Super Duplex SS Pipes
ASTM/ASME SA 789 Super Duplex Tubes
Reliable Steel is a leading manufacturer and exporter of ASTM/ASME SA 789 Super Duplex Tubes in mostly countries. We offer best quality ASTM/ASME SA 789 Tubes which is most durable and cost-effective. We fabricated ASTM/ASME SA 789 Tubes in various sizes and lengths. Our Super Duplex ASTM/ASME SA 789 Tubes has magnetic property, yields strength, tensile strength, outstanding durability, high toughness, long-term working ability etc.
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ASTM/ASME SA 789 refers to the standard specification for Super Duplex stainless steel tubing, which is known for its high strength and excellent resistance to corrosion, particularly pitting and stress corrosion cracking. These grades, such as S32750 and S32760, are used in demanding applications like chemical processing, oil and gas, and heat exchangers, especially in chloride-containing environments. The specification covers both seamless and welded tubing and requires a heat-treated condition for most applications.
Key features of ASTM/ASME SA 789 Super Duplex tubing
- Microstructure: Consists of approximately 50% austenite and 50% ferrite, giving it a combination of properties from both stainless steel types.
- Corrosion resistance: Highly resistant to general and localized corrosion, including pitting and crevice corrosion, due to its high chromium, molybdenum, and nitrogen content.
- Strength: Exhibits higher yield and tensile strength compared to standard duplex stainless steels.
- Limitations: Susceptible to embrittlement if used for extended periods at elevated temperatures (above \(300^{\circ }C\)) or in cryogenic applications (below \(-50^{\circ }C\)).
Prperties of ASTM/ASME SA 789 Super Duplex
| Property |
Value |
| Density |
7.8 g/cm³ (0.281 lb/in³) |
| Melting Point |
1350 °C (2460 °F) |
| Minimum Yield Strength |
450 MPa (65 ksi) |
| Minimum Tensile Strength |
655 MPa (116 ksi) |
| Pitting Resistance Equivalent (PREn) |
Typically ≥ 40.0 |
Chemical Composition of ASTM/ASME SA 789 Super Duplex
| Chromium |
Nickel |
Molybdenum |
Nitrogen |
| 24-26% |
6-8% |
3-5% |
Grades covered
UNS S32750 (2507) and UNS S32760 are common grades.
Application
The robust properties of Super Duplex A/SA A789 make it suitable for a variety of demanding industrial applications.
- Chemical Processing Industry
- Oil & Gas
- Marine & Water Systems
- Pulp & Paper Manufacturing
Important Considerations
- Heat Treatment: A solution heat treatment and rapid cooling (water quenching) are mandatory for all A/SA A789 materials to achieve the desired microstructure and mechanical properties.
- Temperature Limits: This material is susceptible to embrittlement if used for prolonged periods at elevated temperatures, with usage typically restricted to applications below 600°F (316°C).
- Corrosion Resistance: The high chromium, molybdenum, and nitrogen content provide superior resistance to pitting, crevice corrosion, and stress corrosion cracking compared to standard duplex and austenitic stainless steels.