Plated steel sheet
US10501832B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 22, 2016 |
| Grant date | Dec 10, 2019 |
| Priority date | — |
| Expiry date | Jun 27, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A base material (13) included in a plated steel sheet (1) includes a structure, at a ¼ sheet thickness position, represented by, in volume fraction: tempered martensite: 3.0% or more; ferrite: 4.0% or more; and retained austenite: 5.0% or more. An average hardness of the tempered martensite in the base material (13) is 5 GPa to 10 GPa, and a part or all of the tempered martensite and the retained austenite in the base material form an M-A. A volume fraction of ferrite in a decarburized ferrite layer (12) included in the plated steel sheet (1) is 120% or more of the volume fraction of the ferrite in the base material (13) at the ¼ sheet thickness position, an average grain diameter of the ferrite in the decarburized ferrite layer (12) is 20 μm or less, a thickness of the decarburized ferrite layer (12) is 5 μm to 200 μm, a volume fraction of tempered martensite in the decarburized ferrite layer (12) is 1.0 volume% or more, a number density of the tempered martensite in the decarburized ferrite layer (12) is 0.01/μm2 or more, and an average hardness of the tempered martensite in the decarburized ferrite layer (12) is 8 GPa or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.