US3947293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing high-strength cold rolled steel sheet
Assignee: Nippon Steel Corp
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Filing: 1974-12-05
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Granted: 1976-03-30
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Expires: 1994-12-05
Abstract
Abstract A method for producing a high-strength cold rolled steel sheet or strip is disclosed. Steel comprising 0.05 to 0.15% of C; 0.02 to 0.30% of Si; 0.10 to 1.5% of Mn; 0.02 to 0.07% of Al; and A total of 0.02 to 0.15% of at least one of Nb, V, Ti and Zr; With the remainder being iron and unavoidable impurities, Is hot rolled whereafter the hot rolled steel sheet or strip is coiled at a temperature of not more than 750°C. The coiled sheet or strip is then cold rolled whereafter the cold rolled steel sheet or strip is subjected to annealing at a temperature between 670°C and 900°C for 20 seconds to 10 minutes.
Inventors
- 👤 Hiroshi Takechi
- 👤 Koji Ozaki
- 👤 Kazuo Namba
- 👤 Kunihiko Komiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:16
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/14; C21; C21D; C21D8/00; C21D8/02; C21D8/0247; C21D8/0273; C22C38/12; C21D6/00; C21D6/02; C21D8/0221; C21D8/0226; C21D8/0236
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
116 words
A method of producing a high-strength cold rolled steel sheet or strip which comprises: hot rolling steel comprising 0.05 to 0.05% of C; 0.02 to 0.30% of Si; 0.10 to 1.5% of Mn; 0.02 to 0.07% of Al; and a total of 0.02 to 0.15% of at least one metal selected from the group consisting of Nb, V, Ti, and Zr; with the remainder being iron and unavoidable impurities; coiling the hot rolled steel sheet or strip at a temperature not exceeding 750°C. cold rolling the hot rolled steel sheet or strip; subjecting the cold rolled steel sheet or strip to annealing at a temperature between about 670°C and 900°C for 20 seconds to 10 minutes.
Claim 2
Independent Claim
116 words
A method of producing a high-strength cold rolled steel sheet or strip which comprises: hot rolling steel comprising 0.05 to 0.05% of C; 0.02 to 0.30% of Si; 0.10 to 1.5% of Mn; 0.02 to 0.07% of Al; and a total of 0.02 to 0.15% of at least one metal selected from the group consisting of Nb, V, Ti, and Zr; with the remainder being iron and unavoidable impurities; coiling the hot rolled steel sheet or strip at a temperature not exceeding 750°C. cold rolling the hot rolled steel sheet or strip; subjecting the cold rolled steel sheet or strip to annealing at a temperature between about 670°C and 900°C for 20 seconds to 10 minutes.
Claim 3
Dependent Claim
18 words
A method according to claim 1, wherein the coiling is effected at a temperature between 550°C to 750°C.
Claim 4
Dependent Claim
25 words
A method according to claim 1 in which the annealing is conducted at a temperature between 725° and 800°C for 20 seconds to 3 minutes.
Claim 5
Independent Claim
133 words
A method of producing a high-strength cold rolled steel sheet or strip which comprises: hot rolling steel comprising 0.05 to 0.15% of C; 0.02 to 0.30% of Si; 0.10 to 1.5% of Mn; 0.02 to 0.07% of Al; and a total of 0.02 to 0.15% of at least one metal selected from the group consisting of Nb, V, Ti, and Zr; with the remainder being iron and unavoidable impurities; coiling the hot rolled steel sheet or strip at a temperature not exceeding 750°C; cold rolling the hot rolled steel sheet or strip; subjecting the cold rolled steel sheet or strip to annealing at a temperature between about 670°C and 900°C for 20 seconds to 10 minutes; and then subjecting the sheet to a carbide precipitation treatment at a temperature between 300° and 400°C.
Claim 6
Independent Claim
133 words
A method of producing a high-strength cold rolled steel sheet or strip which comprises: hot rolling steel comprising 0.05 to 0.15% of C; 0.02 to 0.30% of Si; 0.10 to 1.5% of Mn; 0.02 to 0.07% of Al; and a total of 0.02 to 0.15% of at least one metal selected from the group consisting of Nb, V, Ti, and Zr; with the remainder being iron and unavoidable impurities; coiling the hot rolled steel sheet or strip at a temperature not exceeding 750°C; cold rolling the hot rolled steel sheet or strip; subjecting the cold rolled steel sheet or strip to annealing at a temperature between about 670°C and 900°C for 20 seconds to 10 minutes; and then subjecting the sheet to a carbide precipitation treatment at a temperature between 300° and 400°C.
Claim 7
Dependent Claim
16 words
A method according to claim 4, in which the coiling temperature is not more than 550°C.
Claim 8
Dependent Claim
27 words
A method according to claim 4, in which the carbide precipitation treatment is effected at a temperature of between 300° and 350°C for 2 to 5 minutes.
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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) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |