UNS S31200 is a duplex stainless steel (DSS) grade, renowned for its excellent combination of corrosion resistance, mechanical strength, and weldability. It is widely specified in various industrial applications where both durability and resistance to harsh environments are critical. Below is a detailed overview of UNS S31200 stainless steel pipes, including their parameters, standards, specifications, equivalent grades, characteristics, and applications.
1. Key Parameters
UNS S31200 stainless steel pipes exhibit the following core material properties, which make them suitable for demanding environments:
2. Applicable Standards
UNS S31200 seamless pipes are primarily manufactured and tested in accordance with ASTM A790, a standard specification for seamless and welded ferritic/austenitic duplex stainless steel pipe. This standard defines requirements for:
- Chemical composition
- Mechanical properties (tensile strength, yield strength, elongation)
- Dimensional tolerances
- Non-destructive testing (e.g., ultrasonic testing, hydrostatic testing)
- Surface finish
3. Specifications
UNS S31200 seamless hollow tubes are available in a range of specifications to meet diverse industrial needs:
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Dimensions:
- Outer Diameter (OD): Typically from 6 mm (0.25 inches) to 610 mm (24 inches), with custom sizes available.
- Wall Thickness (WT): From 0.5 mm (0.02 inches) to 50 mm (2 inches), depending on OD and application requirements.
- Length: Standard lengths include 6 meters (20 feet) or 12 meters (40 feet); cut-to-length options are also offered.
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Surface Finish:
- Annealed and pickled (AP): For general applications, providing a clean, corrosion-resistant surface.
- Polished: Optional (e.g., 2B, BA finishes) for applications requiring enhanced hygiene or aesthetics.
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End Connections:
- Plain ends (PE)
- Beveled ends (for welding)
- Threaded ends (per ASTM A530 or customer specifications)
4.Equivalent Grades of UNS S31200 Stainless Steel
UNS S31200 is known by different designations across international standards. Its key equivalents include:
- European Standard (EN): 1.4462
- ISO: X2CrNiMoN25-7-4
- Japanese Industrial Standard (JIS): SUS 329J4L
- Chinese Standard (GB): 022Cr25Ni7Mo4N
5. Characteristics
UNS S31200 stainless steel pipes offer a unique set of advantages, making them preferred in challenging environments:
6. Applications
Due to their robust properties, UNS S31200 seamless pipes are widely used in industries requiring resistance to corrosion and high strength:
- Marine Engineering: Seawater intake systems, desalination plants, offshore oil and gas platforms.
- Chemical Processing: Piping for handling acids, alkalis, and corrosive chemicals.
- Oil and Gas Industry: Downhole tubing, flowlines, and offshore pipeline components.
- Water Treatment: Piping in wastewater treatment plants and industrial water systems.
- Power Generation: Cooling water systems in thermal and nuclear power plants.
In summary, ASTM A790 UNS S31200 seamless stainless steel pipes are a reliable choice for applications demanding a balance of corrosion resistance, strength, and cost-effectiveness, making them a staple in harsh industrial environments
