US3936323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing ferritic stainless steel having high anisotropy
Assignee: Allegheny Ludlum Corp
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Filing: 1975-01-13
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Granted: 1976-02-03
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Expires: 1995-01-13
Abstract
Abstract There is disclosed a method for preparing nominally 13% chromium-0.3% columbium ferritic stainless steel by producing the steel to have very low content of residuals, carbon and nitrogen, hot rolling the steel, annealing the hot rolled steel, and cold rolling the annealed material to reduce the thickness at least 65 percent.
Inventors
- 👤 Richard Kazeva
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:15
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/02; C21D8/04; C22; C22C; C22C38/00; C22C38/18; C22C38/26
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
81 words
A method for preparing deep drawing, stainless steel comprising: A. preparing an alloy to contain from 12- 14%w chromium, from 0.2- 1.0% columbium, and not more than 0.75%w total of carbon, nitrogen, silicon, manganese, molybdenum, nickel, and copper; B. hot rolling said alloy; C. annealing said hot rolled alloy at a temperature of from 1600°F-1900°F for a period of from 50-150 minutes per inch of thickness; and D. cold rolling the annealed steel to reduce the thickness at least 65 percent.
Claim 2
Independent Claim
81 words
A method for preparing deep drawing, stainless steel comprising: A. preparing an alloy to contain from 12- 14%w chromium, from 0.2- 1.0% columbium, and not more than 0.75%w total of carbon, nitrogen, silicon, manganese, molybdenum, nickel, and copper; B. hot rolling said alloy; C. annealing said hot rolled alloy at a temperature of from 1600°F-1900°F for a period of from 50-150 minutes per inch of thickness; and D. cold rolling the annealed steel to reduce the thickness at least 65 percent.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said alloy contains from about 0.02-0.5%w columbium.
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) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |