Grade dossier
2304 Duplex Stainless Steel for Balanced Corrosion and Strength
A 23% chromium duplex grade offering high strength and corrosion resistance above 304L in many environments without the full alloy content of 2205.
Identity before substitution
Define the grade, product and condition together
A familiar grade name is not a complete purchase specification. Product form, controlling standard, dimensions, condition, finish, certification and service environment determine whether the delivered material is suitable.
Composition control
ASTM A240/A240M flat-product chemistry
Limits are not heat analysis targets
The table summarizes grade limits commonly used for plate, sheet and strip. Pipe, tube, bar, forgings and cast products can be governed by different specifications. Always place the product standard and edition on the purchase order.
| C | 0.030 max |
|---|---|
| Mn | 2.50 max |
| Si | 1.00 max |
| P | 0.040 max |
| S | 0.030 max |
| Cr | 21.50-24.50 |
| Ni | 3.00-5.50 |
| Mo | 0.05-0.60 |
| N | 0.05-0.20 |
| Cu | 0.05-0.60 |
Properties with context
Minimums, typical indicators and delivered condition
Specified annealed flat-product values
| Tensile strength | 600 MPa min |
|---|---|
| 0.2% yield strength | 400 MPa min |
| Elongation | 25% min |
| Hardness | 290 HBW max |
Selection indicators
| Density | about 7.8 g/cm3 |
|---|---|
| Strength | higher than 304L/316L |
| Chloride SCC | better resistance than conventional austenitic grades |
| Design note | Temperature, weld phase balance and toughness matter |
Values depend on product form, thickness, test orientation, condition and governing edition. Use the mill test certificate and the purchase specification for acceptance, not a web table alone.
Selection boundary
Where 2304 belongs and where to escalate
Grade selection is an environmental decision, not a popularity contest. Review the complete medium, temperature, geometry, fabrication, cleaning and inspection requirements.
Good reasons to evaluate it
Water systems and pressure vessels
Pulp-and-paper equipment
Tank and structural applications
Moderate chloride service after testing
Reasons to stop and review
Substituting 2205 in severe chloride duty
Using PRE alone to approve crevices
Unqualified thermal treatment or welding
Ignoring low-temperature impact requirements
Fabrication route
Protect properties through cutting, forming and welding
Use qualified duplex welding consumables and procedures.
Control heat input, interpass temperature and dilution.
Restore the surface after welding.
Specify ferrite, impact and corrosion tests when critical.
Supply definition
Product form changes the applicable requirements
Do not send an RFQ that names only the grade. State form, governing standard, dimensions, tolerances, finish, edge or end condition, quantity, certification and inspection.
Plate, sheet and strip to ASTM A240/A240M
Pipe and tube
Bar, forgings, fittings and flanges
Fabricated tanks and process equipment
Certificate checkpoint
Request heat identity, chemical analysis, mechanical results and compliance to the exact product specification. Add PMI, corrosion testing or supplementary examination only when the application requires it.
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Interactive selection check
Test 2304 against the controlling question
Procurement FAQ
Questions to close before placing the order
Is 2304 stainless steel magnetic?
Magnetic response depends on microstructure and delivered condition.
Can 2304 replace another grade?
Only after checking the governing standard, composition, mechanical properties, corrosion exposure, fabrication route and certification. A commercial name is not a substitution approval.
Does the table apply to every product form?
Not automatically. The values shown use flat-product requirements as a reference. Other forms can use different product standards, dimensions and tests.
What should a 2304 RFQ include?
Product form, standard and edition, UNS or EN designation, dimensions, tolerances, finish, quantity, service, fabrication, certificate and inspection requirements.
Sources, scope and RFQ
Use traceable grade data, then specify the actual product
ASTM A240/A240M requirements for UNS S32304 flat product
Outokumpu Forta DX 2304 official datasheet
Applicable duplex welding qualification standard
Project corrosion and pressure-code requirements