Austenitic stainless steel excellent in fine blankability
US7014719B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2002 |
| Grant date | Mar 21, 2006 |
| Priority date | — |
| Expiry date | Aug 23, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0205
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An austenitic stainless steel comprising (C+½N) up to 0.060 mass %, Si up to 1.0 mass %, Mn up to 5 mass %, S up to 0.003 mass %, S/Mn ratio up to 0.003, 15–20 mass % Cr, 5–12 mass % Ni, Cu up to 5 mass %, 0–3.0 mass % Mo and the balance being Fe except inevitable impurities under the condition that a value Md30 (representing a ratio of a strain-induced martensite) defined by the under-mentioned formula is controlled within a range of −60 to −10. Hardness increase of the steel sheet after being cold-rolled is preferably 20% or more as Vickers hardness. A metallurgical structure of the steel sheet is preferably adjusted to grain size number of #8 to #11 in a finish annealed state. The steel sheet is blanked with high dimensional accuracy, and a die life is also prolonged.Md30=551−462(C+N)−9.2Si−29(Ni+Cu)−8.1Mn−13.7Cr−18.5Mo.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.