After the NSK bearing is installed, the reason for the difficulty of the bearing rotation Enter the NSK bearing, resulting in pad pressure and grinding; 2), moisture, acid, alkali and other corrosive media enter the NSK bearing, causing the NSK bearing to rust; 3), the NSK bearing clearance is too small, or the NSK bearing is working Excessive expansion of the inner ring due to temperature rise; 4), insufficient lubricant, too much or it has been dried out; 5), the manufacturing accuracy of journal, shaft shoulder, NSK bearing seat is too low or deformed during use; 6), installation Incorrect sealing, such as the seal is too tight or the seal is rubbed with related parts; 7), the cage is deformed; 8), for the preloaded NSK bearing, the axial preload is too large. In the process of NSK bearing operation or high-intensity operating environment, there must be overheating. Therefore, in order to prevent the damage of NSK bearings caused by thermal phenomena, we must not take corresponding measures. (1) Strictly control the forging heating temperature and heating and holding time of the lcrl8Ni9]ri stainless steel box and flange parts to prevent the workpiece from overheating and causing coarse grain defects in the workpiece. (2) The solution treatment temperature of heat treatment of NSK bearing workpiece should not be too high, the holding time should not be too long, the heating temperature should not be higher than 1150'C, and the holding time should be calculated as 1-l_5min/mm. (3) In the production of workpiece forging, if the forging ratio is too small, the final forging temperature is too high, and the defects of coarse grain structure are prone to occur. The forging ratio of the workpiece should be suitable and sufficient, and the final forging temperature should be moderate. (4) For the coarse workpiece with overheated structure, the method of forging and refining grains can be used to eliminate defects, prevent the orange peel-like surface defects of the workpiece during cold deformation, and improve the surface quality of the workpiece.