Hard alloys
Abstract
Abstract This invention relates to hard alloys with a chemical composition by weight of 0.7 to 1.5% carbon; 0.1 to 1.0% silicon; 0.15 to 0.50% manganese; 0.03% maximum phosphorus; 0.20% maximum sulphur; 3.5 to 6.0% chromium; 0 to 10% molybdenum; 0 to 10% tungsten; 0 to 4.0% vanadium; 0.1 to 7.0% niobium; 0.2 to 12% cobalt; 0.08% maximum nitrogen; 0.25% maximum aluminum, the balance being iron, and which alloys contain in their raw melt structure and after hot deformation, individual (segregated) single niobium carbides or individual (segregated) double niobium and vanadium carbides, with a morphology controllable by the fabrication technique. After a suitable heat treatment, such alloys have an improved machinability performance over the conventional alloys (containing no niobium).
Inventors
- 👤 Marcos H. C. de Souza
- 👤 Celso A. Barbosa
- 👤 Ivan G. S. Falleiros
- 👤 Fabio Y. Mori
- 👤 Werner Viertler
Bibliographic Details
Claims Analysis
Total Claims: 2References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |