Duplex stainless steel
US5849111A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1996 |
| Grant date | Dec 15, 1998 |
| Priority date | — |
| Expiry date | Nov 6, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/001
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A super duplex stainless steel with low susceptibility to weld cracks and high weldability, as well as the resistance to stress corrosion cracking and toughness of the weld zones. The steel is therefore suitable for a wide range of applications including heat exchangers exposed to sea water, brine-resistant equipment and structures, pipings in chemical plants, line pipes, and oil well pipes. The steel includes, in weight %, 2.0% or less Si, 2.0% or less Mn, 22.0-24.0% Cr, 4.5-6.5% Ni, 4.0-4.8% Mo, 0.001-0.15% Al, and 0.25-0.35% N, the remains of Fe and inevitable impurities including 0.03% or less C, 0.05% or less P and 0.005% or less S, and a RVS, the index of susceptibility to cracking on welding, 7 or less, and a PREW, the index of pitting resistance, greater than 40.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.