Patent US4258467A successfully refreshed from Google Patents.
Patent US4540675A successfully refreshed from Google Patents.
US4540675A
Expired / Lapsed
US
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Carbon-containing refractories with superior erosion and oxidation resistance
Assignee: Vesuvius Crucible Co
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Filing: 1983-05-02
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Granted: 1985-09-10
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Expires: 2003-05-02
Abstract
Abstract An elemental carbon-containing refractory composition having superior erosion and oxidation resistance due to the addition of prescribed amounts of boron carbide.
Inventors
- 👤 Martin Morris
- 👤 Mark K. Fishler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:35
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/101; B; B22; B22D; B22D41/00; B22D41/02; B22D41/14; B22D41/22; B22D41/28; B22D41/30; B22D41/32; B22D41/50; B22D41/52; B22D41/54; C04B35/013; C04B35/48; C04B35/482
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
80 words
A refractory body for controlling the flow of a molten steel stream having a temperature greater than 1400° C. during continuous casting, said refractory body formed of the composition comprising: a refractory material selected from the group consisting of alumina, silica, magnesia, zirconia, zircon and silicon carbide; elemental crystalline carbon; and an effective amount of boron carbide to reduce the oxidation rate of said elemental crystalline carbon when said refractory body is subjected to said temperature greater than 1400° C.
Claim 2
Dependent Claim
80 words
A refractory body for controlling the flow of a molten steel stream having a temperature greater than 1400° C. during continuous casting, said refractory body formed of the composition comprising: a refractory material selected from the group consisting of alumina, silica, magnesia, zirconia, zircon and silicon carbide; elemental crystalline carbon; and an effective amount of boron carbide to reduce the oxidation rate of said elemental crystalline carbon when said refractory body is subjected to said temperature greater than 1400° C.
Claim 3
Dependent Claim
48 words
The refractory body as set forth in claim 1, wherein said elemental crystalline carbon constitutes between about 2 weight percent and about 95 percent of said refractory body, and wherein said boron carbide constitutes between about 1 weight percent and about 10 weight percent of said refractory body.
Claim 4
Dependent Claim
28 words
The refractory body as set forth in claim 2, wherein said boron carbide constitutes between about 3 weight percent and about 7 weight percent of said refractory body.
Claim 5
Dependent Claim
22 words
The refractory body as set forth in claim 1, wherein said boron carbide is included into said refractory body in particulate form.
Claim 6
Dependent Claim
23 words
The refractory body as set forth in claim 4, wherein the particle size of said particulate form is less than about 200 microns.
Claim 7
Dependent Claim
23 words
The refractory body as set forth in claim 4, wherein the particle size of said particulate form is less than about 40 microns.
Claim 8
Dependent Claim
23 words
The refractory body as set forth in claim 4, wherein the particle size of said particulate form is less than about 10 microns.
Claim 9
Dependent Claim
48 words
The refractory body as set forth in claim 1, wherein said elemental crystalline carbon comprises less than about 35 weight percent, wherein said refractory material comprises greater than about 60 weight percent of alumina, and wherein said boron carbide comprises about 5 weight percent of said refractory body.
Claim 10
Dependent Claim
48 words
The refractory body as set forth in claim 1, wherein said elemental crystalline carbon comprises less than about 25 weight percent, wherein said refractory material comprises greater than about 70 weight percent of zirconia, and wherein said boron carbide comprises about 5 weight percent of said refractory body.
Claim 11
Independent Claim
72 words
A method of improving the oxidation resistance at temperatures greater than 1400° C. of a refractory composition containing elemental crystalline carbon and a refractory material selected from the group consisting of alumina, silica, magnesia, zirconia, zircon and silicon carbide, comprising the steps of: adding an effective amount of boron carbide to the refractory composition; and subjecting said refractory composition to a temperature in excess of 1000° F. after practicing said adding step.
Claim 12
Independent Claim
72 words
A method of improving the oxidation resistance at temperatures greater than 1400° C. of a refractory composition containing elemental crystalline carbon and a refractory material selected from the group consisting of alumina, silica, magnesia, zirconia, zircon and silicon carbide, comprising the steps of: adding an effective amount of boron carbide to the refractory composition; and subjecting said refractory composition to a temperature in excess of 1000° F. after practicing said adding step.
Claim 13
Dependent Claim
25 words
The method as set forth in claim 10, wherein said subjecting step is practiced during the formation of a refractory article from said refractory material.
Claim 14
Dependent Claim
20 words
The method as set forth in claim 10, wherein said subjecting step is practiced during use of said refractory material.
Claim 15
Dependent Claim
32 words
The method as set forth in claim 10, wherein said adding step comprises the step of: impregnating said boron carbide into the body of a refractory article formed of said refractory composition.
Claim 16
Dependent Claim
23 words
The method as set forth in claim 13, wherein said impregnating step is practiced on only a selected portion of said refractory article.
Claim 17
Dependent Claim
16 words
The method as set forth in claim 14, wherein said selected portion is a surface portion.
Claim 18
Dependent Claim
61 words
A refractory article formed of a refractory composition, said refractory composition comprising: a refractory material selected from the group consisting of alumina, silica, magnesia, zirconia, zircon and silicon carbide; elemental crystalline carbon; and an effective amount of boron carbide to reduce the oxidation rate of said elemental crystalline carbon when said refractory composition is subjected to temperatures greater than 1400° C.
Claim 19
Dependent Claim
61 words
A refractory article formed of a refractory composition, said refractory composition comprising: a refractory material selected from the group consisting of alumina, silica, magnesia, zirconia, zircon and silicon carbide; elemental crystalline carbon; and an effective amount of boron carbide to reduce the oxidation rate of said elemental crystalline carbon when said refractory composition is subjected to temperatures greater than 1400° C.
Claim 20
Dependent Claim
23 words
The refractory article as set forth in claim 16, wherein said refractory article is a refractory shroud for use in the steel industry.
Claim 21
Dependent Claim
23 words
The refractory article as set forth in claim 16, wherein said refractory article is a refractory nozzle for use in the steel industry.
Claim 22
Dependent Claim
24 words
The refractory article as set forth in claim 16, wherein said refractory article is a refractory closure plate for use in the steel industry.
Claim 23
Dependent Claim
23 words
The refractory article as set forth in claim 16, wherein said refractory article is a refractory crucible for use in the steel industry.
Claim 24
Dependent Claim
24 words
The refractory article as set forth in claim 16, wherein said refractory article is a refractory stopper head for use in the steel industry.
Claim 25
Dependent Claim
24 words
The refractory article as set forth in claim 16, wherein said refractory article is a refractory casting tube for use in the steel industry.
Claim 26
Dependent Claim
23 words
The refractory article as set forth in claim 16, wherein said refractory article is a refractory brick for use in the steel industry.
References Cited (Backward Citations)
SU660964A1
Cited
JPS54122309A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-09 | 1989-03-11 | 1989-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-09 | 1993-03-11 | 1993-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-09 | 1997-03-11 | 1997-09-10 | $7700.00 | Window Closed / Lapsed |