① pitting-The raceway of the inner and outer rings and the surface of the rolling body appear many pitting pits;
② abrasive wear--the surface of raceway, rolling body and the contact part of the cage wear, causing internal loosening;
③ adhesion wear-there are traces of adhesion on the raceway and the surface of the rolling body;
④ fracture--axial and circumferential cracks occur in the inner and outer rings, and the cage cracks;
⑤ plastic deformation-the uneven plastic deformation pits appear on rolling or ring raceway;
⑥ Other-corrosion, electrical corrosion, abnormal temperature rise.