Inappropriate lubricants for ultra-low temperature bearings, excessive load, excessive preload, excessive interference, metal powder and other foreign matter bite, etc. will cause damage to the bearing. After the bearing is damaged, it is necessary to fully understand the use of the bearing. To find out the situation of the accident, and to investigate the bearing damage and various reasons, it is possible to prevent it from happening again. The following will introduce the causes of bearing damage and remedial measures. 1. Bearing peeling When the bearing rotates under the load again, the raceway surface or rolling element surface of the inner ring and the outer ring presents a fish-scale peeling phenomenon due to rolling fatigue. 2. Bearing jamming The so-called jamming of the ultra-low temperature bearing is the surface damage caused by the summation of the micro burns in the part of the sliding surface injury. Linear flaws in the circumferential direction of the sliding surface and the rolling surface. The trochoidal flaw on the roller end face is close to the jamming on the collar face of the roller end face. 3. Bearing cracks, cracks The so-called cracks refer to the crack damage of the raceway wheel or rolling elements. Cracks will develop into cracks with continued use. 4. Bearing pear skin pitting Dark pear skin pitting with weak luster on the raceway surface. 5. Bearing fretting wear The wear caused by the relative repeated micro-slip between the two contact surfaces occurs on the contact part of the raceway surface and the rolling elements. Due to the occurrence of reddish-brown and black wear powder, it is also called fretting corrosion. 6. Bearing creep The so-called creep means that when a gap occurs on the mating surface of the ultra-low temperature bearing, in terms of relative sliding between the mating surfaces, the creeping mating surface presents a mirror bright or dark surface, sometimes with Card damage occurs. 7. Bearing galvanic corrosion The so-called galvanic corrosion refers to the fact that when the current flows in the contact part of the bearing raceway wheel and the rolling element of the recirculating weight, sparks are emitted through the thin lubricating oil film, and the surface is partially melted and uneven. 8. Bearing installation scars Axial linear scars caused on the raceway and rolling surfaces during installation and disassembly.