SAF Duplex 2205 Stainless Steel (UNS S32205 S31803) Alloy Material
SAF Duplex 2205 stainless steel (UNS S32205 formerly known as UNS S31803 and commonly known as “alloy 2205”) has a mixed microstructure of austenite and ferrite, and is a two-phase alloy based on the Fe-Cr-Ni series. Alloy 2205 material has lower nickel and molybdenum contents than austenitic stainless steel and have similar corrosion resistance. Because the price of Ni and Mo is relatively high, duplex stainless steel 2205 is often regarded as a cost-effective alternative to austenitic stainless steel.
Compared with the conventional 300 series stainless steel (e.g. SS 304, SS 316, SS 301, SS 904L, and 303, etc.), the special advantages of duplex 2205 stainless steel are strength (about twice that of austenitic stainless steel), and excellent resistance to chloride SCC and pitting corrosion. High yield strength has sufficient pressure and load capacity, and thin-wall materials can be made to greatly reduce weight.
Duplex 2205 Data Sheet & Specification
The following tables show SAF 2205 duplex stainless steel datasheet and specifications, such as chemical composition, physical properties, mechanical properties, heat treatment, welding, etc.
The following table lists alloy 2205 stainless steel chemical composition based on cast analysis.
|Chemical Composition, %|
|Country||Steel Grade (UNS)||Standard||C, ≤||Si, ≤||Mn, ≤||P, ≤||S, ≤||Cr||Ni||Mo||N|
|US||2205 (UNS S32205, UNS S31803)||ASTM A276/A276M; ASTM A240/A240M||0,030||1,00||2,00||0,030||0,020||22.0-23.0||4,5-6,5||3.0-3.5||0.14-0.20|
- 1 g/cm3 = 1 kg/dm3 = 1000 kg/m3;
- 1 μΩ·m = 1 Ω·mm²/m
- 1 GPa = 1 kN/mm2
|Density, g/cm3 (lb/in3)||7,83 (0.283)|
|Melting point, ℃ (°F)||1385-1440 (2525-2630)|
|Electrical resistivity, μΩ·m||0,85 (20 ℃) (68 °F)|
|0,90 (100 ℃) (212 °F)|
|0,95 (200 ℃) (392 °F)|
|1,0 (300 ℃) (572 °F)|
|Specific heat capacity, J/(kg·K)||470 (20 ℃) (68 °F)|
|500 (100 ℃) (212 °F)|
|530 (200 ℃) (392 °F)|
|560 (300 ℃) (572 °F)|
|Thermal conductivity, (W/m·K)||15,0 (20 ℃) (68 °F)|
|15,9 (100 ℃) (212 °F)|
|17,0 (200 ℃) (392 °F)|
|18,0 (300 ℃) (572 °F)|
|Modulus of elasticity, Gpa||190 (20 ℃) (68 °F)|
|180 (100 ℃) (212 °F)|
|175 (200 ℃) (392 °F)|
|171 (300 ℃) (572 °F)|
|Mean coefficient of thermal expansion, (10-6/K)||13,5 (20-100 ℃) (68 °F – 212 °F)|
|14.0 (20-200 ℃) (68 °F – 392 °F)|
|14.6 (20-300 ℃) (68 °F – 572 °F)|
Duplex 2205 stainless steel mechanical properties at room temperature in various conditions and resistance to intergranular corrosion, including yield strength, tensile strength, and hardness, etc.
|Country (Region)||Standard||AISI Type (UNS)||0.2% proof strength, MPa (ksi), ≥||Tensile strength, MPa (ksi), ≥||Elongation in 50mm (2 in.), %, ≥||Brinell Hardness (HBW), ≤||Rockwell Hardness (HRC), ≥||Condition & Finish|
|US||ASTM A276/A276M||2205 (UNS S32205, UNS S31803)||450 (65)||655 (95)||25||290||–||Annealed, hot-finished or cold-finished|
|ASTM A240/A240M||450 (65)||655 (95)||25||293||31||–|
SAF Duplex 2205 Stainless Steel Heat Treatment
Recommended annealing temperature for duplex 2205 stainless steel is 1040 ℃ (1900 °F), cooling from the annealing temperature must be rapid, water quenching is preferred, but it must also meet the limits of deformation. This treatment is suitable for full solution annealing and stress relief annealing.
Alloy 2205 material hot forming temperature range is 1200-955 °C (2190-1750°F). It is recommended to perform a full annealing with rapid cooling after hot forming, preferably water quenching.
Due to its higher strength, the force required for cold forming of alloy SAF 2205 is greater than the typical force of austenitic stainless steel. Full annealing and quenching are recommended after severe cold forming.
SS 2205 duplex can be welded by all common welding processes (except gas welding), such as MMA/SMAW, MIG/GMAW, TIG/GTAW, FCAW, SAW and PAW, and can be welded to carbon steels, low alloy steels or austenitic stainless steels, filler metal can be duplex, super duplex, E2209, E2594, 309L or 309LMo.
- The maximum interpass temperature is 150°C (300°F),
- Preheating is not necessary,
- and postweld heat treatment is not recommended, if necessary, should be done at 1040°C (1900°F) minimum, followed by rapid cooling.
The high strength makes SAF 2205 stainless steel difficult to machine and therefore requires powerful machines and very strong tool supports. Cutting speed should be reduced by about 20% than the typical type 316L Cutting speed.
Alloy 2205 (UNS S31803, S32205) has much better corrosion resistance than stainless steel 304 and SS 316, such as excellent pitting resistance (PREN = 30.5), superior resistance to chloride SCC, and resistance to abrasion.
The maximum temperature for duplex 2205 stainless steel applications is generally below 300 °C (570 °F), because the high alloy content and the presence of a ferrite matrix make it susceptible to embrittlement and reduced mechanical strength, especially toughness, due to prolonged exposure to high temperatures.
Uses and Applications
Duplex 2205 stainless steel has been widely used in many industries, especially the oil and gas, petrochemical and pulp and paper industries. They are typically used in aqueous, chloride-containing environments and as a substitute for austenitic stainless steels, which are subject to chloride SCC or pitting during use.
SAF Duplex 2205 Equivalent Grade
SAF Duplex 2205 stainless steel (UNS S32205, formerly UNS S31803) equivalent to ASTM AISI SAE, ISO, European (German DIN, British BSI, France NF), Japanese JIS and Chinese GB standard (for reference).
|Duplex 2205 equivalent grade|
|Standard||Grade (UNS)||Standard||Steel Name (Material Number)||Standard||Grade (ISO number )||Standard||Grade (UNS)||Standard||Grade|
|Duplex 2205 (UNS S32205); UNS S31803||EN 10088-2;|
|X2CrNiMoN22-5-3 (1.4462)||ISO 15510||X2CrNiMoN22-5-3 (4462-318-03-I)||GB/T 1220;|
|022Cr22Ni5Mo3N (S22293)||JIS G4303; JIS G4304; JIS G4305||SUS329J3L|