NeoNickel

Alloy 20

A nickel-iron-chromium grade, Alloy 20 is ideal for a wide range of corrosive environments.

With the addition of copper, molybdenum and niobium, Alloy 20 is the alloy of choice for sulphuric acid applications.

  • UNS Number: N08020
  • Werkstoff Number: 2.4660
  • ASTM: A240, B463, B473, B366, B464, B468, B462, B729, B775

Product availability

Flanges
Pipe (Seamless)
Pipe (Welded)
Pipe Fittings
Plate
Round Bar
Sheet
Welding Wire

Chemical analysis

%NiCrMoMnCuSiCSPNb+TaFe
Min32.5192-3----8.0 x C 1.0-
Max352132410.060.0350.035-Balance

Applications

  • Sulphuric acid pickling tanks, racks and heating coils
  • Phosphate coating drums and racks
  • Heat exchangers
  • Process piping
  • Tanks
  • Pumps and valves
  • Gaskets
  • Mechanical seals
  • Process equipment for manufacture of bullet-proof fibre, Kevlar

About Alloy 20

Alloy 20 contains niobium for stabilisation which enhances its corrosion resistance. The alloy is an iron-base, austenitic alloy with excellent corrosion resistance to a wide range of media.

With the high nickel content, Alloy 20 shows good resistance to chloride-induced stress corrosion cracking. In addition the alloy also has good resistance to pitting and crevice corrosion.

In the chemical process market, key applications of Alloy 20 are in sulphuric, phosphoric and nitric acid environments.

The alloy is also commonly used in the food industry for the manufacture of food preservatives (phosphorus oxychloride and phosphorus trichloride).

For complete list of inventory items contact us, or fill in our online quote form.

  • Density: 7.695 g/cm³ annealed
  • Melting range: 1385-1443°C
  • Electrical resistivity: 1.08 x 10<sup>-6</sup> Ω⋅m
  • Poisson's Ratio: 0.31

Mechanical & Physical Properties

Mechanical & Physical Properties21.1°C49.4°C100°C150°C200°C300°C350°C400°C450°C500°C900°C
Ultimate Tensile Strength /MPa551.6----------
0.2% Yield Strength /MPa241.3----------
Reduction of area % (for bar)50----------
Elongation %30----------
Coefficient of Thermal Expansion µm/m⁰C--14.714.915.115.515.715.91617.2
Thermal Conductivity /kcal/(hr.m.°C)-125.9135.1153.3169.6187.5

Aqueos Corrosion Data

MediaCommon NameTemp °F (°C)Corrosion Rate (mpy)
5% CH³CO²H w/AirAcetic Acid70 (21)40
10% CH³CO²HAcetic Acid86 (30)3.4
56% CH³CO²HAcetic Acid176 (80)66
85% CH³CO²H w/AirAcetic Acid70 (21)400
98% CH³CO²HAcetic Acid241 (116)12
50% NaOHCaustic Soda195 (90)0.55
50% NaOHCaustic Soda310 (155)0.5
75% NaOHCaustic Soda250 (120)1.0
90% CH²O²Formic Acid (Liquid)70 (21)4
90% CH²O²Formic Acid (vapour)70 (21)7
1% HCLHydrochloric Acid214 (101)680
10% HCLHydrochloric Acid86 (30)80
10% HCLHydrochloric Acid221 (105)8000
10% HNO3Nitric Acid216 (102)12000
10% H3PO4Phosphoric Acid75 (24)0.6
10% H3PO4Phosphoric Acid214 (101)154
40% H3PO4Phosphoric Acid75 (24)1
500ppm NaClOSodium Hypochlorite77 (25)0.8
2% H2SO4Sulphuric Acid70 (21)2
5% H2SO4Sulphuric Acid140 (60)10
5% H2SO4 w/AirSulphuric Acid86 (30)61
19% H2SO4Sulphuric Acid223 (106)110
20% H2SO4Sulphuric Acid70 (21)4
50% H2SO4 w/AirSulphuric Acid86 (30)16
5% H2SO4Sulphuric Acid255 (124)1000
93% H2SO4 w/AirSulphuric Acid86 (30)10
Proud members of the British Valve & Actuator AssociationProud members of the British Valve & Actuator Association