Duplex 2205 vs SUS304: Strength & Durability Comparison

Strength Comparison

Yield Strength: 2205 is nearly double that of 304 (e.g., 450-550 MPa for 2205 vs. ~205 MPa for 304).

Tensile Strength: 2205 has much higher tensile strength (620-750 MPa) compared to 304 (515 MPa).

Fatigue: 2205 performs better under fatigue stress.

Hardness: 2205 is harder (approx. 290 HB) than 304 (approx. 170 HB).

Durability & Corrosion Resistance

Pitting/Crevice Corrosion: 2205 offers superior resistance, particularly in chloride-rich environments, unlike 304, which is more vulnerable.

General Corrosion: Both offer good resistance, but 2205's higher chromium content provides enhanced protection.

Applications: 2205 is ideal for harsh offshore/chemical settings; 304 is suitable for food processing, kitchenware, and general architectural use.

Other Key Differences

Microstructure: 304 is austenitic; 2205 is a dual-phase (ferrite + austenite) structure.

Cost: 2205 is generally more expensive than 304.

Temperature: 304 has superior plastic toughness, but 2205 isn't recommended above 300°C or below -50°C.

Conclusion

Choose 2205 for applications needing maximum strength, fatigue resistance, and superior pitting/crevice corrosion protection (e.g., structural components, chemical processing). Choose 304 for general-purpose use, good corrosion resistance in milder conditions, and when cost and superior plastic toughness are priorities (e.g., utensils, food equipment).