Method of producing austenitic iron/carbon/manganese steel sheets having a high strength and excellent toughness and being suitable for cold forming, and sheets thus produced
US8926772B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 2004 |
| Grant date | Jan 6, 2015 |
| Priority date | — |
| Expiry date | Feb 19, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/50
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to a hot rolled sheet which is made from austenitic iron/carbon/manganese steel and which has a resistance of greater than 900 MPa, whereby: resistance (MPa) x elongation at rupture (%) is greater than 45000. The chemical composition of the inventive sheet comprises the following concentrations expressed as weight: 0.5%=C=0.7%, 17%=Mn=24%, Si=3%, Al=0.05%, S=0.03%, P=0.08%, N=0.1% and, optionally, one or more elements such as Cr=1%, Mo=0.4%, Ni=1%, Ti=0.5%, Nb=0.5%, V=0.5%, Cu=5%, Cu=5%, the rest of the composition comprising iron and impurities resulting from production. According to the invention, the recrystallised fraction of the steel is greater than 75% and the surface fraction of precipitated carbides of the steel is less than 1.5%, the average grain size of the steel being less than 18 micrometers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.