Ultra fine-grained advanced high strength steel sheet having superior formability
US9976203B2 · kind B2 · utility
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Key dates
| Filing date | Jan 22, 2013 |
| Grant date | May 22, 2018 |
| Priority date | — |
| Expiry date | Mar 1, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/12
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A cold rolled, annealed TRIP steel sheet which has a composition including (in wt. %): C: 0.1-0.3; Mn: 4-10, Al: 0.05-5, Si: 0.05-5; and Nb: 0.008-0.1, the remainder being iron and inevitable residuals. The cold rolled sheet has an ultimate tensile strength of at least 1000 MPa, and a total elongation of at least 15%. The cold rolled sheet may have at least 20% retained austenite in its microstructure and may have greater than 50% lath-type annealed ferrite structure. The cold rolled sheet may have an ultra fine grain size of less than 5 micron for the retained austenite and ferrite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.