Patent US4124413A successfully refreshed from Google Patents.
US4124413A
Expired / Lapsed
US
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Wear and pitting resistant cast iron
Assignee: Toyota Motor Corp
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Filing: 1975-03-18
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Granted: 1978-11-07
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Expires: 1995-03-18
Abstract
Abstract Wear and pitting resistant cast iron consisting essentially of 2.8 - 3.3% carbon, 1.5 - 2.1% silicon, 1.0 - 1.5% chromium, 0.6 - 0.8% molybdenum, 0.2 - 0.5% nickel, balance substantially all iron. The free cementite in the iron in its as-cast state amounts to 20 - 40% by volume and the casting is then held at 860 DEG - 950 DEG C for 1 - 10 hours, followed by quenching, for hardening purposes.
Inventors
- 👤 Yasuhiko Komatsu
- 👤 Shozo Kanbara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:50
CPC Classifications
C; C22; C22C; C22C37/00; C22C37/06; C22C37/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
59 words
Wear and pitting resistant alloyed cast iron consisting essentially of: 2.8-3.3% carbon, 1.5-2.1% silicon, 1.0-1.5% chromium, 0.6-0.8% molybdenum, 0.2-0.5% nickel, not more than 0.05 phosphorus, balance essentially iron, said cast iron having a free cementite content of 20-40% by volume in its as-cast state and having been heated at 860°-950° C. for 1-10 hours after casting, and then quenched.
Claim 2
Dependent Claim
59 words
Wear and pitting resistant alloyed cast iron consisting essentially of: 2.8-3.3% carbon, 1.5-2.1% silicon, 1.0-1.5% chromium, 0.6-0.8% molybdenum, 0.2-0.5% nickel, not more than 0.05 phosphorus, balance essentially iron, said cast iron having a free cementite content of 20-40% by volume in its as-cast state and having been heated at 860°-950° C. for 1-10 hours after casting, and then quenched.
Claim 3
Dependent Claim
18 words
The cast iron of claim 1 which has been heated after casting for 1-10 hours at 860°-900° C.
Claim 4
Dependent Claim
36 words
The cast iron of claim 1 which has first been heated at 900°-950° C. for 1.0-1.5 hours after casting, and then quenched in oil from at ambient temperature to 150° C. after cooling to 820°-850° C.
Claim 5
Dependent Claim
35 words
The cast iron of claim 1 which has been cooled after said heating to 820°-880° C., and then quenched in oil at about 60° C. followed by tempering for about an hour at 150° C.
Claim 6
Dependent Claim
15 words
The cast iron of claim 1 having a Vickers hardness of Hv 750-900 after quenching.
Claim 7
Dependent Claim
23 words
The cast iron of claim 1 wherein the maximum length of free cementite in the cast iron is not greater than 0.12 mm.
Claim 8
Independent Claim
82 words
A method of producing a wear resistant cast iron which comprises the steps of casting a melt consisting essentially of: 2.8-3.3% carbon, 1.5-2.1% silicon, 1.0-1.5% chromium, 0.6-0.8% molybdenum, 0.2-0.55 nickel, not more than 0.05 phosphorus balance substantially all iron, to form a casting having a free cementite content of 20-40% by volume, and then hardening the resulting casting by heating it at 860°-950° C. for 1-10 hours, and then quenching it to produce a product having a Vickers hardness of Hv 750-900.
Claim 9
Independent Claim
82 words
A method of producing a wear resistant cast iron which comprises the steps of casting a melt consisting essentially of: 2.8-3.3% carbon, 1.5-2.1% silicon, 1.0-1.5% chromium, 0.6-0.8% molybdenum, 0.2-0.55 nickel, not more than 0.05 phosphorus balance substantially all iron, to form a casting having a free cementite content of 20-40% by volume, and then hardening the resulting casting by heating it at 860°-950° C. for 1-10 hours, and then quenching it to produce a product having a Vickers hardness of Hv 750-900.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-11-06 | 1982-05-08 | 1982-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-06 | 1986-05-08 | 1986-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-06 | 1990-05-08 | 1990-11-07 | $7700.00 | Window Closed / Lapsed |