C-276 Shaft Straightening
C-276 Shaft Straightening
(OP)
Greetings all
I have a 2.375" diameter x 120" solid C276 shaft. The shaft is for an agitator that spins 155 RPM. The shaft has a coupling at one end, goes through a double mechanical seal and then extends down into the vessel about 9ft. The shaft was bent in process, almost an inch, overall end to end runout.
We tried to have the shaft straightened by spot heating, now the runout is considerably better but still .008 between the coupling and the seal (about a 8 inch distance). I am wondering if we could anneal the shaft while it was hanging upright if that would reduce the stress in it enough that it would straighten out, or then could be straightend by spot heating. Any thoughts on this?
Thanks
StoneCold
I have a 2.375" diameter x 120" solid C276 shaft. The shaft is for an agitator that spins 155 RPM. The shaft has a coupling at one end, goes through a double mechanical seal and then extends down into the vessel about 9ft. The shaft was bent in process, almost an inch, overall end to end runout.
We tried to have the shaft straightened by spot heating, now the runout is considerably better but still .008 between the coupling and the seal (about a 8 inch distance). I am wondering if we could anneal the shaft while it was hanging upright if that would reduce the stress in it enough that it would straighten out, or then could be straightend by spot heating. Any thoughts on this?
Thanks
StoneCold





RE: C-276 Shaft Straightening
You would be better off having someone straighten this in a press. The guys that hone (Scot Ind) can do this.
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Plymouth Tube
RE: C-276 Shaft Straightening
I believe the spot heating is done with a small tipped acetylene torch. The spots are blue/black opon return, about 5/16" in diameter.
Pressing may be an option. I am not sure if it will stay straight though. I really need about .002" TRO between the coupling point and the seal when it is not under load. Mixing causes the shaft to flex and the numbers get worse obviously.
RE: C-276 Shaft Straightening
I agree with ed,that cold press to straighten would have been effective. Localised heating might have caused now damage to the shaft. The alloy has 40% min elongation and about 28kg/mm2 min yield strength,.
RE: C-276 Shaft Straightening
What were you implying by saying "The alloy has 40% min elongation and about 28 kg/mm2 min yield strenght"?
Thanks
StoneCold
RE: C-276 Shaft Straightening
Re-solution treatment should be done by a qualified heat treatment company. You can discuss the specifics with them to re-estbalish the corrosion resistance, and to minimize distortion during the rapid quench operation.
RE: C-276 Shaft Straightening