High-strength stainless steel for oil well and high-strength stainless steel pipe for oil well
US9303296B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 2012 |
| Grant date | Apr 5, 2016 |
| Priority date | — |
| Expiry date | Sep 10, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12292
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength stainless steel for oil well having corrosion resistance excellent in a high-temperature environment, having excellent SSC resistance at normal temperature, and having better workability than 13% Cr steels has a chemical composition containing, by mass percent, C: at most 0.05%, Si: at most 1.0%, Mn: at most 0.3%, P: at most 0.05%, S: less than 0.002%, Cr: over 16% and at most 18%, Mo: 1.5 to 3.0%, Cu: 1.0 to 3.5%, Ni: 3.5 to 6.5%, Al: 0.001 to 0.1%, N: at most 0.025%, and O: at most 0.01%, the balance being Fe and impurities, a microstructure containing a martensite phase, 10 to 48.5%, by volume ratio, of a ferrite phase and at most 10%, by volume ratio, of a retained austenite phase, yield strength of at least 758 MPa and uniform elongation of at least 10%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.