Maraging steel excellent in fatigue characteristics and method for producing the same
US6776855B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 16, 2000 |
| Grant date | Aug 17, 2004 |
| Priority date | — |
| Expiry date | Nov 16, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0205
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a maraging steel excellent in fatigue characteristics and a process for the production thereof.A maraging steel of the first embodiment of the present invention has a chemical composition consisting essentially of, in % by weight: C: 0.01% or less, Ni: 8-19%, Co: 8-20%, Mo: 2-9%, Ti: 0.1-2%, Al: 0.15% or less, N: 0.003% or less, O: 0.0015% or less, and the balance Fe and the Ti component segregation ratio and the Mo component segregation ratio in its structure of 1.3 or less each. A maraging steel of the second embodiment of the present invention has the above composition and contains a nonmetallic inclusion in its structure having a size of 30 &mgr;m or less. The maraging steel of the second embodiment can be obtained easily by appropriate plastic working of a steel ingot with a taper Tp=(D1−D2)×100/H of 5.0-25.0%, a height-diameter ratio Rh=H/D of 1.0-3.0, and a flatness ratio B=W1/W2 of 1.5 or less. The material and production method of the present invention are suitable for various types of maraging steel members for which excellent fatigue characteristics are required.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.