Super Duplex

Super Duplex from Special Piping Materials

DUPLEX 2205

Duplex 2205 products are a staple in Special Piping Materials’ inventory. So, what is Duplex 2205?

Duplex 2205 (UNS S32305/S31803) is an austenitic and ferritic stainless steel.  It is made up of 22% chromium, 3% molybdenum, 5-6% nickel, and can be described as a nitrogen alloyed duplex stainless steel.

It combines the favourable qualities of both ferritic and austenitic stainless steels. This means it has superior pitting and crevice corrosion resistance, as well as high strength, ease of fabrication and stress corrosion cracking resistance.

Duplex 2205 is also characterised by excellent impact toughness and yield strength, as well as lower thermal expansion and higher thermal conductivity than purely austenitic metals, like stainless steel 316.

Duplex 2205 stainless steel is often used as a cost-effective solution for many applications. Its resistance chloride pitting, and crevice corrosion means it is a very important metal for services such as marine environments, brackish water, bleaching operations, closed loop water systems and some food processing applications.

Duplex 2205 properties

The properties of Duplex 2205 include:

• High resistance to chloride stress corrosion cracking
• Resistance to chloride pitting and crevice corrosion
• Good general corrosion resistance
• Good sulphide stress corrosion resistance
• High Strength
• Good weldability and workability

In regard to working at extremes of temperature, at low temperatures duplex stainless steels are known to have better ductility than the ferritic and martensitic grades which means that duplex grades of stainless steel are widely used down to at least -50°C. At the other end of the spectrum, the highest working temperature for duplex is 300°C as the high chromium content of duplex stainless steels that protects against corrosion, causes embrittlement at temperatures over that.

Although duplex 2205 is machinable, its high strength could make machining difficult. As an example, machining of 2205 is around 20% slower than for stainless steel 304.

Duplex 2205 applications

Some of the applications of duplex 2205 are as follows:

• Pressure vessels, tanks, piping, and heat exchangers in the chemical processing industry
• Chemical process vessels
• Pulp and paper mill industry digesters, bleaching equipment, and stock-handling systems
• Food processing equipment
• Biofuels plants
• Cargo tanks for ships and trucks
• Effluent scrubbing systems
• Flue gas desulfurization equipment
• Oil and gas exploration and offshore rigs
• Oil and gas refining
• field piping and heat exchangers
• Marine environments
• Cargo tanks for ships and trucks

Duplex 2205 products available from Special Piping Materials

• Sheet
• Plate
• Bar
• Pipe, seamless & welded (The 2205 Duplex Stainless Pipe produced in accordance to ASTM A790 specification could be created by either a seamless construction or an automatic welding process.
• Fittings (i.e., flanges, slip-ons, blinds, weld-necks, lap-joints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)

To discuss the price of duplex 2205 products, and to find out more about our competitive pricing and specialist services, please contact the Special Piping Materials sales team at one of our offices around the globe: https://specialpipingmaterials.com/contact/

Duplex 2205 ASTM specifications

The Duplex 2205 ASTM specifications are as follows:

• • Pipe seamless: A790
  • Pipe welded: A928
  • Sheet/Plate: A240
  • Bar: A276
  • Flanges & Forgings: A182
  • Buttweld fittings: A815