The term “Super-Duplex” is used to denote highly alloyed, high-performance Duplex steel with a pitting resistance equivalent of >40 (based on Chromium % + 3.3 Molybdenum % + 16 Nitrogen %). Due to a high level of chromium, Super Duplex Steel Fasteners provides outstanding resistance to acids, acid chlorides, caustic solutions and other environments in the chemical/petrochemical, pulp, and paper industries, often replacing stainless steel 300 series, high nickel super austenitic steels and nickel-based alloys.
Super Duplex Steel Fasteners are available in various types such as screws, bolts, nuts, washers, anchor, rivet, studs, hex nuts, stud bolts, plain washers, heavy hex nuts, T bolts, eye bolts, coupling nuts, machine screws, jam nuts, lock washers, etc.
The chemical composition based on high contents of chromium, nickel, and molybdenum improves intergranular and pitting corrosion resistance. Additions of nitrogen promote structural hardening by interstitial solid solution mechanism, which raises the yield strength and ultimate strength values without impairing toughness. Moreover, the dual-phase microstructure guarantees higher pitting resistance and resistance to stress corrosion cracking in comparison with conventional stainless steel.
These Super Duplex 2507 Fasteners have very high strength along with high resistance to pitting, crevice, and general corrosion. It has 25 percent of chromium, 4 percent of molybdenum, and 7 percent of nickel, which has a mixed microstructure of austenite and ferrite (50 / 50) which has improved strength over ferritic and austenitic steel grades. It is not recommended for applications which require long exposures to temperatures above 570 degrees F, for the reason that of the risk of a reduction in toughness.
Super Duplex Steel UNS S32750 Fasteners are designed to handle highly corrosive conditions and situations where high strength is required. High molybdenum, chromium and nitrogen content in Super Duplex UNS S32750 help the fasteners withstand pitting and crevice corrosion. They are also resistant to chloride stress corrosion cracking, erosion-corrosion, to corrosion fatigue, to general corrosion in acids and have good weldability and very high mechanical strength.
Super Duplex Steel UNS S32750 Fasteners are widely used in various sectors like Power, Marine, Chemical, Pulp and Paper, Petrochemical, Water desalinization, and Oil and gas production.
Super Duplex Steel UNS S32950 Fasteners have features like Greater tensile and yield strength, Improved corrosion resistance in comparison to Duplex Steel, reduced material costs without compromising on the quality of the material, Good stress corrosion cracking resistance (SSC), Good ductility and toughness, etc.
Super Duplex Steel UNS S32950 Fasteners have applications in various industries like shipbuilding, heavy equipment, power generation, oil and gas, electrical equipment, agricultural applications, etc.