High strength hot-rolled steel plate exhibiting excellent acid pickling property, chemical conversion processability, fatigue property, stretch flangeability, and resistance to surface deterioration during molding, and having isotropic strength and ductility
US8852360B2 · kind B2 · utility
0Cited by
0References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2010 |
| Grant date | Oct 7, 2014 |
| Priority date | — |
| Expiry date | Apr 6, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This high strength hot-rolled steel sheet includes: in terms of percent by mass, C: 0.05 to 0.12%; Si: 0.8 to 1.2%; Mn: 1.6 to 2.2%; Al: 0.30 to 0.6%; P: 0.05% or less; S: 0.005% or less; and N: 0.01% or less, with the remainder being Fe and unavoidable impurities, wherein a microstructure includes specific ranges (in area %) of ferrite phases as well as martensite phases, and a maximum concentration of Al detected by a glow discharge emission spectroscopic analysis is in a range of 0.75 mass % or less in a region from a surface of the steel sheet to a thickness of 500 nm after being acid-pickled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.