Patent US4314849A successfully refreshed from Google Patents.
US4314849A
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US
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Maximizing the corrosion resistance of tin containing stainless steel powder compacts
Assignee: SCM Metal Products Inc
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Filing: 1980-01-21
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Granted: 1982-02-09
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Expires: 2000-01-21
Abstract
Abstract The corrosion resistance of stainless steel powder compacts containing tin and silicon is maximized if the compacts are sintered at temperatures in excess of 2300° F. in highly reductive atmospheres until the ratio of Sn:Si on the surface of the compact is at least about 1:1. Stainless steel powders atomized in an oxidizing atmosphere and containing up to about 1 percent oxygen can be utilized.
Inventors
- 👤 David H. Ro
- 👤 Erhard Klar
- 👤 C. I. Whitman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:28
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/06; B22F9/08; B22F9/082; C; C22; C22C; C22C33/00; C22C33/02; C22C33/0235; B22F2009/0824; B22F2009/0828; B22F2999/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
93 words
A process for maximizing the corrosion resistance of a low carbon stainless steel powder compact containing at least about 0.5% silicon and a predetermined amount of tin of at least about 0.01% which comprises, sintering said compact at a temperature not substantially below about 2300° F. at a dew point of at least about -60° F. for a time sufficient for establishing a tin:silicon ratio on the surface of said compact of at least about 1:1, while substantially preserving the microstructure of the powder contained therein, said time being at least 1/2 hour.
Claim 2
Dependent Claim
93 words
A process for maximizing the corrosion resistance of a low carbon stainless steel powder compact containing at least about 0.5% silicon and a predetermined amount of tin of at least about 0.01% which comprises, sintering said compact at a temperature not substantially below about 2300° F. at a dew point of at least about -60° F. for a time sufficient for establishing a tin:silicon ratio on the surface of said compact of at least about 1:1, while substantially preserving the microstructure of the powder contained therein, said time being at least 1/2 hour.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said powder compact further contains copper in an amount up to 3%.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein said predetermined amount of tin is between about 0.5 to about 5%.
Claim 5
Dependent Claim
23 words
The process of claim 1 wherein said powder compact is made from irregularly-shaped powder having a long-to-short ratio of at least about 2:1.
Claim 6
Dependent Claim
15 words
The process of claim 3 wherein said compact contains about 0.7 to about 1.0% silicon.
Claim 7
Dependent Claim
25 words
The stainless steel powder compact of claim 1 wherein said powder was atomized in an oxidizing atmosphere and contains about 0.6 to about 1.0% oxygen.
Claim 8
Dependent Claim
9 words
The sintered stainless steel powder compact of claim 1.
Claim 9
Dependent Claim
9 words
The sintered stainless steel powder compact of claim 6.
Claim 10
Dependent Claim
32 words
An irregularly-shaped, low-carbon, corrosion-resistant stainless steel powder atomized in an oxidizing atmosphere containing at least about 0.01% tin, at least about 0.5% silicon, about 0.6-1.0% oxygen, and up to about 3% copper.
Claim 11
Dependent Claim
32 words
An irregularly-shaped, low-carbon, corrosion-resistant stainless steel powder atomized in an oxidizing atmosphere containing at least about 0.01% tin, at least about 0.5% silicon, about 0.6-1.0% oxygen, and up to about 3% copper.
Claim 12
Dependent Claim
14 words
The powder of claim 9 having a long-to-short ratio of at least about 2:1.
Claim 13
Dependent Claim
13 words
The powder of claim 9 which contains about 0.5 to about 5% tin.
Claim 14
Dependent Claim
13 words
The powder of claim 11 which contains about 0.7 to about 1.0% silicon.
Claim 15
Dependent Claim
12 words
A coherent compact of the powder of claim 9 formed under pressure.
References Cited (Backward Citations)
US4240831A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-02-08 | 1985-08-10 | 1986-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-08 | 1989-08-10 | 1990-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-08 | 1993-08-10 | 1994-02-09 | $7700.00 | Window Closed / Lapsed |