The austenitic-ferritic chromium-nickel-molybdenum steel, F51 material / Duplex 2205, is rust and acid resistant. It is characterized by its good corrosion resistance to pitting and surface corrosion. Resistance to seawater is given.
Duplex 2205 magnetic stainless steel has high yield strength, molybdenum addition and low nickel content.
Its particular strength is resistance to stress corrosion.
Duplex 2205 stainless steel is used in construction industry, shipbuilding, food industry, chemical industry, mechanical engineering, seawater desalination plants, offshore and for oil and gas industry. SS steel high pressure pumps.
International identifiers
ASTM A182F51, SUS329J3L, STS329J3LTP, S31803, SS2377, Z3CND22-05Az, 1.4462, Duplex 2205, Alloy 2205
Chemical Composition
Density | Test Method | Test Lab | Result | Reach the standard | |
Apparent Density (g/cm3) | ASTM B212 | AMCP Lab | 4.12 | YES | |
Tap Density (g/cm3) | ASTM B527 | AMCP Lab | 4.82 | YES | |
Chemical Composition (wt%) | Test Method | Test Lab | Expected Result | Tested Results | Reach the standard |
Carbon (C) | C/S Analyzer | AMCP Lab | ≤0.03 | 0.012 | YES |
Chromium (Cr) | ICP-AES | AMCP Lab | 22.00-23.00 | 22.26 | YES |
Nickel (Ni) | ICP-AES | AMCP Lab | 4.50-6.50 | 5.54 | YES |
Molybdenum (Mo) | ICP-AES | AMCP Lab | 3.00-3.50 | 3.17 | YES |
Nitrogen (N) | O/N/H Analyzer | AMCP Lab | 0.14-0.20 | 0.17 | YES |
Iron (Fe) | ICP-AES | AMCP Lab | Balance | Balance | YES |
Silicon (Si) | ICP-AES | AMCP Lab | ≤1.00 | 0.11 | YES |
Manganese (Mn) | ICP-AES | AMCP Lab | ≤2.00 | 0.40 | YES |
Sulphur (S) | ICP-AES | AMCP Lab | ≤0.020 | 0.005 | YES |
Phosphorus (P) | ICP-AES | AMCP Lab | ≤0.020 | 0.0033 | YES |
Oxygen (O) | O/N/H Analyzer | AMCP Lab | -- | 0.024 | YES |
Forging
F51 duplex / AISI 318 must be heated slowly to 1200°C, as it reacts sensitively to thermal shock stresses. With subsequent rapid cooling in air or water, it can be forged in the temperature range between 1200°C – 900°C.
Welding
Weldability of Alloy 2205 is difficult. Working with unsuitable welding parameters can lead to poor results.
Corrosion resistance
Duplex 2205 has excellent corrosion resistance in acid environments, pitting corrosion and chloride-containing media. Against intergranular corrosion and stress corrosion cracking, this stainless steel is strongly superior to austenitic steel grades due to the duplex structure of austenite and ferrite.
Machining
F51 / AISI 318 is machinable only under difficult properties due to the two-phase structure. The machinability allows ideal cutting conditions and are in the smaller range than of austenites. Therefore, it is advisable to use cermet or coated carbide tips.
Duplex Stainless Steel Description by ISSF
Duplex Stainless steels have a structure of half ferrite and half austenite, which means this kind of steel has a body centered cubic crystallographic structure and a face centered cubic crystallographic structure. To achieve this, elements which stabilize the ferrite phase (Cr, Mo, Si, W...) are balanced by elements which stabilize the austenite phase (Ni, N, Mn...). The ferrite/ austenite ratio depends not only on the alloying elements but also on heat treatments.
Duplex stainless steels show high corrosion resistance in a variety of environments like oxidizing industrial solutions, sulphuric acid containing solutions, organic acids, diluted mineral acids and hot alkaline solutions due to the high contents of Cr, Mo and N.
They show an exceptional combination of high strength and good corrosion resistance (Figure 3.1), making it possible to design lighter components and consequentially to decrease the materials and manufacturing costs. This led to the use of duplex stainless steel in applications such as oil and gas, reactors and tanks in the chemical industry, water treatment equipment, desalination plants and heat exchangers.
”Duplex Stainless Steel” by International Stainless Steel Forum
Well-Proportioned PSD
High Sphericity
Low Oxygen Content
Cost Effective
