25 to 35% compared to untreated electrodes.
  • EXAMPLE 2 A graphite crucible 200 mm. in diameter, 500 mm. high and with 20 mm. wall thickness is slowly rotated on a turntable, e.g. at 30 rpm. An approximately 0.1 mm. thick primary layer of 95% Si+3% Ti+1.5% Fe+0.5% Al is applied by means of a powder fiame injection pistol. The coating which is still approximately 70 C. is injection coated with a cover layer of 0.2 mm. thickness, comprised of 98.2% Al+1.5% Mg+0.3% Mn, by Using a wire flame injection pistol, The coated crucible is subsequently dipped briefly into a 20% sodium phospiate solution (pH 5) and thereafter dried. at 120 When employed to operate in a copper casting installation, the above-described crucibles achieve a life span which is 4 to 6 times longer than in untreated crucibles.
  • Formed bodyof carbonor graphite having an oxidation arresting protective layer which encompasses a primary layer on the carbon or graphite formed body and a metallic cover layer on the primary layer, said primary layer being comprised of 90 to 100% silicon and 0 to 10% of sodium, magnesium, calcium, boron, aluminum, titanium, zirconium, manganese, iron, carbon, nitrogen, phosphorus and oxygen, separately or in combination, the cover layer being comprised of to 100% aluminum and 0 to 15% sodium, magnesium, boron, silicon, phosphorus, oxygen, copper, zinc, lead, titanium, zirconium, chromium, manganese, iron, cobalt and nickel, separately or in combination.
  • the primary layer comprises to 98.9% silicon and 1.1 to 5.0% of a material selected from. sodium, magnesium, calcium, boron, aluminum, titanium, zirconium, manganese, iron, carbon, nitrogen, phosphorus, oxygen and mixtures thereof and the cover layer comprises 93 to 99.5% aluminum and 0.5 to 7% sodium, magnesium, boron, silicon, phosphorus, oxygen, copper, zinc, lead, titanium, zirconium, chromium, manganese, iron, cobalt and nickel and mixtures thereof.

Abstract

THIS INVENTION RELATES TO A CARBON OR GRAPHITE FORMED BODY, AND MORE PARTICULARLY AN ARC ELECTRODE HAVING A PROTECTIVE LAYER WHICH ARRESTS OXIDATION, AND WHICH INCLUDES A PRIMARY LAYER, APPLIED UPON A CARBON OR GRAPHIC FORMED BODY, AND A METALLIC COVER LAYER COMPRISED ESSENTIALLY OF ALUMINUM OVER THE PRIMARY LAYER. THE PRIMARY LAYER IS COMPRISED OF 90 TO 100%, PREFERABLY 95 TO 98.9%, OF SILCON AND 0 TO 10%, PREFERABLY 1.1 TO 5.0%, OF SODIUM, MAGNESIUM, CALCIUM, BORON, ALUMINUM, TITANIUM, ZIRCONIUM, MANGANESE, IRON, CARBON, NITROGEN PHOSPHORUS AND OXYGEN, SEPARATELY OR IN COMBINATION. THE COVER LAYER IS COMPRISED OF 85 TO 100%, PREFERABLY 93 TO 99.5%, ALUMINUM AND 0 TO 15%, PREFERABLY 0.5 TO 7%, SODIUM, MAGNESIUM, BORON, SILICON, PHOSPHORUS, OXYGEN, COPPER, ZINC, LEAD, TITANIUM, ZIRCONIUM, CHROMIUM, MANGANESE, IRON, COBALT AND NICKEL, SEPARATELY OR IN COMBINATION.

Description

CARBGN R GRAPHZTE FORMED BODY ttrnar Rubisch, Meitingen, near Augsburg, Germany, assignor to Sigri Elel-rtrographit Gescllschatt mit beschranltter lilaftung, Mcitingen, near Augsburg, Gerfective protection against oxidation of the aforementioned formed body of graphite or carbon. According to the 428 408e XR 395539010 SR 12 assault; a g Patented ,.laln. 5, 1971 invention, the primary layer is comprised of 90 to 100%, 3,553,010
preferably 95 to 98.9%, of silicon and 0 to 10%, preferably 1.1 to 5%, of sodium, magnesium, calcium, boron. aluminum, titanium, zirconium, manganese, iron, carbon, nitrogen, phosphorus and oxygen, separately or in com- 5 an bmatron, and the cover layer of 85 to 100%, preferably ia l lirgssi iig l il sd ifiiz? 719 08. Ser. No. 747,129 93 to 99.5%, of aluminum and 0 to 15%, preferably 0.5 Claims priority, application Germany, July 26, 1967, to 7%, of sodium, magnesium, boron, SlilCOl'l, phosphorus,
1,571,055 oxygen, copper, zinc, lead, titanium, zirconium chro- B443 1/20 mium manganese, iron, cobalt and nickel, separately or in 3 CL 117-217 5 Claims combination. All percentages used in this application are by weight. 1 b ff 5 The a lication of such a double ayer may e e ecte ABSTRACT OF THE DISCLOSURE in a kn ii'n manner by means of flame injection. It is This invention relates to a carbon or graphite formed particularly preferable to provide the primary layer with body, and m r p r y n rc el r ing a a layer thickness of 0.01 to 0.15 preferably p pg o protective layer which arrests oxidation, and which in- 0.1 rrrnm, and the comm a thickness 033i cludes a primary layer, applied. upon a carbon or graphite Winn, preferably ill to 0.3 mm. formed body, and a metallic cover layer comprised essen- Wen such a proEE'tiVlfiYE-"r" is applied by flame injectial y of aluminum r the P y y The p y -2 tion, it is only mechanically bound to the carbon or layer is comprised of 90 to 100%, preferably 95 to graphite formed body. It was found that when the thus 9 9%, of silicon and 0 to 10%, preferably 1.1 to 5.0%, coated bodies are heated above approximately 550 C., of Sodium, magnesium, Calcium, 13 aluminum, titathe components of the double layer react with each othernium, Zirconium, manganese, iron, carbon, nit ogen p to form a low melting, eutectic alloy which closes the phorus and oxygen, separately or in combination. The pores formed by the flame injection. Finally, I also found cover layer is'comprised of 85 to 100%, preferably 93 that silicon which is dissolved mainly in aluminum, reacts to 99.5%, aluminum and 0 to 15%, pref bly 0.5 to 7%, with the carbon of the fundamental body forming silicon sodium, magnesium, boron, silicon, phosphorus, oxygen, carbide when the operational temperature of the procopper, zinc, lead, titanium, zirconium, chromium, mantected parts exceeds about 550 C. which leads to a tearg fi, irOXl, Cobalt and nickel, lfi y in flflfree and solid bond between the protective layer to the tion. carbon part. This bond is resistant to temperature changes. Carbon or graphite bodies provided with such coatings have shown a long lasting excellent stability with respect My invention relates to a carbon or graphite formed to oxidation, at approximately 1700 C., due to the aforebody, and more particularly an arc electrode having a described alloying effect. During a particularly strong protective layer which arrests oxidation, and which inoxidation attack, the protective effect of the double layer "eludes a primary layer, applied upon a carbon or graphite upon the body can be increased by an additional melting formed. body, and a metallic cover layer, comprised essenof the already applied coating. This melting is carried out tially of aluminum, over the primary layer. in a known manner by an argon are or a direct plasma Carbon or graphite formed bodies are very widely used burner. The subsequent melting of the protective layers I in chemical and metallurgical arts because of their excelre ult in an elimination of the pores and in a chemical \X J lent mechanical and thermal qualities. Frequently, howanchoring, which leads to a considerable improvement of ,1 ,yever. the burning err, which occurs in these materials at the protection againstburning olf.
? temperatures above 550 C. in an oxidizing atmosphere, A similar additional increase of the protective action ;z is disturbing 5 may be obtained by sealing the metallic double layer with y ,f, It is kn wn that burning Off of the carbon and graphite a coating of an aqueous solution of -10 to 30% alkali bodies can be reduced by impregnation with phosphate. borate and/or phosphate and/0r silicate. ll This, b reduces ihe burning Off y p r The effect of the cover layer is also heightened through I tures up to approximately 1100 C. the fact that during operation of the arc furnace, the l t It is further known to reduce the burning Off through current load of the electrodes is so measured that the the utilization of clover layers on carbon or graphite cover layer is heatedio above its melting point or soften- 1,; bodies. It is preferred to produce said cover layers of ing point. This counteracts an otherwise possible tear transition metal silicides. The effect of such layers comformation in the cover layer caused by a. dilference in the prised of transition metal silicides is limited, though, to thermal expansion coefficients of the fundamental material high temperatures within a range of 1200 to 1700 C. and the cover layer, thus preventing increased oxidation Furthermore, the application of said layers is possible which is feasible inand near the tears. only by means of expensive techniques. It is also known In this type of operation, the coating layers in the to apply double layer coatings upon carbon or graphite total region between the electrode holder which serves as bodies. The base layer may be a carbide layer, e.g. a a current supply and the are, are in a fluid or even in a silicon carbide layer, while the cover layer may either plastic state, so that no voltages whatsoever can be proconstitute a layer of an oxide mixture or a metal or siliduced in the coating layer through the dilferent expan- .cide layer. But even these layers do not yet afford an adesions of the coating layer and the fundamental body. quate protection, since it was not possible, heretofore, to Previously formed tears are automatically sealed by the adjust the expansion coefficients of the body to be proplastic or fluid coating layer. Therefore a breaking off of tected and the applied layer, to each other. in the aforethe applied protective layer is not possible. mentioned double layers, the melting point is so high that I found it particularly advantageous to produce, using tears which form cannot be recovered by thellow of the aforementioned preferred method of operation, coatthe layer. As a result, the layer is undercut by oxidation ings of components which in a temperature range beand breaks off. tween 600 and 1200 (3., preferably 700 to i000" (3., The Present invention, lhefefofa, has 85 an j t rfform melting eutectics and to measure the current load such that the melting point of the eutectic is at least obtained on the electrode surface.
The atoredescrihed invention will now be disclosed with some embodiment examples.
EXAMPLE 1' A graphite electrode with a diameter of 450 mm. and a length of 2000 mm. is left to rotate at about 50 revolutions per minute, following the customary, accurately scaled turning oft", in a rotating lathe. Two tlame injection elec rodes, arranged in sequence at a distance of 200 mm., uniformly coat the electrode surface (injection dis tance 100 mm.), first with an 0.05 mm. thick. primary layer of 98.5% silicon+0.8% Fe+0.5% Al+0.2% Ca and thereafter with an 0.15 mm. thick cover layer of 99% Al+0.7% Mg+0.3% Si.
When used in an arc furnace, electrodes coated in this manner result in a graphite saving of 25 to 35% compared to untreated electrodes.
EXAMPLE 2 A graphite crucible 200 mm. in diameter, 500 mm. high and with 20 mm. wall thickness is slowly rotated on a turntable, e.g. at 30 rpm. An approximately 0.1 mm. thick primary layer of 95% Si+3% Ti+1.5% Fe+0.5% Al is applied by means of a powder fiame injection pistol. The coating which is still approximately 70 C. is injection coated with a cover layer of 0.2 mm. thickness, comprised of 98.2% Al+1.5% Mg+0.3% Mn, by Using a wire flame injection pistol, The coated crucible is subsequently dipped briefly into a 20% sodium phospiate solution (pH 5) and thereafter dried. at 120 When employed to operate in a copper casting installation, the above-described crucibles achieve a life span which is 4 to 6 times longer than in untreated crucibles.
I claim:
1. Formed bodyof carbonor graphite having an oxidation arresting protective layer which encompasses a primary layer on the carbon or graphite formed body and a metallic cover layer on the primary layer, said primary layer being comprised of 90 to 100% silicon and 0 to 10% of sodium, magnesium, calcium, boron, aluminum, titanium, zirconium, manganese, iron, carbon, nitrogen, phosphorus and oxygen, separately or in combination, the cover layer being comprised of to 100% aluminum and 0 to 15% sodium, magnesium, boron, silicon, phosphorus, oxygen, copper, zinc, lead, titanium, zirconium, chromium, manganese, iron, cobalt and nickel, separately or in combination.
2. The body of claim 1 wherein the primary layer comprises to 98.9% silicon and 1.1 to 5.0% of a material selected from. sodium, magnesium, calcium, boron, aluminum, titanium, zirconium, manganese, iron, carbon, nitrogen, phosphorus, oxygen and mixtures thereof and the cover layer comprises 93 to 99.5% aluminum and 0.5 to 7% sodium, magnesium, boron, silicon, phosphorus, oxygen, copper, zinc, lead, titanium, zirconium, chromium, manganese, iron, cobalt and nickel and mixtures thereof.
3. The body of claim 1, wherein the primary. layer has a ltgglgnessmmgl tgfl 15 mrn and the cover layer has a thickness of 0.05150 M 4;"Fheh6dybf claim 1, wherein the primary layer has a thickness of 0.02 to 0.1 mm. and the cover layer has a thickness of 0.1 to 0.3 mm.
5. The body of claim 4, wherein a sealing layer consisting of alkali borate, phosphate, silicate or mixtures thereof is on the cover layer.
References Cited UNITED STATES PATENTS 2,295,379 9/1942 Beck et a1 117--223X 3,120,453 2/1964 Fitzer et a1. 117-217 3,348,929 10/1967 Valtschev et a1. 1172l7X 3,390,013 6/1968 Rubisch 117-221X 3,476,586 11/1969 Valtchev ct a1. 117-217X r ALFRED L. LEAVITT, Primary Examiner C. K. WEIFFENBACH, Assistant Examiner US. Cl. XJR-
US747129A 1967-07-26 1968-07-24 Carbon or graphite formed body Expired - Lifetime US3553010A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE1615404A DE1615404C3 (en) 1967-07-26 1967-07-26 Arc furnace
DE19671671065 DE1671065C3 (en) 1967-07-26 1967-07-26 Carbon or graphite moldings

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US3553010A true US3553010A (en) 1971-01-05

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FR (1) FR1587074A (en)
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Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770488A (en) * 1971-04-06 1973-11-06 Us Air Force Metal impregnated graphite fibers and method of making same
US3864164A (en) * 1971-10-22 1975-02-04 British Steel Corp Method for depositing protective coatings on carbon articles
US3881039A (en) * 1971-01-22 1975-04-29 Snam Progetti Process for the treatment of amorphous carbon or graphite manufactured articles, for the purpose of improving their resistance to oxidation, solutions suitable for attaining such purpose and resulting product
US3921023A (en) * 1969-07-21 1975-11-18 Dmz Lennin Bg1969072112705 Method for joining carbon electrodes and product thereof
FR2283874A1 (en) * 1974-09-09 1976-04-02 Secr Defence Brit ANTI-OXIDATION COATING FOR CARBON PARTS
US4000026A (en) * 1973-03-12 1976-12-28 Union Carbide Corporation Method and cement for bonding carbon articles
US4418097A (en) * 1981-12-11 1983-11-29 Martin Marietta Corporation Coating for graphite electrodes
US4487804A (en) * 1982-08-02 1984-12-11 Nalco Chemical Company Coating to prevent the oxidation of electrodes during electric furnace steel making
EP0146013A2 (en) * 1983-11-30 1985-06-26 Mitsumaru Chemical & Synthetic Industrial Co., Ltd. Coating composition for preventing high temperature oxidation for electrodes
EP0175136A1 (en) * 1984-08-13 1986-03-26 N P P Po Elektrotermia Protecting coating for graphite electrodes
US4617232A (en) * 1982-04-15 1986-10-14 Kennecott Corporation Corrosion and wear resistant graphite material
US4621017A (en) * 1982-04-15 1986-11-04 Kennecott Corporation Corrosion and wear resistant graphite material and method of manufacture
US4668579A (en) * 1984-02-01 1987-05-26 The United States Of America As Represented By The Secretary Of The Air Force Interstitially protected oxidation resistant carbon-carbon composite
US4716572A (en) * 1984-12-19 1987-12-29 Sigri Gmbh Method for coating carbon and graphite bodies
US4716078A (en) * 1983-08-08 1987-12-29 Kao Corporation Substrate for a magnetic disc and method manufacturing same
US4772514A (en) * 1985-12-24 1988-09-20 Ceskoslovenska Akademie Ved Protective layer for carbonaceous materials and method of applying the same
US4824733A (en) * 1986-04-25 1989-04-25 Canadian Patents And Development Limited/Societe Anti-oxidant barrier for carbon based material
US5695883A (en) * 1991-09-17 1997-12-09 Tocalo Co., Ltd. Carbon member having a metal spray coating
US6555173B1 (en) 2000-11-08 2003-04-29 Honeywell International Inc. Carbon barrier controlled metal infiltration layer for enhanced oxidation protection
WO2005113844A1 (en) * 2004-05-14 2005-12-01 Sgl Carbon Ag Gas impervious electrodes for carbothermic reduction furnace
US20060115243A1 (en) * 2002-12-23 2006-06-01 Jae-In Jeong Resistance-heated boat and manufacturing method thereof
US20090129762A1 (en) * 2005-07-01 2009-05-21 Ulrich Goetz Initial Wetting Auxiliary Material for a Vaporiser Body
US8923360B2 (en) 2010-07-01 2014-12-30 Graftech International Holdings Inc. Graphite electrodes
WO2022187638A1 (en) * 2021-03-05 2022-09-09 Ecolab Usa Inc. Coatings for electrodes in electric arc furnaces

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Cited By (28)

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Publication number Priority date Publication date Assignee Title
US3921023A (en) * 1969-07-21 1975-11-18 Dmz Lennin Bg1969072112705 Method for joining carbon electrodes and product thereof
US3881039A (en) * 1971-01-22 1975-04-29 Snam Progetti Process for the treatment of amorphous carbon or graphite manufactured articles, for the purpose of improving their resistance to oxidation, solutions suitable for attaining such purpose and resulting product
US3770488A (en) * 1971-04-06 1973-11-06 Us Air Force Metal impregnated graphite fibers and method of making same
US3864164A (en) * 1971-10-22 1975-02-04 British Steel Corp Method for depositing protective coatings on carbon articles
US4000026A (en) * 1973-03-12 1976-12-28 Union Carbide Corporation Method and cement for bonding carbon articles
FR2283874A1 (en) * 1974-09-09 1976-04-02 Secr Defence Brit ANTI-OXIDATION COATING FOR CARBON PARTS
US4418097A (en) * 1981-12-11 1983-11-29 Martin Marietta Corporation Coating for graphite electrodes
US4621017A (en) * 1982-04-15 1986-11-04 Kennecott Corporation Corrosion and wear resistant graphite material and method of manufacture
US4617232A (en) * 1982-04-15 1986-10-14 Kennecott Corporation Corrosion and wear resistant graphite material
US4487804A (en) * 1982-08-02 1984-12-11 Nalco Chemical Company Coating to prevent the oxidation of electrodes during electric furnace steel making
US4716078A (en) * 1983-08-08 1987-12-29 Kao Corporation Substrate for a magnetic disc and method manufacturing same
EP0146013A2 (en) * 1983-11-30 1985-06-26 Mitsumaru Chemical & Synthetic Industrial Co., Ltd. Coating composition for preventing high temperature oxidation for electrodes
EP0146013A3 (en) * 1983-11-30 1985-08-07 Mitsumaru Chemical & Synthetic Industrial Co., Ltd. Coating composition for preventing high temperature oxidation for electrodes
US4668579A (en) * 1984-02-01 1987-05-26 The United States Of America As Represented By The Secretary Of The Air Force Interstitially protected oxidation resistant carbon-carbon composite
EP0175136A1 (en) * 1984-08-13 1986-03-26 N P P Po Elektrotermia Protecting coating for graphite electrodes
US4750187A (en) * 1984-08-13 1988-06-07 N P P Po Elektrotermia Graphitic electrode with protective coating
US4716572A (en) * 1984-12-19 1987-12-29 Sigri Gmbh Method for coating carbon and graphite bodies
US4772514A (en) * 1985-12-24 1988-09-20 Ceskoslovenska Akademie Ved Protective layer for carbonaceous materials and method of applying the same
US4824733A (en) * 1986-04-25 1989-04-25 Canadian Patents And Development Limited/Societe Anti-oxidant barrier for carbon based material
US5695883A (en) * 1991-09-17 1997-12-09 Tocalo Co., Ltd. Carbon member having a metal spray coating
US6555173B1 (en) 2000-11-08 2003-04-29 Honeywell International Inc. Carbon barrier controlled metal infiltration layer for enhanced oxidation protection
US20060115243A1 (en) * 2002-12-23 2006-06-01 Jae-In Jeong Resistance-heated boat and manufacturing method thereof
WO2005113844A1 (en) * 2004-05-14 2005-12-01 Sgl Carbon Ag Gas impervious electrodes for carbothermic reduction furnace
US20090129762A1 (en) * 2005-07-01 2009-05-21 Ulrich Goetz Initial Wetting Auxiliary Material for a Vaporiser Body
US8923360B2 (en) 2010-07-01 2014-12-30 Graftech International Holdings Inc. Graphite electrodes
US9253827B2 (en) 2010-07-01 2016-02-02 Graftech International Holdings, Inc. Graphite electrodes
US9497804B2 (en) 2010-07-01 2016-11-15 Graftech International Holdings Inc. Graphite electrode
WO2022187638A1 (en) * 2021-03-05 2022-09-09 Ecolab Usa Inc. Coatings for electrodes in electric arc furnaces

Also Published As

Publication number Publication date
SE329966B (en) 1970-10-26
AT285195B (en) 1970-10-12
FR1587074A (en) 1970-03-13
GB1166429A (en) 1969-10-08

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