What Makes an Alloy a Superalloy
Superalloys are nickel-base alloys designed to keep their strength, creep resistance and oxidation resistance close to their melting point. Most rely on ordered γ′ precipitates, Ni₃(Al,Ti), and on refractory elements such as tungsten, tantalum, molybdenum and rhenium. The rotating model above shows René N5 with γ′ regions outlined.
Cast and Wrought Superalloys
| Cast (revert) | Wrought | |
|---|---|---|
| Examples | René N5, René 80, MAR-M 247, GTD-111, Inconel 713C, IN-939 | Inconel 718, Haynes 282, Nimonic 80A, Nimonic C-263, Inconel 706 |
| Typical parts | Blades, vanes, nozzles, integral wheels | Discs, shafts, rings, casings, combustor sheet |
| Identification | XRF plus OES or lab for Al, Ti, Hf, Re | XRF, OES for light elements |
Superalloy Families
| Family | Grades | Nickel | Key alloying elements | HS heading |
|---|---|---|---|---|
| René alloy scrap | 6 | 59–66% | Co, Cr, W, Ta | 7503.00 |
| MAR-M alloy scrap | 3 | 10–60% | Co, Cr, W, Al | 7503.00 |
| GTD alloy scrap | 4 | 51–61% | Cr, Co, Ti, W | 7503.00 |
| MGA superalloy scrap | 3 | 48–59% | Cr, Co, W, Ta | 7503.00 |
| PWA single-crystal alloy scrap | 2 | 60–60% | Cr, Co, Ta, W | 7503.00 |
| Cobalt alloy scrap | 2 | 0–10% | Co, Cr, W, Mo | 8105.30 |
Single-grade superalloys: Udimet 500 and C1023.
Superalloy Grades Across All Families
Handling Revert
- Sort by exact alloy, never by appearance.
- Keep coated and uncoated parts apart.
- Keep service revert apart from foundry revert.
- Never mix rhenium-bearing alloys such as René N5 with rhenium-free material.
- Record engine or turbine model and part type.
Read how superalloy revert returns to the melt and why tramp elements matter.
FAQ
What is superalloy revert?
Cast superalloy scrap that goes back to the melt: foundry gates, risers and rejected castings, plus retired blades and vanes.
Why must superalloy scrap be sorted by exact alloy?
Superalloy melts have tight chemistry limits. Alloys that look identical can differ in cobalt, tungsten, tantalum, hafnium or rhenium, and mixing them makes the scrap unusable for its highest-value route.
Is Inconel 718 a superalloy?
Yes. It is the most widely used wrought nickel superalloy, strengthened mainly by γ″ precipitates.