Ferritic Cr-containing steel sheet having excellent ductility, formability, and anti-ridging properties
US6500280B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 2001 |
| Grant date | Dec 31, 2002 |
| Priority date | — |
| Expiry date | Sep 5, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0405
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Producing a ferritic Cr-containing steel sheet having excellent ductility, formability, and anti-ridging properties, and exhibiting excellent surface quality after forming, wherein a ferritic Cr-containing steel sheet contains, by mass %, about 0.001 to 0.12% of C, about 0.001 to 0.12% of N, and about 9 to 32% of Cr, and has a crystal grain structure in which in a section of a hot-rolled annealed steel sheet in the thickness direction parallel to the rolling direction, an elongation index of crystal grains is 5 or less at any position, and in a section of a cold-rolled annealed steel sheet in the thickness direction parallel to the rolling direction, any colony of coarse grains oriented in the rolling direction has an aspect ratio of 5 or less. The production method includes hot rolling, pre-rolling by cold or warm rolling with a rolling reduction of about 2 to 15%, hot-rolled sheet annealing, cold rolling, and finish annealing; preferably the FDT of hot rolling is 850° C., and 0.0002 to 0.0030% of B is added.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.