Comparison of Stainless Steel Grades
| Property | 304 | 310 | 316 | 321 | 347 | 2205 (Duplex) | 2507 (Super Duplex) |
| Composition | 18% Cr, 8% Ni | 25% Cr, 20% Ni | 16% Cr, 10% Ni, 2% Mo | 18% Cr, 10% Ni, Ti stabilized | 18% Cr, 10% Ni, Nb stabilized | 22% Cr, 5% Ni, 3% Mo, N | 25% Cr, 7% Ni, 4% Mo, N |
| Corrosion Resistance | Good in general environments | Moderate, especially at high temps | Superior, especially to chlorides | Good, resistant to intergranular corrosion | Excellent, similar to 321 but Nb-stabilized | Excellent, high pitting and crevice resistance | Outstanding, extreme pitting and crevice resistance |
| High-Temp Performance | Up to 870°C (1600°F) | Up to 1150°C (2100°F) | Up to 870°C (1600°F) | Up to 870°C (1600°F), stabilized | Up to 870°C (1600°F), stabilized | Up to 300°C (572°F) | Up to 300°C (572°F) |
| Oxidation Resistance | Moderate | Excellent | Good | Moderate | Moderate | Moderate | Moderate |
| Strength | Moderate | Moderate | Moderate | Moderate | Moderate | High | Very High |
| Weldability | Excellent | Good | Excellent | Good (needs heat stabilization) | Good (needs heat stabilization) | Moderate (due to high strength) | Moderate (requires expertise) |
| Pitting Resistance | Low (not suitable for chlorides) | Low | High | Moderate | Moderate | Very High | Outstanding |
| Cost | Affordable | High | Moderate | Moderate | Moderate | High | Very High |
Apr 7, 2025
