ASTM A790 Pipes

Super Duplex SS Pipes

Super Duplex A/SA A790 pipes

Reliable Steel is a leading manufacturer and exporter of ASTM/ASME SA 790 Super Duplex Pipes in mostly countries. We offer best quality ASTM/ASME SA 790 pipes which is most durable and cost-effective. We fabricated ASTM/ASME SA 790 pipes in various sizes and lengths. Our Super Duplex ASTM/ASME SA 790 pipes has magnetic property, yields strength, tensile strength, outstanding durability, high toughness, long-term working ability etc.

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Super Duplex A/SA A790 pipes are a type of seamless or welded pipe made from a super duplex stainless steel alloy (often UNS S32750 or UNS S32760) that combines high strength with excellent corrosion resistance. This is achieved through a unique duplex microstructure and high concentrations of chromium, molybdenum, and nitrogen, making them ideal for demanding industrial applications like chemical processing, offshore oil and gas, and seawater systems.


Key Characteristics, Properties & Composition

Characteristics

  • Material: Super duplex stainless steel, such as grades UNS S32750 and UNS S32760.
  • Microstructure: A two-phase mixture of austenite and ferrite, providing a combination of high strength and corrosion resistance.
  • Composition: A high alloy content, including 25% chromium, 4% molybdenum, and 7% nickel.
  • Corrosion resistance: Excellent resistance to chloride-ion stress corrosion cracking, pitting, crevice corrosion, and general corrosion.
  • Mechanical properties: High mechanical strength (up to twice that of austenitic steels) and good ductility.

Properties of ASTM/ASME SA 790 Super Duplex

Super Duplex A/SA A790 pipes feature a mixed microstructure of austenite and ferrite, which provides high mechanical strength and excellent resistance to localized corrosion.

Property Value
Density 7.8 g/cm³ (0.281 lb/in³)
Minimum Yield Strength 550 MPa (80 ksi)
Minimum Tensile Strength 800 MPa (116 ksi)
Pitting Resistance Equivalent (PREn) Typically ≥ 40.0

Composition of ASTM/ASME SA 790 Super Duplex

Chromium Nickel Molybdenum Nitrogen
24.0–26.0% 6.0–8.0% 3.0–5.0%  

Application

The A/SA A790 super duplex pipes are used in harsh environments where conventional stainless steels fail.

  • Oil & Gas Industry
  • Chemical Processing
  • Marine & Desalination
  • Pulp & Paper Manufacturing

Manufacturing and Forms

A/SA A790 pipes are produced as seamless or by an automatic welding process without the use of a filler metal. They undergo mandatory solution annealing and rapid cooling to ensure optimal mechanical properties and microstructure.

  • Forms: Available in various shapes, including round, square, rectangular, and "U" shaped tubes.
  • Sizes: Seamless pipes typically range from 1/2" NB to 8" NB, while welded pipes can be available in larger diameters.
  • Testing: Non-destructive electric tests (Eddy Current or Ultrasonic) and hydrostatic tests are performed to confirm product integrity.