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Patent US3619172A successfully refreshed from Google Patents.
US3619172A
Expired / Lapsed
US
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Process for forming spheroidal graphite in hypereutectoid steels
Assignee: Air Liquide SA
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Filing: 1970-04-24
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Granted: 1971-11-09
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Expires: 1990-04-24
Abstract
Abstract Process for improving the castability and the mechanical characteristics of iron-carbon alloys containing between 0.8 and 2.5% by weight of carbon by precipitating at least part of the carbon in excess of that of the eutectoid in the form of spheroidal graphite. This process comprises injecting into the molten iron alloy argon or other rare gas in the form of a multitude of very fine bubbles.
Inventors
- 👤 Noel Lutgen
- 👤 Pierre Karinthi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:22
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/52; C21C5/5211; C21C5/5217; B; B22; B22D; B22D1/00; B22D1/002; B22D1/005; C21C5/5241; Y; Y02; Y02P; Y02P10/00; Y02P10/25
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
14 words
A process as claimed in claim 1, in which said rare gas is argon.
Claim 2
Dependent Claim
14 words
A process as claimed in claim 1, in which said rare gas is helium.
Claim 3
Dependent Claim
23 words
A process as claimed in claim 1, in which said alloy contains from about 0.3 to about 1.0 percent by weight of manganese.
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) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |