Super Duplex 32750 Plates | UNS S32750 High-Strength Seawater & Chloride Protection for Chemical, Oil & Gas, Marine, Pharma & Power
Table of Contents:
A large offshore gas compression platform had already upgraded from 316L and Duplex 2205 to thicker plates in its seawater lift pumps, riser clamps and splash‑zone manifolds, but after a few years in 35 °C natural seawater the NDT reports still showed pitting around welds, crevice attack under gaskets and fatigue damage where waves and vibration combined with corrosion. When the integrity and procurement teams rebuilt those critical structures in Super Duplex 32750 Plates (UNS S32750, 1.4410), they chose a super duplex stainless steel designed for highly corrosive seawater and high‑load service, with about 24–26% chromium, 6–8% nickel, 3–5% molybdenum and roughly 0.24–0.32% nitrogen; plate data show tensile strength around 795–800 MPa minimum, 0.2% yield strength around 550–80 MPa minimum depending on specification, elongation about 15–25%, together with excellent resistance to pitting, crevice corrosion and chloride stress‑corrosion cracking in natural seawater. Subsequent inspection campaigns reported stable wall thickness and minimal localised corrosion in areas where previous materials had failed repeatedly, even under long‑term exposure to warm, aerated seawater and cyclic mechanical loading.
Super Duplex 32750 (often referred to as Super Duplex 2507) is a super duplex stainless steel with a mixed austenitic–ferritic microstructure and high chromium, molybdenum and nitrogen contents that give it outstanding resistance to pitting, crevice corrosion and stress‑corrosion cracking in chloride‑containing environments. Typical compositional ranges reported for UNS S32750 include about 24–26% chromium, 6–8% nickel, 3–5% molybdenum and around 0.24–0.32% nitrogen with a maximum carbon content of about 0.03%, and producers highlight that this chemistry gives higher strength and better corrosion resistance than Duplex 2205 in seawater and sour‑service conditions.
For procurement heads, design and corrosion engineers, fabricators, OEM manufacturers and hardware or industrial supply stores serving chemical, oil & gas, marine, pharma and power‑generation sectors, Super Duplex 32750 plates offer a way to reduce thickness and total cost of ownership where 316L, 904L and even Duplex 2205 face unacceptable pitting, crevice attack or stress‑corrosion cracking. Representative data for ASTM A240 UNS S32750 plate list minimum tensile strength 795–800 MPa, minimum yield strength 550–80 ksi (≈550 MPa) and minimum elongation around 15–25%, alongside Brinell hardness up to about 290–310 HBW, which gives a strength‑to‑weight ratio significantly higher than standard austenitic stainless steels and many duplex grades. Corrosion references emphasise that Super Duplex 32750 can withstand long‑term service in natural seawater with about 19 000 ppm chlorides with minimal risk of pitting or SCC, and application notes highlight excellent resistance to uniform corrosion in sulfuric and hydrochloric acids at moderate concentrations and temperatures.
High-quality Super Duplex 32750 Plates ready for industrial use.
Specification Overview
| Supplier & Role | Aurico Alloys LLP – Super Duplex 32750 Plates supplier, stockist, exporter in India to abroad |
|---|---|
| Alloy Description | Super duplex stainless steel with high Cr, Mo, Ni and N designed for highly corrosive seawater, chloride and sour‑service environments combining very high strength with excellent corrosion resistance |
| UNS / EN / Werkstoff | UNS S32750, EN 1.4410, often described as X2CrNiMoN25‑7‑4 or F53 in some specifications |
| Main Plate Standards | ASTM A240 / ASME SA‑240 for plate, sheet and strip; producers also note compliance with offshore standards such as NORSOK M‑630 for certain Super Duplex S32750 plate products |
| Thickness Range | 4.75 mm – 150 mm |
| Pitting & Crevice Resistance | High PREN (typically >40) and data highlighting excellent resistance to pitting and crevice corrosion in natural seawater and chloride‑containing environments |
| Price | INR 800 – 1,200 per kg. Indicative USD 9 – 14 per kg; quoted against grade, form, size and quantity. |
UNS & Equivalent Grades
| Property | Value |
|---|---|
| UNS number | S32750 |
| Werkstoff / EN number | 1.4410 |
| EN designation | X2CrNiMoN25-7-4 |
| Density | 7.80 g/cm3 |
| Melting range | 1445 °C |
| Specific heat (20 °C) | 460 J/kg·K |
| Thermal conductivity (20 °C) | 13.5 W/m·K |
| Coefficient of expansion (20–200 °C) | 14.0 µm/m·K |
| Coefficient of expansion (20–400 °C) | 14.5 µm/m·K |
| Electrical resistivity (20 °C) | 0.8 Ω·mm²/m |
| Young's modulus (20 °C) | 200 GPa |
| Magnetic | yes |
| Oil and gas conformance | NACE MR0175 / ISO 15156-3 · NACE MR0103 / ISO 17945 · Norsok M-630 MDS D55 (Aperam DX2507 Technical Data Sheet) |
| Plate, sheet and strip specification | ASTM A240 |
Identifiers and physical constants for Duplex 32750. A dash means no such designation is published for this grade.
Stock & Product Availability
As a Super Duplex 32750 Plates stockist, Aurico Alloys LLP can supply plate and sheet sizes suitable for topside and subsea structures, riser clamps, manifolds, reactors, scrubber and absorber shells, tube sheets and channel covers used in chemical, oil & gas, marine, pharma and power‑generation installations, in thickness and width ranges similar to those listed for ASTM A240 UNS S32750 plate.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Carbon (C) | 0.025 nominal | |
| Chromium (Cr) | 25.8 nominal | |
| Nickel (Ni) | 7.0 nominal | |
| Molybdenum (Mo) | 3.8 nominal | |
| Nitrogen (N) | 0.27 nominal | |
| Manganese (Mn) | 0.8 nominal | |
Nominal composition for Duplex 32750. These are nominal figures rather than acceptance limits, and they are not measured values for a lot; the mill test certificate supplied with your order states the actual analysis.
Mechanical & Physical Properties
| Property (Room Temperature, Plate) | Typical Value – Super Duplex 32750 |
|---|---|
| Ultimate Tensile Strength | ≥795–800 MPa (≈116 000 psi) minimum for plate in solution‑annealed condition |
| 0.2% Yield Strength | ≥550 MPa (≈80 000 psi) minimum for plate, significantly higher than duplex 2205 and 316L |
| Elongation | ≥15–25% depending on specification and product form |
| Hardness | ≤32 HRC or ≈290–310 HBW for plate products |
| Modulus of Elasticity | ≈200 GPa at 20 °C, decreasing slightly with temperature |
| Thermal Conductivity | ≈15 W/(m·K) at 20 °C, rising to about 18 W/(m·K) at 300 °C |
| Stress‑Corrosion Cracking | Datasheets and corrosion notes emphasise excellent resistance to chloride‑induced SCC in comparison with austenitic stainless steels and good performance in sour environments. |
Applications & Benefits
- Chemical & Oil & Gas: Super Duplex 32750 plates are widely used in heat exchangers, pressure vessels, piping and manifolds in chemical plants and upstream oil & gas, where high Cr–Mo–N and duplex strength provide excellent resistance to pitting, crevice corrosion, SCC and erosion‑corrosion in chloride‑bearing and sour media at high pressure.
- Marine & Desalination: UNS S32750 / 1.4410 plates are selected for seawater lift pumps, RO frames, desalination heat exchangers, coastal structures and splash‑zone components because they can withstand long‑term exposure to natural seawater with minimal risk of pitting or SCC, outperforming duplex 2205 in the harshest seawater conditions.
- Pharma & Power: In pharma utilities, FGD absorbers, condensers and coastal power‑plant cooling systems, Super Duplex 32750 combines high strength, low thermal expansion and high thermal conductivity, which helps reduce thermal stresses and improve reliability in high‑temperature, high‑velocity and cyclic‑duty service.
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Conclusion
Super Duplex 32750 Plates from Aurico Alloys LLP, supplied to UNS S32750 / EN 1.4410 chemistry limits and ASTM A240 mechanical requirements, give chemical, oil & gas, marine, pharma and power‑generation users a super duplex solution that combines very high strength with exceptional resistance to seawater, chlorides and sour service in their most critical assets are your highest‑risk seawater, brine and chloride‑exposed systems still relying on lower‑alloy plates instead of optimised Super Duplex 32750 plates?