S32550 / AMAZON 256

Oil & Gas

S32550 / AMAZON 256

S32550, marketed by Columbia Metals as AMAZON 256, is an exceptional stainless steel designed for high strength use with good resistance to chemical corrosion and attack from seawater. It has a finely tuned, well-balanced chemical composition and a tightly controlled production procedure all of which ensure an optimisation of mechanical properties, corrosion resistance and workability.

The alloy has an equal balance of austenite and ferrite in the duplex microstructure that ensures mechanical properties at least 40% higher than those of 316 stainless steel as well as superior toughness and ductility to ferritic stainless steels.

S32550 is also designed with a composition formulated to guarantee a PREN (%Cr + 3.3times%Mo + 16times%N) of greater than 40.0 and ensures a critical pitting temperature above 40ºC, a critical crevice corrosion temperature of greater than 30ºC and a very high corrosion resistance in seawater as well as in sulphuric acid, nitric acid, phosphoric acid and a large number of organic acids.

Related Specifications of S32550

  • ASTM A240
  • ASTM A479
  • 1.4507
  • X2CrNiMoCuN25-6-3

Nominal Composition of S32550

Fe rem, Cr 26.0%, Ni 6.0%, Mo 3.5%, Cu 2.0% N 0.2%

Mechanical Properties of S32550

Ultimate Tensile Strength (N/mm²) Proof Stress (N/mm²) Elongation (%) Hardness (HB)
760 550 25 280 max

Key Features of S32550

  • Very good mechanical properties
  • Excellent resistance to fatigue and corrosion fatigue
  • Excellent general corrosion resistance
  • High resistance to erosion and abrasion in flowing systems
  • Good machinability and weldability

Applications of S32550

Offshore & marine | Offshore platforms, components for gas, oil and process cooling plants; instrumentation, wellhead and subsea wellhead fittings; desalination plants, seawater cooled heat exchangers, cargo heating systems, marine shafts (for boats etc) and high strength fasteners

Chemical processing | Equipment handling organic or dilute sulphuric acid, process solutions contaminated with chlorides, refinery equipment, desulphurising and distillation units; sewage plant components, fire extinguishing systems, general processing; mixing plant and high strength fasteners

Other | Nuclear waste casks, medical instruments, paper mill equipment and chemical process plants; mechanical components including springs, screws, bolts, gears, bushes and wear rings

Columbia Metals – a leading supplier of S32550

With decades of experience and a huge range of stock, Columbia Metals is an industry leader in the supply of S32550 and other high quality specialist engineering alloys.

To buy or learn more about S32550 contact us now, or fill in the enquiry form on the right hand side and we will be in touch shortly.

  Related Specifications Mechanical Properties
Alloy Name BS UNS BS EN Others Ultimate Tensile Strength N/mm² Minimum Yield Strength N/mm² Elongation % Hardness HB  
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