2304 vs 2205 Stainless Steel
Side-by-side comparison · Composition · Properties · Selection guide
Lean duplex 2304 and standard duplex 2205 both provide high strength and resistance to chloride stress-corrosion cracking. Nickel- and molybdenum-lean 2304 is economical for moderate environments, while 2205 adds molybdenum and nitrogen for a substantial step up in pitting and crevice-corrosion resistance.
Full datasheets:2304 Stainless Steel·2205 Stainless Steel
At a Glance
| 2304 | 2205 | |
|---|---|---|
| Type | Duplex (lean) | Duplex (austenitic-ferritic) |
| UNS | S32304 | S32205 |
| Standard | ASTM A240/A240M | ASTM A240/A240M, A276 |
| Density | 7.75 g/cm³ | 7.8 g/cm³ |
Corrosion Resistance and Service Limits
2304
- 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.
2205
- 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 and Heat Treatment
| Operation | 2304 | 2205 |
|---|---|---|
| Welding | Use a qualified duplex procedure with controlled heat input, interpass temperature and filler to maintain phase balance, toughness and corrosion resistance. | 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. | 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. | 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. | 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. |
Chemical Composition (wt%)
| Element | 2304 | 2205 |
|---|---|---|
| C | ≤0.030 | ≤0.030 |
| Mn | ≤2.50 | ≤2.00 |
| Si | ≤1.00 | ≤1.00 |
| Cr | 21.5–24.5 | 22.0–23.0 |
| Ni | 3.0–5.5 | 4.5–6.5 |
| Mo | 0.05–0.60 | 3.0–3.5 |
| N | 0.05–0.20 | 0.14–0.20 |
| Cu | 0.05–0.60 | — |
| P | ≤0.040 | ≤0.030 |
| S | ≤0.030 | ≤0.020 |
Mechanical Properties
| Property | 2304 | 2205 |
|---|---|---|
| Tensile strength | ≥600 MPa (87 ksi) | ≥655 MPa (95 ksi) |
| Yield strength (0.2%) | ≥400 MPa (58 ksi) | ≥450 MPa (65 ksi) |
| Elongation (50 mm) | ≥25% | ≥25% |
| Hardness | ≤290 HBW | — |
| PREN | — | ≥34 |
Which One Should You Choose?
Choose 2304 for:
- Water tanks, bridges and structural applications
- Moderate chloride exposure beyond 304 capability
- Projects seeking duplex strength with lower alloy cost
- Equipment where 2304 has a documented service history
Choose 2205 for:
- Brackish water and chemical process systems
- Marine splash and more aggressive chloride duty
- Pressure equipment needing broader duplex availability
- Applications where pitting margin justifies molybdenum
Our verdict
2304 is the value duplex for moderate corrosion and strength-driven structures; 2205 is the safer general duplex when chloride concentration, temperature or crevices rise. Do not substitute 2304 into a 2205 specification from strength data alone, because the primary difference is localized-corrosion margin.
Cost and Availability
Compare the current stock position, mill route, minimum production quantity, processing yield, testing and delivered cost for 2304 and 2205 at quotation time. A fixed price ratio would be misleading because product form, size, condition and market timing can change the commercial result.
Do Not Substitute Without Review
Do not replace 2304 with 2205, or the reverse, from the grade name alone. Recheck chemistry, mechanical-property condition, product standard, dimensions, corrosion environment, welding procedure and project approval before substitution.
2304 & 2205 Products We Export
Frequently Asked Questions
Is 2304 as strong as 2205?
Their specified strength is in the same duplex range, though exact minimums vary by product standard and thickness. Corrosion resistance, not headline strength, usually decides.
Why does 2205 resist pitting better?
Its roughly 3% molybdenum and higher nitrogen raise PREN and improve resistance to chloride pitting and crevice attack compared with lean duplex 2304.
Are the welding controls similar?
Both need duplex procedures controlling heat input and interpass temperature. Consumables and qualification must match the exact grade and service requirements.
RFQ
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Technical content updated: 2026-07-29
Organizational author: Tsingshan (Shandong) Iron & Steel Co., Ltd..Review method, status and limitations.