Stainless Steel Pipe Fittings

1.4410 2507 S32750 Super Duplex Stainless Steel By

Written by
1.4410 2507 S32750 Super Duplex Stainless Steel By

2507 S32750 Super Duplex Stainless Steel is super duplex stainless steel with 25% chromium, 4% molybdenum, and 7% nickel designed for demanding applications which require exceptional strength and corrosion resistance, such as chemical process, petrochemical, and seawater equipment. The steel has excellent resistance to chloride stress corrosion cracking, highthermal conductivity, and a low coefficient of thermal expansion. 

Super duplex stainless steel grades have enhanced pitting and crevice corrosion resistance when compared with 300-series austeniticstainless steel or conventional duplex alloys. This can be attributed to the enhanced levels of chromium, molybdenum and nitrogen found in these materials. Alloy 2507 is the most common “super” duplex grade.

Usage of Super Duplex 2507 should be limited to applications below 6000 F (3160 C). Extended elevated temperature exposure can reduce both the toughness and corrosion resistance of alloy 2507.The high chromium, molybdenum, and nitrogen levels provide excellent resistance to pitting, crevice, and general corrosion.the duplex structure provides 2507 with exceptional resistance to chloride stress corrosion cracking. 

Super 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 saving in weight can reduce the overall cost of fabrication.

Super Duplex Stainless Steel Corrosion Resistance, The high chromium and molybdenum content of Super Duplex Stainless Steelmakes it extremely resistant to uniform corrosion by organic acids like formic and acetic acid. Super Duplex also provides excellent resistance to inorganic acids, especially those containing chlorides.

High resistance to chloride stress corrosion cracking
•High Strength
•Superior resistance to chloride pitting and crevice corrosion 
•Good general corrosion resistance
•Suggested for applications up to 6000 F
•Low rate of thermal expansion
•Combination of properties given by austenitic and ferritic structure
•Good weldability and workability 

2507 S32750 Super Duplex Stainless Steel Applications: 

  • 2507 S32750 Super Duplex Stainless Steel tubes and 2507 S32750 Super Duplex Stainless Steel pipes for production and handling of gas and oil,
  • 2507 S32750 Super Duplex Stainless Steel Pipes in desalination plants,
  • Mechanical and structural components,
  • Power industry FGD systems,
  • 2507 S32750 Super Duplex Stainless Steel Pipes in process industries handling solutions containing chlorides,
  • Utility and industrial systems, rotors, fans, shafts and press rolls where the high corrosion fatigue strength can be utilized,
  • Cargo tanks, vessels, piping and welding consumables for chemical tankers.
  • High-strength, highly resistant wiring.

  • Super Duplex Stainless Steels and their characteristics
    (1.4410) UNS S32750 2507 Super Duplex Stainless Steel
     Elbow 90 Degree

    S32205 S31803(1.4462) Duplex Stainless Steel Pipes
    S32304 (1.4362) Duplex Stainless Steel Pipes

    Product Information for 2507 S32750 Super Duplex Stainless Steel Pipes

    Sizes Standard Tolerances
    Products OD Wall Lengths and/or coils Grades OD Wall Lengths
    Pressure &Corrosion Tubing

    Meets or exceeds requirements forwelded

    Specification: ASTM-A789

    1/16″ (1.59 mm) to 4″ (101.6 mm)

    Metric sizes available

    0.010″ (0.25 mm) to 0.220″ (5.59 mm) Random or cut lengths up to 40′ (12.2 m)

    Coils to 1-1/2″ OD

    Super Duplex 2507
    <1-1/2″ (38.1 mm) ±0.005″ (0.13 mm)
    1-1/2″ (38.1 mm) to 3″ (76.2 mm) ±0.010″ (0.25 mm)
    3-1/2″ (88.9 mm) to 4″ (101.6 mm) ±0.015″ (0.38 mm)
    ±10% Randoms up to +2″ (50.8 mm)

    Cuts +1/8″ (3 mm) -0″

    Coils to 80,000′ (24,384 m)

    Subsea Umbilical Tubing

    Specifications: ASTM-A789 and ASTM-A790

    3/8″ (9.53 mm) to 1-1/2″ (38.1 mm) 0.039″ (0.99 mm) to 0.125″ (3.18 mm) Cut lengths to 60′ (18.3 m)

    Coils to 1-1/2″ OD*

    Super Duplex 2507 ±0.005″ (0.127 mm) ±10% Coils to 80,000′ (24,384 m)

    Physical Properties of 2507 S32750 Super Duplex Stainless Steel Pipes in the Annealed Condition at -20°F to +100°F

          Tensile Strength Yield Strength            
    Alloy UNS Spec. psi MPa ksi psi MPa ksi Elongation in 2 in. (min.) % Grain Size Req. Max. Hardness Modulus of Elasticity (x106 psi) Mean Coefficient of Thermal Expansion (IN./IN./°F x 10-6) Thermal Conductivity (BTU-in/ ft2-h-°F)
    Super Duplex 2507 S32950 A789,A790 100,000 690 100 70,000 485 70 20 30.5 Rc
    Super Duplex 2507 S32750 A789, A790 116,000 800 116 80,000 550 80 15 32 Rc 27.5 7.2 98

    Composition of 2507 S32750 Super Duplex Stainless Steel Pipes

    Grade Super Duplex 2507
    UNS Designation S32750
    Carbon (C) Max. 0.030
    Manganese (Mn) Max. 1.20
    Phosphorous (P) Max. 0.035
    Sulphur (S) Max. 0.020
    Silicon (Si) Max. 0.80
    Chromium (Cr) 24.0–26.0
    Nickel (Ni) 6.0–8.0
    Molybdenum (Mo) 3.0–5.0
    Nitrogen (N) 0.24–0.32
    Iron (Fe) Bal.
    Copper (Cu) 0.50
    Other Elements

    Super Duplex 2507 Product Range

    Alloy UNS Designation Werkstoff NR. Specifications*
    Super Duplex 2507 S32750 1.4410 A/SA789, A/SA790

    *Note: The specifications noted including ASTM, ASME, or other applicable authorities are correct at the time of publication. Other specifications may apply for use of these materials in different applications.

    Source: Zhejiang Yaang Pipe Industry Co., Limited (

    Article Categories:
    Duplex Stainless Steel

    Leave a Comment

    Your email address will not be published. Required fields are marked *