High-strength steel sheet and galvanized steel sheet having very good balance between hole expansibility and ductility, and also excellent in fatigue resistance, and methods of producing the steel sheets
US8460481B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 2009 |
| Grant date | Jun 11, 2013 |
| Priority date | — |
| Expiry date | Oct 24, 2029 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention is directed to providing, for application in automobiles, construction materials, household appliances and the like, high-strength sheets excellent in formability properties such as hole expansibility and ductility, and also in fatigue resistance, characterized in comprising, in specified contents expressed in mass %, C, Si, Mn, P, S, Al, N and O and a balance of iron and unavoidable impurities, and having a steel sheet structure composed mainly of ferrite and hard structures, a crystal orientation difference between some ferrite adjacent to hard structures and the hard structures of less than 9°, and a maximum tensile strength of 540 MPa or greater.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.