Chromising of ferrous metal substrates
Abstract
Abstract THIS INVENTION PROVIDES A PROCESS FOR CHROMISING FERROUS METAL SUBSTRATES. A POROUS ADHERENT CHROMIUM-CONTAINING COATING IS APPLIED TO THE SURFACE OF A FERROUS METAL SUBSTRATE. THE COATED SUBSTRATE IS THEN HEATED IN CONTACT WITH A GASEOUS STREAM CONTAINING A HYDROGEN HALIDE AND ALSO HYDROGEN AND/OR IN INERT GAS TO A TEMPERATURE SUCH THAT THE HYDROGEN HALIDE REACTS WITH THE SURFACE OF THE COATED SUBSTRATE SAID TEMPERATURE BEING BELOW THAT AT WHICH ANY APPRECIABLE AMOUNTS OF THE RESULTANT METAL HALIDES WOULD BE REMOVED THEREFROM BY EVAPORATION. THE FLOW OF THE GAS IS THEN STOPPED AND THE COATED SUBSTRATE HEATED TO A TEMPERATURE OF A LEAST 750*C. FOR A PERIOD SUFFICIENT TO ALLOY THE CHROMIUM IN THE INITIAL COATING WITH THE SUBSTRATE AND FORM AN ALLOY COATING OF THE DESIRED THICKNESS.
Inventors
- 👤 Kenneth Urmston Holker
- 👤 Colin Wells
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |