High-strength hot-formed steel sheet member
US10060005B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 2015 |
| Grant date | Aug 28, 2018 |
| Priority date | — |
| Expiry date | Sep 30, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D9/48
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength hot-formed steel sheet member exhibiting both a consistent hardness and delayed-fracture resistance, and is characterized in that: the high-strength hot-formed steel sheet member has a prescribed chemical composition; the degree of Mn segregation α (=[maximum Mn concentration (mass %) at the sheet center in the thickness direction]/[average Mn concentration (mass %) at a depth of ¼ of the total thickness of the sheet from the surface]) is less than or equal to 1.6; the steel purity value as defined in JIS G 0555 (2003) is less than or equal to 0.08%; the average grain size for prior γ grains is less than or equal to 10 μm; and the number density of the residual carbides is less than or equal to 4×103 particles/mm2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.