2304 (UNS S32304) is a 23% chromium, 4% nickel, molybdenum-free duplex stainless steel. The Alloy 2304 has corrosion resistance properties similar to 316L. Furthermore, its mechanical properties, i.e., yield strength, are twice those of 304L/316L 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 and low nickel and high chromium contents, the alloy has improved stress corrosion resistance properties compared to 304 and 316 austenitic grades.
Duplex Stainless 2304 Applications
▪ Bridges
▪ Storage tanks
▪ Water heaters
▪ Heat exchangers
▪ Pressure vessels
▪ Feedwater tubes
▪ Heat exchangers
▪ Flue-gas cleaning
▪ Seawater systems
▪ Desalination plants
▪ Parts for structural design
▪ Rotors, impellers and shafts
▪ Firewalls and blast walls on offshore platforms
▪ Cargo tanks and pipe systems in chemical tankers
▪ Piping and instrumentation tubing for general service
Duplex Stainless 2304 Chemical Composition
| 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 |
Duplex Stainless 2304 Mechanical Properties
| °C |
Rp 0.2MPa |
Rp 1.0MPa |
Rp 1.0MPa |
°F |
YS 0.2%Offset KSI |
YS 0.1%Offset KSI |
UTSKSI |
Elongation% |
| 20 |
400 |
440 |
600 |
68 |
58 |
64 |
87 |
25 |
| 100 |
330 |
365 |
570 |
212 |
48 |
53 |
83 |
25 |
| 200 |
280 |
310 |
530 |
392 |
41 |
45 |
77 |
20 |
| 300 |
230 |
260 |
490 |
572 |
33 |
38 |
71 |
20 |
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.
Hot working can be done after heating the material to 954-1093°C (1750-2000°F), which is followed rapid cooling. Annealing after working is recommended. For annealing, the material is heated to 930-1050°C (1710-1920°F) and then rapidly quenched.
Available Sizes And Specifications
| 2304 stainless steel plate sizes and specifications |
| Grade |
2304 |
| Cold rolled stainless steel plate |
Thickness: 0.3mm- 16.0mm, Width: 1000mm - 2000mm,Length: as requirements, Surface: 2B/BA/SB/8K/HL/1D/2D etc |
| Hot rolled stainless steel sheet |
Thickness: 3.0mm - 300mm, Width: 1000mm - 3000mm
Length: as requirements, Surface: No.1/pickling |
| Standard |
ASTM A240/A480, ASTM B688, ASTM B463/SB463, ASTM B168/SB168, ASTM B443/SB443/B424/SB424B625/SB625 B575/SB575, JIS G4303,
BS 1449, DN17441, G4305 |
| Stainless steel plate |
Thickness: 8.0mm - 300mm, Width: 1000mm - 3000mm
Length: as requirements, Surface: No.1/pickling |
