The general administration of quality supervision, inspection and quarantine of the state recently announced the third batch of bearing steel product quality supervision results, a total of 46 enterprises of 46 products, the number of enterprises about 30% of the number of production license enterprises, can reflect the overall quality of bearing steel products. After testing, all 46 batches of products from 46 enterprises are qualified, and the qualified rate of selected enterprises and products is 100%.

Bearing steel is used to manufacture ball, roller and sleeve of rolling bearings, as well as precision measuring tools, cold punching die and machine tool screw.

In recent years, China's bearing industry has developed rapidly, and China has become one of the world's largest bearing producers. The domestic bearing industry mainly focuses on automobiles, motorcycles, household appliances, railway bearings, agricultural machinery, metallurgical and mining machinery, petrochemical machinery and textile machinery.

This spot check focused on the bearing steel chemical composition, micro pores, decarburization layer, microstructure, carbide band, carbide network, carbide liquid chromatography, low power test and non-metallic inclusion and other indicators were tested.

The test results showed that the chemical composition test and the anneal hardness test of the products were all qualified, and the microscopic pores, decarburization layer, microstructure, carbide band, carbide network, carbide liquid chromatography, low-power test and non-metallic inclusion test all met the standard requirements. However, from the analysis of inspection data, it can be seen that due to the low level of production equipment and poor production control in some enterprises, the stability of product quality still needs to be improved. The spot check also revealed that some large state-owned enterprises produce high levels of non-metallic inclusions in bearing steel, proving that they are not strict enough in bearing steel smelting control.