Rotating Equipment - Polyethylene erosion on steel shaft
Rotating Equipment - Polyethylene erosion on steel shaft
(OP)
Hi all,
Reference thread: http://www.eng-tips.com/viewthread.cfm?qid=63814
We have a machine that is eroding in one area of the shaft. The process is mostly ethylene. The erosion caused a radius cut in a step area of the shaft such that material is being taken away in a J shape and the diameter of the shaft at the location of the erosion is about .600" less than OEM.
We have to bring the shaft back to dimension. The shaft is Carbon Steel (A668). Options that seem reasonable to me:
1) Weld repair with Carbon Steel, HVOF with xxx to reduce possible erosion in future.
2) Weld repair with Inconel (or xxx)
The thread I linked above calls out ceramics as well. I have no experience with ceramics or how they are applied.
Our shop is located in Houston, TX.
Cheers,
Reference thread: http://www.eng-tips.com/viewthread.cfm?qid=63814
We have a machine that is eroding in one area of the shaft. The process is mostly ethylene. The erosion caused a radius cut in a step area of the shaft such that material is being taken away in a J shape and the diameter of the shaft at the location of the erosion is about .600" less than OEM.
We have to bring the shaft back to dimension. The shaft is Carbon Steel (A668). Options that seem reasonable to me:
1) Weld repair with Carbon Steel, HVOF with xxx to reduce possible erosion in future.
2) Weld repair with Inconel (or xxx)
The thread I linked above calls out ceramics as well. I have no experience with ceramics or how they are applied.
Our shop is located in Houston, TX.
Cheers,
RE: Rotating Equipment - Polyethylene erosion on steel shaft
I do not know what the aluminum seal looks like at this point. I only know what the rotor looks like and it is heavily eroded. Another possible solution may have to do with the laby seal material. However, if the two surfaces rub, the seal should be sacrificial. Galling is unacceptable.
I am keeping my question to material choice only. I will solve any other issues.
RE: Rotating Equipment - Polyethylene erosion on steel shaft
I have used both ceramic spray and carbide overlay in wear applications. I prefer the tungsten carbide, it is denser and adheres better.
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P.E. Metallurgy, Plymouth Tube
RE: Rotating Equipment - Polyethylene erosion on steel shaft
It's an interesting choice of steel given that nothing is specified on the chemical req's except: Mn, P, S. However, we limit our carbon content to 0.35% per S4 of the ASTM spec.
RE: Rotating Equipment - Polyethylene erosion on steel shaft
I will have to talk with weld engineering if we do anything that inconel overlay. I'm not sure what type of heat treat would be required for something like that.