Strange corrosion of Steel Journal
Strange corrosion of Steel Journal
(OP)
We have a failure of a swivel arrangement which sits in a load path of a derrick.
The fauilure takes the form of material loss from the journal surface (dia abt 150mm) leaving being a very uniform patten of hemispherical lumps which one assumes must have been related to some fabrication or previous repair process. the lumps are about 10mm in diameter.
I have attached a pitcure of one of the journals. The damage is repeated in a negtive complimentary way in the brass/bronze journal.
Can anybody shed any light
The fauilure takes the form of material loss from the journal surface (dia abt 150mm) leaving being a very uniform patten of hemispherical lumps which one assumes must have been related to some fabrication or previous repair process. the lumps are about 10mm in diameter.
I have attached a pitcure of one of the journals. The damage is repeated in a negtive complimentary way in the brass/bronze journal.
Can anybody shed any light





RE: Strange corrosion of Steel Journal
Is there grease or other lubricant used in this bearing?
RE: Strange corrosion of Steel Journal
"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein
RE: Strange corrosion of Steel Journal
RE: Strange corrosion of Steel Journal
Yes it is supposed to be greased but there was evidence of this
The bearing in which it runs appears to be a brass/bronze and has dimples which match the humps.
We do not believe that there are no additional bits that have disappeared although there are no assembly drawings
It definitely appears as the non-deliberate result of some manufacturing process.
RE: Strange corrosion of Steel Journal
RE: Strange corrosion of Steel Journal
What is the bearing model?
RE: Strange corrosion of Steel Journal
I studied the photo and the more I look at this I can't come to grips with an explanation of how this surface texture was created - manufactured or caused by some effect in service.
RE: Strange corrosion of Steel Journal
But bubble wrap shouldn't be there in service, and I'm having a hard time figuring how it could corrode two surfaces if it were present.
Mike Halloran
Pembroke Pines, FL, USA
RE: Strange corrosion of Steel Journal
Brinelling and fretting are the most likely way I know that will transfer patterns.
Another possibility is abrasive transfer if the shaft is stationary and vibrates.