Alloy 2304 (also called UNS S32304, F68 or 2304) is a ferritic-austenitic duplex stainless steel with a lower Molybdenum content (lean duplex) whose duplex structure containing approximately equal amounts of ferrite or austenite, is able to offer a sufficient resistance to pitting and uniform corrosion, a very good stress corrosion cracking resistance, together with high mechanical properties and toughness.
| Zeon Grade | Alloy Name | UNS | EN / DIN / W Nr. | AISI / ASTM | Trademarks |
|---|---|---|---|---|---|
| Zeon51 | Alloy 2304 | UNS S32304 | 1.4362 | - | SAF2304 |
| Grade | C | Mn | Si | P | S | Cr | Cu | Ni | N | |
|---|---|---|---|---|---|---|---|---|---|---|
| 2304 (UNS S32304) | Min | 0.03 | 2.5 | 1.0 | 0.04 | 0.03 | 21.5 | 0.05 | 3.0 | 0.05 |
| Max | - | - | - | - | - | 24.5 | 2.0 | 3.5 | 2.0 |
| Grade | Density (kg/m3) | Elastic Modulus (GPa) | Mean Co-eff of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat 0-100°C (J/kg.K) |
Electrical Resistivity (nΩ.m) |
|||
|---|---|---|---|---|---|---|---|---|---|
| 0-100°C | 0-315°C | 0-538°C | at 100°C | at 500°C | |||||
| 2304 | 7.8 | - | 13 | 13.5 | 14 | 15 | - | 500 | 0.8 |
| Grade | Tensile Str (MPa) min |
Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
|---|---|---|---|---|---|
| Rockwell C (HR C) | Brinell (HB) | ||||
| 2304 | 87(600) | 58(400) | 25 | 31^J | 293 |
| Corrosion Resistance Properties of Alloy 2304 |
|---|
| Due to its high chromium content of 23%, the corrosion resistance properties of Duplex 2304 are practically equivalent to those of Alloy 316L Its duplex microstructure and low nickel and high chromium contents allows Duplex 2304 to have improved stress corrosion resistance properties compared to the 304L and 316L standard austenitic grades. More resistant to pitting and crevice corrosion resistance that Alloy 316L Outperforms Alloys 304L and 316L in stress corrosion cracking resistance in chloride containing aqueous solutions Its corrosion rate in boiling nitric acid (65%) is higher than that of Alloy 316L Its high yield strength allows Duplex 2304 to perform well in abrasion/corrosion applications |
| HOT FORMING | Hot forming must be performed in the 1150°/900°C (2100°/1650°F) temperature range.After forming, a new solution annealing treatment is recommended in the 950°/1050°C (2100°/1650°F) temperature range to fully restore corrosion resis- tance properties and mechanical properties. Parts formed with 2304 must be supported carefully during heating to avoid creep deformation. |
|---|---|
| COLD FORMING | Alloy 2304 may be cold formed without any problem. The same equipment as used for the cold forming of 304L and 316L grades can be used. Due to its higher mechanical properties, including the yield strength, higher stresses are required for cold forming. A final solution annealing heat treatment is also recommended after cold forming in order to restore the mechanical and corrosion resistance properties, as described in ‘hot forming.’ |
| WELDABILITY | Can be successfully welded by TIG manual and automatic, PLASMA, MIG, SMAW, SAW, FCAW Duplex microstructure renders the alloy less sensitive to hot cracking Pre-heating and post welding is not required Filler metal should be a balanced ferrite/austenitic type |
| MACHINABILITY | Exhibits improved machinability properties particularly when considering drilling Low speeds and high feeds will minimize this alloys tendency to work harden |
| Applications Of Alloy 2304 | |||
|---|---|---|---|
| Chloride containing environments | Welded pipe systems within the Pulp and Paper | Transportations, Chemical and Petrochemical | Heat exchanger tubes |
| Architecture, building, construction | Pressure vessels | Food industry | Water Treatment industries |