Martensitic stainless steel strengthened by Ni3Ti η-phase precipitation
US7879159B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2006 |
| Grant date | Feb 1, 2011 |
| Priority date | — |
| Expiry date | Mar 2, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A precipitation-hardened stainless maraging steel which exhibits a combination of strength, toughness, and corrosion resistance comprises by weight about: 8 to 15% chromium (Cr), 2 to 15% cobalt (Co), 7 to 14% nickel (Ni), and up to about 0.7% aluminum (Al), less than about 0.4% copper (Cu), 0.5 to 2.6% molybdenum (Mo), 0.4 to less than about 0.75% titanium (Ti), up to about 0.5% tungsten (W), and up to about 120 wppm carbon (C), the balance essentially iron (Fe) and incidental elements and impurities, characterized in that the alloy has predominantly lath martensite microstructure essentially without topologically close packed intermetallic phases and strengthened primarily by a dispersion of intermetallic particles primarily of the eta-Ni3Ti phase and wherein the titanium and carbon (Ti) and (C) levels are controlled such that C can be dissolved during a homogenization step and subsequently precipitated during forging to provide a grain-pinnning dispersion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.