US3893873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing spheroidal graphite cast iron
Assignee: Nippon Kinzoku Co Ltd
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Filing: 1973-05-07
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Granted: 1975-07-08
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Expires: 1993-05-07
Abstract
Abstract A method for manufacturing spheroidal graphite cast iron characterized by plastically deforming spherulitic graphite cast iron at a draft of 30 to 80% and then heat-treating for obtaining high tensile strength.
Inventors
- 👤 Kenichi Hanai
- 👤 Tsukasa Fukumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:39
CPC Classifications
C; C21; C21C; C21C1/00; C21C1/10; C21D; C21D8/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
42 words
A METHOD FOR MANUFACTURING SPHEROIDAL GRAPHITE CAST IRON COMPRISING APPLYING HOT PLASTIC DEFORMATION TREATMENT TO A SPHERICAL GRAPHITE CAST IRON AT A REDUCTION RATIO OF 30 TO 80% AND SUBSEQUENTLY SUBJECTING THE SAID MATERIAL TO HEAT TREATMENT TO OBTAIN HIGH TENSILE STRENGTH.
Claim 2
Independent Claim
42 words
A METHOD FOR MANUFACTURING SPHEROIDAL GRAPHITE CAST IRON COMPRISING APPLYING HOT PLASTIC DEFORMATION TREATMENT TO A SPHERICAL GRAPHITE CAST IRON AT A REDUCTION RATIO OF 30 TO 80% AND SUBSEQUENTLY SUBJECTING THE SAID MATERIAL TO HEAT TREATMENT TO OBTAIN HIGH TENSILE STRENGTH.
Claim 3
Dependent Claim
22 words
A mEthod for manufacturing spheroidal graphite cast iron as recited in claim 1, wherein the said heat treatment comprises quenching and tempering.
Claim 4
Dependent Claim
20 words
A method for manufacturing spheroidal graphite cast iron as recited in claim 1, wherein the said heat treatment comprises austempering.
Claim 5
Dependent Claim
34 words
A method for manufacturing spheroidal graphite cast iron as recited in claim 1, wherein the said spheriodal graphite cast iron contains 0.05 to 2.5% of at least one element selected from niobium and tantalum.
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) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |