Damaged Bearing Race
Damaged Bearing Race
(OP)
I have a large bearing from a pump that has surface damage on both the inner and outer race but not to the rollers. Macroscopic discoloration of the undamaged areas and smooth "globular" regions in the damaged areas made me first think that the damage may have been caused by a stray welding arc. However, after mounting and etching the sample I found no evidence of melting (cast-like surface structure I would have expected). The material is tempered martensite with a carburized layer. Could this still be due to a stray arc despite the lack of melted material in the micro and the lack of damage to the rollers or is it more likely that this is fatigue spalling?





RE: Damaged Bearing Race
Overtempered martensite would be less resistant to initiation of cracks from Hertzian stresses.
Jesus is THE life,
Leonard
RE: Damaged Bearing Race
RE: Damaged Bearing Race
Jesus is THE life,
Leonard
RE: Damaged Bearing Race
RE: Damaged Bearing Race
RE: Damaged Bearing Race
Carburize...You make an excellent point. This thought was bothering me but would not quite surface. If there is evidence on few rollers it would tend to corroborate the arcing theory.
Jesus is THE life,
Leonard
RE: Damaged Bearing Race
Thanks for everyone's help. I only have about a year and a half of experience doing failure analysis so it's great to be able to receive the advice of more experienced people.