Reason for traction motor bearing failure

The traction motor bearing of a certain type of locomotive malfunctioned during operation. The cause of bearing failures was analyzed using methods such as macroscopic observation, chemical composition analysis, dimensional and geometric accuracy measurement, hardness testing, metallographic examination, scanning electron microscopy and energy spectrum analysis. The results show that during the maintenance welding process, poor grounding caused electrical corrosion in the bearings, ultimately led to bearing failure.