Alloy 28

Introduction :

Alloys are composed of nickel-chromium-iron as the primary elements. Additives that are used in this alloy to enhance its strength, corrosion resistance include molybdenum, copper and nitrogen. These alloys are classified as super alloys due to their high strength and ability to function at high temperatures.

Chemical Composition

The chemical composition of  Alloy 028 is given in the following table.

Element Content (%)
Iron, Fe 29-40.4
Nickel, Ni 30-34
Chromium, Cr 26-28
Molybdenum, Mo 3-4
Manganese, Mn ≤2.5
Others Remainder

Physical Properties

The following table discusses the physical properties of INCOLOY alloy 028.

Properties Metric Imperial
Density 8 gm/cm3 0.289 lb/in3

Mechanical Properties

The mechanical properties of INCOLOY alloy 028 are tabulated below.

Properties Metric Imperial
Tensile strength(annealed) 500 MPa 72.5 ksi
Yield strength(annealed) 214 MPa 31 ksi
Elongation at Break(Cold worked) 15% 50%
Modulus of Elasticity 200 GPa 29000 ksi
Hardness, Rockwell B 80-90 80-90
Hardness, Rockwell C 33 33

Other Designations

Some of the designations used to denote INCOLOY alloy 028 are listed below:

  • UNS N08028
  • ASTM B 668
  • ASTM B709
  • ASTM B829


Alloy 028 is used in the following applications:

  • Chemical and petrochemical processing industry
  • Downhole service in deep sour gas wells.

Alloy 28 Avaliability

Alloy 28 Specifications

Alloy 28 Tensile Requirements