Grinding is a common method of metal cutting in the machinery manufacturing industry, and is also widely used in the bearing processing industry. The bearing parts quenched by heat treatment may have a network of cracks or more regular arrangement of fine cracks during grinding, which is called grinding cracks.
1, bearing grinding crack characteristics:
The grinding crack is obviously different from the general quenching crack, the grinding crack only occurs on the grinding surface, the depth is shallow basically the same.
2, bearing grinding crack causes:
Bearing grinding cracks are caused by grinding heat, and the bearing surface temperature can reach 800-1000 degrees Celsius or higher during grinding. They are in a state of expansion (without tempering treatment), causing local expansion of the bearing surface, increasing the surface stress of the part, resulting in grinding stress concentration, and continuing grinding will accelerate the generation of surface grinding cracks.
On the other hand, when grinding parts on the grinder, both pressure and tension on the parts contribute to the generation of grinding cracks. If the cooling is not sufficient during grinding, the surface layer will generate additional organizational stress due to the heat generated during grinding, and the heat generated by grinding will cause the bearing surface temperature to rise very fast and cool very fast, and the superposition of organizational stress and thermal stress may lead to grinding cracks on the grinding surface.
