Seamless Duplex Steel UNS S32205 Pipe
Our S32205 pipes feature a higher nitrogen content than standard UNS S31803, ensuring an enhanced Pitting Resistance Equivalent Number (PREN ≥ 35). This makes them exceptionally resistant to chloride pitting and stress corrosion cracking (SCC) in harsh environments. With a yield strength approximately double that of conventional 300-series stainless steels, these pipes allow for lighter wall designs and increased pressure ratings in petrochemical, marine engineering, and energy infrastructure. Through advanced cold-drawing and precision solution annealing, GZH guarantees optimal phase balance and a high-integrity surface finish for mission-critical applications.
"Our S32205 pipes are dual-certified to meet both S31803 and S32205 specifications, ensuring higher chromium and nitrogen levels for superior corrosion resistance."
Seamless Duplex Steel UNS S32205 Pipes
SeamlessDuplex Stainless Steel S32205 pipes, commonly referred to as Duplex 2205 seamless pipes, are high-strength corrosion-resistant piping products manufactured from a solid billet through hot extrusion or piercing processes.
Unlike welded pipes, seamless Duplex pipes contain no longitudinal weld seams, ensuring superior structural integrity, uniform wall thickness, and enhanced reliability in high-pressure and corrosive environments.
UNSS32205 is an improved nitrogen-alloyed version of UNS S31803, offering enhanced corrosion resistance and mechanical performance. The alloy features a dual-phase microstructure composed of approximately 50% ferrite and 50% austenite, combining the advantages of both stainless steel structures.
This unique metallurgical balance provides:
- High mechanical strength
- Excellent resistance to chloride-induced stress corrosion cracking (SCC)
- Outstanding pitting and crevice corrosion resistance
Because of these properties, ASTM A790 UNS S32205 seamless pipes are widely used in offshore, chemical, and marine industries.
Key Features and Engineering Advantages of Duplex S32205 Pipes
Excellent Corrosion Resistance
Duplex 2205 stainless steel provides exceptional resistance to:
- Chloride-induced stress corrosion cracking (SCC)
- Pitting corrosion
- Crevice corrosion
- Intergranular corrosion
Compared with conventional stainless steels such as 316L, Duplex S32205 offers significantly improved corrosion resistance in chloride-containing environments.
High Mechanical Strength
Duplex S32205 pipes typically provide approximately twice the yield strength of standard austenitic stainless steels, enabling:
- Thinner wall thickness
- Reduced weight
- Lower material and installation costs
Superior Pressure Performance
Theseamless manufacturing process ensures consistent wall thickness and enhanced structural reliability, making these pipes suitable for high-pressure subsea and chemical processing applications.
Cost-Effective Alloy Composition
Compared with high-nickel austenitic stainless steels, Duplex 2205 contains lower nickel content, resulting in improved price stability while maintaining superior mechanical and corrosion performance.
Improved Thermal Efficiency
Duplex stainless steel offers:
- Lower thermal expansion
- Higher thermal conductivity
These properties improve performance in heat exchangers and thermal processing equipment.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Duplex Steel UNS S32205.
Table 1: Chemical Composition of Duplex Steel UNS S32205
The composition of Duplex Steel UNS S32205 is carefully balanced to achieve its superior corrosion resistance and high strength.
| Grade | C | Mn | P | S | Si | Ni | Cr | Mo | N | Cu | Ohters |
| 31803 | ≤0.03 | ≤2.00 | ≤0.03 | ≤0.02 | ≤1.00 | 4.50-6.50 | 21.00-23.00 | 2.50-3.50 | 0.08-0.20 | … | … |
| 32205 | ≤0.03 | ≤2.00 | ≤0.03 | ≤0.02 | ≤1.00 | 4.50-6.50 | 22.00-23.00 | 3.00-3.50 | 0.14-0.20 | … | … |
| 31500 | ≤0.03 | 1.20-2.00 | ≤0.03 | ≤0.03 | 1.40-2.00 | 4.20-5.20 | 18.00-19.00 | 2.50-3.00 | 0.15-0.10 | 1.50-2.50 | … |
| 32550 | ≤0.04 | ≤1.50 | ≤0.04 | ≤0.03 | ≤1.00 | 4.50-6.50 | 24.00-27.00 | 2.90-3.90 | 0.10-0.25 | … | … |
| 32750 | ≤0.03 | ≤1.20 | ≤0.035 | ≤0.02 | ≤0.80 | 6.00-8.00 | 24.00-26.00 | 3.00-5.00 | 0.24-0.32 | ≤0.50 | … |
| 32760 | ≤0.05 | ≤1.00 | ≤0.030 | ≤0.01 | ≤1.00 | 6.00-8.00 | 24.00-26.00 | 3.00-4.00 | 0.20-0.30 | 0.50-1.00 | W 0.50 -1.00 |
| 32950 | ≤0.08 | ≤2.00 | ≤0.035 | ≤0.01 | ≤0.60 | 3.50-5.20 | 26.00-29.00 | 1.00-2.50 | 0.15-0.35 | … | … |
| 32906 | ≤0.03 | 0.80-1.50 | ≤0.030 | ≤0.03 | ≤0.50 | 5.80-7.50 | 28.00-30.00 | 1.50-2.60 | 0.30-0.40 | ≤0.80 | … |
Table 2: Typical Mechanical Properties of S32205 Duplex Stainless Steel
S32205’s dual-phase structure provides a significant increase in yield strength compared to standard austenitic grades.
| Tensile Strength | Yield Strength | Elongation | Hardness |
| ≥ 655 MPa | ≥ 450 MPa | ≥ 25% | ≤ 293 HBW |
Table 3: Typical Physical Properties of S32205 Duplex Stainless Steel
| Property | Value |
| Density | 7.82 g/cm³ |
| Melting Point | 1385-1440 ℃ |
| Thermal Expansion | 13.0 µm/m·℃ |
| Thermal Conductivity | 14.6 W/m·K |
Table 4: The Standard of ASTM A790 Size Tolerance Size Chart :
| NPS Designator (Inches) | Permissible Variations in Outside Diameter (Inches) |
| 1⁄8 to 1 1⁄2, inclusive | Over: 1⁄64 in. (0.015 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 1 1⁄2 to 4, inclusive | Over: 1⁄32 in. (0.031 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 4 to 8, inclusive | Over: 1⁄16 in. (0.062 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 8 to 18, inclusive | Over: 3⁄32 in. (0.093 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 18 to 26, inclusive | Over: 1⁄8 in. (0.125 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 26 to 34, inclusive | Over: 5⁄32 in. (0.156 in.) |
| Under: 1⁄32 in. (0.031 in.) | |
| Over 34 to 48, inclusive | Over: 3⁄16 in. (0.187 in.) |
| Under: 1⁄32 in. (0.031 in.) |
The wall thickness tolerances are defined by the nominal wall thickness (t) and the outside diameter (D).
1. Minimum Wall Thickness
The minimum wall thickness at any point on the pipe shall not be more than {12.5%} under the nominal (specified) wall thickness.
2. Maximum Wall Thickness (Percentage Over Nominal)
The maximum allowable wall thickness variation depends on the size and the t/D ratio (ratio of nominal wall thickness to ordered outside diameter):
| NPS Designator (Inches) | t/D Ratio | Permissible Variation (Over Nominal WT) |
| 1/8 to 2, inclusive | All ratios | +20.0% |
| 3 to 18, inclusive | t/D ≤ 5% | +22.5% |
| 3 to 18, inclusive | t/D >5% | +15.0% |
| 20 and larger (Seamless) | t/D ≤ 5% | +22.5% |
| 20 and larger (Seamless) | t/D >5% | +15.0% |
| 20 and larger (Welded) | All ratios | +17.5% |
For pipe ordered to a Specific Cut Length, the standard tolerance is +1⁄8 in. [3.2 mm], -0 in. [0 mm].
Pipe is typically supplied in Single Random Lengths (17 to 24 ft) or Double Random Lengths (38 to 40 ft), unless otherwise specified.
Disclaimer: These tolerances are based on the common requirements found in ASTM A790, primarily through its reference to ASTM A999. The full and most current specification document must always be consulted for official design and procurement purposes.
Industrial Applications of Duplex S32205 Pipes
Due to their high strength and excellent corrosion resistance, Duplex 2205 seamless pipes are widely used in demanding industrial environments.
Oil and Gas Industry
- Subsea flowlines
- Offshore platform piping
- Risers and manifolds
- Process piping in refineries
Chemical Processing
- Pressure vessels
- Heat exchangers
- Chemical storage tanks
- Chloride-containing process systems
Marine and Desalination
- Seawater piping systems
- Reverse osmosis (SWRO) desalination plants
- Shipboard piping
Pulp and Paper Industry
- Digesters
- Bleach plant equipment
- Chemical liquor tanks
Quality Assurance and Testing Standards
All Duplex S32205 pipes undergo strict quality control procedures to ensure compliance with international standards.
Positive Material Identification (PMI)
100% PMI testing verifies the chemical composition of the alloy.
Corrosion Testing
- ASTM G48 pitting corrosion test
- Intergranular corrosion testing
Non-Destructive Testing (NDT)
Each pipe is inspected using:
- Ultrasonic Testing (UT)
- Eddy Current Testing (ET)
Microstructure Verification
Metallographic analysis confirms the balanced 50/50 ferrite-austenite duplex structure.
Documentation
Material Test Certificates (MTC) are supplied according to:
EN 10204 3.1 or 3.2 standards
