High-strength coated steel sheet and method for manufacturing the same
US11142805B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2017 |
| Grant date | Oct 12, 2021 |
| Priority date | — |
| Expiry date | Mar 19, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Provided are a high-strength coated steel sheet and a method for manufacturing the same.The high-strength coated steel sheet has a base steel sheet and a coating layer formed on a surface of the base steel sheet. The base steel sheet has a specified chemical composition and a microstructure, including a martensite phase and a ferrite phase. A volume fraction of the martensite phase is 50% to 80%. A volume fraction of tempered martensite with respect to the whole martensite phase is 50% or more and 85% or less. An average grain diameter of the ferrite phase is 13 μm or less. A volume fraction of ferrite grains having an aspect ratio of 2.0 or less with respect to the whole ferrite phase is 70% or more. Yield strength (YP) of the high-strength coated steel sheet is 550 MPa or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.