ASTM A790 S32205 Duplex Stainless Steel Pipe for Oil Gas Industry

ASTM A790 S32205 Duplex Stainless Steel Pipe for Oil and Gas Industry

ASTM A790 specification covers seamless and straight seam welded ferritic/austenitic steel pipes for general corrosive environments, with particular emphasis on resistance to stress corrosion cracking. Long-term exposure to temperatures above 300°C may lead to brittle phase separation and embrittlement, so high temperature applications need to be carefully evaluated.

S32205 is the material under this standard, which complies with ASTM A790/ASME SA790 standards and is equivalent to European EN 1.4462 (X2CrNiMoN22-5-3). Its chemical composition is shown in the following table.

ASTM A790 S32205 Duplex Stainless Steel Pipe Chemical Composition

ASTM A790 S32205 Duplex Stainless Steel Pipe Key Features and Benefits

• Duplex Microstructure: ASTM A790 S32205 duplex stainless steel pipe is composed of approximately 50% ferrite and 50% austenite. This combines the advantages of both microstructures, maintaining high strength, good stress corrosion cracking resistance, and thermal conductivity, while also maintaining excellent toughness, good ductility, and weldability.
• High Strength: The yield strength and tensile strength of ASTM A790 S32205 duplex stainless steel pipe are significantly higher than those of standard austenitic stainless steels such as 304 and 316L, typically approximately twice as high. This means that at the same design pressure, ASTM A790 S32205 duplex stainless steel pipe can use a thinner wall, reducing weight and material cost.
• Excellent corrosion resistance: Resistance to pitting and crevice corrosion (especially in chloride-containing environments), stress corrosion cracking, and general corrosion (in acids, alkalis, and saline solutions). Good weldability (weldability is good, typically requiring no post-weld heat treatment).

• Good fatigue resistance.

• Good thermal conductivity and low coefficient of thermal expansion: The thermal conductivity and coefficient of thermal expansion of ASTM A790 S32205 duplex stainless steel pipe are between those of carbon steel and austenitic stainless steel.

• Magnetic properties: Due to the presence of a ferrite phase, ASTM A790 S32205 duplex stainless steel pipe exhibits magnetic properties, though weaker than those of ferritic stainless steel.

The yield strength (σ0.2) of ASTM A790 S32205 duplex stainless steel pipe is ≥450 MPa, tensile strength (σb) is ≥655 MPa, elongation (δ) is ≥25%, and hardness is ≤290 HBW. The main advantage of ASTM A790 S32205 duplex steel pipe is that its strength is about twice that of 304/316 austenitic stainless steel, which allows the design of thinner wall thickness and reduces material cost.

ASTM A790 S32205 Duplex Stainless Steel Pipe Mechanical Properties

ASTM A790 S32205 Duplex Stainless Steel Pipe Core application areas

• Oil and gas industry: subsea pipelines, Christmas tree components, acid gas transportation.
• Chemical/petrochemical: heat exchangers, reaction vessels, corrosive fluid pipelines.
• Seawater treatment: desalination equipment, seawater cooling systems.
• Energy and environmental protection: flue gas desulfurization (FGD) systems, geothermal fluid transportation.