Hot stamped steel and method for producing hot stamped steel
US9945013B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 2013 |
| Grant date | Apr 17, 2018 |
| Priority date | — |
| Expiry date | Apr 9, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A hot stamped steel according to the present invention satisfies an expression of (5×[Si]+[Mn])/[C]>11 when [C] represents an amount of C by mass %, [Si] represents an amount of Si by mass %, and [Mn] represents an amount of Mn by mass %, a metallographic structure after hot stamping includes 40% to 90% of a ferrite and 10% to 60% of a martensite in an area fraction, a total of an area fraction of the ferrite and an area fraction of the martensite is 60% or more, a hardness of the martensite measured with a nanoindenter satisfies an H2/H1<1.10 and σHM<20, and TS×λ, which is a product of a tensile strength TS and a hole expansion ratio λ is 50000 MPa·% or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.