High-strength cold-rolled steel sheet having excellent bendability
US10329635B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 2014 |
| Grant date | Jun 25, 2019 |
| Priority date | — |
| Expiry date | Oct 23, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high strength cold-rolled steel sheet has a component composition containing specific amounts of C, Si, Mn, P, S, N and Al, respectively with a remainder being iron and inevitable impurities. The steel sheet contains 95% or more of martensite in terms of area ratio, and contains 5% or less (inclusive of 0%) of residual austenite and ferrite in terms of a total area ratio. An average size of a carbide is 60 nm or less in terms of an equivalent circle diameter, and a number density of the carbide having the equivalent circle diameter of 25 nm or more is 5.0×105 pieces or less per mm2. The steel sheet has a yield strength of 1,180 MPa or more and a tensile strength of 1,470 MPa or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.