That's two that don't know the difference between 'steal' and 'steel' Paul , you wander what they learn at school these days .
For the ones that don't know the exhaust wheels are " inconel", a nickel-base alloy with chromium and iron, used in gas-turbine blades . Inconel alloys are typically used in high temperature applications, There are lots of different grades of this exotic alloy with different properties.
Inconel 600: Solid solution strengthened
Inconel 625: Acid resistant, good weldability
Inconel 690: Low cobalt content for nuclear applications
Inconel 718: Gamma double prime strengthened with good weldability
The above are some, probably lots more, not sure which one garrett use in the RB26 turbos.
When people refer to RB 26 turbos as 'ceramic' its incorrect they are not ceramic however when they smash they become tiny little pieces .
The so called steel wheel turbos , are not steel either, a magnet will not stick to them, some kind of alloy as well .
If anyone wants these temp me with an offer, even a silly one otherwise they are going on E-Bay, I don't feel like keeping themto do a swap in my car when time comes to sell it..