Patent US3098833A successfully refreshed from Google Patents.
Patent US4233073A successfully refreshed from Google Patents.
US4233073A
Expired / Lapsed
US
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Iron-base sintered alloy for valve seat and method of making the same
Assignee: Riken Piston Ring Industrial Co Ltd
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Filing: 1978-04-24
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Granted: 1980-11-11
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Expires: 1998-04-24
Abstract
Abstract An iron-base sintered alloy especially suitable for valve seat manufacture having excellent wear resistance and being able to be machine-cut is provided. The alloy is produced by combining specifically atomized pre-alloyed powder, iron powder, nickel powder and graphite powder by means of compacting and sintering processes, and has a microstructure comprising pearlite and globular hard alloy phase formed with said atomized pre-alloyed hard alloy powder uniformly dispersed in said pearlite and martensite surrounding said hard alloy phase.
Inventors
- 👤 Kazutoshi Takemura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:34
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0278; C22C33/0292; C22C33/0207; C22C38/00; C22C38/18; C22C38/40; C22C38/52
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
Wear resistant and machinable sintered iron-base alloy especially suitable for valve seat manufacture, having a chemical composition by weight of 0.6-2.1% carbon, 1.0-8.0% chromium, 0.5-4.0% tungsten, 2.0-12.0% cobalt, 1.0-5.0% nickel and balance essentially iron, having a microstructure comprising pearlite and globular hard alloy phase uniformly dispersed in said pearlite with martensite surrounding said hard alloy phase being formed with atomized powder of pre-alloyed hard metal having chemical composition by weight of 1.0-3.0% carbon, 20-40% chromium, 10-20% tungsten and 40-60% cobalt.
Claim 2
Dependent Claim
80 words
Wear resistant and machinable sintered iron-base alloy especially suitable for valve seat manufacture, having a chemical composition by weight of 0.6-2.1% carbon, 1.0-8.0% chromium, 0.5-4.0% tungsten, 2.0-12.0% cobalt, 1.0-5.0% nickel and balance essentially iron, having a microstructure comprising pearlite and globular hard alloy phase uniformly dispersed in said pearlite with martensite surrounding said hard alloy phase being formed with atomized powder of pre-alloyed hard metal having chemical composition by weight of 1.0-3.0% carbon, 20-40% chromium, 10-20% tungsten and 40-60% cobalt.
Claim 3
Dependent Claim
84 words
Method of producing sintered iron-base alloy especially suitable for valve seat manufacture, comprising the steps of mixing 5-20% by weight of pre-alloyed and atomized hard alloy powder having chemical composition by weight of 1.0-3.0% carbon, 20-40% chromium, 10-20% tungsten and 40-60% cobalt; 0.6-1.5% graphite powder, 1.0-5.0% nickel powder and remainder of iron powder; compacting the mixture into a desired shape; and sintering said compacted mixture at a temperature ranging 1100° to 1200° C., then cooling said compacted and sintered mixture to a room temperature.
Claim 4
Dependent Claim
84 words
Method of producing sintered iron-base alloy especially suitable for valve seat manufacture, comprising the steps of mixing 5-20% by weight of pre-alloyed and atomized hard alloy powder having chemical composition by weight of 1.0-3.0% carbon, 20-40% chromium, 10-20% tungsten and 40-60% cobalt; 0.6-1.5% graphite powder, 1.0-5.0% nickel powder and remainder of iron powder; compacting the mixture into a desired shape; and sintering said compacted mixture at a temperature ranging 1100° to 1200° C., then cooling said compacted and sintered mixture to a room temperature.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |