The common losses of rolling mill bearing parts and the causes of rolling mill bearing failure are analyzed and introduced, which can be roughly divided into the following aspects:
1. The fatigue spalling on the surface of rolling element and ring raceway is referred to as the fatigue spalling on the working surface of rolling mill bearing
Under the repeated action of contact stress, the surface metal of rolling element and ferrule raceway peels off in flakes, which is called fatigue peeling, also known as pitting corrosion. This kind of spalling is very small at first, then pits appear and gradually expand, and then large-area flake spalling. This phenomenon will lead to the gradual loss of rolling element and ring raceway of rolling mill bearing, which will shorten the service life of rolling mill bearing and lead to the failure of rolling mill bearing.
2. The ring of rolling mill bearing is broken
The cracking of rolling mill bearing ring can be divided into fatigue cracking, overload cracking, defect cracking and assembly cracking.
3. The rolling element of rolling mill bearing is broken
Rolling element fragmentation can also be divided into fatigue fragmentation, overload fragmentation, defect fragmentation and assembly fragmentation.
The cause of bearing ring breakage and rolling element breakage of rolling mill is generally caused by long service time
4. Cracked and worn cage
The reasons for cage fragmentation are improper use of raw materials, unreasonable design, irregular processing process and so on.
5. Wear and tear
The rolling surface and sliding surface of the bearing may be worn. The wear of rolling mill bearings generally includes abrasive wear, bonding wear, creep wear, corrosion wear and strength wear. These wear may occur alone or mixed.
6. Indentation
(1) During bearing assembly, the inner and outer rings are inclined, and after impact, the raceway and roller are easy to produce indentation (scratch) in the axial direction.
(2) The bearing bears excessive load or impact load under static or low speed, resulting in plastic deformation of the rolling surface. For example, when the rolling mill is stuck.
(3) . external foreign matters are immersed to produce indentation. Oxide scale, sand, etc.
(4) The hardness of bearing parts is low.
7. Overheated or burnt bearing
The rolling mill bearing shall not feel hot during normal operation. If the service temperature of the bearing is close to or more than 100 ℃, it indicates that the bearing is overheated. If the temperature is too high, the bearing will change color (blue, purple, black). Burnt or burnt. There are many reasons for overheating or burning of rolling mill bearings, such as bearing itself, lubrication and sealing, rolling mill speed, bearing load, bearing installation, rolling mill adjustment, rolling mill transmission and so on.