High strength cold rolled steel sheet and method of producing same
US11365459B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2018 |
| Grant date | Jun 21, 2022 |
| Priority date | — |
| Expiry date | Oct 5, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C18/04
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high strength cold rolled steel sheet has a composition which contains, in terms of mass %, more than 0.15% and not more than 0.45% of C, 0.50-2.50% of Si, 1.50-3.00% of Mn, not more than 0.050% of P, not more than 0.0100% of S, 0.010-0.100% of Al and not more than 0.0100% of N, with the remainder including Fe and unavoidable impurities, has a total content of ferrite and bainitic ferrite of 20-80%, has a retained austenite content of more than 10% and not more than 40%, has a martensite content of more than 0% and not more than 50%, and is such that the proportion of retained austenite that has an aspect ratio of not more than 0.5 is not less than 75%, and the proportion of retained austenite having an aspect ratio of not more than 0.5 that is present at Bain group boundaries is not less than 50%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.