High-strength steel sheet excellent in impact resistance and manufacturing method thereof, and high-strength galvanized steel sheet and manufacturing method thereof
US10351937B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2012 |
| Grant date | Jul 16, 2019 |
| Priority date | — |
| Expiry date | Aug 14, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a high-strength steel sheet excellent in impact resistance. The high-strength steel sheet contains predetermined contents of C, Si, Mn, P, S, Al, Ti, N, and O, with the balance being iron and inevitable impurities, and has a steel sheet structure in which, in a ⅛ thickness to ⅜ thickness region across ¼ of a sheet thickness, 1 to 8% retained austenite is contained in volume fraction, an average aspect ratio of the retained austenite is 2.0 or less, an amount of solid-solution Mn in the retained austenite is 1.1 times an average amount of Mn or more, and TiN grains having a 0.5 μm average grain diameter or less are contained, and a density of AlN grains with a 1 μm grain diameter or more is 1.0 pieces/mm2 or less, wherein a maximum tensile strength is 900 MPa or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.