Duplex steel

Duplex steel

Duplex Stainless Steels, also referred to as austenitic-ferritic stainless steels, are a family of grades with about equal proportions of ferrite and austenite. These steels have a duplex microstructure which contributes to their high strength and high resistance to stress corrosion cracking. Due to their high content of chromium, nitrogen and molybdenum, duplex steels offer good resistance to local and uniform corrosion. Duplex stainless steels have good weldability.

DUPLEX 2205 (ASTM A 182, A 240, A 276, A 789, A 790, A 815 UNS S31803, S32205 NACE MR0175)

The duplex 2205 (UNS S31803/32205) grade is the most frequently used duplex grade. The grade generally has a higher corrosion resistance compared to the austenite steels. The grade also has a yield strength, double that of conventional austenitic stainless steels.

The designation 2205 reflects the amounts of chromium (22%) and nickel (5%) in the alloy.The chemical composition range that was first set for SAF 2205 (UNS S31803), was found to be too broad. The composition was modified to optimize corrosion resistance and to avoid inter-metallic phases. The modified version of SAF 2205 (UNS S32205), has a tighter range for chromium, molybdenum and nitrogen in the higher end of the original range.

Because of it's good corrosion resistance, high yield strength and weldability, SAF 2205 is used within a wide range of different industries and applications. In the oil and gas industry duplex 2205 is used in: Pipes, valves, pumps, Xmas trees, bolting, connectors, manifolds and more.

SUPER DUPLEX 2507 (UNS S32750)

Duplex 2507 is a super duplex stainless steel designed for applications which demand exceptional strength and corrosion resistance. Alloy 2507 has 25% chromium, 4% molybdenum, and 7% nickel. This high molybdenum, chromium and nitrogen content results in excellent resistance to chloride pitting and crevice corrosion attack and the duplex structure provides 2507 with exceptional resistance to chloride stress corrosion cracking.

Duplex 2507 possesses excellent mechanical properties. Often a light gauge of 2507 material can be used to achieve the same design strength of a thicker nickel alloy. The resulting savings in weight can dramatically reduce the overall cost of fabrication.

2507 Duplex is highly resistant to uniform corrosion by organic acids such as formic and acetic acid. It is also highly resistant to inorganic acids, Alloy 2507 is highly resistant to carbide-related intergranular corrosion. Due to the ferritic portion of the duplex structure of the alloy it is very resistant to stress corrosion cracking in warm chloride containing environments. Through additions of chromium, molybdenum and nitrogen localized corrosion such as pitting and crevice attack are improved. Alloy 2507 has excellent localized pitting resistance.

Forms Available in

Round Bar, Rod, Plate, Sheet, Flat Bar, Forging, Circles, Scrap



UNS 31803 (F51) and UNS 32205 (F60) 2205. , UNS 31803 (F51) and UNS 32205 (F60) 2205.

  • Thickness : 3mm to 30mm.
  • Width : 1000mm above.
  • Length : 1000mm abve
  • Features
  • Robust and flawless
  • Industry leading prices
  • Highly resistance and durable
  • Application
  • Offshore platforms
  • Fire-fighting systems
  • Injection & ballast water systems
  • Typical chemical composition for duplex stainless steel

    Grade  EN No/UNS Type Approx Composition
          Cr Ni Mo N Mn W Cu
    2101 LDX 1.4162/
     Lean 21.5  1.5 0.3 0.22 5 - -
    DX2202 1.4062/ S32202 Lean 23 2.5 0.3 0.2 1.5 - -
    RDN 903 1.4482/
    Lean 20 1.8 0.2  0.11 4.2 - -


     Lean 23 4.8  0.3  0.10 - - -
    2205 1.4462/
    Standard  22 5.7 3.1 0.17 - - -
    2507 1.4410/
    Super 25 7 4 0.27 - - -
    Zeron 100 1.4501/
    Super 25  7 3.2 0.25 - 0.7 0.7
    Uranus 2507Cu
    Super 25 6.5 3.5 0.25 - - 1.5