Super Duplex Stainless Steel Plate High Strength Corrosion Resistant
Super duplex stainless steel plate is a high-performance material that combines the advantageous properties of both austenitic and ferritic stainless steel microstructures. With a balanced duplex microstructure (approximately 50% ferrite / 50% austenite), super duplex grades offer approximately twice the yield strength of conventional austenitic stainless steels (e.g., 304, 316) while providing exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking.
These plates are specifically designed for extreme service conditions involving high chloride concentrations, elevated temperatures, and aggressive chemical environments. Common applications include offshore platforms, seawater desalination plants, chemical processing vessels, and sour gas pipelines.
Typical Grades: UNS S32750 (EN 1.4410 / SAF 2507 / F53), UNS S32760 (EN 1.4501 / Zeron 100 / F55)
| Feature | Benefit |
|---|---|
| High Strength | Yield strength ≥ 550 MPa – allows weight reduction through thinner gauges |
| Excellent Corrosion Resistance | PREn (Pitting Resistance Equivalent Number) > 40 – superior to 316L and standard duplex |
| Stress Corrosion Cracking Resistance | Highly resistant to chloride-induced SCC – ideal for marine and chemical applications |
| Good Weldability | Can be welded using standard methods with matching filler metals |
| High Thermal Conductivity | Better heat transfer than austenitic grades – beneficial for heat exchangers |
| Low Thermal Expansion | Reduced thermal stress compared to austenitic stainless steels |
| Element | UNS S32750 (2507 / 1.4410 / F53) | UNS S32760 (Zeron 100 / 1.4501 / F55) |
|---|---|---|
| Carbon (C) | ≤ 0.030 | ≤ 0.030 |
| Chromium (Cr) | 24.0 – 26.0 | 24.0 – 26.0 |
| Nickel (Ni) | 6.0 – 8.0 | 6.0 – 8.0 |
| Molybdenum (Mo) | 3.0 – 5.0 | 3.0 – 4.0 |
| Nitrogen (N) | 0.24 – 0.32 | 0.20 – 0.30 |
| Manganese (Mn) | ≤ 1.20 | ≤ 1.00 |
| Silicon (Si) | ≤ 0.80 | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.035 | ≤ 0.030 |
| Sulfur (S) | ≤ 0.020 | ≤ 0.010 |
| Copper (Cu) | ≤ 0.50 | 0.50 – 1.00 |
| Tungsten (W) | — | 0.50 – 1.00 |
| Iron (Fe) | Balance | Balance |
Note: The addition of tungsten (W) and copper (Cu) in UNS S32760 further enhances corrosion resistance in specific aggressive environments.
| Property | UNS S32750 | UNS S32760 |
|---|---|---|
| Tensile Strength (MPa), min | 800 | 800 |
| Yield Strength (MPa), min | 550 | 550 |
| Elongation (%), min | 15 | 15 |
| Hardness (HB), max | 310 | 310 |
| Hardness (HRC), max | 32 | 32 |
| Impact Toughness (J, min @ -40°C) | 40 | 40 |
| Property | Value (Typical) |
|---|---|
| Density | 7.8 g/cm³ |
| Melting Range | 1350 – 1400 °C |
| Modulus of Elasticity | 200 GPa |
| Thermal Conductivity (20°C) | 15 W/(m·K) |
| Specific Heat Capacity (20°C) | 480 J/(kg·K) |
| Electrical Resistivity | 0.8 µΩ·m |
| Thermal Expansion Coefficient (20–100°C) | 13.5 * 10⁻⁶ /K |
| PREn (Pitting Resistance Equivalent) | > 40 |
PREn calculation: PREn = %Cr + 3.3*%Mo + 16*%N
| Parameter | Range / Details |
|---|---|
| Material Grades | UNS S32750 / UNS S32760 (EN 1.4410 / 1.4501 / SAF 2507 |
| Manufacturing Process | Hot rolled / Cold rolled |
| Thickness | 2 mm – 100 mm |
| Width | 1000 mm – 3200 mm |
| Length | 2000 mm – 12000 mm |
| Thickness Tolerance | ASTM A480 (typical ±0.1 mm to ±0.5 mm depending on thickness) |
| Width / Length Tolerance | 0 / +5 mm (typical) |
| Surface Finish | Hot rolled & pickled (No.1) / Cold rolled & pickled (2B) / Bright annealed (BA) / Polished / Blasted |
| Edge Condition | Mill edge / Sheared edge / Flame cut |
| Delivery Condition | Solution annealed (quenched in water or rapid cooling) + pickled or blasted |
| Heat Treatment | 1040 – 1120 °C, followed by rapid cooling |
| Testing | PMI, Hydrostatic (for pipe), UT, Mechanical, Corrosion (ASTM G48), Ferrite measurement |
Custom sizes available upon request.
| Thickness (mm) | Width (mm) | Length (mm) | Typical Applications |
|---|---|---|---|
| 2 – 5 | 1000 – 2000 | 2000 – 6000 | Pressure vessels, liners, baffles |
| 6 – 20 | 1500 – 2500 | 3000 – 8000 | Structural plates, offshore topsides |
| 21 – 50 | 1500 – 3200 | 4000 – 10000 | Heavy fabrication, pipe spools |
| 51 – 100 | 1500 – 3000 | 4000 – 8000 | Flanges, heavy machinery components |
| Finish Code | Description | Typical Application |
|---|---|---|
| No.1 (Hot rolled, annealed & pickled) | Rough, matte surface, oxide-free | General industrial fabrication |
| 2B (Cold rolled, annealed & pickled) | Smooth, matte finish | Precision components, moderate surface requirement |
| BA (Bright Annealed) | Bright, reflective finish (cold rolled + bright annealing) | Decorative, hygienic applications |
| Polished (No.4 / No.8) | Brushed or mirror finish | Architectural, food processing |
| Blasted (bead or shot) | Uniform matte texture | Pressure vessels, marine structures |
| Parameter | Requirement |
|---|---|
| Solution Annealing Temperature | 1040 – 1120 °C |
| Cooling Method | Water quenching or rapid cooling (air cooling not recommended for thick sections) |
| Cooling Rate | As fast as possible to avoid intermetallic phase precipitation (σ, χ) |
| Post-Heat Treatment | Generally not required for welded structures; re-solution annealing may be needed after certain hot working operations |
Critical Warning: Super duplex stainless steels are susceptible to embrittlement from sigma (σ) phase and chi (χ) phase precipitation when exposed to temperatures in the range of 300–950°C for prolonged periods. Avoid slow cooling through this range.
Each super duplex plate is subject to rigorous quality control in accordance with ASTM A240 / A480 and customer specifications:
| Test / Inspection | Standard / Method | Frequency |
|---|---|---|
| Chemical Analysis | Per heat (OES) | Each heat |
| Tensile Testing | Room temperature / Elevated (if required) | Per heat/per thickness |
| Hardness Testing | Brinell or Rockwell | per plate or per batch |
| Impact Testing (Charpy V-notch) | At -40°C or -46°C (as specified) | Per heat/direction |
| Intergranular Corrosion Test | ASTM A262 Practice E or C | Upon request |
| Pitting Corrosion Test | ASTM G48 (Critical Pitting Temperature / CPT) | Upon request |
| Ferrite Content Measurement | Metallographic or magnetic | Upon request |
| Ultrasonic Testing (UT) | ASTM A435 / A577 / A578 | Upon request |
| PMI (Positive Material Identification) | XRF | 100% upon request |
| Visual & Dimensional Inspection | Per A480 | 100% |
Certificates Available:
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Mill Test Certificate (EN 10204 3.1)
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Third-party inspection report (SGS, BV, DNV, TUV – upon request)
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NACE MR0175 / ISO 15156 compliance certificate
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Heat treatment charts (time-temperature records)
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UW-30 (ASME Section VIII) data report (if applicable)
| Industry | Application | Why Super Duplex |
|---|---|---|
| Offshore Oil & Gas | Topside modules, subsea manifolds, flowline jumpers, risers | High strength, seawater corrosion resistance, SCC resistance |
| Desalination | Evaporator vessels, brine heaters, and high-pressure piping | PREn >40 resists chloride pitting and crevice corrosion |
| Chemical Processing | Reactors, distillation columns, and heat exchangers for acetic/formic acid | Resists organic acids and chloride contamination |
| Pulp & Paper | Digesters, bleach plants (chlorine dioxide) | High strength reduces thickness and corrosion resistance |
| Flue Gas Desulfurization (FGD) | Scrubbers, ductwork, absorber towers | Resists high-chloride, low-pH environments |
| Marine & Shipbuilding | Seawater cooling systems, firewater mains, propeller shafts | Excellent seawater corrosion resistance, erosion resistance |
| Hydrometallurgy | Autoclaves, pressure leach vessels for nickel/cobalt extraction | Handles high chloride + acid + elevated temperature |
| Chemical Tankers | Cargo tanks for aggressive chemicals (e.g., sulfuric, phosphoric acid) | High strength allows lighter tank construction |
| Property | 316L (Austenitic) | 2205 (Duplex) | Super Duplex (S32750/S32760) |
|---|---|---|---|
| Yield Strength (MPa) | ~220 | ~450 | ~550 |
| Tensile Strength (MPa) | ~520 | ~620 | ~800 |
| PREn | ~25 | ~35 | >40 |
| Critical Pitting Temperature (°C in 6% FeCl₃) | ~15 | ~35 | ~50+ |
| Chloride SCC Resistance | Poor (susceptible) | Excellent | Excellent |
| Cost (relative to 316L) | 1.0x | ~1.3x | ~1.8x |
| Typical Applications | General purpose | Moderate chloride | Extreme chloride / sour |
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Plasma cutting, laser cutting, water jet, or mechanical shearing
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For thermal cutting, apply paste or grinding to remove the heat-affected zone (HAZ) if corrosion resistance is critical
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Super duplex has higher strength – requires greater force than austenitic grades
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Springback is higher – adjust tooling accordingly
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Annealed condition recommended for severe forming
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Filler metals: Matching super duplex (e.g., 2509 for S32750, 2594 for S32760)
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Heat input: 0.5 – 2.5 kJ/mm typical
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Interpass temperature: ≤ 150°C
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Preheating: Generally not required (but optional for heavy sections)
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Post-weld heat treatment: Not normally required for corrosion resistance; may be needed for dimensional stability
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Use rigid setups and sharp carbide tooling
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Lower cutting speeds (20–30% less than 316L)
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Use positive rake angles and adequate coolant
| Item | Method |
|---|---|
| Plate Packaging | Paper interleaving between plates, moisture-proof paper wrapping, steel strapping, plywood pallet, or wooden skid |
| Edge Protection | Cardboard corner protectors |
| Surface Protection | Removable PVC film (on polished or 2B finishes) – optional |
| Marking | Grade, dimensions, heat number, standard, and inspection stamp clearly stenciled or labeled |
| Documentation | Packing list, MTC, commercial invoice, (if applicable: COO, third-party report) |
| Port of Loading | Major Chinese ports (Shanghai, Tianjin, Ningbo, Guangzhou) |
| Shipping Terms | FOB, CFR, CIF, EXW |
For inquiries, technical support, or to request a quotation for super duplex stainless steel plates, please contact our sales team using the information below. All messages will be responded to within 24 hours.
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