| Property | Value | Significance in Applications |
| Tensile Strength | ≥95 ksi (655 MPa) | Enables use in high-pressure systems, reducing wall thickness requirements. |
| Yield Strength | ≥65 ksi (450 MPa) | Ensures structural integrity under sustained loading without permanent deformation. |
| Elongation at Break | ≥25% | Provides ductility for forming, bending, and resistance to impact loads. |
| Hardness (HBW) | ≤290 | Balances wear resistance with machinability for fabrication and installation. |
| Impact Toughness | ≥40 J/cm² at 20°C | Maintains fracture resistance in low-temperature environments like LNG processing. |
Manufacturing & Quality Control
Process Flow:
Hot-rolling of billets into hollow shells
Cold-drawing or extrusion for dimensional precision
Annealing to restore ductility and uniform microstructure
Pickling to remove scale and expose a clean surface
Surface Treatments:
Pickled & Annealed (standard): Removes oxidation products, ideal for general corrosion resistance.
Polished (Ra ≤0.8μm): Enhances hygienic properties for pharmaceutical/food applications.
Bright Annealed: Maintains a lustrous surface via controlled atmosphere heating, minimizing post-treatment needs.
Testing Regime:
100% Positive Material Identification (PMI) to verify chemical composition.
Non-destructive testing (UT/ET) for internal defects.
Hydrostatic pressure testing to ensure leak-tightness.
Intergranular corrosion (IGC) testing per ASTM A262 to confirm resistance to sensitization.
Certification & Traceability
Mill Test Certificates (MTC): Compliant with EN 10204 3.1 and 3.2, detailing chemical analysis, mechanical properties, and heat treatment records.
Third-Party Inspection: Available from accredited bodies (e.g., Lloyd’s, DNV) for critical projects.
Traceability Marking: Each pipe is laser-marked with material grade, size, heat number, and manufacturer logo for full lifecycle traceability.
Application Scenarios
Marine Engineering & Seawater Systems
UNS S32205 seamless pipes excel in marine environments, serving as the material of choice for seawater cooling pipelines and desalination equipment in coastal power plants and desalination plants. Their high resistance to pitting in high-salinity conditions ensures long-term reliability. Additionally, in offshore platforms, these pipes are used for components and pump valves, where their high strength allows for reduced material thickness, minimizing weight while withstanding constant seawater erosion.
Oil & Gas Industry
In the oil and gas sector, UNS S32205 pipes are critical for oil well tubing and gathering pipelines, performing exceptionally well in acidic environments rich in H₂S and CO₂, and meeting the stringent NACE MR0175 standards. They are also used in pressure vessels and heat exchangers in oil-gas processing facilities, effectively preventing chloride-induced stress corrosion and ensuring the safety and efficiency of operations.
Chemical & Pharmaceutical Sectors
For chemical processing, these pipes are utilized in reactors and distillation columns, providing reliable resistance to strong acids such as sulfuric and hydrochloric acid, which are common in fertilizer and pesticide production. In the pharmaceutical industry, UNS S32205 seamless pipes meet strict hygienic standards, resist disinfectants, and are easy to clean, making them ideal for pharmaceutical-grade pipes and tanks.
Power & Environmental Engineering
In power generation, especially in coastal power plants, UNS S32205 pipes are employed in Flue Gas Desulfurization (FGD) systems, withstanding sulfite corrosion in wet desulfurization processes. They are also used in wastewater treatment facilities, where they resist the corrosive effects of chloride-laden wastewater and sludge in both municipal and industrial settings.
Pulp & Paper Industry
Within the pulp and paper industry, these pipes are essential for digesters and bleaching equipment. Their ability to maintain stability in chloride-based bleaching agents prevents equipment perforation and leakage, ensuring continuous and efficient production processes.
FAQ (Frequently Asked Questions)
Q: How does S32205 differ from 316L stainless steel?
A: S32205 offers over twice the strength of 316L (450 MPa vs. 205 MPa yield strength) and superior chloride resistance. Its PREN (34-38) far exceeds 316L’s PREN (≈24), making it ideal for high-salinity applications.
Q: Can S32205 be used at high temperatures?
A: Service temperatures above 300°C are not recommended. Prolonged exposure may cause intermetallic phase precipitation, reducing corrosion resistance and ductility. Consider super duplex or nickel-based alloys for higher temperatures.
Q: Does S32205 require special welding procedures?
A: Yes. Use low-heat-input methods (e.g., TIG welding) with interpass temperatures ≤250°C. ER2209 filler wire is recommended. Post-weld heat treatment is typically unnecessary, but avoid overheating to maintain phase balance.
Q: How to verify the authenticity of S32205 material?
A: Each batch is marked with a heat number for traceability. Confirm chemical composition via PMI testing or cross-reference with Mill Test Certificates (MTC) for mechanical properties. Third-party certification is available upon request.
Q: What’s the application difference between S32205 and S32750 (2507)?
A: S32205 is a standard duplex steel for moderate corrosion, while S32750 is a super duplex with higher Mo/N content (PREN ≥41) for extreme conditions (e.g., deep-sea oil, concentrated acids). S32205 also offers a cost advantage.
Q: What is the lead time for custom-sized orders?
A: Standard sizes are available within 2-4 weeks. Non-standard dimensions (OD/thickness) require 6-8 weeks, depending on production scheduling and testing. Rush orders can be arranged for urgent needs.
