High-strength cold-rolled steel sheet and manufacturing method therefor
US11473164B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2019 |
| Grant date | Oct 18, 2022 |
| Priority date | — |
| Expiry date | Mar 22, 2039 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12972
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This high-strength cold-rolled steel sheet has a predetermined chemical composition, wherein a microstructure at a ¼ position of a sheet thickness from a surface includes predetermined ranges of volume percentages of tempered martensite, residual austenite, ferrite and bainite, and martensite, wherein a microstructure at a position 25 μm from the surface includes, predetermined ranges of volume percentage of ferrite and bainite, and martensite and tempered martensite, wherein in the position 25 μm from the surface, an average grain size of the martensite and the tempered martensite is 5.0 μm or less, a tensile strength is 1,310 MPa or more, and a uniform elongation is 5.0% or more, and R/t is 5.0 or less, the R/t being a ratio of a limit bend radius R in 90° V-bending to a sheet thickness t.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.