ASTM A240 2507 (S32750) Super Duplex Stainless Steel Pipe
ASTM A240 2507 (S32750) Super Duplex Stainless Steel Pipe
Complete material data for ASTM A240 2507 (UNS S32750) super duplex stainless steel pipe: chemical composition, mechanical properties, physical properties, international equivalents, and application guidance.
Hot forming, cold forming, machining, welding (using over-alloyed filler such as 2209), solution annealing
- Phone : +8618037372205
- Email : [email protected]
- WhatsApp: Contact via Whtsapp
- WeChat: +8618037372205
ASTM A240 2507 Super Duplex Stainless Steel Pipe Introduction
ASTM A240 2507, also designated UNS S32750, is a super duplex stainless steel with a mixed microstructure of austenite and ferrite. It delivers exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride-containing environments. Compared to conventional austenitic grades, 2507 offers approximately twice the yield strength and excellent weldability. Its high chromium (25%), nickel (7%), molybdenum (4%), and nitrogen content ensure superior corrosion resistance in aggressive media such as seawater, acids, and chlorides. This material is widely used in demanding applications across chemical processing, oil and gas, and marine engineering. Pipes manufactured to ASTM A240/A240M are typically supplied in the solution-annealed condition to optimize both mechanical properties and corrosion resistance.
ASTM A240 2507 Super Duplex Stainless Steel Pipe Chemical Composition as per ASTM A240
The chemical composition of 2507 (UNS S32750) is carefully balanced to achieve an optimal ferrite-austenite microstructure and the required mechanical and corrosion properties. The high chromium, molybdenum, and nitrogen additions provide exceptional resistance to localized corrosion. All values below are specified in ASTM A240/A240M for S32750.
| Element | Standard Requirement | Remarks |
|---|---|---|
| Carbon (C) | ≤0.030 | Maximum |
| Manganese (Mn) | ≤1.20 | Maximum |
| Silicon (Si) | ≤0.80 | Maximum |
| Phosphorus (P) | ≤0.035 | Maximum |
| Sulfur (S) | ≤0.020 | Maximum |
| Chromium (Cr) | 24.0 – 26.0 | As specified |
| Nickel (Ni) | 6.0 – 8.0 | As specified |
| Molybdenum (Mo) | 3.0 – 5.0 | As specified |
| Nitrogen (N) | 0.24 – 0.32 | As specified |
| Copper (Cu) | ≤0.50 | Maximum; residual |
| Iron (Fe) | Balance | Remainder |
ASTM A240 2507 Super Duplex Stainless Steel Pipe Thermal and Electrical Physical Properties
The physical properties of 2507 (UNS S32750) are provided as typical reference values for design purposes. They are not part of the ASTM A240 specification but represent accepted data for super duplex stainless steel grades. These properties are influenced by the dual-phase microstructure.
| Property | Typical Value | Unit | Test Condition |
|---|---|---|---|
| Density (ρ) | 7.8 | g/cm³ | 20 °C |
| Elastic Modulus (E) | 200 | GPa | 20 °C, tension |
| Shear Modulus (G) | 77 | GPa | 20 °C, estimated |
| Poisson's Ratio (ν) | 0.30 | - | 20 °C |
| Thermal Expansion Coefficient (α) | 13.0 x 10⁻⁶ | /°C | 20–100 °C |
| Thermal Expansion Coefficient (α) | 14.0 x 10⁻⁶ | /°C | 20–200 °C |
| Thermal Expansion Coefficient (α) | 14.5 x 10⁻⁶ | /°C | 20–300 °C |
| Thermal Conductivity (λ) | 15 | W/m·K | 20 °C |
| Thermal Conductivity (λ) | 17 | W/m·K | 100 °C |
| Thermal Conductivity (λ) | 19 | W/m·K | 200 °C |
| Specific Heat Capacity (cp) | 500 | J/kg·K | 20 °C |
| Electrical Resistivity (ρe) | 0.80 | µΩ·m | 20 °C |
ASTM A240 2507 Super Duplex Stainless Steel Pipe Mechanical Properties at Room Temperature
The following mechanical properties are required for 2507 (UNS S32750) in the solution-annealed condition according to ASTM A240/A240M. The alloy exhibits very high strength combined with good ductility. Hardness values are also controlled. All tests are performed at ambient temperature.
| Property | Standard Requirement | Unit | Test Condition |
|---|---|---|---|
| Tensile Strength (Rm) | ≥795 | MPa | Room temperature, tension test |
| Yield Strength (ReH, 0.2% offset) | ≥550 | MPa | Room temperature, tension test |
| Elongation (A) in 50 mm (2 in.) | ≥15 | % | Room temperature, tension test |
| Brinell Hardness (HBW) | ≤310 | - | Room temperature, converted if necessary |
| Rockwell Hardness (HRC) | ≤32 | - | Room temperature |
ASTM A240 2507 Super Duplex Stainless Steel Pipe Completely Equivalent Standards and Substitute Grades
| Country/Region | Standard | Grade/Designation | Remarks |
|---|---|---|---|
| USA | ASTM A240/A240M | UNS S32750 (2507) | Primary standard for plates, sheets, and strips; also covered by ASTM A789/A790 for pipes |
| Europe | EN 10088-2, EN 10088-3 | 1.4410 – X2CrNiMoN25-7-4 | Fully equivalent super duplex grade |
| China | GB/T 3280, GB/T 1220 | 022Cr25Ni7Mo4N (S22573) | Corresponds exactly to 2507/1.4410 |
| Japan | JIS G4304, G4305, G4312 | SUS 329J4L | Equivalent super duplex composition; slight nomenclature difference |
| International | NACE MR0175 / ISO 15156 | UNS S32750 | Listed for sour service environments |
ASTM A240 2507 Super Duplex Stainless Steel Pipe Application Introduction
2507 super duplex stainless steel (UNS S32750) is designed for the most demanding corrosive environments. The combination of high strength and exceptional chloride stress corrosion cracking resistance allows for lighter, more cost-effective designs compared to conventional austenitic or duplex grades.
Product Applications: Seamless and welded pipes for corrosive fluid transport, Heat exchanger tubes and tube sheets, Pressure vessels and storage tanks, Bolting, fasteners, and springs, Pump casings, valve bodies, and impellers, Structural components in offshore platforms
Processed into products: Pipe spools and flanges for subsea flowlines, Tube bundles in shell-and-tube heat exchangers, Centrifugal pump shafts and wear rings, Valve stems and seats, High-pressure connectors and fittings, Seawater intake grates and screens, Flexible hose couplings
Application industries: Oil & Gas (offshore platforms, subsea pipelines, refinery equipment), Chemical and petrochemical processing (tanks, reactors, heat exchangers), Marine and shipbuilding (seawater cooling pipes, propulsion shafts), Desalination plants (evaporators, brine heaters, high-pressure piping), Pulp & paper (digesters, bleach plants), Pollution control (flue gas desulfurization scrubbers), Food and pharmaceutical processing (where high cleanliness and corrosion resistance are required)
ASTM A240 2507 Super Duplex Stainless Steel Pipe Similar or Comparable Materials for Potential Substitution
| Country/Region | Standard | Grade/Designation | Remarks |
|---|---|---|---|
| Global | Various | UNS S32760 (Zeron 100, 1.4501) | Slightly higher W and Cu; often used in similar aggressive environments; intermediate properties |
| Global | Various | UNS S32550 (Ferralium 255, 1.4507) | Higher Cu content; good general corrosion resistance but lower PREN than 2507 |
| Global | Various | UNS S32950 (SAF 2507 is a trade name for S32750) | SAF 2507 is a manufacturer's designation for UNS S32750, not a distinct grade |
Notes:
Welding: Use over-alloyed filler metals such as ER2209 or ERNiCrMo-3 to compensate for nitrogen loss and maintain corrosion resistance. Heat treatment: Solution annealing at a minimum of 1040–1120 °C followed by rapid quenching is mandatory to restore full corrosion resistance after hot working or welding. Machining: The high strength and work-hardening rate require rigid tooling, low cutting speeds, and proper cooling. Testing: ASTM A923 tests for intermetallic phase detection may be required to ensure proper heat treatment.
- Share
