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Premature bearing failures due to white etching cracks (WECs) occur when the rolling contact is subjected to a so-called additional load such as an electrical current flow through the bearing in ad...

White etching crack (WEC) early bearing failures occur when the rolling contact is subjected to a so-called additional load such as an electrical current flowing through the bearing, in addition to the pure rolling load (pHz). Tests on rolling bearings showed that a low electrical direct current flow, such as that resulting from electrostatic charges, can lead to WEC failures in oil-lubricated roller bearings and greased ball bearings.The WEC formation in the performed tests was dependent on the current, electrical polarity, load type (rotating or stationary ring load), and bearing load. A black oxidation of the WEC critical bearing ring led to a significant increase in lifetime. Based on the findings, the failure hypothesis “cathodic WEC fatigue” for electrical direct current-initiated WEC failures was established.