Duplex S31803

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Duplex S31803


We are stockists of 31803 duplex alloys in sheet, plate, and bar directly distributed globally from our UK stockholding warehouse, combined with our large capacity cutting capabilities we can meet requirements for many industries.


Properties of 31803


  • Stainless ferritic-austenitic Cr-Ni-Mo steel with nitrogen addition.
  • High corrosion resistance, especially against stress corrosion cracking in solutions containing chloride.
  • Good strength properties.
  • Resistant to intergranular corrosion in the temperature range up to 300°C.
  • Heat treatment subsequent to welding not necessary.
  • Surface condition for optimum corrosion resistance: pickled, heat treated free from scale or machined.

  • Application

    Components in the chemical industry, e.g. separator and heat exchanger parts, from the paper industry, oil and gas production, compressor parts, seawater desalination plants.

    Technical Info

    Chemical Composition(%)


    C Si Mn Cr Mo Ni N
    0.025 0.60 1.30 22.60 3.20 5.80 0.17

    Standards

    EN / DIN ASTM UNS AFNOR
    <1.4462 >
    X2CrNiMoN22-5-3
    A240 S31803 Z2CND22-5 Az

    Hot Forming

    Forging

    1200 to 950°C / Air cooling

    Heat Treatment

    Solution annealing:

    1020 to 1100°C
    Water , air (thickness below 2mm)

    Structure

    Ferrite + Austenite

    Mechanical Properties

    Condition: solution annealed

    Product Dimension
    Size
    mm
    0.2% proof stress
    N/mm2
    min.
    Tensile strength
    N/mm2
    Elongation A5
    % min.
    L Q T
    Impact strength
    (ISO-V)
    J min.
    L Q T
    St ≤ 160 450 650 – 880 25 - – - - 100 - – - -
    Bl ≤ 75 460 640 – 840 252) 252) - - 90 60 - -

    St = Bar ,
    Bl = Sheet or plate
    L = Longitudinal, Q = Transverse, T = Tangential
    1) For sheet or plate < 3mm = A80mm specimen
    The values for other products and dimensions shall be established by agreement.

    High Temperature Properties

    Condition: solution annealed

    0.2% yield strength
    N/mm² min.
    Temperature
    100°C 150°C 200°C 250°C
    360 335 315 300

    Welding

    Good weldability. Welding is possible with all processes usual for stainless steels. We recommend depending on applications electric arc welding with covered electrodes, inert gas welding or SA-welding. Preheating and heat treatment after welding is not necessary. For high stressed heavy walled constructions the limited preheat temperature of 150°C maximum is recommendable. Maximum interpass temperature 150°C. Keep heat input low especially for small wall thicknesses. The TIG-process should be given reference for root welding.

    Physical Properties

    Thermal conductivity at ……………….. 20°C ………………15.0 ………W/(m.K)
    Specific heat at …………………………..20°C ………………500 ……….J/(kg.K)
    Electrical resistivity at …………………. 20°C ………………0.80 ………Ohm.mm2/m
    Modulus of elasticity at ……………….. 20°C ………………200 x 103 N/mm2
    Magnetic properties ……………………………………………..magnetic

    Thermal expansion between
    20°C and …°C, 10-6 m/(m.K) at
    Temperature 10-6 m/(m.K)
    100°C 13.0
    200°C 13.5
    300°C 14.0

    Modulus of elasticity, 103 N/mm2 at Temperature 103 N/mm2
    20°C 200
    100°C 194
    200°C 186
    300°C 180

    As regards applications and processing steps that are not expressly mentioned in this product description/data sheet, the customer shall in each individual case be required to consult us.

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