VDM® Alloy 825

Alternative and trade names
Nicrofer 4221, Incoloy 825, VDM® Alloy 825
Want to keep this datasheet? Save it now in your required format

Description

2.4858 (NiCr21Mo) is a titanium-stabilized fully austenitic nickel-iron-chromium alloy with additions of copper and molybdenum that shows the following features and properties:


  • High resistance to chloride-induced stress corrosion
  • Good resistance to chloride-induced pitting and crevice corrosion
  • Good resistance to oxidizing and non-oxidizing hot acids
  • Good toughness, even under continuous operation, at both room and elevated temperatures, up to approximately 550°C
  • Approval for pressure vessels with wall temperatures up to 450 °C (842°F) acc. to VdTÜV and 538 °C (1,000°F) for Section VIII Division 1 vessels acc. to ASME.
  • Equivalent Materials

    This material data has been provided by VDM Metals.

    All metrics apply to room temperature unless otherwise stated. SI units used unless otherwise stated.
    Equivalent standards are similar to one or more standards provided by the supplier. Some equivalent standards may be stricter whereas others may be outside the bounds of the original standard.

    Ashby charts

    See where falls on the material property chart for against in your materials selection and design process. Our Ashby charts are interactive with more technical data upon clicking. Sign up to get access to this premium feature for free.

    Properties

    General

    PropertyValueTemperature

    Density

    8.14 g/cm³

    Show Supplier Material materials with Density of 8.14 g/cm³ at 23.0 °C

    23.0 °C

    Mechanical

    PropertyValueTemperature

    Elastic modulus

    195 GPa

    Show Supplier Material materials with Elastic modulus of 195 GPa at 20.0 °C

    20.0 °C

    190 GPa

    Show Supplier Material materials with Elastic modulus of 190 GPa at 100.0 °C

    100.0 °C

    185 GPa

    Show Supplier Material materials with Elastic modulus of 185 GPa at 200.0 °C

    200.0 °C

    179 GPa

    Show Supplier Material materials with Elastic modulus of 179 GPa at 300.0 °C

    300.0 °C

    174 GPa

    Show Supplier Material materials with Elastic modulus of 174 GPa at 400.0 °C

    400.0 °C

    168 GPa

    Show Supplier Material materials with Elastic modulus of 168 GPa at 500.0 °C

    500.0 °C

    161 GPa

    Show Supplier Material materials with Elastic modulus of 161 GPa at 600.0 °C

    600.0 °C

    154 GPa

    Show Supplier Material materials with Elastic modulus of 154 GPa at 700.0 °C

    700.0 °C

    142 GPa

    Show Supplier Material materials with Elastic modulus of 142 GPa at 800.0 °C

    800.0 °C

    130 GPa

    Show Supplier Material materials with Elastic modulus of 130 GPa at 900.0 °C

    900.0 °C

    119 GPa

    Show Supplier Material materials with Elastic modulus of 119 GPa at 1000.0 °C

    1000.0 °C

    Elongation

    30 %

    Show Supplier Material materials with Elongation of 30 % at 23.0 °C

    23.0 °C

    Impact strength, Charpy notched

    1500 kJ/m²

    Show Supplier Material materials with Impact strength, Charpy notched of 1500 kJ/m² at 23.0 °C

    23.0 °C

    Tensile strength

    585 MPa

    Show Supplier Material materials with Tensile strength of 585 MPa at 20.0 °C

    20.0 °C

    530 MPa

    Show Supplier Material materials with Tensile strength of 530 MPa at 100.0 °C

    100.0 °C

    525 MPa

    Show Supplier Material materials with Tensile strength of 525 MPa at 150.0 °C

    150.0 °C

    515 MPa

    Show Supplier Material materials with Tensile strength of 515 MPa at 200.0 °C

    200.0 °C

    510 MPa

    Show Supplier Material materials with Tensile strength of 510 MPa at 250.0 °C

    250.0 °C

    500 MPa

    Show Supplier Material materials with Tensile strength of 500 MPa at 300.0 °C

    300.0 °C

    495 MPa

    Show Supplier Material materials with Tensile strength of 495 MPa at 350.0 °C

    350.0 °C

    490 MPa

    Show Supplier Material materials with Tensile strength of 490 MPa at 400.0 °C

    400.0 °C

    485 MPa

    Show Supplier Material materials with Tensile strength of 485 MPa at 450.0 °C

    450.0 °C

    Unlock all property charts

    Yield strength Rp0.2

    240 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 240 MPa at 20.0 °C

    20.0 °C

    205 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 205 MPa at 100.0 °C

    100.0 °C

    190 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 190 MPa at 150.0 °C

    150.0 °C

    180 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 180 MPa at 200.0 °C

    200.0 °C

    175 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 175 MPa at 250.0 °C

    250.0 °C

    170 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 170 MPa at 300.0 °C

    300.0 °C

    165 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 165 MPa at 350.0 °C

    350.0 °C

    160 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 160 MPa at 400.0 °C

    400.0 °C

    155 MPa

    Show Supplier Material materials with Yield strength Rp0.2 of 155 MPa at 450.0 °C

    450.0 °C

    Unlock all property charts

    impactTransVNotch

    1000 kJ/m²

    Show Supplier Material materials with impactTransVNotch of 1000 kJ/m² at 23.0 °C

    23.0 °C

    Thermal

    PropertyValueTemperature

    Coefficient of thermal expansion

    1.41E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.41E-5 1/K at 100.0 °C

    100.0 °C

    1.49E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.49E-5 1/K at 200.0 °C

    200.0 °C

    1.52E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.52E-5 1/K at 300.0 °C

    300.0 °C

    1.56E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.56E-5 1/K at 400.0 °C

    400.0 °C

    1.58E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.58E-5 1/K at 500.0 °C

    500.0 °C

    1.6E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.6E-5 1/K at 600.0 °C

    600.0 °C

    1.67E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.67E-5 1/K at 700.0 °C

    700.0 °C

    1.72E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.72E-5 1/K at 800.0 °C

    800.0 °C

    1.76E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.76E-5 1/K at 900.0 °C

    900.0 °C

    1.79E-5 1/K

    Show Supplier Material materials with Coefficient of thermal expansion of 1.79E-5 1/K at 1000.0 °C

    1000.0 °C

    Unlock all property charts

    Melting point

    1370 - 1400 °C

    Show Supplier Material materials with Melting point of 1370 - 1400 °C

    Specific heat capacity

    440 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 440 J/(kg·K) at 20.0 °C

    20.0 °C

    462 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 462 J/(kg·K) at 100.0 °C

    100.0 °C

    488 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 488 J/(kg·K) at 200.0 °C

    200.0 °C

    514 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 514 J/(kg·K) at 300.0 °C

    300.0 °C

    540 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 540 J/(kg·K) at 400.0 °C

    400.0 °C

    565 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 565 J/(kg·K) at 500.0 °C

    500.0 °C

    590 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 590 J/(kg·K) at 600.0 °C

    600.0 °C

    615 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 615 J/(kg·K) at 700.0 °C

    700.0 °C

    655 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 655 J/(kg·K) at 800.0 °C

    800.0 °C

    680 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 680 J/(kg·K) at 900.0 °C

    900.0 °C

    710 J/(kg·K)

    Show Supplier Material materials with Specific heat capacity of 710 J/(kg·K) at 1000.0 °C

    1000.0 °C

    Unlock all property charts

    Thermal conductivity

    10.8 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 10.8 W/(m·K) at 20.0 °C

    20.0 °C

    12.4 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 12.4 W/(m·K) at 100.0 °C

    100.0 °C

    14.1 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 14.1 W/(m·K) at 200.0 °C

    200.0 °C

    15.6 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 15.6 W/(m·K) at 300.0 °C

    300.0 °C

    16.9 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 16.9 W/(m·K) at 400.0 °C

    400.0 °C

    18.3 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 18.3 W/(m·K) at 500.0 °C

    500.0 °C

    19.6 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 19.6 W/(m·K) at 600.0 °C

    600.0 °C

    21 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 21 W/(m·K) at 700.0 °C

    700.0 °C

    23.2 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 23.2 W/(m·K) at 800.0 °C

    800.0 °C

    25.7 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 25.7 W/(m·K) at 900.0 °C

    900.0 °C

    28.1 W/(m·K)

    Show Supplier Material materials with Thermal conductivity of 28.1 W/(m·K) at 1000.0 °C

    1000.0 °C

    Unlock all property charts

    Electrical

    PropertyValueTemperature

    Electrical resistivity

    1.12E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.12E-6 Ω·m at 20.0 °C

    20.0 °C

    1.14E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.14E-6 Ω·m at 100.0 °C

    100.0 °C

    1.18E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.18E-6 Ω·m at 200.0 °C

    200.0 °C

    1.2E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.2E-6 Ω·m at 300.0 °C

    300.0 °C

    1.24E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.24E-6 Ω·m at 400.0 °C

    400.0 °C

    1.26E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.26E-6 Ω·m at 500.0 °C

    500.0 °C

    1.26E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.26E-6 Ω·m at 600.0 °C

    600.0 °C

    1.27E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.27E-6 Ω·m at 700.0 °C

    700.0 °C

    1.28E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.28E-6 Ω·m at 800.0 °C

    800.0 °C

    1.29E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.29E-6 Ω·m at 900.0 °C

    900.0 °C

    1.3E-6 Ω·m

    Show Supplier Material materials with Electrical resistivity of 1.3E-6 Ω·m at 1000.0 °C

    1000.0 °C

    Unlock all property charts

    Magnetic

    PropertyValueTemperatureComment

    Relative magnetic permeability

    1.01 [-]

    Show Supplier Material materials with Relative magnetic permeability of 1.01 [-] at 23.0 °C

    23.0 °C

    max.

    Chemical properties

    Property

    Aluminium

    0.2 %

    max.

    Carbon

    0.025 %

    max.

    Chromium

    19.5 - 23.5 %

    Cobalt

    1 %

    max.

    Copper

    1.5 - 3 %

    Iron

    20 - 38 %

    Manganese

    1 %

    max.

    Molybdenum

    2.5 - 3.5 %

    Nickel

    38 - 46 %

    Phosphorus

    0.02 %

    max.

    Silicon

    0.5 %

    max.

    Sulfur

    0.015 %

    max.

    Titanium

    0.6 - 1.2 %

    Technological properties

    Property
    Application areas

    VDM® Alloy 825 is used in the oil and gas industry and in a wide variety of chemical processes. Typical application fields include: Pipes, tubes and fittings in the oil and gas extraction, e. g. in heat exchangers, evaporators, washers, immersion pipes in sea water cooled heat exchangers, offshore piping, components in sulfuric acid pickling plants like heating coils, vessels, boilers, baskets and chains, heat exchangers, evaporators, washers, immersion pipes in phosphoric acid production, food industry, approval for pressure vessels with wall temperatures up to 450 °C acc. to VdTÜV and 538 °C or Section VIII Division 1 vessels acc. to ASME.

    Cold Forming

    Cold working should be carried out on annealed material. VDM® Alloy 825 has a higher work hardening rate than austenitic stainless steels. This must be taken into account during design and selection of forming tools and equipment and during the planning of the forming processes. Intermediate annealing may be necessary at high degrees of cold working deformation. After cold working with more than 15 % of deformation the material should be soft annealed.

    Corrosion properties

    VDM ® Alloy 825 is a versatile engineering alloy with resistance to corrosion in acids and alkalis under both oxidizing and reducing conditions. The high nickel content gives the alloy virtual immunity to stress corrosion cracking. The corrosion resistance in various media like sulfuric, phosphoric, nitric and organic acids is good, as well as the corrosion resistance in alkalis or ammoniac, sea water and caustic chloride. The versatility of VDM® Alloy 825 is illustrated by its use in nuclear fuel element dissolvers where a variety of corrosive media, e. g. sulfuric and nitric acids and sodium hydroxide, are handled in the same equipment.

    General machinability

    VDM® Alloy 825 should be machined in the annealed temper. As the alloy is prone to work-hardening, low cutting speeds and appropriate feed rates should be used and the tool should be engaged at all times. Sufficient chip depths are important to get below the work-hardened surface layer. The optimum dissipation of heat through the use of large amounts of appropriate, preferably water containing cooling lubricants is crucial for a stable machining process.

    Heat Treatment

    Soft or stabilizing annealing should be carried out at temperatures between 920 and 980°C (1,690 to 1,800°F), preferably at 940±10°C (1,725±15°F). Water quenching should be carried out rapidly to achieve optimum corrosion characteristics. Workpieces of less than 3 mm (0.12 in) thickness can be cooled down using air nozzles. The workpiece has to be put into the pre-heated furnace. The furnace should be heated up to the maximum annealing temperature. The retention time during annealing depends on the workpiece thickness.

    Hot forming

    VDM® Alloy 825 may be hot-worked in the temperature range 1,150 to 900 °C (2,100 to 1,650 °F) with subsequent rapid cooling down in water or by using air. The workpieces should be placed in the furnace heated to hot working temperature in order to heat up. Once the temperature has equalised, a retention time of 60 minutes for each 100mm (4 in) of workpiece thickness is recommended. After this, the workpieces should be removed immediately and formed during the stated temperature window. If the material temperature falls below the minimum hot working temperature, the workpiece must be reheated. Heat treatment after hot working is recommended in order to achieve optimum properties and corrosion resistance.

    Other

    VDM® Alloy 825 has a face-centered-cubic crystal structure.

    Welding

    VDM® Alloy 825 can be joined to itself and to many other metals by conventional welding processes. These include GTAW (TIG), plasma arc, GMAW (MIG/MAG) and SMAW (MMA). Pulsed arc welding is the preferred technique. For the MAG process the use of a multi-component shielding gas (Ar + He + H2 + CO2) is recommended. For welding, VDM® Alloy 825 should be in the annealed temper and be free from scale, grease and markings. When welding roots, sufficient protection of the root needs to be ensured with pure argon (Ar 4.6) so that the welding seam is free of oxides after welding. Root backing is also recommended for the first intermediate pass following the initial root pass and in some cases even for the second pass, depending on the weld set-up. Any discoloration/heat tint should be removed preferably by brushing with a stainless steel wire brush while the weld metal is still hot.