Super Duplex Steel

Super Duplex Stainless Steel

Brown McFarlane holds stock of Super Duplex stainless steel plate specifications UNS S32750 (1.4410) and UNS S32760 (1.4501). In order to get more specific information on these steel grades click the following links:

A Super Duplex stainless steel is a type of Duplex stainless steel with enhanced corrosion resistance which is categorised by its PREN being greater than 40. A standard Duplex like the S31803 grade stocked by Brown McFarlane has a PREN of around 35. The Pitting Resistance Equivalent Number (PREN) is widely used as a means of comparing the relative corrosion resistance of different steel grades. The PREN is obtained by applying a mathematical formula to the chemical composition of a steel so that PREN = %Cr + (3.3 x %Mo) + (16 x %N). 

As a part of the Duplex family of stainless steels Super Duplex stainless has a microstructure which is split roughly 50:50 between austenite and ferrite. It differs from Duplex in its chemical composition (with increased amounts of Molybdenum, Nickel, and Chromium) and its mechanical properties (higher proof stress and tensile strength). This highly alloyed product is especially designed for marine, chemical, and oil engineering applications requiring both high mechanical strength and resistance to corrosion in extremely aggressive environments (chloride-containing acids etc.).

Super Duplex stainless steel, relative to other stainless steel products, gives

  • High corrosion resistance
  • High resistance to stress corrosion cracking
  • High yield strength and tensile strength

It is used extensively for offshore oil and gas applications and can be found in flow lines, risers, process vessels, separators, coolers, manifolds, and process piping. Onshore it can be found in heat exchangers, boilers, and pressure vessels in petrochemical and chemical processing plant.

Contact Brown McFarlane’s specialist stainless steel team for all sales and technical enquiries. We also hold stocks of Duplex stainless to UNS S31803, 1.4462, and UNS S32205. Click here for more details.

Super Duplex Stainless Steel Plate

Brown McFarlane holds an extensive stock of Super Duplex stainless steel plate and is one of the few companies to keep both S32750 (1.4410) and S32760 (1.4501) material grades.  All stock plate is manufactured by Western European steel makers, third party inspected, and certified in accordance with EN 10204 3.2. All plates are also certified in accordance with NORSOK MDS D55 and any plates up to an including 35 mm thick will be to NORSOK MDS D55 Revision 4. 

Plates are stocked as large format (up to 12,000 mm long and 2,500 mm wide) which is designed to minimise fabrication costs for our customers by reducing the amount of welding required. The large format also gives us the opportunity to make the best possible use of each plate when “nesting” the shapes required by our customers. Given the specialised nature of this type of steel it is no great surprise that the majority of our sales are made in cut and processed form.

For more details of our stock range in Super Duplex plates, click on the following links:



Plate Cutting

Plate Processing

  • Weld preparations
  • Grinding
  • Drilling and tapping
  • Pressing
  • Machining
  • Shotblasting and painting
  • Rolling
  • Rolled shells
  • Dished ends
  • Clad plates


 Stainless Steel, Duplex pdf icon

A full list of sizes, specifications and processing facilities of our range of wide, large area stainless and super steel plate.

     Download (1MB)


Or, contact the stainless steel team directly on: | +44 (0) 1922 748 710