2304 Stainless Steel (UNS S32304)
Duplex (lean) · ASTM A240/A240M · Density 7.75 g/cm³
2304 (UNS S32304) is a lean duplex stainless steel with substantially higher minimum yield strength than common 304/316 flat product and only a small molybdenum addition. It can improve resistance to chloride stress-corrosion cracking in tanks, structures and water-heating equipment, while the actual alloy surcharge and section economy remain quotation- and design-specific.
Quotation brief
Quote 2304 When
Quote 2304 when a lean-duplex flat product can use higher yield strength and resistance to chloride stress-corrosion cracking without requiring the molybdenum-rich pitting margin of 2205. It is suited to moderate chloride water, tanks and structural work only after the design checks pitting, crevices, weld phase balance and section economy; it is not a price-equivalent substitute for 304 or 316L.
Best fit
- Tanks, water heaters and structural components where duplex yield strength can support an approved reduction in section thickness.
- Moderate chloride or hot-water duties where resistance to chloride stress-corrosion cracking matters more than high-molybdenum pitting resistance.
- Flat-product and bar orders that can use a qualified duplex fabrication, solution-annealing and inspection route.
Limits to check
- Low molybdenum means 2304 has less pitting and crevice-corrosion margin than 2205 in aggressive, hot or concentrated chloride service.
- Higher strength increases forming load and springback, while welding must preserve phase balance and remove heat tint when corrosion service requires it.
- Section reduction, alloy surcharge and total installed cost are design- and quotation-specific; the grade name alone does not prove an economic saving.
Quoted product forms
Quoted product forms for 2304 Stainless Steel (UNS S32304)
We quote 2304 Stainless Steel as sheet / plate, coil / strip, bar against the named product standard.
- Traceability: heat or lot identity plus the inspection document named in the RFQ (EN 10204 3.1 when that route supports it).
- Processing: decoiling, cutting, polishing, shearing and beveling as ordered.
- Next step: send product form, size and quantity; we quote the supply route.
Chemical Composition (wt%)
| C | Mn | Si | Cr | Ni | Mo | N | Cu | P | S |
|---|---|---|---|---|---|---|---|---|---|
| ≤0.030 | ≤2.50 | ≤1.00 | 21.5–24.5 | 3.0–5.5 | 0.05–0.60 | 0.05–0.20 | 0.05–0.60 | ≤0.040 | ≤0.030 |
Single values are maximums unless a range is shown. Balance: Fe. Per ASTM A240/A240M.
Mechanical Properties
| Tensile strength | ≥600 MPa (87 ksi) |
|---|---|
| Yield strength (0.2%) | ≥400 MPa (58 ksi) |
| Elongation (50 mm) | ≥25% |
| Hardness | ≤290 HBW |
Room-temperature minimum values are summarized for annealed flat product under ASTM A240/A240M unless a condition is named in the property label; product form and thickness can change the requirement.
Physical Properties & Structure
| Density | 7.75 g/cm³ |
|---|---|
| Magnetic response | Magnetic because the microstructure contains a substantial ferrite fraction. |
| Microstructure | Duplex (lean) |
Corrosion Resistance & Limits
- The mixed austenitic-ferritic structure provides high strength and improved resistance to chloride pitting and stress-corrosion cracking relative to 304/316-type grades.
- PREN is only a screening index. Temperature, crevices, weld phase balance, heat tint, deposits and actual solution chemistry still govern suitability.
Fabrication & Heat Treatment
| Welding | Use a qualified duplex procedure with controlled heat input, interpass temperature and filler to maintain phase balance, toughness and corrosion resistance. |
|---|---|
| Forming | Higher yield strength increases forming load and springback. Severe cold work may require solution annealing under a qualified route. |
| Machining | Use rigid equipment, positive feeds and lower cutting speed than common austenitic grades because high strength and work hardening raise cutting load. |
| Heat treatment | Solution anneal and rapid cooling are used to restore the specified duplex structure. Local stress relief can form harmful intermetallic phases and is not a generic remedy. |
Equivalent Grades
The closest international equivalents of 2304 Stainless Steel are 1.4362 (X2CrNiN23-4) in the EN system, 022Cr23Ni4MoCuN in the GB system.
These are common corresponding designations, not unconditional substitutes. Verify chemistry, mechanical properties, product standard, delivery condition, dimensions and project approval before changing designation.
| System | Designation |
|---|---|
| UNS | S32304 |
| EN | 1.4362 (X2CrNiN23-4) |
| GB | 022Cr23Ni4MoCuN |
Ordering Checks for 2304
- State UNS S32304 or EN 1.4362, the governing product standard, form, dimensions, thickness, finish and delivery condition.
- Provide chloride level, operating temperature, pH, flow, deposits, crevices and design-life basis for corrosion screening.
- Define solution-annealed condition, ferrite or phase-balance controls, impact, PMI, NDE and certificate requirements where the project requires them.
- Ask the quotation to identify the proposed product route and distinguish reference dimensional ranges from confirmed availability.
Reference Product Forms & Dimensional Ranges
Common reference product forms for 2304 stainless steel: Sheet / Plate, Coil / Strip, Bar.
| Finishes | No.1, 2B |
|---|---|
| Sheet / coil thickness | 0.5–6.0 mm |
| Plate thickness | 6–60 mm |
Common surface and delivery options
- No.1, 2B, BA or mechanically polished finish when supported by the product route
- Hot rolled, peeled, bright drawn, ground or polished bar condition according to tolerance
These published ranges are engineering references, not a live-stock or production-capability promise. Send the required product form, dimensions, condition and finish; we quote the matching supply route.
Browse related product hubs:Sheet & plate,Coil & strip,Pipe & tube,Bar & rod.
Typical Applications
- Storage tanks and pressure vessels
- Domestic and industrial water heaters
- Structural members and bridge components
- Food and beverage process equipment
- Reinforcing bar in chloride-exposed concrete
2304 Compared With Other Grades
Frequently Asked Questions
What is the difference between 2304 and 2205?
2205 carries more molybdenum and nitrogen than 2304, so its calculated PREN and pitting margin are normally higher. The leaner 2304 chemistry may be considered for less aggressive conditions, but selection still requires the actual chloride exposure, temperature, crevices, fabrication route and current delivered quotation.
Why choose 2304 over 304 or 316L?
Its stated minimum yield strength can let the designer evaluate a thinner section than with common annealed austenitic flat product. Any reduction must still satisfy the design code, loads, buckling, welding, corrosion allowance and fabrication limits; the grade also provides a duplex option where chloride stress-corrosion cracking is part of the material review.
Is 2304 weldable?
Yes, with duplex practice: matching 2307 or over-alloyed 2209 filler, controlled heat input and interpass temperature below ~150 °C to keep the austenite-ferrite balance. Post-weld annealing is not required for normal sections.
Published by Tsingshan (Shandong) Iron & Steel Co., Ltd..Sources, update policy and technical limitations.
Quote request
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Send the product, grade and quantity you already have. We will complete the specification and quote the supply route.