F55 Steel ( UNS S32706 / 1.4501 )

Short Introduction:

  • F55 Steel ( UNS S32706 / 1.4501 ) is among the most common super duplex grade in the market. UNS S32760 is a duplex stainless steel especially designed for service in aggressive chloride-containing environments and has additions of W and Cu compared to UNS S32750. It has very good resistance to localized corrosion and stress corrosion cracking in combination with high mechanical strength.

    Description

    F55 Steel ( UNS S32706 / 1.4501 )

    Material grades and equivalents:UNS S32706 / 1.4505 / F55 / S27603 / 022Cr25Ni7Mo4WCuN / X2CrNiMoWN25-7-4

    Special properties:

    The characteristic features of high strength and corrosion resistance exhibited by the dual microstructure (50% Austenite, 50% Ferrite) associated with Duplex Stainless Steels, are enhanced by a further addition of Chromium (to 25%), and also Tungsten and Copper.

    The alloy’s pitting and Crevice Corrosion resistance is better than Standard F51 duplex, The pitting index (PREN) is increased to 40 min from standard F51 Duplex value of 33 min.

    Thin sections (Tubulars) are capable of being cold worked to give yield strength of 105 KSI min.

    To optimise mechanical properties, avoid clinking, and to avoid deleterious intermetallics within the microstructure; special high temp forming and heat treatment control practices must be followed during processing.

    F55 Duplex Stainless SteelChemical composition:

    Weight %

    C

    Si

    Mn

    S

    P

    Cr

    Ni

    Mo

    N

    Cu

    W

    Min.

     24,00

     6,00

     3,00

     0,20

     0,50

    0,50

    Max.

     0,030

     1,00

     1,00

     0,010

     0,030

     26,00

     8,00

     4,00

     0,30

     1,00

     1,00

    F55 Duplex Stainless Steel Mechanical Properties:

    UNS S32706

    1.4501

    F55

    Yield strength Rp0.2,

    Tensile strength Rm,

    Elongation

    Hardness

    Impact, Charpy-V, -46ºC

    Pre

    MPa

    MPa

    [%]

    [HB]

    [J]

    BAR

     ≥ 550

     ≥ 750

     ≥ 25

    ≤ 310

     ≥ 45

     ≥ 40

    PLATE CR (COIL)

     ≥ 550

     750 – 1000

     ≥ 25

    ≤ 310

     ≥ 45

     ≥ 40

    PLATE HR (COIL)

     ≥ 550

     750 – 930

     ≥ 25

    ≤ 310

     ≥ 45

     ≥ 40

    PLATE (QUARTO)

     ≥ 550

     750 – 930

     ≥ 25

    ≤ 310

     ≥ 45

     ≥ 40

    F55 Duplex StainlessSteel Physical properties:

    Density (Kg/m3)

    7810

    Magnetic Permeability (20°C)

    33

    Young’s Modulus (kN/mm2)

    199

    Specific Electrical Resistance, 20°C (µΩ.m)

    0.8

    Mean coefficient of thermal expansion, 20-300°C (m/m/oC)

    11.1 x 10-6

    Specific Heat, 20°C (J/kg.K)

    475

    Thermal conductivity, 20°C (W/m.K)

    14.2

    Fracture Toughness, kQ (MPa/m2)

    98

    F55 Duplex Stainless Steel  Specifications:

    1.4501

    ASTM A276/A476

    X2CrNiMoCuWN 25-7-4

    UNS S32760 (Super Duplex 32760)

    Z3CND25.06Az

    ASME A182 F55

    Norsok MDS D57

    CD3MWCuN (Cast grade)

    SAF32760

    25Cr

    Key Features:

    • Excellent corrosion resistance in a wide variety of corrosive chemicals

    • Pitting Resistance Equivalent number (PREN) of >40

    • Outstanding resistance to pitting and crevice corrosion in seawater and other chloride containing environments

    • Critical Pitting Temperature exceeding 50°C

    • High strength compared to austenitic and 22%Cr duplex stainless steels

    • Excellent ductility and impact strength at both ambient and sub-zero temperatures

    • High resistance to abrasion, erosion and cavitation erosion

    • Excellent resistance to stress corrosion cracking in chloride containing environments

    • Listed in NACE MR 0175 for sour service

    • ASME Approval for Pressure Vessel application

    F55 ( UNS S32706 / 1.4501 ) Duplex Stainless Steel Applications

    • Process industry components in nitric acid, dioxide, polypropylene & PVC

    • production, caustic evaporators

    • Equipment handling organic & fatty acids

    • Marine industry and shipbuilding propellers, shafts, rudders, shaft seals, pumps, bolts, fasteners, valves, instrumentation

    • Oil and chemical tankers

    • Oil & Gas industry pumps, valves, pipe, vessels, wellhead equipment, subsea equipment

    • Pollution control systems, fans and pumps, wet scrubbers, incinerators, flue gas desulphurisation (FGD)

    • Pulp & paper industry components such as black liquor heater tubes, digester blow valves, rotary feed valves, I.D.fans, brownstock washers, precipitators, bleaching components

    • Food Industry applications including sugar cane centrifuges, corn and vegetable processing plant

    • Agrochemicals production such as fertilisers (based on wet phosphoric acid)
      Sewage treatment, seawater cooling, desalination plants