Patent US1500966A successfully refreshed from Google Patents.
Patent US3720512A successfully refreshed from Google Patents.
US3720512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Closed die forging method of making high density ferrous sintered alloys
Assignee: Mitsubishi Metal Corp
•
Filing: 1970-05-06
•
Granted: 1973-03-13
•
Expires: 1990-05-06
Abstract
Abstract Closed die forging method of high density ferrous sintered alloys, wherein an mixture iron based and added components is preformed, then the preform is presintered at a predetermined temperature, subsequently rapidly heated for a short period and finally hot-formed.
Inventors
- 👤 T Yamaguchi
- 👤 I Shunichi
- 👤 Y Saito
- 👤 Y Nishino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:34
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
122 words
Closed die forging method of high density ferrous sintered alloys which comprises steps of: a. press-forming a powder mixture consisting of metal iron powder and at least one powdered alloying component selected from group consisting of carbon, nickel, chromium, manganese, molybdenum, and tungsten; b. subjecting the pressed preform to a pre-sintering at a temperature selected in the range 600*-1200*C, at which said components do not diffuse into the iron powder, until any work-hardening resulting from said press-forming is relieved: c. rapidly heating the preformed material to a hot-forming temperature within a period of time short enough to preclude diffusion of any substantial portion of said components; and d. then hot-forming the heated preform at a pressure ranging from 4 to 7 tons/cm2.
Claim 2
Dependent Claim
122 words
Closed die forging method of high density ferrous sintered alloys which comprises steps of: a. press-forming a powder mixture consisting of metal iron powder and at least one powdered alloying component selected from group consisting of carbon, nickel, chromium, manganese, molybdenum, and tungsten; b. subjecting the pressed preform to a pre-sintering at a temperature selected in the range 600*-1200*C, at which said components do not diffuse into the iron powder, until any work-hardening resulting from said press-forming is relieved: c. rapidly heating the preformed material to a hot-forming temperature within a period of time short enough to preclude diffusion of any substantial portion of said components; and d. then hot-forming the heated preform at a pressure ranging from 4 to 7 tons/cm2.
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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |