See all Blog Posts What is Duplex Steel? Category: Steel Posted: April 13, 2022 What is Duplex Steel? Duplex Steel is a type of stainless steel that has two different grain phases, known as Austenite and Ferrite, present in the microstructure. The Austenite and Ferrite phases have different atomic structures and exhibit different physical properties, and as Duplex Steel contains roughly 50% of each phase it can exhibit beneficial traits from both material types. These properties include: Relatively high strength when compared to other stainless steel products Improved ductility and toughness when compared to ferritic steel products, however these values remain less than austenitic products Excellent corrosion resistance How is Duplex Steel Made? Like all types of Stainless Steel, Duplex Steel is smelted by combining the raw materials containing nickel, iron ore, chromium, molybdenum, and other alloying elements in a furnace to be melted down and mixed together. Compared to other stainless steels, Duplex Steel contains a higher chromium content of around 25%, a reduced nickel content of below 9% and a small about of nitrogen. The alloy content of Duplex Steel is defined in ranges and are typically designated by their chromium content. The molten Duplex Steel mix solidifies as a completely ferritic solid, however as it cools to room temperature half the material changes from the ferritic phase to the austenite phase. What is Duplex Steel used for? The high strength, high corrosion resistance and relatively low alloy content (especially nickel) typically makes Duplex Steel a low-cost option for high strength, high corrosion risk applications. They are used extensively in the offshore oil and gas industry for pipework systems, manifolds, risers, etc and in the petrochemical industry in the form of pipelines and pressure vessels. Although duplex stainless steels have high corrosion and oxidation resistance they cannot be used at elevated temperatures due to the formation of brittle phases in the ferrite at relatively low temperatures. These phases have a significant effect on the toughness of the steel and these applications should be avoided. Metal Supermarkets offers over 8,000 types, shapes and grades of metal. Find metal for your next project. Shop Now. Metal Supermarkets Metal Supermarkets is the world’s largest small-quantity metal supplier with over 100 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985. At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: mild steel, stainless steel, aluminum, tool steel, alloy steel, brass, bronze and copper. We stock a wide range of shapes including: bars, tubes, sheets, plates and more. And we can cut metal to your exact specifications. Visit one of our 100+ locations across North America today. Share: Facebook Twitter LinkedIn E-Mail Related blog articles Different Types of Metal Finishing: Processes & Techniques Windsor Welcomes Metal Supermarkets The World’s Largest Supplier of Small Quantity Metals What is the Difference Between 7050 vs 7075 Aluminum?