Cold-rolled high-strength steel having tensile strength of not less than 1500 MPA and excellent formability, and manufacturing method therefor
US11279986B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2017 |
| Grant date | Mar 22, 2022 |
| Priority date | — |
| Expiry date | Feb 19, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Provided is a cold-rolled high-strength steel having a tensile strength of not less than 1500 MPa and an excellent formability, the chemical elements thereof having the following mass percent ratios: 0.25%-0.40% of C, 1.50%-2.50% of Si, 2.0%-3.0% of Mn, 0.03%-0.06% of Al, P≤0.02%, S≤0.01%, N≤0.01% and at least one of 0.1%-1.0% of Cr and 0.1%-0.5% of Mo, with the balance being Fe and other unavoidable impurities. The microstructure of the cold-rolled high-strength steel has 5%-20% of residual austenite and 70%-90% of martensite, and the carbon concentration ratio of the residual austenite to the martensite is greater than 3.5 and less than 15. The cold-rolled high-strength steel sheet has a high strength and an excellent formability through a rational ingredient design and microstructure control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.