Hot-pressed steel sheet member, method of manufacturing the same, and steel sheet for hot pressing
US10253387B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 2013 |
| Grant date | Apr 9, 2019 |
| Priority date | — |
| Expiry date | Oct 8, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A hot-pressed steel sheet member includes a specific chemical composition and further includes a steel structure in which an area ratio of ferrite in a surface layer portion ranging from a surface to 15 μm in depth is equal to or less than 1.20 times an area ratio of ferrite in an inner layer portion being a portion excluding the surface layer portion, and the inner layer portion contains a steel structure represented, in area %, ferrite: 10% to 70%; martensite: 30% to 90%; and a total area ratio of ferrite and martensite: 90% to 100%. A concentration of Mn in the martensite is equal to or more than 1.20 times a concentration of Mn in the ferrite in the inner layer portion, and a tensile strength of the hot-pressed steel sheet member is 980 MPa or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.