Why Cast Superalloys Must Be Sorted to the Grade
Cast superalloys look the same: grey, heavy, often coated, and shaped as blades, vanes, wheels or gates and risers from the foundry. Their chemistry is not the same. A foundry remelting MAR-M 247 revert wants its hafnium and tungsten; a foundry pouring René 80 does not. Mixed lots can only be sold at the value of the least useful grade in them, so the work done identifying each piece is paid back in the offer.
Most of these alloys have no UNS number, so trade names and part numbers carry the identity. This guide uses the nominal compositions listed on our grade pages to show which elements separate them.
The Marker Elements, Grade by Grade
Nickel, chromium and aluminium are in all of them. The elements that sort them are cobalt, tungsten, tantalum, hafnium, rhenium and titanium.
Sorting a Cast Part by Its Reading
Handheld XRF reads cobalt, tungsten, tantalum, hafnium and rhenium well. It is weaker on aluminium and light elements, and coatings can distort a surface reading, so test a ground or cut face. See XRF, OES or a lab?
WhatsApp photos of the parts, any part numbers and a reading if you have one. We review incoming enquiries and respond with relevant next steps.
Cobalt-Base Vanes: MAR-M 509, ECY-768, X-40 and FSX-414
| Grade | Separating point |
|---|---|
| MAR-M 509 | About 3.5% tantalum and 0.5% zirconium |
| ECY-768 | Same tantalum as 509, zirconium 0.05% or less |
| X-40 | No tantalum; about 25.5% chromium |
| FSX-414 | No tantalum; about 29% chromium, with boron |
Zirconium is the hard one: it is the main difference between MAR-M 509 and ECY-768, and it is small. Records or a lab analysis settle it.
Hafnium Grades: MAR-M 247, René 108 and René 125
| Grade | Separating point |
|---|---|
| MAR-M 247 | W about 10%, Ta 3%, Hf 1.5%, Ti about 1% |
| René 108 | W about 9.5%, Ta 3%, Hf 1.5%, Ti about 0.7% |
| René 125 | W about 7%, Ta 3.8%, Ti 2.5%, Mo 2% |
| MAR-M 246 | W 10% like 247, but no hafnium |
MAR-M 247 and René 108 are so close in nominal chemistry that a reading alone rarely separates them. Part numbers, the engine model or the foundry's casting records do.
Rhenium Grades: René N5 and PWA 1484
Both are single-crystal blade alloys with about 3% rhenium. René N5 carries about 6.5% tantalum and 7% chromium; PWA 1484 about 8.7% tantalum and 5% chromium. Rhenium-bearing revert is kept apart from everything else: one rhenium blade in a lot of ordinary blades is lost value for the seller.
Land Turbine Blade and Nozzle Grades: GTD, IN-738, IN-939, MGA
| Grade | Part | Separating point |
|---|---|---|
| GTD-111 | Buckets (blades) | Ti about 4.9%, Ta 2.8% |
| IN-738 | Blades | Cr 16%, Nb 2% |
| MGA 1400 | Rotating blades | Ta about 4.7%, Ti 2.7% |
| GTD-222 | Nozzles | Cr 22.5%, Co 19%, Ta about 1% |
| GTD-241 | Nozzles | No tantalum, Nb about 1.35% |
| GTD-262 | Nozzles | As 241 with Al about 1.7% |
| IN-939 | Vane segments | Cr 22.4%, Co 19%, Ti 3.7% |
Preparing Cast Superalloy Scrap for Sale
- Sort by the flow above and bag each grade separately.
- Keep part numbers, engine model and overhaul or casting records with each bag.
- Declare coatings, ceramic core, braze and attached steel.
- Weigh and photograph each bag.
- Send the list by WhatsApp or the enquiry form.
Mipra Steel buys cast superalloy revert and retired parts from sellers across India, much of it from South India. See superalloy scrap, René alloy scrap, MAR-M alloy scrap and GTD alloy scrap, and the turbine parts scrap map.
Send the grade, form, quantity and delivery location.
Source a GradeCast superalloy identification FAQ
How do you identify MAR-M 247 scrap?
By about 10% tungsten, 10% cobalt, 3% tantalum and 1.5% hafnium. René 108 is almost the same, so part numbers or casting records are needed to separate the two.
What is the difference between MAR-M 247 and MAR-M 509?
MAR-M 247 is a nickel-base blade alloy with hafnium; MAR-M 509 is a cobalt-base vane alloy with about 55% cobalt and 23.5% chromium.
How is René 80 told apart from GTD-111?
Both have about 5% titanium and 9.5% cobalt. GTD-111 carries about 2.8% tantalum; René 80 has none.
Which cast superalloys contain rhenium?
Single-crystal grades such as René N5 and PWA 1484, each with about 3% rhenium.
Can XRF identify cast superalloy scrap?
For most grades, yes, on a clean, uncoated face. Close grades and light elements such as zirconium may need a lab analysis or the part records.
Does Mipra Steel buy cast superalloy scrap in India?
Yes. Mipra Steel buys blades, vanes and casting revert by grade from sellers across India, much of it from South India.
Sources and Review
Figures are quoted as published in these sources; any value we could not confirm has been left out.
- Nominal compositions as listed on this site's grade pages, each of which names its producer data sheet or standard: René 77, René 80, René 108, René 125, René N5, PWA 1484, MAR-M 246, MAR-M 247, MAR-M 509, ECY-768, X-40 and FSX-414, GTD-111, GTD-222, GTD-241, GTD-262, IN-738, IN-792, IN-939, MGA 1400, Inconel 713C.
Published by Mipra Steel, Khetwadi, Mumbai · Last updated