High-strength steel plate having excellent formability, toughness and weldability, and production method of same
US12305266B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 2018 |
| Grant date | May 20, 2025 |
| Priority date | — |
| Expiry date | Jun 28, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength steel sheet excellent in formability, toughness and weldability has a chemical composition including: by mass %, C: 0.05 to 0.30%, Si: 2.50% or less, Mn: 0.50 to 3.50%, P: 0.100% or less, S: 0.0100% or less, Al: 0.001 to 2.500%, N: 0.0150% or less, O: 0.0050% or less, and the balance consisting of Fe and inevitable impurities. The high-strength steel sheet has a microstructure in a region from ⅛ t (t: sheet thickness) to ⅜ t (t: sheet thickness) from a steel sheet surface, the microstructure including: by volume %, acicular ferrite (3): 20% or more, and martensite (4): 10% or more, polygonal ferrite: 20% or less, residual austenite: 2.0% or less, and the martensite satisfies a formula (A),
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.