What is Super Duplex Steel?
Super duplex pipes are a very practical metal that is widely utilized all over the globe. Its composition of two distinct metal classes is the source of its name. Duplex is essentially a Fe-Ni-Cr alloy and features a two-phase ferritic-austenitic stainless steel microstructure at room temperature.
In comparison to austenitic stainless steels, duplex steels have higher chromium (19–28%), molybdenum (up to 5%), and lower nickel concentrations. The two most popular duplex stainless steel plates are 2507 (25% chromium, 7% nickel) and 2205 (22% chromium, 5% nickel); 2507 is also referred to as “super duplex” due to its superior corrosion resistance.
Combining ferritic and austenitic grades has the benefit of creating a metal with a two-phase metallurgical structure that benefits from the characteristics of both microstructures. Due to these qualities, duplex steel is highly valued in heavy sectors like nuclear and chemical processing as well as oil and gas extraction.
Features and Benefits of Super Duplex Steel Pipes:
Strength: Super duplex pipes are roughly twice as strong as standard austenitic or ferritic stainless steels in terms of strength.
Ductility and toughness: Duplex stainless steels are ductile and tougher than ferritic grades, while they are not as strong as austenitic grades.
Corrosion Resistance: As with all stainless steels, corrosion resistance is mostly determined by the material’s composition, with the amounts of chromium, molybdenum, and nitrogen being the most crucial. Duplex stainless steels have very high resistance to stress corrosion cracking and are incredibly corrosion resistant, even in settings with chloride and sulfide (SCC). Tensile tension, a corrosive environment, and a high enough temperature are necessary conditions for the occurrence of SCC, a particular type of corrosion.
Resistance to Heat: Compared to austenitic steels, duplex stainless steel has a higher heat conductivity and a lower thermal expansion. Because they are more ductile at low temperatures than ferritic steel grades, they can be used down to at least 50 °C with ease.
Cost: Compared to their austenitic counterparts, duplex stainless steels have lower nickel and molybdenum concentrations. Due to the decreased alloying content, duplex stainless steels are more affordable. Due to its improved yield strength, duplex stainless steel may also allow for a reduction in thickness. Products that are thinner allow for significant weight reduction.
Weldability: Despite not being as easily welded as austenitic grades, duplex stainless steels often have high weldability and may be joined using all common welding techniques.
Applications of Super Duplex Steel Pipes:
Due to its various advantages, duplex stainless steel can be utilized in a wide range of applications, including processing, moving, and storing chemicals. It is also used in the oil and gas industry for oil and gas production and transportation pipes. Offshore rigs are used for oil and gas exploration and the refinery of gas and oil. along with that used in habitats in the ocean, pollution prevention tools, pulp, and paper production, chemical processing facilities, mechanical and structural elements, exchangers of heat, and cooling conduits.
