Duplex steel
Duplex grades have a ferritic-austenitic microstructure that combines many of the beneficial properties of ferritic and austenitic stainless steels. The duplex microstructure also contributes to high strength and high resistance to stress corrosion cracking.Duplex stainless steels are characterized by high chromium content (20.1–25.4%) and low nickel content (1.4–7%) compared to austenitic grades. The low nickel content makes duplex grades more price stable.Molybdenum (0.3–4%) and nitrogen are added to improve corrosion resistance, while nitrogen also increases strength. Due to their ferrite content the duplex grades are magnetic.
Carbon steels offer the proper combination of strengths, ductility, toughness, and weldability. The carbon content is rarely over 0.25% (above this level, toughness, and weldability are reduced) or below 0.15% for reasons of strength. Besides carbon, the most significant alloying element is manganese, which is added to increase yield and tensile strength without reducing ductility. The use of carbon steels is limited to temperatures under 1000°F (538°C). The most widely used carbon steels are SA 36, SA 285 Grade C, and SA 515 and 516 Grade 70.
Characteristic properties
• Good to very good resistance to uniform corrosion
• Good to very good resistance to pitting and crevice corrosion
• High resistance to stress corrosion cracking and corrosion fatigue
• High mechanical strength
• Good abrasion and erosion resistance
• Good fatigue resistance
• High energy absorption
• Low thermal expansion
• Good weldability
Applications
• Pulp and paper industry
• Desalination plants
• Flue-gas cleaning
• Cargo tanks and pipe systems in chemical tankers
• Seawater systems
• Firewalls and blast walls on offshore platforms
• Bridges
• Components for structural design
• Storage tanks
• Pressure vessels
• Heat exchangers
• Water heaters
• Rotors, impellers and shafts
• Reinforcing bars for concrete structures
Duplex Steel Grades
Stainless Steel Alloy Duplex 2205, UNS S32205
Duplex 2205
Duplex 2205, also known as UNS S32205, is a nitrogen-enhanced stainless steel. Users choose Duplex 2205 for its excellent corrosion resistance along with its high strength. It is important to note that Duplex 2205, offers much higher levels of corrosion resistance than most other austenitic stainless steels. ● High resistance to pitting and crevice corrosion
● Excellent in most caustic environments
● Good weldability
Stainless Steel Alloy 2304, Duplex 2304
Duplex 2304
Duplex 2304, also called Alloy 2304, is a molybdenum-free duplex stainless steel. It has a structure that is a balance of ferritic and austenitic and is often used as a replacement for Alloys 304L and 316L. Some of Duplex 2304 stainless steel’s other properties include
● Outstanding corrosion resistance
● Yield strength (twice that of 304L/316L)
● Suitable for applications covering -50ºC/+300ºC temperature range
● Resistance to pitting and crevice corrosion
● Improved machinability and weldability
Stainless Steel Alloy Duplex 2202, DX2202
Duplex 2202
Duplex 2202, or DX2202, is an austenitic-ferritic stainless steel. It offers users general resistance to corrosion that is comparable to Type 304L. Some of the other key characteristics of Duplex 2202 include.
● Improved mechanical strength
● Service temperature range of -50 °C to 300°C
● Stress corrosion resistance that is often double other austenitic stainless steels
● Can be used in combination with nitric acid
Stainless Steel Alloy 2507, Duplex 2507
Duplex 2507
Duplex 2507, is a commonly used super duplex stainless steel. Also sold as Alloy 2507, this alloy is used in situations where exceptional strength and corrosion resistance are in demand. Some of the applications and industries that utilize Duplex 2507 include.
● Chemical process industries
● Heat exchangers, vessels, and piping
● Desalination plants and other saltwater applications
● Power industry FGD systems
● Offshore platforms including fire-fighting systems
Stainless Steel Alloy Zeron® 100, Super Duplex Stainless , Super Duplex
Zeron® 100
Zeron® 100, which is also sold under the names Super Duplex Stainless and Super Duplex, is a highly alloyed stainless steel that is designed for use in difficult and aggressive environments.
Because of its outstanding strength, Zeron 100 is known as a super duplex stainless steel. Originally created for applications that demand corrosion resistance to seawater in the North Sea, Zeron 100 is also perfect for other industries and applications. These include:.
● Oil and gas,
● Pulp and paper
● Power generation
● Chemical
● Pharmaceutical
● Mining
● Desalination,