Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/50—Pouring-nozzles
  • B22D41/52—Manufacturing or repairing thereof
  • B22D41/54—Manufacturing or repairing thereof characterised by the materials used therefor
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
  • C04B35/48—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
  • C04B35/48—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates
  • C04B35/481—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates containing silicon, e.g. zircon
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
  • C04B35/48—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates
  • C04B35/482—Refractories from grain sized mixtures
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
  • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
  • C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
  • C04B41/5025—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials with ceramic materials
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
  • Y10T428/249967—Inorganic matrix in void-containing component
  • Y10T428/24997—Of metal-containing material
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]

Definitions

• the molten metal is fed from a ladle to what is called a tundish ladle.
• the purpose of the tundish ladle is to maintain a uniform ferrostatic head.
• the nozzle opens from a lower portion of the tundish. It is this nozzle which is so critical and important to controlling flow rate and stream cross-section to the cooling stage mold. It must be characterized by resistance to skulling. Skulling can be defined as localized build-up of solidified metal and slag on interior surfaces of the nozzle and about its exit orifice.
• the nozzle must be substantially inert to the molten metal and slag passing through it. If it is not inert, there will be erosion or corrosion of interior nozzle walls and a change in the characteristics of the nozzle orifice, thereby also disadvantageously modifying and changing evolving stream configuration and volume.
• the nozzle must have good thermal shock resistance. It is not practical to heat the nozzle to the temperature of molten steel prior to contacting the nozzle with molten steel. There is usually a substantially difference in temperatures when the molten steel first touches the nozzle, for example, 800 to 1200 F.
• denser nozzles are more prone to thermal shock because they have a less yielding microstructure. Also, they are more prone to skulling as they have higher thermal conductivity. On the other hand, denser refractories have better resistance to slag and metal attack or erosion.
• a nozzle for use in continuous casting of steel consists essentially of a tubular shape usually having a relatively large top opening converging to an exit orifice at its bottom.
• nozzles are porous ceramically bonded zircon or zirconia compositions which are partially impregnated with noncolloidal chromic oxide, zirconia, or zircon particles.
• porous is meant to 30% porosity.
• the zirconia refractory suitable for use according to this invention is what is known as partially stabilized.
• partially stabilized we mean normally at least about 70% "Ice stabilized.
• Stabilized zirconia is zirconia substantially entirely exhibiting a cubic crystallized structure, the individual crystals of which are propped, to prevent their disintegration at lower temperatures.
• calcium oxide is conventionally used to produce a stabilized zirconia refractory material.
• stabilization is brought about in one method by mixing from 3 to 6%, by weight, of 99% pure calcium oxide with 97 to 94% zirconia.
• Other materials such as magnesia and yttria have been used to stabilize zirconia.
• Zircon refractories are refractories made substantially entirely from zircon or zirconium metasilicate.
• the properties of zircon refractories can be altered somewhat by making various additions such as silica, mullite, chromic oxide and so on.
• the particular refractory oxides used for impregnation, according to this invention range in size from about 0.1 micron to about 5 microns.
• the particles range in size from 0.5 to about 5 microns.
• Nozzles according to the teaching of this invention are manufactured by first manufacturing a ceramically bonded zircon or zirconia nozzle shape by conventional techniques. That is, they are prepared from a size-graded refractory batch formed into shapes, for example, by pressing with the aid of a temporary binder, and burned at temperatures sufficient to provide a ceramic bond.
• Zirconi-a refractories typically have a major portion of their open and connected pores with a minimum size that ranges from 9 to 45 microns. The pores of zircon refractories are noticeably smaller and range from a minimum of about 4 to 15 mircons. This is because zircon brick are generally prepared from batches having a finer particles size distributron.
• the nozzles are then impregnated by immersing them in a suspension of noncolloidal ceramic particles, agitating or vibrating the suspension for a period sufiicient to impregnate at least the surface of the nozzles.
• the suspension for example, is prepared by mixing the noncolloidal particles with from about 50 to of a suitable carrier fluid.
• a readily available carrier fluid is water. It has been found desirable to prepare the slurry using a dispersmg agent appropriate to both the noncolloidal particles and the carrier fluid.
• the agitation or vibration can be applied in a number of ways, for example, mechanically. Frequency of vibration can range from about 20 cycles/ sec. to ultrasonic vibrations in the range of 40 kcs/sec.
• the amplitude of vibration is usually limited by the equip ment. However, it has been found for a given frequency the largest possible amplitude is desirable.
• a zircon refractory is prepared from a size-graded batch consisting essentially of 95% zircon and 5% ball clay.
• the batch is tempered with a temporary binder and pressed into nozzle shapes. They burn at approximately 2700 F. to a density of about 225 lbs./cu./ft. and have an apparent porosity of approximately 20%.
• the preferred nozzles were placed on the 20% aqueous suspension of pigment grade chromic oxide which was prepared by blending the chromic oxide into water with the aid of a sodium phosphate dispersent.
• the zircon nozzles was immersed in the supension and the suspension was vibrated at 60 cycles/sec. for about 30 minutes. The zircon nozzle was penetrated to a depth of about ,4 to
• Nozzles made according to the teachings of this invention have decreased surface porosity and, therefore, are more resistant to erosion and corrosion by slags.
• their overall density is not substantially increased and, therefore, their thermal conductivity remains about the same. Therefore, their resistance to skulling is not decreased.
• the overall density of the nozzles is not increased, their tendency towards thermal spalling is not increased.
• Nozzles for use in continuous casting of steel said nozzle being porous and consisting essentially of ceramically bonded refractory oxides selected from the group 4 consisting of zirconia and zircon, said nozzle impregnated to a depth of at least about from the surface with noncolloidal refractory particles selected from the group consisting of chro-mic oxide, zirconia, and zircon.
• Nozzle according to claim 1 in which the nozzle has a pore diameter predominantly between 5 and 100 microns.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Composite Materials (AREA)
• Inorganic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Compositions Of Oxide Ceramics (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24726053

Family Applications (1)

Country Status (8)

Families Citing this family (7)

• 1967
  • 1967-10-30 US US679222A patent/US3698942A/en not_active Expired - Lifetime
• 1968
  • 1968-09-23 LU LU56943D patent/LU56943A1/xx unknown
  • 1968-09-27 AT AT944468A patent/AT290746B/de not_active IP Right Cessation
  • 1968-10-05 ES ES358892A patent/ES358892A1/es not_active Expired
  • 1968-10-15 GB GB48766/68A patent/GB1194458A/en not_active Expired
  • 1968-10-24 FR FR1593602D patent/FR1593602A/fr not_active Expired
  • 1968-10-25 BE BE722880D patent/BE722880A/xx unknown
  • 1968-10-30 DE DE19681806939 patent/DE1806939A1/de active Pending

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