High-strength cold-rolled steel sheet
US11008635B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2017 |
| Grant date | May 18, 2021 |
| Priority date | — |
| Expiry date | Dec 24, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Provided is a high-strength cold-rolled steel sheet has a chemical composition containing, by mass %, C: 0.10% or more and 0.6% or less, Si: 1.0% or more and 3.0% or less, Mn: more than 2.5% and 10.0% or less, P: 0.05% or less, S: 0.02% or less, Al: 0.01% or more and 1.5% or less, N: 0.005% or less, Cu: 0.05% or more and 0.50% or less, and the balance being Fe and inevitable impurities, and a tensile strength of 1180 MPa or more, in which a steel sheet surface coverage of oxides mainly containing Si is 1% or less, a steel sheet surface coverage of iron-based oxides is 40% or less, CuS/CuB is 4.0 or less, and a tensile strength is 1180 MPa or more, where CuS denotes a Cu concentration in a surface layer of a steel sheet and CuB denotes a Cu concentration in base steel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.