The cracks of quality 6800 Series Bearing are generally linear, with indeterminate directions, corresponding lengths and widths, and sharp roots and edges. Cracks can be divided into inner cracks and surface cracks, which are visible and invisible to the naked eye. For cracks that are not visible to the naked eye, non-destructive testing methods are required to be observed. The cracks of the quality 6800 Series Bearing are generally in the shape of thin lines, and the direction is intermittently distributed along the rolling direction of the steel, with corresponding lengths and widths, sometimes single or several.The reasons for cracks in the quality 6800 Series Bearing are complex, and there are many influencing factors, such as raw materials, forging, stamping and folding, heat treatment, grinding, and local excessive stress. The reason for the formation of cracks in the quality 6800 Series Bearing may also be the bubbles or inclusions generated in the smelting process of the steel, which exist on the surface of the bearing material after rolling deformation.
The main measures to avoid cracks in the quality 6800 Series Bearing are to control the defects of raw materials such as non-metallic inclusions, surface slag inclusions, folding, microscopic pores, shrinkage holes, and air bubbles in manufacturing. Control the processing strength of the quality 6800 Series Bearing, such as internal stress (thermal stress and tissue stress), grinding stress, stamping stress, etc. generated during heat treatment and quenching. During the use and installation of the quality 6800 Series Bearing, care should be taken not to knock maliciously, install according to regulations, ensure lubrication, enhance the sealing effect, control the inflow of external impurities and avoid contact with corrosive substances.