UNS S32750 is the most common Super Duplex grade, equivalent to A182 F53, combining high tensile and impact strength, with a low co-efficience for thermal expansion and a high thermal conductivity.
The high chromium (25%), molybdenum (4%) and nitrogen levels provide excellent resistance to pitting, crevice and general corrosion, meaning that UNS S32750 is designed for use in demanding applications which require exceptional strength and corrosion resistance such as chemical process, petrochemical and offshore platforms and seawater equipment.
Other uses of S32750 include heat exchangers, pressure vessels and boilers, fire-fighting systems, desalination plants, high pressure RO-plant and seawater piping, absorber towers, ducting & piping and power industry FGD systems.
UNS S32750 also contains excellent mechanical properties, meaning that a light gauge of S32750 can be used to achieve the same design strength of a thicker nickel alloy – saving both weight and overall cost of fabrication.
UNS S32760, UNS S31803, UNS S32750,
UNS S32760 is a Super Duplex stainless steel equivalent to A182 F55 with a microstructure of 50:50 austenite and ferrite. The high chromium and molybdenum content of Super Duplex makes S32760 extremely resistant to uniform corrosion by both organic and inorganic acids – especially those containing chloride.
The higher than average molybdenum and chromium content also gives UNS S32760greater heat resistance quality and is also designed, as a Super Duplex alloy stainless steel, to feature high tensile & yield strength, pitting resistance, strong weldability, resistance to stress corrosion cracking, erosion & crevice corrosion and corrosion fatigue and good toughness.
UNS S32760 is used in equipment for the oil & gas industry, on offshore platforms, in heat exchangers, chemical processing, pressure vessels and boilers as well as in the petrochemical industry and desalination plants, including seawater piping.
UNS S31803 is a Duplex stainless steel equivalent to A182 F51 (1.4462) created as a austenitic ferretic iron chromium-nickel alloy with molybdenum addition.
Designed to combine improved resistance to stress corrosion cracking, pitting and crevice corrosion, S31803 is roughly double the strength of standard austenitic stainless steel. This means that UNS S31803 can be used successfully as an alternative to standard stainless steel specifications where a higher strength and higher stress corrosion resistance is required.
As Duplex material, UNS S31803 offers the benefits of high strength and corrosion resistance as well as low thermal expansion, higher heat conductivity than austenitic steels, high energy absorption and good workability and weldability.
Uses of UNS S31803 include forged or rolled alloy steel pipe flanges, primarily for the petrochemical industry, forged fittings and valves for high temperature application, heat exchangers, chemical tanks, refineries, compressor parts for seawater desalination plants and offshore pressure vessel parts.