High-strength galvanized steel sheet and method for manufacturing the same
US10590503B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2014 |
| Grant date | Mar 17, 2020 |
| Priority date | — |
| Expiry date | May 20, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Provided are a high-strength galvanized steel sheet which can preferably be used as a material for automobile parts and a method for manufacturing the steel sheet. The steel sheet has a C content of 0.15% or less, in which an area ratio of ferrite is 10% or less, an area ratio of bainitic ferrite is 2% or more and 30% or less, an area ratio of martensite is 60% or more and 98% or less, an area ratio of retained austenite is less than 2%, an average grain diameter of martensite adjacent to bainite is 15 μm or less, a proportion of massive martensite adjacent only to bainite to the whole metallographic structure is 10% or less, and a value (ΔHv) calculated by subtracting the Vickers hardness at a position located at 20 μm from the surface of the steel sheet from the Vickers hardness at a position located at 100 μm from the surface of the steel sheet is 30 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.