Matrix coatings on endless flexible metallic belts for continuous casting machines method of forming such coatings and the coated belts

An endless flexible casting belt for use in a continuous metal casting machine for continuously casting molten-metal, said belt having fusion bonded to a surface thereof, a protective insulative coating comprising:

• a metallic material having the properties of:
• (a) heat resistance relative to the temperature of the metal to be cast and resistance to thermal cycling,
• (b) thermal fusion bonding compatibility with the belt surface,
• (c) a modicum of ductility for withstanding repeated flexing around a pulley roll,
• (d) sufficient resistance to oxidation under the conditions of thermal spraying and also under the conditions to be encountered in continuous casting for avoiding undue oxidation, and
• (e) thermal expansion rates compatible with predetermined nonmetallic refractory material,
• said predetermined nonmetallic refractory material being dispersed substantially uniformly throughout said metallic material, and
• said metallic material being in the form of a matrix holding, supporting and anchoring said nonmetallic material on the belt, said coating having a desired accessible porosity of at least 6% of the total volume of the coating to enhance the non-wettability of the coating by molten-metal.

An endless flexible casting belt for use in a continuous metal casting machine for continuously casting molten-metal, said belt having fusion bonded to a surface thereof, a protective insulative coating comprising:

• a metallic material having the properties of:
• (a) heat resistance relative to the temperature of the metal to be cast and resistance to thermal cycling,
• (b) thermal fusion bonding compatibility with the belt surface,
• (c) a modicum of ductility for withstanding repeated flexing around a pulley roll,
• (d) sufficient resistance to oxidation under the conditions of thermal spraying and also under the conditions to be encountered in continuous casting for avoiding undue oxidation, and
• (e) thermal expansion rates compatible with predetermined nonmetallic refractory material,
• said predetermined nonmetallic refractory material being dispersed substantially uniformly throughout said metallic material, and
• said metallic material being in the form of a matrix holding, supporting and anchoring said nonmetallic material on the belt, said coating having a desired accessible porosity of at least 8% of the total volume of the coating to enhance the non-wettability of the coating by molten-metal.

The method of forming a fusion-bonded insulative and protective matrix coating on the clean, roughened surface of an endless flexible metallic casting belt for use in a continuous casting machine, comprising the steps of:

• providing a powder mixture containing (1) heat-resisting metallic material, and (2) insulative, nonmetallic refractory material,
• said metallic material constituting such a weight percent of said powder that subsequent thermal spraying of said powder onto said surface results in a continuous matrix of said metallic alloy with said nonmetallic material dispersed throughout said matrix and with said matrix holding said nonmetallic material and securing said nonmetallic material to said surface, and
• thermal spraying said powder mixture onto said surface for forming said insulative and protective matrix coating, and wherein said powder mixture has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Aluminum 4 to 5 Molybdenum 2 to 3 Nickel, plus trace impurities 55 to 57.5 Nonmetallic component:
• Zirconia 35 Calcium oxide, in the zirconia 1.5 to 2 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

The method of forming a fusion-bonded insulative and protective matrix coating on the clean, roughened surface of an endless flexible metallic casting belt for use in a continuous casting machine, comprising the steps of:

• providing a powder mixture containing (1) heat-resisting metallic material, and (2) insulative, nonmetallic refractory material,
• said metallic material constituting such a weight percent of said powder that subsequent thermal spraying of said powder onto said surface results in a continuous matrix of said metallic alloy with said nonmetallic material dispersed throughout said matrix and with said matrix holding said nonmetallic material and securing said nonmetallic material to said surface, and
• thermal spraying said powder mixture onto said surface for forming said insulative and protective matrix coating, and wherein said powder mixture has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Aluminum 6 Molybdenum 4 Nickel, plus trace impurities 52 Nonmetallic component:
• Zirconia 22 to 23 Calcium oxide, in the zirconia 1 to 1.5 Graphite 13 to 14.8 Spherical fumed silica 0.2 to 0.5 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

The method of forming a fusion-bonded insulative and protective matrix coating on the clean, roughened surface of an endless flexible metallic casting belt for use in a continuous casting machine, comprising the steps of:

• providing a powder mixture containing (1) heat-resisting metallic material, and (2) insulative, nonmetallic refractory material,
• said metallic material constituting such a weight percent of said powder that subsequent thermal spraying of said powder onto said surface results in a continuous matrix of said metallic alloy with said nonmetallic material dispersed throughout said matrix and with said matrix holding said nonmetallic material and securing said nonmetallic material to said surface, and
• thermal spraying said powder mixture onto said surface for forming said insulative and protective matrix coating, and wherein said powder mixture has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Nickel, plus trace impurities 57 to 60 Nonmetallic component:
• Zirconia 25 to 28.8 Calcium oxide, in the zirconia 1 to 1.5 Graphite 13 to 15 Spherical fumed silica 0.2 to 0.5 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

The method of forming a fusion-bonded insulative and protective matrix coating on the clean, roughened surface of an endless flexible metallic casting belt for use in a continuous casting machine, comprising the steps of:

• providing a powder mixture containing (1) heat-resisting metallic material, and (2) insulative, nonmetallic refractory material,
• said metallic material constituting such a weight percent of said powder that subsequent thermal spraying of said powder onto said surface results in a continuous matrix of said metallic alloy with said nonmetallic material dispersed throughout said matrix and with said matrix holding said nonmetallic material and securing said nonmetallic material to said surface, and
• thermal spraying said powder mixture onto said surface for forming said insulative and protective matrix coating, and wherein said powder mixture has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Chromium 14 Nickel, plus trace impurities 54 Nonmetallic component:
• Zirconia 29.8 to 30.4 Calcium oxide, in the zirconia 1.4 to 1.6 Spherical fumed silica 0.2 to 0.6 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

The method of forming a fusion-bonded insulative and protective matrix coating on the clean, roughened surface of an endless flexible metallic casting belt for use in a continuous casting machine, comprising the steps of:

• providing a powder mixture containing (1) heat-resisting metallic material, and (2) insulative, nonmetallic refractory material,
• said metallic material constituting such a weight percent of said powder that subsequent thermal spraying of said powder onto said surface results in a continuous matrix of said metallic alloy with said nonmetallic material dispersed throughout said matrix and with said matrix holding said nonmetallic material and securing said nonmetallic material to said surface, and
• thermal spraying said powder mixture onto said surface for forming said insulative and protective matrix coating, and wherein said powder mixture has the composition:
• ______________________________________ Component Weight percent ______________________________________ Metallic component 38 to 90 Nonmetallic component 62 to 10 100% Constituents of metallic component:
• Aluminum 0 to 35 Nickel, plus trace impurities balance Constituents of nonmetallic component:
• Graphite 0 to 40 Spherical fumed silica 0.3 to 0.8 Lime 4 to 20 of the sum of Zirconia plus Lime Zirconia balance ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

An endless flexible casting belt for use in a continuous casting machine for continuously casting molten metal comprising:

• a flexible, metallic belt having a thickness greater than 0.025 of an inch (0.63 mm),
• said belt having bonded on a surface which faces the molten metal an insulative, heat-resistant coating comprising a thermally sprayed mixture comprising as deposited:
• a continuous matrix or reticulum of a heat-resistant metallic material having interspersed throughout such matrix or reticulum at least one nonmetallic insulative refractory material, wherein said insulative heat-resistant coating has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Aluminum 4 to 5 Molybdenum 2 to 3 Nickel, plus trace impurities 55 to 57.5 Nonmetallic component:
• Zirconia 35 Calcium oxide, in the zirconia 1.5 to 2 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

An endless flexible casting belt for use in a continuous casting machine for continuously casting molten metal comprising:

• a flexible, metallic belt having a thickness greater than 0.025 of an inch (0.63 mm),
• said belt having bonded on a surface which faces the molten metal an insulative, heat-resistant coating comprising a thermally sprayed mixture comprising as deposited:
• a continuous matrix or reticulum of a heat-resistant metallic material having interspersed throughout such matrix or reticulum at least one nonmetallic insulative refractory material, wherein said insulative heat-resistant coating has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Aluminum 6 Molybdenum 4 Nickel, plus trace impurities 52 Nonmetallic component:
• Zirconia 22 to 23 Calcium oxide, in the zirconia 1 to 1.5 Graphite 13 to 14.8 Spherical fumed silica 0.2 to 0.5 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

An endless flexible casting belt for use in a continuous casting machine for continuously casting molten metal comprising:

• a flexible, metallic belt having a thickness greater than 0.025 of an inch (0.63 mm),
• said belt having bonded on a surface which faces the molten metal an insulative, heat-resistant coating comprising a thermally sprayed mixture comprising as deposited:
• a continuous matrix or reticulum of a heat-resistant metallic material having interspersed throughout such matrix or reticulum at least one nonmetallic insulative refractory material, wherein said insulative heat-resistant coating has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Nickel, plus trace impurities 57 to 60 Nonmetallic component:
• Zirconia 25 to 28.8 Calcium oxide, in the zirconia 1 to 1.5 Graphite 13 to 15 Spherical fumed silica 0.2 to 0.5 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

An endless flexible casting belt for use in a continous casting machine for continously casting molten metal comprising:

• a flexible, metallic belt having a thickness greater than 0.025 of an inch (0.63 mm),
• said belt having bonded on a surface which faces the molten metal an insulative, heat-resistant coating comprising a thermally sprayed mixture comprising as deposited:
• a continuous matrix or reticulum of a heat-resistant metallic material having interspersed throughout such matrix or reticulum at least one nonmetallic insulative refractory material, wherein said insulative heat-resistant coating has the composition:
• ______________________________________ Constituent Weight percent ______________________________________ Metallic component:
• Chromium 14 Nickel, plus trace impurities 54 Nonmetallic component:
• Zirconia 29.8 to 30.4 Calcium oxide, in the zirconia 1.4 to 1.6 Spherical fumed silica 0.2 to 0.6 ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.

An endless flexible casting belt for use in a continous casting machine for continuously casting molten metal comprising:

• a flexible, metallic belt having a thickness greater than 0.025 of an inch (0.63 mm),
• said belt having bonded on a surface which faces the molten metal an insulative, heat-resistant coating comprising a thermally sprayed mixture comprising as deposited:
• a continuous matrix or reticulum of a heat-resistant metallic material having interspersed throughout such matrix or reticulum at least one nonmetallic insulative refractory material, wherein said insulative heat-resistant coating has the composition:
• ______________________________________ Component Weight percent ______________________________________ Metallic component 38 to 90 Nonmetallic component 62 to 10 100% Constituents of metallic component:
• Aluminum 0 to 35 Nickel, plus trace impurities balance Constituents of nonmetallic component:
• Graphite 0 to 40 Spherical fumed silica 0.3 to 0.8 Lime 4 to 20 of the sum of Zirconia plus Lime Zirconia balance ______________________________________
• wherein the sum of the metallic and nonmetallic components is equal to 100 weight percent.