# US 8,739,773 B2 · Oven rack having integral lubricious, dry porcelain surface > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,773 B2 - Document ID: US8739773B2 - Status: Granted - Kind: B2 - Application number: 12/301,718 - Filed: 2007-05-24 - Published: 2010-03-11 - Granted: 2014-06-03 - Earliest claimed: 2006-05-25 - Assignees: SSW Holding Company, Inc. - Applicants: Jeffrey A. Ambrose; Gail Mackiewicz-Ludtka; Vinod K. Sikka; Jun Qu - Inventors: Jeffrey A. Ambrose; Gail Mackiewicz-Ludtka; Vinod K. Sikka; Jun Qu - Web page: https://patentgrep.com/patent/US8739773B2 ## CPC - C23C 26/00: Coating not provided for in groups C23C2/00 - C23C24/00 - F24C 15/16: Shelves, racks or trays inside ovens; Supports therefor - Y10T 29/49885: with coating before or during assembling - Y10T 428/2982: Particulate matter [e.g., sphere, flake, etc.] - C23C: COATING 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 (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - F24C: DOMESTIC STOVES OR RANGES (exclusively for solid fuels F24B); DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A lubricious glass-coated metal cooking article capable of withstanding repeated heating and cooling between room temperature and at least 500° F. without chipping or cracking the glass coating, wherein the glass coating includes about 0.1 to about 20% by weight of a homogeneously distributed dry refractory lubricant material having a particle size less than about 200 μm. The lubricant material is selected from the group consisting of carbon; graphite; boron nitride; cubic boron nitride; molybdenum (FV) sulfide; molybdenum sulfide; molybdenum (IV) selenide; molybdenum selenide, tungsten (IV) sulfide; tungsten disulfide; tungsten sulfide; silicon nitride (Si3N4); TiN; TiC; TiCN; TiO2; TiAlN; CrN; SiC; diamond-like carbon; tungsten carbide (WC); zirconium oxide (ZrO2); zirconium oxide and 0.1 to 40 weight % aluminum oxide; alumina-zirconia; antimony; antimony oxide; antimony trioxide; and mixtures thereof. ## Claims ### Claim 1 A lubricious glass-coated metal cooking article capable of withstanding repeated heating and cooling between room temperature and at least 500° F. without chipping or cracking the glass coating, wherein: the glass coating includes about 0.1 to about 20% by weight of a homogeneously distributed dry refractory lubricant material, the dry refractory lubricant material consists of particles having a particle size less than 45 μm and an aspect ratio of less than 2:1, and the dry refractory lubricant material is selected from the group consisting of carbon; graphite; boron nitride; cubic boron nitride; molybdenum (IV) sulfide; molybdenum sulfide; molybdenum (IV) selenide; molybdenum selenide, tungsten (IV) sulfide; tungsten disulfide; tungsten sulfide; silicon nitride (Si3N4); TiN; TiC; TiCN; TiO2; TiAlN; CrN; SiC; diamond-like carbon; tungsten carbide (WC); zirconium oxide (ZrO2); zirconium oxide and 0.1 to 40 weight % aluminum oxide; alumina-zirconia; antimony; antimony oxide; antimony trioxide; and mixtures thereof. ### Claim 2 (depends on 1) The lubricious glass-coated, metal article of claim 1, wherein the metal is drawn steel rod and the amount of carbon and the degree of diameter reduction of the steel rod are selected to provide sufficient cavities in the drawn steel such that the glass coating does not chip or crack when the glass-coated article is heated to a temperature above 900° F. ### Claim 3 (depends on 2) The lubricious glass-coated, drawn steel rod article of claim 2, wherein the glass coating is a porcelain material applied in a thickness is the range of 1 to 20 mils. ### Claim 4 (depends on 3) The lubricious glass-coated, drawn steel rod article of claim 3, wherein the glass coating is a porcelain material applied in a thickness is the range of 4 to 10 mils. ### Claim 5 (depends on 1) The lubricious glass-coated, metal article of claim 1, wherein the article is a cooking surface selected from an oven rack, oven ladder rack, burner grate, and a barbeque grill rack. ### Claim 6 (depends on 3) The lubricious glass-coated, drawn steel article of claim 3, wherein the glass coating is a porcelain enamel material. ### Claim 7 (depends on 6) The lubricious glass-coated, drawn steel article of claim 6, wherein the porcelain is applied in multiple coating steps. ### Claim 8 (depends on 1) The lubricious glass-coated, metal article of claim 1, wherein the metal is a metal rod drawn to reduce the diameter at least about 20%. ### Claim 9 (depends on 8) The lubricious glass-coated, metal article of claim 8, wherein the metal is a metal rod drawn to reduce the diameter at least about 30%. ### Claim 10 (depends on 9) The lubricious glass-coated, metal article of claim 9, wherein the metal rod is drawn to reduce the diameter at least about 40%. ### Claim 11 (depends on 10) The lubricious glass-coated, metal article of claim 10, wherein the metal rod is drawn to reduce the diameter at least about 45%. ### Claim 12 (depends on 11) The lubricious glass-coated, metal article of claim 11, wherein the metal rod is drawn to reduce the diameter at least about 50%. ### Claim 13 (depends on 1) The lubricious glass-coated, metal article of claim 1, wherein the metal is a steel rod drawn through cold dies to gradually reduce the rod diameter. ### Claim 14 (depends on 1) The lubricious glass-coated, metal article of claim 1, wherein the metal is steel rod drawn in a cold die to provide sufficient cavities in the metal for receiving hydrogen emitted from the metal such that the glass coating is not damaged by the emitted hydrogen when the article is heated to a temperature above 900° F. ### Claim 15 (depends on 1) The lubricious glass-coated, metal article of claim 1, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 0.5% to about 10% by weight of the glass coating. ### Claim 16 (depends on 15) The lubricious glass-coated, metal article of claim 15, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 5% by weight of the glass coating. ### Claim 17 (depends on 16) The lubricious glass-coated, metal article of claim 16, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 3% by weight of the glass coating. ### Claim 18 (depends on 1) The lubricious glass-coated, metal article of claim 1, wherein the dry refractory lubricant material has an aspect ratio of about 1:1. ### Claim 19 A lubricious glass-coated steel article, said article capable of withstanding a hydrogen-emitting temperature sufficient to emit hydrogen gas from the steel such that hydrogen gas emitted from the steel is contained within cavities formed in the steel during drawing, without escaping through the glass coating, such that the glass coating does not chip or crack at said hydrogen-emitting temperature, wherein the steel rod is drawn to reduce the diameter of the steel rod at least 20%, and the steel comprises the following components by weight: Iron: about 80% to about 99.9%; Carbon: up to about 0.08%; and A transition metal selected from Vn, Ta, Ti, Ni or mixture of any two or more: 0.001% to about 0.2%, wherein the amount of carbon in the steel rod material, the amount of carbon stabilizing transition metal in the steel rod material and the degree to which the diameter of the cross-sectional area of the steel rod material is reduced, when the steel wire is drawn from the steel rod material, are selected to prevent chipping of the glass material away from the outer surface of the article due to the release of hydrogen gas from the steel wire members when the glass-coated steel wire members are heated to a temperature above 900° F.; and wherein the glass surface includes a dry refractory lubricant material, and the dry refractory lubricant material consists of particles having a particle size less than 45 μm and an aspect ratio of less than 2:1. ### Claim 20 (depends on 19) The lubricious glass-coated, metal article of claim 19, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 0.5% to about 10% by weight of the glass coating. ### Claim 21 (depends on 20) The lubricious glass-coated, metal article of claim 20, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 5% by weight of the glass coating. ### Claim 22 (depends on 21) The lubricious glass-coated, metal article of claim 21, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 3% by weight of the glass coating. ### Claim 23 (depends on 19) The lubricious glass-coated, metal article of claim 19, wherein the dry refractory lubricant material has an aspect ratio of about 1:1. ### Claim 24 (depends on 23) The lubricious glass coated, drawn steel rod article of claim 23, wherein the amounts of iron, carbon, and transition metal and the degree of diameter reduction of the steel rod are selected to provide sufficient cavities in the drawn steel such that the glass coating does not chip or crack when the glass-coated article is heated to a temperature above 900° F. ### Claim 25 (depends on 24) The lubricious glass-coated, drawn steel rod article of claim 24, wherein the glass coating is a porcelain material applied in a thickness is the range of 1 to 20 mils. ### Claim 26 (depends on 25) The lubricious glass-coated, drawn steel rod article of claim 25, wherein the glass coating is a porcelain material applied in a thickness is the range of 4 to 10 mils. ### Claim 27 (depends on 23) The lubricious glass-coated, drawn steel product of claim 23, wherein the article is a cooking surface selected from an oven rack, oven ladder rack, burner grate, and a barbeque grill rack. ### Claim 28 (depends on 25) The lubricious glass-coated, drawn steel article of claim 25, wherein the glass coating is a porcelain enamel material. ### Claim 29 (depends on 28) The lubricious glass-coated, drawn steel article of claim 28, wherein the porcelain enamel material is applied in multiple coating steps. ### Claim 30 (depends on 23) The lubricious glass-coated, drawn steel article of claim 23, wherein the steel rod is drawn to reduce the diameter of the steel rod at least about 30%. ### Claim 31 (depends on 30) The lubricious glass-coated, drawn steel article of claim 30, wherein the steel rod is drawn to reduce the diameter of the steel rod at least about 50%. ### Claim 32 (depends on 30) The lubricious glass-coated, drawn steel article of claim 30, wherein the steel rod is drawn through cold dies to gradually reduce the rod diameter. ### Claim 33 (depends on 19) The lubricious glass-coated, metal article of claim 19, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 0.5% to about 10% by weight of the glass coating. ### Claim 34 (depends on 33) The lubricious glass-coated, metal article of claim 33, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 5% by weight of the glass coating. ### Claim 35 (depends on 34) The lubricious glass-coated, metal article of claim 34, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 3% by weight of the glass coating. ### Claim 36 (depends on 15) The lubricious, glass-coated drawn steel article of claim 15, wherein the dry refractory lubricant material has a particle size less than about 45 μm and is selected from the group consisting of consisting of carbon; graphite; boron nitride; cubic boron nitride; molybdenum (IV) sulfide; molybdenum disulfide; molybdenum sulfide; molybdenum (IV) selenide; molybdenum selenide; tungsten (IV) sulfide; tungsten disulfide; tungsten sulfide; silicon nitride (Si3N4); TiN; TiC; TiCN; TiO2; TiAlN; CrN; SiC; diamond-like carbon; tungsten carbide (WC); zirconium oxide (ZrO2); zirconium oxide and 0.1 to 40 weight % aluminum oxide; alumina-zirconia; antimony; antimony oxide; antimony trioxide; and mixtures thereof. ### Claim 37 (depends on 36) The lubricious glass-coated, metal article of claim 36, wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 5% by weight of the glass coating. ### Claim 38 (depends on 37) The lubricious glass-coated, metal article of claim 37 wherein the dry refractory lubricant material is present in the glass coating in an amount of about 2% to about 3% by weight of the glass coating. ### Claim 39 (depends on 36) The lubricious glass-coated, metal article of claim 36, wherein the dry refractory lubricant material has an aspect ratio of about 1:1. ### Claim 40 A lubricious glass-coated steel wire oven rack comprising: a plurality of elongated steel wire members joined together to form an oven rack having an outer surface; the plurality of elongated steel wire members being made from a steel rod material containing up to about 0.08% by weight carbon; the plurality of elongated steel wire members being made from the steel rod material by drawing the steel rod material to form steel wire; wherein the diameter of the cross-sectional area of the steel rod material is reduced by at least about 20% when the steel rod material is drawn to form the steel wire; the outer surface of the oven rack being coated by a dry lubricious glass material containing a dry refractory lubricant, the dry refractory lubricant consisting of particles having a particle size less than 45 μm and an aspect ratio of less than 2:1; wherein the amount of carbon in the steel rod material and the degree to which the diameter of the cross-sectional area of the steel rod material is reduced, when the steel wire is drawn from the steel rod material, are selected to prevent chipping of the glass material away from the outer surface of the article due to the release of hydrogen gas from the steel wire members when the glass-coated steel wire members are heated to a temperature above 900° F. ### Claim 41 (depends on 40) The lubricious glass-coated steel wire oven rack of claim 40, wherein the glass material is porcelain coated onto the outer surface of the steel wire members by first applying a base coat and thereafter applying a lubricious top coat containing 0.1% to about 20% by weight of the dry lubricant material homogenously dispersed in the lubricious top coat, wherein the dry lubricant material is selected from the group consisting of carbon; graphite; boron nitride; cubic boron nitride; molybdenum (IV) sulfide; molybdenum disulfide; molybdenum sulfide; molybdenum (IV) selenide; molybdenum selenide; tungsten (IV) sulfide; tungsten disulfide; tungsten sulfide; silicon nitride (Si3N4); TiN; TiC; TiCN; TiO2; TiAlN; CrN; SiC; diamond-like carbon; tungsten carbide (WC); zirconium oxide (ZrO2); zirconium oxide and 0.1 to 40 weight % aluminum oxide; alumina-zirconia; antimony; antimony oxide; antimony trioxide; and mixtures thereof. ### Claim 42 (depends on 40) The lubricious glass-coated steel wire oven rack of claim 40, wherein the coating thickness is in the range of 4 to 10 mils and the dry refractory lubricant comprises about 1 to about 10 percent by weight of the coating composition that contains the dry lubricant. ### Claim 43 (depends on 40) The lubricious glass-coated steel wire oven rack of claim 40, wherein the lubricious glass material coating includes two separate applied coatings in which a first ground coat of powdered glass is applied and then a second top coat of lubricious powdered glass containing the dry lubricant is applied in a subsequent coating application. ### Claim 44 (depends on 43) The lubricious glass-coated steel wire oven rack of claim 43, wherein the two applied glass coatings are electrostatically applied. ### Claim 45 A method of making a lubricious glass-coated steel wire oven rack, comprising the steps of: a) providing steel rod material containing from about 80 to about 99.9% by weight of iron, up to about 0.08% by weight of carbon and from about 0.001 to about 0.2% by weight of carbon stabilizing transition metal selected from the group consisting of Vanadium, Tantalum, Titanium and Niobium; b) drawing the steel rod material to form steel wire, wherein the diameter of the cross-sectional area of the steel rod material is reduced by at least about 20%; c) forming a plurality of elongated steel wire members from said steel wire; d) joining the plurality of steel wire members to one another to form interconnected parts of a steel wire oven rack; and e) coating the steel wire oven rack with a lubricious porcelain containing about 1% to about 10% by weight of a dry refractory lubricant, the dry refractory lubricant consisting of particles having a particle size less than 45 μm and an aspect ratio of 2:1; wherein the amount of carbon in the steel rod material, the amount of carbon stabilizing transition metal in the steel rod material and the degree to which the diameter of the cross-sectional area of the steel rod material is reduced, when the steel wire is drawn from the steel rod material, are selected to prevent chipping or spalling of the glass material away from the outer surface of the article due to the release of hydrogen gas from the steel wire members when the glass-coated steel wire members are heated to a temperature above 900° F. ### Claim 46 (depends on 45) The method of claim 45, wherein the lubricious porcelain is coated onto the steel wire oven rack in a wet coating process selected from the group consisting of electrostatic dry powder spray, wet spray, electrostatic wet spray, wet flow coating, wet dip, electro-phoretic deposition, and a combination thereof, followed by heating to a temperature of about 1500° F. to about 1600° F. or higher. ### Claim 47 (depends on 45) The method of claim 45, wherein the lubricious porcelain is coated onto the steel wire oven rack by an immersion or flow coating method selected from the group consisting of hand dipping, tong dipping, automatic dip machine coating, electrophoretic deposition, flow coating, and a combination thereof, followed by heating to a temperature of about 1550° F. or higher. ### Claim 48 (depends on 46) The method of claim 46, wherein the lubricious porcelain coated steel wire oven rack is heated to about 1500° F. to about 1600° F. for about 25 minutes prior to cooling. ### Claim 49 (depends on 45) The method of claim 45, wherein the steel rod is drawn through cold dies to gradually reduce the diameter of the steel rod at least about 20%. ### Claim 50 (depends on 45) The method of claim 45, wherein the coated lubricious porcelain comprises porcelain enamel including a dry lubricant having a particle size less than about 45 μm and an aspect ratio less than 2:1, selected from the group consisting of carbon; graphite; boron nitride; cubic boron nitride; molybdenum (IV) sulfide; molybdenum disulfide; molybdenum sulfide; molybdenum (IV) selenide; molybdenum selenide; tungsten (IV) sulfide; tungsten disulfide; tungsten sulfide; silicon nitride (Si3N4); TiN; TiC; TiCN; TiO2; TiAlN; CrN; SiC; diamond-like carbon; tungsten carbide (WC); zirconium oxide (ZrO2); zirconium oxide and 0.1 to 40 weight % aluminum oxide; alumina-zirconia; antimony; antimony oxide; antimony trioxide; and mixtures thereof. ### Claim 51 (depends on 50) The method of claims 50 wherein the porcelain enamel and dry lubricant portion of the porcelain enamel are one of milled together and mixed, wherein the porcelain enamel has a particle size in the range of about 5 μm to about 200 μm. ### Claim 52 (depends on 51) The method of claim 51, wherein the porcelain enamel has a particle size in the range of about 10 μm to less than about 45 μm. ### Claim 53 A method of cleaning a porcelain-coated steel wire oven rack capable of withstanding oven cleaning temperatures above 900° F. without porcelain chipping or cracking, comprising the steps of: heating the oven to a temperature above 900° F., said oven containing said porcelain-coated steel wire oven rack formed by steps a)-e): a) providing steel rod material containing from about 80 to about 99.9% by weight of iron, up to about 0.08% by weight of carbon and from about 0.001 to about 0.2% by weight of carbon stabilizing transition metal selected from the group consisting of Vanadium, Tantalum, Titanium and Niobium; b) drawing the steel rod material to form steel wire, wherein the diameter of the cross-sectional area of the steel rod material is reduced by at least about 20% to form cavities in the steel wire in which hydrogen, emitted from the steel wire, is received and compressed at the oven cleaning temperature, without chipping or cracking the porcelain coating; c) forming a plurality of elongated steel wire members from said steel wire; d) joining the plurality of steel wire members to one another to form interconnected parts of a steel wire oven rack; and e) coating the steel wire oven rack with a lubricious porcelain containing a dry refractory lubricant material, the dry refractory lubricant material consisting of particles having a particle size less than 45 μm and an aspect ratio of less than 2:1, wherein the amount of carbon in the steel rod material, the amount of carbon stabilizing transition metal in the steel rod material and the degree to which the diameter of the cross-sectional area of the steel rod material is reduced, when the steel wire is drawn from the steel rod material, are selected to prevent chipping of the glass material away from the outer surface of the article due to the release of hydrogen gas from the steel wire members when the glass-coated steel wire members are heated to a temperature above 900° F. ### Claim 54 (depends on 53) The method of claim 53, wherein the lubricious porcelain coating includes about 1% to about 10% of a homogeneously distributed dry refractory lubricant material having a particle size in the range of about 20 nm to less than 45 μm selected from the group consisting of carbon; graphite; boron nitride; cubic boron nitride; molybdenum (IV) sulfide; molybdenum disulfide; molybdenum sulfide; molybdenum (IV) selenide; molybdenum selenide; tungsten (IV) sulfide; tungsten disulfide; tungsten sulfide; silicon nitride (Si3N4); TiN; TiC; TiCN; TiO2; TiAlN; CrN; SiC; diamond-like carbon; tungsten carbide (WC); zirconium oxide (ZrO2); zirconium oxide and 0.1 to 40 weight % aluminum oxide; alumina-zirconia; antimony; antimony oxide; antimony trioxide; and mixtures thereof. ### Claim 55 (depends on 1) The lubricious, glass-coated metal article of claim 1, wherein the dry refractory lubricant material is TiO2. ### Claim 56 (depends on 19) The lubricious, glass-coated steel article of claim 19, wherein the dry refractory lubricant material is TiO2. ### Claim 57 (depends on 40) The lubricious, glass-coated steel oven rack of claim 40, wherein the dry refractory lubricant material is TiO2. ### Claim 58 (depends on 45) The method of claim 45, wherein the dry refractory lubricant material is TiO2. ### Claim 59 (depends on 53) The method of claim 53, wherein the dry refractory lubricant material is TiO2.