A ductile iron and method of making it
Abstract
Abstract For a ductile iron of the type which has been heated, after casting, to its austenization temperature and austenized and subsequently heat-treated isothermally by quenching in a hot bath to start a bainite reaction which is continued until a desired fraction of the austenite have formed into bainite, improved properties are achieved by adding as alloying elements molybdenium 0.10 - 0.26 % and magnanese 0.3 - 1.4 % by weight and preferably also an additional alloying element which promotes the formation of a pearlite micro-structure during casting and, consequently, accelerates the austenization, said additional element consisting of nickel in an amount less than 2.5 % by weight, and tin and/or copper. Preferably said iron contains molybdenium 0.15 - 0.22 % by weight and less than 0.2 % by weight of tin and/or less than 1.0 % by weight of copper.
Inventors
- 👤 Jouko Vourinen
- 👤 Yrjo Ingman
- 👤 Matti Johansson
- 👤 Martti Kurkinen
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |