Duplex Steel Round Bar
It has a two-phase microstructure consisting of grains of ferrite and austenitic stainless steel. When it is melted it solidifies from the liquid phase to completely ferrite structure. The result is roughly 50% austenite and 50% ferrite.
Types
- Lean duplex – grade that is UNS (Unified Numbering System) S32303, S32004 and S32101 which contains little or no deliberate Mo addition.
- Standard duplex – it is 22% Cr Grade S32205, the workhorse grade accounting for more than 80% of duplex use.
- Super duplex – with 25-26 Cr and increased Mo and N, such as S32750, S32760 and S32550.
- Hyper duplex – it refers to duplex grades with a PREN greater than 48 and examples are S32707 and S33207.
Properties
- Strength – it is twice as strong as regular austenitic or ferrite stainless steels.
- Toughness and ductility – it has better toughness and ductility than ferrite grades. They do not reach the best value of austenitic grades.
- Corrosion resistance – it has a range of corrosion resistance, similar to the range for austenitic stainless steel.
- Stress corrosion cracking resistance – they have inherited from ferrite side. SCC can be a problem under certain circumstances like humidity, chlorides for standard austenite such as types 304 and 316.
- Cost – it has lower nickel and molybdenum contents than their austenitic counterparts of similar corrosion resistance. It can be lower at cost, especially in high alloy surcharges.
Application
- Food and drink industry
- Oil and gas application
- Desalination plants
- Process plants
- Brewing tanks
- Pressure vessels and storage tanks
- Structural application like bridges,
building structure, architecture - Swimming pool structures
- Hot water tanks and boilers
- Bio fuel tanks
- Food and drink industry