US3946793A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a high-temperature abrasion-resistant coating on a ferrous metal substrate
Assignee: United States Steel Corp
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Filing: 1974-09-09
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Granted: 1976-03-30
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Expires: 1994-09-09
Abstract
Abstract A method of forming a high-temperature abrasion-resistant hard facing or coating on a ferrous metal substrate by employing an aluminothermic reduction reaction. The resultant article has a hard facing layer containing from 2 to 8 percent boron. Hard faced composite articles made by the invented method, such as sintering machine crash decks, coke pusher ram shoes and grizzly bars are also disclosed.
Inventors
- 👤 Robert H. Kachik
- 👤 Arthur J. Pignocco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:31
CPC Classifications
C; C23; C23C; C23C26/00; C23C26/02; B; B23; B23K; B23K23/00; B23K35/00; B23K35/22; B23K35/34; C23C30/00
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
67 words
A method of producing a high-temperature, abrasion-resistant layer on the surface of a metal base, comprising igniting on said surface an exothermic reaction mixture, said mixture consisting essentially of an exothermic fuel powder, a particulate matrix-forming material consisting essentially of a reducible oxide of at least one matrix-base metal, and sufficient ferroboron to provide from 20 to 90 volume percent of Fe 2 B in said layer.
Claim 2
Independent Claim
67 words
A method of producing a high-temperature, abrasion-resistant layer on the surface of a metal base, comprising igniting on said surface an exothermic reaction mixture, said mixture consisting essentially of an exothermic fuel powder, a particulate matrix-forming material consisting essentially of a reducible oxide of at least one matrix-base metal, and sufficient ferroboron to provide from 20 to 90 volume percent of Fe 2 B in said layer.
Claim 3
Dependent Claim
28 words
A method according to claim 1 wherein said exothermic fuel powder is selected from the group consisting of aluminum, calcium, magnesium, silicon, calcium silicon alloy and mixtures thereof.
Claim 4
Dependent Claim
12 words
A method according to claim 1 wherein said fuel powder is aluminum.
Claim 5
Dependent Claim
20 words
A method according to claim 1 wherein said fuel powder has a particle size between -20 mesh and +325 mesh.
Claim 6
Dependent Claim
17 words
A method according to claim 1 wherein said particulate matrix-forming material is at least partly iron oxide.
Claim 7
Dependent Claim
22 words
A method according to claim 1 wherein the size of said particulate matrix-forming material is at least as fine as -35 mesh.
Claim 8
Dependent Claim
26 words
A method according to claim 1 wherein sufficient ferroboron is present in said mixture to provide from 11/2 to 8 weight percent boron in said layer.
Claim 9
Dependent Claim
26 words
A method according to claim 1 wherein sufficient ferroboron is present in said mixture to provide from 4 to 7 weight percent boron in said layer.
Claim 10
Dependent Claim
37 words
A method according to claim 1 wherein said exothermic reaction mixture is contained in a refractory perimeter positioned around the portion of the surface of the metal base on which the abrasion-resistant layer is to be produced.
Claim 11
Independent Claim
133 words
A method of making a ferrous metal article having a hard facing resistant to abrasion at high temperatures comprising: forming a ferrous metal substrate of any desired configuration; positioning a refractory perimeter around the portion of the substrate to be hard faced; placing an exothermic reaction mixture within the perimeter to a generally uniform depth of at least about 1/2 inch, said charge consisting essentially of 65 to 85 parts iron oxide powder, 15 to 35 parts fuel powder, and sufficient ferroboron to provide from 11/2 to 8 weight percent boron in the hard facing composition; igniting the charge to set off an exothermic reduction reaction, allowing the metal to form a tightly adherent alloy metallurgically bonded to the substrate and a brittle slag layer thereon, cooling the product, and removing the perimeter.
Claim 12
Independent Claim
133 words
A method of making a ferrous metal article having a hard facing resistant to abrasion at high temperatures comprising: forming a ferrous metal substrate of any desired configuration; positioning a refractory perimeter around the portion of the substrate to be hard faced; placing an exothermic reaction mixture within the perimeter to a generally uniform depth of at least about 1/2 inch, said charge consisting essentially of 65 to 85 parts iron oxide powder, 15 to 35 parts fuel powder, and sufficient ferroboron to provide from 11/2 to 8 weight percent boron in the hard facing composition; igniting the charge to set off an exothermic reduction reaction, allowing the metal to form a tightly adherent alloy metallurgically bonded to the substrate and a brittle slag layer thereon, cooling the product, and removing the perimeter.
Claim 13
Dependent Claim
21 words
A method according to claim 10 wherein the substrate is preheated to any temperature below the fusion point of the substrate.
Claim 14
Dependent Claim
17 words
A method according to claim 10 wherein the substrate is preheated to temperature between 1400° and 2000°F.
Claim 15
Dependent Claim
16 words
A method according to claim 10 wherein said iron oxide is Fe 2 0 3 .
Claim 16
Dependent Claim
21 words
A method according to claim 10 wherein said iron oxide powder has a size at least as fine as -35 mesh.
Claim 17
Dependent Claim
12 words
A method according to claim 10 wherein said fuel powder is aluminum.
Claim 18
Dependent Claim
20 words
A method according to claim 10 wherein said fuel powder has a particle size between -20 mesh and +325 mesh.
Claim 19
Dependent Claim
21 words
A method according to claim 10 wherein said ferroboron is crushed to a size at least as fine as -20 mesh.
Claim 20
Dependent Claim
28 words
A method according to claim 10 wherein sufficient ferroboron is present in said mixture to provide from 4 to 7 weight percent boron in the hard facing composition.
Claim 21
Dependent Claim
28 words
A method according to claim 10 wherein sufficient ferroboron is present in said mixture to provide from 5.5 to 7 weight percent boron in the hard facing composition.
Claim 22
Dependent Claim
17 words
A method according to claim 10 wherein the cooling of the product is accomplished by air cooling.
Claim 23
Dependent Claim
46 words
A method according to claim 10 further comprising placing refractory cover plates on the perimeter above the mixture prior to igniting the charge, to contain the heat of reaction and to force the heat into the substrate to enhance the adherence of the hard facing thereto.
Claim 24
Dependent Claim
23 words
A method according to claim 21 further comprising removing said cover plates after the reaction is complete and insulating the resulting composite article.
Claim 25
Dependent Claim
23 words
A method according to claim 22 wherein insulating said resulting composite article is accomplished by placing a sand blanket atop said slag layer.
Claim 26
Dependent Claim
21 words
A method according to claim 22 wherein insulating said resulting composite article is accomplished by placing sand atop said slag layer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |