Steel for oil well pipe with high corrosion resistance to wet carbon dioxide and seawater, and a seamless oil well pipe
US6217676A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1999 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | May 27, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/909
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel for oil well pipe, which has excellent resistance to localized corrosion in CO.sub.2 environments and corrosion in seawater, and a seamless pipe made of the steel. The steel includes, in weight %, more than 0.10 to 0.30% C, 0.10 to 1.0% Si, 0.1 to 3.0% Mn, 2.0 to 9.0% Cr, 0.01 to 0.10% Al and optionally 0.05 to 0.5% Cu, and the balance including Fe and incidental impurities including not more than 0.03% P and not more than 0.01% S. The steel has a substantially single phase martensitic structure in the as-quenched or as-normalized condition, and yield strength of not lower than 552 MPa in the as-quenched-tempered or as-normalized-tempered condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.