Seamless Duplex Tubes conforming to SA789-S31803 are typically made of a duplex stainless steel grade known as S31803, which is also referred to as 2205 stainless steel. These tubes are characterized by their excellent corrosion resistance, high strength, and good weldability, making them suitable for various applications in industries such as oil and gas, chemical processing, and marine engineering.
1. Seamless Duplex Tube SA789-S31803 Standard Specification:
SA789-S31803 seamless duplex pipe generally complies with one of the following standard specifications:
- ASTM A789/A789M: "Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service"
2. Seamless Duplex Tube SA789-S31803 Chemical Composition (Typical Values, %):
|
Element
|
Maximum Value
|
|
Chromium (Cr)
|
22.0-23.0
|
|
Nickel (Ni)
|
4.50-6.50
|
|
Molybdenum (Mo)
|
3.00-3.50
|
|
Manganese (Mn)
|
2.00
|
|
Silicon (Si)
|
1.00
|
|
Phosphorus (P)
|
0.030
|
|
Sulfur (S)
|
0.020
|
|
Carbon (C)
|
0.030
|
|
Nitrogen (N)
|
0.08-0.20
|
|
Iron (Fe)
|
Balance
|
These constituents ensure the pipe has a duplex structure, providing excellent corrosion resistance and mechanical properties.
3. Seamless Duplex Tube SA789-S31803 Physical Properties:
- Density: Approximately 7.8 g/cm³, making it relatively lightweight for engineering applications.
- Melting Point: Around 1400°C, indicating stability at high temperatures.
- Thermal Conductivity: Approximately 14.2 W/(m·K), showing good heat conduction for high-temperature applications.
- Coefficient of Thermal Expansion: About 11.2 × 10^-6 /K (20°C to 100°C), indicating minimal linear expansion with temperature changes.
4. Seamless Duplex Tube SA789-S31803 Mechanical Properties:
- Yield Strength: At least 450 MPa, indicating the onset of plastic deformation under external forces.
- Tensile Strength: At least 620 MPa, indicating the maximum stress the pipe can withstand under tension.
- Elongation: At least 25%, indicating good ductility to prevent fracture to a certain extent.
- Hardness: Approximately 190 HB, indicating moderate hardness, resistant to deformation or damage.
These properties make SA789-S31803 perform exceptionally well under high pressure and temperature.
5. Seamless Duplex Tube SA789-S31803 Manufacturing Process:
- Material Selection: Select raw materials that meet chemical composition standards to ensure the quality of the pipe.
- Heat Treatment: Perform solution annealing and rapid cooling to eliminate cold work hardening and improve material toughness and stability.
- Processing Techniques: Employ hot rolling, cold drawing, and other processes to produce pipes.
- Testing and Quality Control: Conduct quality inspection of pipes using non-destructive testing methods to ensure compliance with standards.
6. Seamless Duplex Tube SA789-S31803 Applications:
- SA789-S31803 seamless duplex pipes are widely used in chemical, petroleum, natural gas, marine engineering, and food processing industries for high-temperature and high-pressure pipelines, equipment, and structures.
- They excel in marine environments, offering outstanding corrosion resistance and are suitable for marine platforms, pipelines, and structures.
- In the food processing industry, SA789-S31803 seamless duplex pipes are extensively used in processing equipment and pipelines due to their excellent corrosion resistance and hygiene.
Seamless Duplex Tube SA789-S31803 |
