Well…. There’s your problem!

[u/KnownSoldier04]

Customer hired us to do some testing to see if they can revive this old 70s GE turbine generator. Nozzle ring is made of haynes556 but it’s cracked in a bunch of places.

These little comp. blades are made of an unidentified alloy, 50%Fe, 40%Ni, 10% Cr. If anyone recognizes the alloy, I’d like to know a bit.

At some point, someone put the wrong bolt in the right spot and damaged the whole stage… they want to cut, weld and grind new blades in place… worrying tbh.

More carnage

[u/bingagain24]

Former field turbine specialist, that's scrap metal.

[u/intronert → u/bingagain24]

I get it, but could one not in principle grind off the bad vanes, and others for balance, and still have a less efficient but workable turbine? I am ignorant, obviously.

[u/Gears_and_Beers → u/intronert]

In principle sure.

But you’d end up breaking even more things faster. The lower pressure rise in that stage would mean all downstream stages are off design, combustion pressure is lower, meaning less power and less efficiency

Gas turbines tend not to be hacked back together like farm tractors. They drive very expensive processes. So it’s worth fixing it right away

[u/Wise-Parsnip5803 → u/Gears_and_Beers]

Missing a few vanes would add a lot of turbulence even if it was balanced. 

[u/Aerospace_supplier42 → u/Wise-Parsnip5803]

The pressure rises across each set of vanes. I would think a missing vane would act like a hole letting flow go backwards at that point.

[u/intronert → u/Aerospace_supplier42]

While true, the engineering question is always “by how much”? A little is ok, a lot is not.