US4032336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sintered liquid phase stainless steel
Assignee: KEYSTONE CARBON COMPANY A PA CORP
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Filing: 1976-06-25
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Granted: 1977-06-28
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Expires: 1996-06-25
Abstract
Abstract A sintered stainless steel having an overall density of at least 95% of full density and a morphology comprised of regions of sintered austenitic stainless steel and regions of solidified liquid phase. Moreover, a sintered steel which is made by: pressing and sintering pre-alloyed powder consisting essentially of, by weight, up to 0.05% carbon, 22 to 26% chromium, 10 to 24% nickel, 2.7 to 5% molybdenum, 0.1 to 1% boron, up to 2.0% manganese, up to 2.0% silicon, balance iron and residuals.
Inventors
- 👤 Orville Reen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:52
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/40; C22C38/54; C22C33/00; C22C33/02; C22C33/0257; C22C33/0278; C22C33/0285
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
106 words
A method of making sintered stainless steel having an overall density of at least 98% of full density and a morphology comprised of regions of sintered austenitic stainless steel and regions of solidified liquid phase, which comprises the steps of: subjecting pre-alloyed stainless steel powder consisting essentially of, by weight, up to 0.05% carbon, 22 to 26% chromium, 10 to 24% nickel, 2.7 to 5% molybdenum, 0.1 to 1% boron, up to 2.0% manganese, up to 2.0% silicon, balance iron and residuals, to at least one pressing; and sintering said pressed compact in a substantially non-oxidizing atmosphere at a temperature of from 2250° to 2375° F.
Claim 2
Independent Claim
106 words
A method of making sintered stainless steel having an overall density of at least 98% of full density and a morphology comprised of regions of sintered austenitic stainless steel and regions of solidified liquid phase, which comprises the steps of: subjecting pre-alloyed stainless steel powder consisting essentially of, by weight, up to 0.05% carbon, 22 to 26% chromium, 10 to 24% nickel, 2.7 to 5% molybdenum, 0.1 to 1% boron, up to 2.0% manganese, up to 2.0% silicon, balance iron and residuals, to at least one pressing; and sintering said pressed compact in a substantially non-oxidizing atmosphere at a temperature of from 2250° to 2375° F.
Claim 3
Dependent Claim
16 words
A method according to claim 1, wherein said sintering temperature is from 2275° to 2350° F.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein said pre-alloyed powder has from 22.3 to 26% chromium and from 3 to 5% molybdenum.
Claim 5
Dependent Claim
16 words
A method according to claim 1, wherein said pre-alloyed powder has from 0.2 to 0.5% boron.
Claim 6
Dependent Claim
32 words
A method according to claim 1, wherein said pre-alloyed powder has from 22.3 to 26% chromium, from 13 to 18% nickel, from 3 to 5% molybdenum and from 0.2 to 0.5% boron.
Claim 7
Dependent Claim
15 words
A method according to claim 1, wherein said pre-alloyed powder has at least 16% nickel.
References Cited (Backward Citations)
US2238382A
Cited
US3859085A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |