Summary
Inconel 600 is the older, simpler alloy, still widely used in furnaces and caustic service. Inconel 625’s molybdenum and niobium make it far more resistant to pitting and acids, which is why it replaced 600 in many corrosive applications. The same molybdenum and niobium make 625 scrap more valuable per tonne.
Side by Side
| Inconel 600 | Inconel 625 | |
|---|---|---|
| Alloying approach | Ni-Cr-Fe | Ni-Cr-Mo-Nb |
| Best at | Oxidation, caustic, chloride SCC | Pitting, crevice and acid corrosion |
| Typical service | Furnaces, caustic evaporators, older nuclear tubing | Offshore, scrubbers, chemical plant, aerospace ducting |
Composition Compared
Nominal compositions compared element by element. Change either grade to compare others.
On the XRF
Switch the grade to see how the fingerprint changes. See how XRF sorts nickel alloys.
FAQ
What is the main difference between Inconel 600 and Inconel 625?
Inconel 600 is a plain nickel-chromium-iron alloy with about 15.5% chromium and 8% iron. Inconel 625 adds about 9% molybdenum and 3.6% niobium and raises chromium to 21.5%.
Can Inconel 600 and Inconel 625 scrap be mixed?
No. Keep them separate. A melter buying either one needs its chemistry to stay within the grade’s limits, and mixing can mean a re-sort or a different valuation.