Duplex Steel

• Item Code: SA479

• UNS S31803, S32205
• EN Number 1.4462
• EN Name X2CrNiMoN 22-5-3
• W.Nr. 1.4462
• DIN X2CrNiMoN 22 5 3
• SS 2377
• AFNOR Z2.CND22.05.03

2205 is a duplex (austenitic-ferritic) stainless steel characterized by:

• High resistance to stress corrosion cracking (SCC) in chloride-bearing environments
• High resistance to stress corrosion cracking (SCC) in environments containing hydrogen sulfide
• High resistance to general corrosion, pitting, and crevice corrosion
• High resistance to erosion corrosion and corrosion fatigue
• High mechanical strength - roughly twice the proof strength of austenitic stainless steel
• Physical properties that offer design advantages
• Good weldability

Duplex Steel Pipes and Tubes
Duplex is a material that has approximately equal amounts of austenite and ferrite. These combine excellent corrosion resistance with high strength. Mechanical properties are approximately double those of singular austenitic steel and resistance to stress corrosion cracking is superior to type 316 stainless steel in chloride solutions. Duplex material has ductile or brittle transition at approximately -50 degrees. High Temperature use is usually restricted to a maximum temperature of 300 degrees for indefinite use due to embrittlement.
Duplex stainless steels have a mixed microstructure of austenite and ferrite, the aim being to produce a 50/50 mix, although in commercial alloys, the mix may be 40/60 respectively. Duplex steels have improved strength over austenitic stainless steels and also improved resistance to localised corrosion, particularly pitting, crevice corrosion and stress corrosion cracking. They are characterised by high chromium (19-28%) and molybdenum (up to 5%) and lower nickel contents than austenitic stainless steels. The most used Duplex Stainless Steel are the 2205 (22% Chromium, 5% Nickel) and 2507 (25% Chromium, 7% Nickel); the 2507 is also known as "Super Duplex" due to its higher corrosion resistance.
Super Duplex
Super duplex pipe is known to have better stress corrosion, cracking resistance and mechanical properties. The high corrosion resistance of super duplex pipeline supplies makes them ideal for onshore and offshore environments in oil and gas applications. Please see our industry pages for more information regarding the implications of Super Duplex piping. Super Duplex is an Austenitic Ferritic Iron Chromium - Nickel Alloys with Molybdenum addition. It has good resistance to pitting and a very high tensile strength and high resistance too stress corrosion cracking at moderate temperatures compared to that of conventional austenitic stainless steels.

Carbon steels:

• A105, A266 Cl1 to Cl4, SA765 Gr.2
• A372 Gr.A / Gr.B
• A350 LF2 Cl1 to Cl3 for low temperature service
• A516 Gr.60 and Gr.70
• S45C
• A738C / S355J2 / 1.0577

Alloy steels (for machine building)

• 42CrMo4 (Q+T) / AISI 4140 / DIN EN 1.7225
• 25CrMo4 /AISI 4130 / DIN EN 1.7213
• 34CrNiMo6 /AISI 4340/ DIN EN 1.6582
• AISI 8660 Tripel Alloy Steel

High strength /high yield carbon steels

• A694 F42, F45, F52, F55, F60, F65, F70

Austenitic stainless steels

• A182 F304 / 304L (UNS S30403), F310 (UNS S31000)
• A182 F316/316L (UNS S31603), F316Ti, F317/317L (UNS S31703)
• A182 F321 (UNS S32100), F347 (UNS S34700)
• A182 F44 (254SMO), 904L (UNS N08904)
• 17-4 PH, 15-5 PH (SUS 630)

Ferritic stainless steels

• A182 F429, F430, F440A

Martensitic stainless steels

• A182 F6a, A182 F6NM

Low alloy steels

Ferritic alloy steel forgings for high-pressure and high-temperature parts, such as boilers and pressure vessels.

• A182 / A336 F1, F5, F9, F91, F92
• A182 / A336 F11, F12, F22, F23
• A508 Cl.2 / Cl.3

Duplex and superduplex

• A182 F51 (UNS S31803), A182 F60, F53 (UNS S32750)

Nickel alloys

• Alloy 20, Alloy 59, Alloy 400, Alloy 625, Alloy 800/800H/800HT, Alloy 825