High-strength steel sheet and method for producing the same
US12139771B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 2019 |
| Grant date | Nov 12, 2024 |
| Priority date | — |
| Expiry date | Jun 2, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/009
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength steel sheet that has a predetermined component composition, that has a steel microstructure in which an area percentage of ferrite ranges from 5% to 50% in a thickness cross-section in a rolling direction, a total area percentage of fresh martensite and retained γ ranges from 2% to 30%, each of the fresh martensite and the retained γ has an average grain size of 5 μm or less, and a ratio of the fresh martensite and the retained γ adjacent only to ferrite with respect to the fresh martensite and the retained γ from a surface to 200 μm in the thickness direction is 30% or less in total area percentage, and that has a yield strength of 550 MPa or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.