High-toughness and high-strength ferritic steel and method of producing the same
US6827755B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 2002 |
| Grant date | Dec 7, 2004 |
| Priority date | — |
| Expiry date | Jul 2, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2999/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength and high-toughness ferritic steel having a tensile strength of not less than 1,000 MPA and a Charpy impact value of not less than 1 MJ/m2 is provided. A ferritic steel comprising, by weight, not more than 1% Si, not more than 1.25% Mn, 8 to 30% Cr, not more than 0.2% C, not more than 0.2% N, not more than 0.4% O, a total amount of not more than 12% of at least one compound-forming element selected from the group of Ti, Zr, Hf, V and Nb in amounts of not more than 3% Ti, not more than 6% Zr, not more than 10% Hf, not more than 1.0% V and not more than 2.0% Nb, also containing where necessary not more than 0.3% Mo, not more than 4% W and not more than 1.6% Ni, and the balance consisting of Fe and unavoidable impurities, and having an average crystal grain size of not more than 1 &mgr;m, can be obtained by a method comprising encapsulating a steel powder produced by mechanical alloying, and subjecting the encapsulated steel powder to plastic deformation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.