INA bearing premature failure cause analysis, and matters needing attention

1. Obviously loose defects in the finished product INA bearing ring is not allowed on there. It will reduce the density of ring, enrichment of the internal more micro pore, low melting point impurity, gas and nonmetallic inclusions. It like banded carbide, dividing matrix continuity effect, cause the composition segregation, matrix embrittlement, greatly reduce the comprehensive mechanics performance of the ring. 2. Black and white state quenching tempering martensite matrix concentration, the higher macro hardness value and the loose defects and so on, also is a when grinding cracks induced potential factors which cannot be ignored. Black and white concentration difference appeared in the original organization exists serious banded carbide, the resulting take between the belt and the concentration of carbon, segregation, so after quenching increases the overheating tendency between the belt and Ms point of the difference in height. 3. Grinding quality of INA bearing premature failure can decide from the above test results, the influence of the grinding crack on one side of the raceway grinding burn is ring and split, a direct cause of the premature bearing failure, a crack in this example reveals macro morphology and distribution feature of grinding burn, the original position of raceway partial or race R not round, make on one side of the raceway grinding allowance increases, when the coarse grinding phase feeding, grinding speed, the whole race is uneven grinding. If the grinding wheel dressing, not in time to chip embedded or sticky pore blockage caused by grinding wheel and passivation, thus will cause increased grinding wheel unbalance, spindle vibration, even machine tool vibration and grinding chatter. Grinding force is obviously cyclical change, form discontinuity burns a stripe. 4. In order to further understand the ring hardness distribution and microstructure quenching tempering and the microstructure characteristics of the surface layer, choose some split inner ring and its pieces, in the face and upper macro hardness, and the cutting method in split near interception longitudinal metallographic specimen. INA bearings at work, because of the influence of the external or internal factors, change the original fit clearance, lower accuracy, and the change of 'killed' called clearance failure. , large amount of the external factors such as interference of installation does not reach the designated position, temperature rise caused by the expansion, instantaneous overload, etc. , internal factors such as residual austenite and the residual stress in a state of flux and so on all is the main reason for the failure caused by clearance changes. 1. If get good lubrication, and cut off the right moisture and debris, said oil seal should not wear. However, best when open the bearing box, check the bearing and periodically check the oil seal. Check of the condition of the near the bearing oil seal, in order to ensure that they are enough to prevent hot liquid along the axis of infiltration or corrosive liquid or gas bearing, oil seal if already wear should be replaced as soon as possible. 2. High temperature often said INA bearings is in abnormal situation. High temperature also harmful to within the bearing lubricant. Sometimes bearing overheating can be attributed to bearing lubricant. If the bearing in more than 125 degrees Celsius temperature operation for a long time, will reduce the bearing life. The causes of high temperature bearing include: insufficient lubrication or excessive lubrication, lubricants containing magazine, heavy load, bearing damage, clearance, and the oil seal of high temperature and friction and so on. 3. Check the status of the operation of the machine, monitoring, lest cause the equipment downtime.