US3607456A
Expired / Lapsed
US
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Deep drawing steel and method of manufacture
Assignee: Bethlehem Steel Corp
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Filing: 1969-04-15
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Granted: 1971-09-21
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Expires: 1989-04-15
Abstract
Abstract A ferrous metal sheet having an r in the range of 2.5 to 3.3 and an ASTM grain size of 6.0 to 9.0 is produced by hot rolling to intermediate gauge strip ferrous metal containing 0.15 to 0.30 wt. percent titanium and small amounts of oxygen, carbon and nitrogen, the weight ratio of the titanium to the sum of the carbon and nitrogen being a minimum of 7:1. The steel is finished hot, coiled cold, cold reduced and batch annealed at temperatures approaching the alpha-gamma transformation temperature.
Inventors
- 👤 James L Forand Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:36
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/04; C21D8/0421; C21D8/0426; C21D8/0436; C21D8/0447; C21D8/0473
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
76 words
An article as recIted in claim 1, in which said sheet has an ASTM grain size of 6.5 to 8.5, said ferrous metal consisting essentially of carbon 0.010 wt. percent max., manganese 0.20 to 0.50 wt. percent, titanium 0.15 to 0.20 wt. percent, nitrogen 0.005 wt. percent max., oxygen 0.010 wt. percent max., balance essentially iron, the weight ratio of the titanium to the sum of the carbon and the nitrogen being at least about 12:1.
Claim 2
Independent Claim
165 words
A method of producing ferrous metal strip comprising: a. hot rolling to intermediate gauge strip ferrous metal consisting essentially of carbon 0.020 wt. percent max., manganese 0.60 wt. percent max., titanium 0.15 to 0.30 wt. percent, nitrogen 0.010 wt. percent max., oxygen 0.015 wt. percent max., balance essentially iron, the weight ratio of the titanium to the sum of the carbon and the nitrogen being a minimum of 7:1, b. finishing said hot rolling at a temperature above 1,550* F., c. rapidly cooling the hot-rolled strip to a temperature within the range of 900* F. to 1,200* F., coiling said strip at said temperature, and cooling said strip to room temperature, d. cold reducing said strip by 50 to 85 percent, and e. batch annealing said strip at a temperature within the range of 1,550* F. to the alpha-gamma transformation temperature for a time sufficient to develop an r of at least 2.5 and an ASTM grain size within the range of 6.0 to 9.0.
Claim 3
Dependent Claim
38 words
The method as recited in claim 3, in which during said batch annealing said strip is held at said temperature within the range of 1,550* F. to the alpha-gamma transformation temperature for a minimum time of 1 hour.
Claim 4
Dependent Claim
17 words
The method as recited in claim 3, in which said strip is open coiled during step (e).
References Cited (Backward Citations)
US3522110A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |