Patent US3574069A successfully refreshed from Google Patents.
US3574069A
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Method of forming a protective coating on a ferrous surface
Assignee: Bethlehem Steel Corp
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Filing: 1967-08-18
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Granted: 1971-04-06
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Expires: 1987-08-18
Abstract
Abstract IN A PROCESS OF FORMING A PROTECTIVE COATING ON FERROUS ARTICLES, SUCH AS STEEL STRIP, THE ARTICLE IS TREATED IN AN AQUEOUS ELECTROPLATING BATH OF CHROMIC ACID, A SILICOFLUORIDE AND SULFATE. THE STRIP, ACTING AS CATHODE, IS SUBJECTED TO THE ELECTROLYTIC ACTION OF THE BATH AT A RELATIVELY HIGH CURRENT DENSITY FOR A PERIOD SUFFICIENT TO DEPOSIT A THIN FILM OF CHROMIUM THEREON. THE STRIP IS THEN GIVEN A SIMILAR TREATMENT IN A LESS CONCENTRATED BATH OF THE SAME CHEMICAL COMPOSITION AS THAT OF THE FIRST BATH.
Inventors
- 👤 Carlton E Roberts
- 👤 George W Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:02
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/10; C25D5/12; C25D5/14; C25D3/00; C25D3/02; C25D3/04; C25D5/627; C25D7/00; C25D7/06; C25D7/0614; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/934; Y10S428/935; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/12847; Y10T428/12854
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |