2205 duplex stainless steel (UNS S32205/S31803) is a nitrogen-enhanced alloy with a balanced microstructure of approximately 50% austenite and 50% ferrite phases. This hybrid structure synergizes the best properties of both phases:

• Ferritic advantages: High strength and chloride stress corrosion cracking (SCC) resistance.

• Austenitic advantages: Toughness and fabricability
  Our pipes comply with ASTM A790, A928, and EN 10216-5 standards, ensuring performance in extreme environments.

Why Choose Luokaiwei’s 2205 Duplex Pipes? Key Benefits

1. Unmatched Strength:
   Yield strength (≥640 MPa) is twice that of 316L, enabling weight reduction up to 50% for cost savings on structural supports.

2. Superior Corrosion Resistance:

   • Withstands pitting/crevice corrosion in chloride-rich media (PREN ≥34)

   • Immune to stress corrosion cracking (SCC) in sour gas (H₂S) environments per NACE MR0175.

3. Economic Efficiency:
   Replaces high-nickel alloys at 30–40% lower cost while outperforming 316L in aggressive media like seawater and acids.

4. Thermal & Mechanical Stability:
   Serviceable from -50°C to 300°C (-58°F to 572°F), with low thermal expansion similar to carbon steel for simplified cladding.

Technical Specifications: Precision Engineered Performance

Table 1: Chemical Composition (Weight %)

Table 2: Mechanical Properties vs. Competing Alloys

Applications: Where Our 2205 Pipes Excel

• Oil & Gas: Subsea pipelines, topside process piping, and separator vessels (850+ km deployed globally)

• Desalination: Seawater reverse osmosis (SWRO) high-pressure tubing and brine heaters

• Chemical Processing: Reactor effluent coolers, sulfuric acid transport lines (≤20% concentration)

• Pollution Control: Flue gas desulfurization (FGD) scrubbers and chimney liners

• Pulp & Paper: Bleach washers and digesters resisting chlorine dioxide corrosion

Manufacturing Excellence at Luokaiwei

Our vertically integrated production ensures traceability and quality:

1. Material Sourcing: Virgin billets from ISO-certified mills (e.g., Outokumpu, TISCO).

2. Pipe Formation:

   • Seamless: Hot extruded for SCH 40–160 pipes (1/8″–24″).

   • Welded: Laser/TIG welded for large diameters (up to 48″ OD).

3. Solution Annealing: Rapid quenching at 1020–1100°C to fix 50/50 phase balance.

4. Finishing:

   • Pickling/passivation for optimal corrosion resistance.

   • Custom surfaces: Mill finish, polished (#4, #8), or bright annealed (BA).

5. Testing: Hydrostatic, eddy current, and PMI validation with EN 10204 3.1/3.2 certifications.

Installation & Fabrication Best Practices

• Welding:

  • Use ER2209 filler wire with 98% Ar + 2% N₂ shielding gas.

  • Limit heat input to 0.5–1.5 kJ/mm; interpass temperature ≤100°C.

• Cold Bending: Minimum radius ≥3× OD to avoid phase imbalance.

• Avoid:

  • Prolonged exposure to 300–525°C (risk of 885°F embrittlement).

  • Contact with carbon steel/copper alloys without insulation.

5 Critical FAQs

Q1: Can 2205 pipes handle seawater cooling systems?
A: Yes. With PREN ≥34, they resist pitting in seawater ≤70°C. For chlorinated water, upgrade to 2507 super duplex.

Q2: What filler metals are used for welding 2205 to carbon steel?
A: Use ER309L for dissimilar joints. Post-weld solution annealing is recommended for high-corrosion services.

Q3: Does Luokaiwei supply NACE-compliant pipes for sour service?
A: Absolutely. We provide NACE MR0175-certified pipes with SSC/HIC test reports for H₂S environments.

Q4: What sizes and forms do you offer?
A: Our standard range includes:

Q5: How does 2205 compare to 254SMO super austenitic steel?
A: 254SMO (PREN ≥42) offers higher pitting resistance but costs 50% more. 2205 provides better value for non-oxidizing acids and moderate chlorides.

Order Your 2205 Duplex Pipes Today!
Luokaiwei delivers precision-engineered solutions with:
✅ Rapid Lead Times: 30% faster delivery than industry average
✅ Customization: U-bends, flanged ends, clad systems
✅ Certification: Full material traceability with MTCs

Request a Quote: Email sales@luokaiweipipe.com or call +86 18912200505