2205 Stainless Steel (UNS S32205)
Duplex (austenitic-ferritic) · ASTM A240/A240M, A276 · Density 7.8 g/cm³
2205 (UNS S32205) is a duplex stainless steel with a mixed austenitic-ferritic structure. It roughly doubles the yield strength of 304/316 and strongly resists chloride pitting and stress-corrosion cracking, making it ideal for chemical tanks, desalination plants, and marine and structural service.
Chemical Composition (wt%)
| C | Mn | Si | Cr | Ni | Mo | N | P | S |
|---|---|---|---|---|---|---|---|---|
| ≤0.030 | ≤2.00 | ≤1.00 | 22.0–23.0 | 4.5–6.5 | 3.0–3.5 | 0.14–0.20 | ≤0.030 | ≤0.020 |
Single values are maximums unless a range is shown. Balance: Fe. Per ASTM A240/A240M, A276.
Mechanical Properties
| Tensile strength | ≥655 MPa (95 ksi) |
|---|---|
| Yield strength (0.2%) | ≥450 MPa (65 ksi) |
| Elongation (50 mm) | ≥25% |
| PREN | ≥34 |
Room-temperature minimum values are summarized for annealed flat product under ASTM A240/A240M, A276 unless a condition is named in the property label; product form and thickness can change the requirement.
Physical Properties & Structure
| Density | 7.8 g/cm³ |
|---|---|
| Magnetic response | Magnetic because the microstructure contains a substantial ferrite fraction. |
| Microstructure | Duplex (austenitic-ferritic) |
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 2205 Stainless Steel are 1.4462 (X2CrNiMoN22-5-3) in the EN system, SUS329J3L in the JIS system, 022Cr23Ni5Mo3N 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 | S32205 / S31803 |
| EN | 1.4462 (X2CrNiMoN22-5-3) |
| JIS | SUS329J3L |
| GB | 022Cr23Ni5Mo3N |
Reference Product Forms & Dimensional Ranges
Common reference product forms for 2205 stainless steel: Sheet / Plate, Pipe / Tube, Bar.
| Finishes | No.1, 2B |
|---|---|
| Plate thickness | 3–60 mm |
| Bar diameter | 10–250 mm |
Common surface and delivery options: No.1, 2B, BA or mechanically polished finish when supported by the product route; Annealed and pickled, descaled or polished tube finish as specified; 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. Confirm the required product form, dimensions, condition, finish and supply route in the quotation.
Typical Applications
- Chemical and cargo tanks
- Desalination and brine systems
- Marine shafts and structures
- Pressure vessels and heat exchangers
- Bridges and load-bearing architecture
2205 Products We Export
Frequently Asked Questions
What are the advantages of 2205 over 316L?
About twice the yield strength (450 vs 170 MPa minimum), much better resistance to chloride pitting and stress-corrosion cracking, and often a lower lifetime cost because sections can be thinner. The trade-offs are harder forming and stricter welding practice.
Is 2205 duplex magnetic?
Partly — the structure is roughly half ferrite, so 2205 attracts a magnet noticeably more than 304/316 but less than a ferritic grade. This is inherent to duplex steel, not a defect.
What is the service temperature range of 2205?
Roughly −50 °C to +300 °C. Above ~300 °C embrittling phases can form during long service, and below −50 °C the ferrite phase loses toughness, so duplex grades are not used for cryogenic or furnace duty.
2205 Compared With Other Grades
Organizational author: Tsingshan (Shandong) Iron & Steel Co., Ltd..Review method, status and limitations.
Other stainless steel grades:
304304L316316L201321310S410430202301309S316Ti347904L409L4204394414442507303317L254 SMO440C17-4 PH2304
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