Stainless Steel Duplex 2304 / S32304 / 1.4363

Standards :

URONORM	1.4003 X2CrNi12
AFNOR	Z3 CN 23.04 Az
DIN	W. Nr 1.4362
ASTM	A240 – UNS S32304

 

SPECIFICATIONS:

GRADE Lean Duplex | UNS S32304 | ASTM/ASME A240 |Werkstoff 1.4362

Lean duplex 2304 is a 23‰ Cr, 4‰ Nickel, Mo free duplex stainless steel (23.04). We hold stock of duplex alloys in plate, sheet, and bar from our warehouse in the UK. We often meet specialist alloy profiling requirements and are a global supplier.

The alloy lean duplex 2304 has similar corrosion resistance properties to 316L. Furthermore, its mechanical properties i.e. yield strength, are twice those of 304/316 austenitic grades. This allows the designer to save weight, particularly for properly designed pressure vessel applications.

The alloy is particularly suitable for applications covering the -50°C/+300°C (-58°F/572°F) temperature range. Lower temperatures may also be considered, but need some restrictions, particularly for welded structures.

With its duplex microstructure, low nickel and high chromium contents, the alloy has improved stress corrosion resistance properties compared to 304 and 316 austenitic grades.

Stainless steel grade Duplex 2304 is a duplex stainless steel type with a structure that is a balance of ferritic and austenitic. It has high strength and toughness, resistance to stress corrosion cracking, high thermal conductivity, low thermal expansion, and easy fabrication. It is recommended that this steel is not used in areas where the steel would be exposes to temperatures over 1058°C (570°F) for prolonged periods.

The following datasheet provides an overview of stainless steel grade Duplex 2304.

Availability :
Alloy 32304 is available as round / flat / sheet / hexagonal / plate/ square / coil / pipe & fittings.

 

Chemical Composition

The chemical composition of stainless steel grade Duplex 2304 is outlined in the following table.

Element	Content (%)
Iron, Fe	72.679
Chromium, Cr	23
Nickel, Ni	4
Molybdenum, Mo	0.20
Nitrogen, N	0.1
Carbon, C	0.02
Sulfur, S	0.001

Mechanical Properties

The mechanical properties of stainless steel grade Duplex 2304 are displayed in the following table.

Properties	Metric	Imperial
Tensile strength	≥ 600 MPa	≥ 87000 psi
Yield strength (@strain 0.200 %)	≥ 400 MPa	≥ 58000 psi
Modulus of elasticity	200 GPa	29000 ksi
Shear modulus (@temperature 20°C/ 68°F)	75.0 GPa	10900 ksi
Poisson’s ratio	0.333	0.333
Elongation at break	≥ 25 %	≥ 25 %
Hardness, Rockwell C	≤ 20.0	≤ 20.0
Hardness, Brinell	180 - 230	180 - 230

Other Designations

Equivalent materials to stainless steel grade Duplex 2304 are given below:

• ASTM A240
• ASTM A276
• ASTM A480
• ASTM A789
• ASTM A790
• DIN 1.4362

Manufacturing Process

Machining of stainless steel grade Duplex 2304 is performed at low speeds, and constant feeds help to reduce its tendency to work harden. This material is tougher than grade 304 and 316 stainless steels due to its long stringy chip. Chip breakers are recommended. Unlike the 300 series stainless steel, Duplex 2304 steel requires more pressure while performing forming due to its higher yield strength. Its low ductility characteristic tends to make it difficult to perform forming operations.

Welding can be performed using most of the traditional methods such as gas–tungsten arc welding (GTAW), submerged arc welding (SAW), and gas–metal arc welding (GMAW). The filler metal should be a balanced of ferrite/ austenite type like 2205 or 2304.

Applications

Stainless steel grade Duplex 2304 is used by various industries including pulp and paper, coal handling, potash, food and beverage, and waste water.

The specific applications are as follows:

1. Bridges
2. Storage tanks
3. Water heaters
4. Heat exchangers
5. Pressure vessels
6. Feedwater tubes
7. Heat exchangers
8. Flue-gas cleaning
9. Seawater systems
10. Desalination plants
11. Parts for structural design
12. Rotors, impellers and shafts
13. Firewalls and blast walls on offshore platforms
14. Cargo tanks and pipe systems in chemical tankers
15. Piping