Release time : 2015-06-10 06:59:12
Rrecently, the AQSIQ issued the spot check results on the quality of the 3rd batch?of bearing steel from 46 batches products of 46 enterprises under national supervision. The number of the enterprises involved is about 30 percent of the number for the?ones with production permission certifications, so the results could reflect the general quality situation for current bearing steel products. All of the 46 batches from 46 companies are up to grade after detection and the selective test ratios for both the products and companies are 100 percent.
The bearing steel is widely used in manufacturing balls, rollers and sleeves of antifriction bearings and also could be used in manufacturing presicion measuring implements, cold-punched die and machine screw!
In recent years, Chinese bearing
industry is developing rapidly and China has become one of the world's largest manufacturers. Domestic industries using bearings mainly concentrated on automobile, motor cycles, house-hold applicanes, railway bearings, agricultural machinery, metallurgy, mining machinery, textile machinery and so on.
The spot check mainly focus on testing chemical components, microscopic pore space, decarburization layer, microstructure, banded carbide, network carbide, liquation carbonide, macroscopic examination and non-metallic inclusion of these bearing steels.
The spot check results show that all of the above indexes have reached the standard requirements. But from the test data analysis, we can also see that some companies couldn't control production well because of low level of production equipments and their products' stability remains to be improved. It also show the relatively higher grade of non-metallic inclusion of the bearing steel produced by some of the state-owned companies, which proves that they're not strict enough in smelting bearing steel controlling.