Seamless Super Duplex Steel S32950 Tube
Designed for superior performance in chloride-rich media, our S32950 super duplex tubes provide exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC). These tubes deliver a strategic combination of high tensile and yield strength alongside remarkable impact toughness, making them the optimal choice for high-pressure heat exchangers, desalination infrastructure, and offshore platforms. Through advanced cold-drawing and specialized solution annealing, GZH ensures every tube maintains optimal phase balance and a high-integrity surface finish for mission-critical reliability.
"Our S32950 tubes offer an optimized PREN value that ensures exceptional durability in brackish water and industrial chemical media."
What Is a Super Seamless Super Duplex Steel S32950 Tube?
Seamless Super Duplex Steel S32950 Tube is a cylindrical tube crafted from a single, solid billet of a high-performance duplex stainless steel alloy. Unlike welded tubes, it has no weld joint, ensuring superior structural integrity and reliability, especially under high-stress and corrosive conditions. The"S32950"designation refers to a specific grade of super duplex stainless steel known for its balanced combination of high strength and exceptional corrosion resistance. This alloy contains a high content of chromium, molybdenum, and nitrogen, giving it a unique two-phase microstructure of roughly equal parts austenite and ferrite. This structure provides high tensile strength, excellent resistance to stress corrosion cracking, and superior resistance to pitting and crevice corrosion, making it a top choice for demanding applications in harsh environments.
Key Features and Advantages
Super Duplex Steel S32950 seamless tubes offer a unique combination of benefits that make them invaluable in the most demanding industries:
Exceptional Corrosion Resistance: It provides outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride-containing environments. This is a direct result of its high PREN (Pitting Resistance Equivalent Number) value.
High Strength: The duplex (austenite-ferrite) microstructure provides a high tensile and yield strength, approximately double that of standard austenitic stainless steels like 316L.
Excellent Toughness: It maintains good toughness at both low and ambient temperatures, making it suitable for a wide range of operational conditions.
High Pressure Tolerance: The seamless construction eliminates a potential weak point, allowing the tube to safely handle high internal pressures, which is critical in many fluid transfer and structural applications.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Super Duplex Steel S32950.
Table 1: Chemical Composition of S32950
The composition of S32950 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 S32950
S32950 is specifically designed to maintain its strength and shape in high-stress, corrosive environments.
| Property | Value |
| Tensile Strength | ≥795 MPa |
| Yield Strength | ≥550 MPa |
| Elongation | ≥25% |
| Hardness | ≤290 HBW |
Table 3: Typical Physical Properties of S32950
These physical properties highlight the material's ability to perform reliably under a wide range of conditions.
| Property | Value |
| Density | 7.8 g/cm3 |
| Melting Point | 1400−1440 ∘C approx. |
| Thermal Expansion | 13.0 μm/m⋅∘C (20−100∘C) |
| Thermal Conductivity | 15 W/m⋅K (20∘C) |
| Modulus of Elasticity | 200 GPa |
| Electrical Resistivity | 0.80×10−6 Ω⋅m (20∘C) |
Table 4: The Standard of ASTM A789 Size Tolerance Size Chart :
| Specified Outside Diameter (OD) (Inches) | Permissible Variations in OD (± Inches) |
| 1⁄2 to 1 | ±0.005 |
| Over 1 to 1-1⁄2 | ±0.008 |
| Over 1-1⁄2 to 2 | ±0.010 |
| Over 2 to 2-1⁄2 | ±0.012 |
| Over 2-1⁄2 to 3-1⁄2 | ±0.014 |
| Over 3-1⁄2 to 5 | ±0.020 |
| Specified Outside Diameter (OD) (Inches) | Specified Wall Thickness (WT) (Inches) | Permissible Variation (± Inches) |
| 1⁄2 to 1 (Inclusive) | 0.025 to 0.065(Inclusive) | ±0.010 |
| Over 0.065to 0.134 (Inclusive) | ±0.012 | |
| Over 1 to 1-1⁄2 (Inclusive) | 0.025 to 0.065 (Inclusive) | ±0.010 |
| Over 0.065 to 0.134 (Inclusive) | ±0.012 | |
| Over 1-1⁄2 to 2 (Inclusive) | 0.025 to 0.049 (Inclusive) | ±0.011 |
| Over 0.049 to 0.083 (Inclusive) | ±0.012 | |
| Over 0.083 to 0.148 (Inclusive) | ±0.014 | |
| Over 2 to 2-1⁄2 (Inclusive) | 0.032 to 0.065 (Inclusive) | ±0.013 |
| Over 0.065 to 0.109 (Inclusive) | ±0.015 | |
| Over 0.109 to 0.165 (Inclusive) | ±0.017 | |
| Over 2-1⁄2 to 3-1⁄2 (Inclusive) | 0.032 to 0.165 (Inclusive) | ±0.020 |
| Over 0.165 to 0.220 (Inclusive) | ±0.025 | |
| Over 3-1⁄2 to 5 (Inclusive) | 0.083 to 0.165 (Inclusive) | ±0.025 |
| Over 0.165 to 0.220 (Inclusive) | ±0.030 |
Length Tolerance
ForSpecific Cut Lengths, the standard tolerance is +1⁄8 in. [3 mm], -0 in. [0 mm].
Important Note: The values presented here are based on the common tables in the ASTM A789 standard. The full specification, particularly the referenced ASTM A1016/A1016M (General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel Tubes), contains other essential requirements like straightness and details for tubes with ODs outside of this range. Always consult the latest official standard for design and procurement.
Common Applications
The combination of high strength and exceptional corrosion resistance of Super Duplex Steel S32950 seamless tubes makes them a preferred choice for:
Oil and Gas Industry: Used in offshore platforms, piping systems, and subsea equipment where resistance to chloride and sour gas corrosion is critical.
Chemical Processing: In heat exchangers, pressure vessels, and piping for corrosive environments.
Desalination Plants: For piping and vessels where components must handle high-chloride water.
Marine Engineering: In propeller shafts, pump components, and other parts exposed to harsh saltwater environments.
Manufacturing Process
The manufacturing of a Seamless Duplex Steel Tube is a precise, multi-step process:
- Heating: A solid billet of S32950 is heated to a high temperature.
- Piercing: A piercing mill pushes a mandrel through the center of the heated billet to form a hollow shell.
- Rolling and Sizing: The hollow shell is then rolled and drawn to reduce its diameter and wall thickness to the desired dimensions.
- Finishing: The tube is cut to length, heat-treated, and subjected to finishing processes to ensure it meets the highest standards for performance and reliability in the most demanding applications. This meticulous process ensures that every S32950 seamless tube meets the highest standards for performance and reliability.
