Difference Between Inconel and Incoloy

Inconel

Inconel is a family of austenitic nickel-chromium-based superalloys.

Inconel Composition

Inconel Element (% by mass)
Ni Cr Fe Mo Nb Co Mn Cu Al Ti Si C S P B
600 72.0 14.0–17.0 6.0–10.0 1.0 0.5 0.5 0.15 0.015
617 44.2–56.0 20.0–24.0 3.0 8.0–10.0 10.0–15.0 0.5 0.5 0.8–1.5 0.6 0.5 0.15 0.015 0.015 0.006
625 58.0 20.0–23.0 5.0 8.0–10.0 3.15–4.15 1.0 0.5 0.4 0.4 0.5 0.1 0.015 0.015
690 59.5 30 9.2 0.35 0.01 0.02 0.35 0.019 0.003
718 50.0–55.0 17.0–21.0 balance 2.8–3.3 4.75–5.5 1.0 0.35 0.2–0.8 0.65–1.15 0.3 0.35 0.08 0.015 0.015 0.006
X-750 70.0 14.0–17.0 5.0–9.0 0.7–1.2 1.0 1.0 0.5 0.4–1.0 2.25–2.75 0.5 0.08 0.01

Inconel alloys

Alloys of inconel include:

  • Inconel 600: Solid solution strengthened
  • Inconel 601
  • Inconel 625: Acid resistant, good weldability. The LCF version is typically used in bellows.
  • Inconel 690: Low cobalt content for nuclear applications, and low resistivity
  • Inconel 713C: Precipitation hardenable nickel-chromium base cast alloy
  • Inconel 718: Gamma double prime strengthened with good weldability
  • Inconel 751: Increased aluminium content for improved rupture strength in the 1600 °F range
  • Inconel 792: Increased aluminium content for improved high temperature corrosion properties, used especially in gas turbines
  • Inconel 939: Gamma prime strengthened to increase weldability

Incoloy

Incoloy refers to a range of superalloys produced by the Special Metals Corporation group of companies.

Incoloy Compositions (percentages)

Alloy name Balance metal Chromium Aluminum Titanium Carbon Yttrium oxide Copper Manganese Cobalt Nickel Phosphorus Silicon Sulphur Molybdenum Nb+Ti
020 Fe (~40%) 20 n/p n/p <0.07 n/p 3.5 <2.0 n/p 35 <0.045 <1.0 <0.035 2.5 about 1
DS Fe (~40%) 18 n/p 0.2 0.1 nil 0.5 0.8-1.5 18 (Co+Ni 38) 18 (Co+Ni 38) n/p 2.3 0.03
MA956 Fe (~75%) 20 4.75 0.4 <0.1 0.5 <0.15 <0.3 <0.3 <0.5 <0.02 n/p n/p