Stainless Steel Duplex Type 2205
2205 stainless steel (UNS S31803 and/or S32205) is a nitrogen-enhanced duplex stainless steel alloy and is the most widely used of the duplex stainless steels. The nitrogen serves to significantly improve the corrosion resistance of the alloy, especially in the welded condition. To impart the metallurgical benefits of nitrogen to both improved corrosion performance and as-welded properties, 2205 stainless steel can be produced to a 0.15% minimum nitrogen content compared to the ASTM range of 0.08-0.20% for S31803 and 0.14-0.20% for S32205. The minimum Cr, Mo and Ni contents of 2205 (22.0, 3.1 and 5.5% respectively) can satisfy the requirements of both the UNS S31803 and S32205 composition specifications.
When heat-treated properly, the composition of 2205 stainless steel produces a microstructure that consists of a nearly equal mixture of austenitic and ferritic phases. The microstructure and composition of 2205 provides corrosion resistance to many environments that is superior to Types 316 or 317, and a minimum yield strength that is more than double that of conventional austenitic stainless steels.
Choosing the Right Material for Your Application
Read our blog: Duplex 2205 vs 316 Stainless Steel
Stainless Duplex Type 2205 Chemical Composition
Chemical Composition (wt%) limits as specified in ASTM A276 and ASME SA276*
| Element | S31803 | S32205 |
| Carbon | 0.030 | 0.030 |
| Chromium | 21.0-23.0 | 22.0-23.0 |
| Nickel | 4.5-6.5 | 4.5-6.5 |
| Molybdenum | 2.5-3.5 | 3.0-3.5 |
| Manganese | 2.00 | 2.00 |
| Silicon | 1.00 | 1.00 |
| Nitrogen | 0.08-0.20 | 0.14-0.20 |
| Phosphorus | 0.030 | 0.030 |
| Sulfur | 0.020 | 0.020 |
*Maximum, unless range is indicated
Stainless Duplex Type 2205 Physical Properties
| Density, lb/in3 | 0.285 |
| Modulus of Elasticity, psi | 27.5 x 106 |
| Coefficient of Thermal Expansion, 68-212˚F, /˚F | 7.6 x 10-6 |
| Thermal Conductivity, Btu/ft hr ˚F | 11 |
| Specific Heat, Btu/lb ˚F | 0.10 |
| Electrical Resistivity, Microhm-in | 31.5 |
Stainless Duplex Type 2205 Mechanical Properties
Mechanical property requirements for annealed product as specified in ASTM A276 and ASME SA276
| Property | S31803 | S32205 |
| Yield Strength, min. (ksi) | 65 | 65 |
| Tensile Strength, min. (ksi) | 90 | 95 |
| Elongation, min. (%) | 25 | 25 |
| Hardness, max. (HBW) | 290 | 290 |
Stainless Duplex Type 2205 Standards
Typical standards for Type 2205
| ASTM A276 |
| ASTM A479 |
| ASME SA276 |
| ASME SA479 |
Your Source for Stainless Duplex Type 2205
At Double Eagle Alloys, we supply Stainless Duplex Type 2205 in long bar, flanges, pipe, sheet, gaskets, fittings and header plugs engineered for these demanding services. Contact our team to learn how Stainless Duplex Type 2205 can support long-term performance and reliability.
Questions? We’d love to help. Contact us today to discuss your needs or to check current availability.
Contact Us
Data shown are typical and provided for informational purposes only. Values should not be considered minimums or maximums for specification or final design. Actual product data may vary, and information may be revised without notice.