Ferritic heat-resistant steel and method for production thereof
US7211159B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Apr 19, 2002 |
| Grant date | May 1, 2007 |
| Priority date | — |
| Expiry date | Jul 25, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D6/002
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A ferritic heat-resistant steel, which exhibits excellent creep characteristics even at a high temperature exceeding 600° C., comprises, on the basis of percent by weight, 1.0 to 13% of chromium, 0.1 to 8.0% of cobalt, 0.01 to 0.20% of nitrogen, 3.0% or less of nickel, 0.01 to 0.50% of one or more of elements selected from a group consisting of vanadium, niobium, tantalum, titanium, hafnium, and zirconium that are MX type precipitate forming elements, and 0.01% or less of carbon and a balance being substantially iron and inevitable impurities, wherein the MX type precipitates precipitate on grain boundaries and in entire grains and the grain boundary existing ratio of an M23C6 type precipitate precipitating on the grain boundaries is 50% or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.