I agree with you.... the stray current phenomenon in constant speed induction AC electric motor may not 100% applicable to our bearing failure...
In AC electric motor.. the worn damage cavities (that look like welding on the bearing inner race circurmference) is in full circurmference of bearing inner race... whereas in your wheel bearing the damage is on the opposite (not full circurmference).
One thing that might contribute to this.... could be the atmospheric environment as well... I see on your photo.. a lot of corrosion throughout the whole places on your car...
The car was built 2012 right? Mine 2012 LGT BM9 with 7+,+++km, but mine doesn't have any sort of that kind corrosion issue.. event my 1993 Civic EG3 is same too. I live in tropical climate always 3+degC with dry humidity & not near to the beach.
Therefore.... I believe atmospheric condition (temp variation between season, humidity, present of salty environment) really play significant roles with corrossion + your bearing failure...
Bear in mind...if we refer to corrosion engineering point of view:
1) In salty + humid environment the air become conductive for electrolisis process (similar to battery concept)
2) Plus with 2 disimilar material/metal joint/touching each other (in our case... bearing & its housing)
3) The resultant could result the same phenomenon as anodic/galvanic corrosion
Refer to this article at the bottom page:
http://www.dootalk.com/forums/topic/1292626-very-good-read-on-bearing-failures/
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