Maraging steel excellent in fatigue characteristics and method for producing the same
US7323070B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2004 |
| Grant date | Jan 29, 2008 |
| Priority date | — |
| Expiry date | Oct 16, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0205
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process of producing a maraging steel includes melting a steel of a defined composition, casting the molten steel to obtain a steel ingot, hot forging the steel ingot at a forging ratio of at least 4, then soaking the forged piece one or more times to keep the forged piece in a temperature range of 1100-1280° C. for 10-100 hours, and then plastic working the forged piece. A process of producing a maraging steel of another defined composition includes casting the molten steel to obtain a steel ingot with a defined taper, a defined height to diameter ratio and a defined flatness ratio and plastic working the steel ingot so that the size of a nonmetallic inclusion is 30 μm or less expressed as the diameter of a circle of circumference equal to the perimeter (“circumference”) of the inclusion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.