Stainless steel
US5888449A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1997 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | May 30, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Precipitation hardening (PH) stainless steels heat treatable to yield strength levels in the range of 200 ksi with exceptionally high fracture toughness are achieved in alloys consisting essentially of 12.25-13.25% chromium, 7.5-8.5% nickel, 2.0-2.5% molybdenum, 0.8-1.35% aluminum, not over 0.05% carbon, not over 0.10% silicon, not over 0.10% manganese, not over 0.010% phosphorus and with especially critical amounts of not over 0.0020% (20 ppm) nitrogen, not over 0.0020% (20 ppm) sulfur, not over 0.0026% (26 ppm) nitrogen plus sulfur; not over 0.04% titanium, and remainder essentially Fe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.