Microstructural Studies of the Material of Rings of Foreign Bearings

It was shown that, to ensure import substitution of bearings and improve the quality of bearing steel produced in Belarus, it is necessary to study the structure of original bearings manufactured by leading foreign companies, the products of which are known for their high quality and are in high demand in the world market. The composition of the material of bearing rings, and the microstructure and morphology of the metal matrix and carbide inclusions were studied by optical and scanning electron microscopy at magnifications from 1000 to 20 000, emission spectroscopy, and electron probe microanalysis. It was demonstrated that the high quality of bearing steel is ensured by the fine-grained structure of martensite, uniform distribution of dispersed carbides (Fe, Cr)3C with a size of about 1 μm, and low content of detrimental impurities (sulfur and phosphorus) and nonmetallic inclusions. The results of the studies can be used to improve the production technology of high-quality bearing steels at OAO BMZ—Management Company of BMK Holding within the framework of the import substitution program.