Material for high strength steel sheets, hot rolled material for high strength steel sheets, hot-rolled and annealed material for high strength steel sheets, high strength steel sheet, high strength hot-dip-coated steel sheet, high strength electroplated steel sheet, and method of manufacturing same
US10858717B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2016 |
| Grant date | Dec 8, 2020 |
| Priority date | — |
| Expiry date | May 14, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high strength steel sheet having excellent surface quality and formability with a tensile strength of 980 MPa or more and a TS-El balance of 30000 MPa % or more is provided. A high strength steel sheet comprises: a chemical composition containing C: 0.08% to 0.30%, Si: 2.0% or less, Mn: more than 3.0% and 10.0% or less, P: 0.05% or less, S: 0.01% or less, Al: 1.5% or less, Ti: 0.010% to 0.300%, and N: 0.0020% to 0.0100% in a range satisfying 1.1≤(Ti+Mn1/2/400)/(0.01+5N)≤6.0; and a microstructure including a retained austenite phase and a ferrite phase, wherein a ratio γMn/αMn of an average Mn concentration (γMn) of the retained austenite phase to an average Mn concentration (αMn) of the ferrite phase is 1.5 or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.