High strength thin steel excellent in hole expansibility, ductility and chemical treatment characteristics
US7780797B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 2003 |
| Grant date | Aug 24, 2010 |
| Priority date | — |
| Expiry date | Aug 29, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/005
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
High strength hot rolled steel sheet having at least a 590 N/mm2 tensile strength and excellent in elongation and ability of phosphate coating, that is, high strength hot rolled steel sheet excellent in burring, elongation, and ability of phosphate coating having a tensile strength of 590 N/mm2 or more comprising a steel composition containing, by mass %, C: 0.02 to 0.08%, Si: 0.50% or less, Mn: 0.50 to 3.50%, P: 0.03% or less, S: 0.01% or less, Al: 0.15 to 2.0%, and the balance of iron and unavoidable impurities, satisfying Mn+0.5×Al<4, having a microstructure of the steel sheet having a ratio of ferrite having a grain size of 2 μm or more of 40% or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.