The bearing steel tube is mainly used to manufacture the rolling body and ring of rolling bearing.
Due to bearing should have long life, high precision, low calorific value, recommend suite, high rigidity, low noise, high abrasion resistance and other characteristics, so the requirement of bearing steel tube should have: high hardness, uniform hardness, high elastic limit, high contact fatigue strength, must be certain hardenability and tenacity, in the atmospheric corrosion resistance of lubricant. In order to meet the above performance requirements, the chemical composition uniformity, non-metallic inclusion content and type, carbide size and distribution, decarburization and other requirements are strict.
On the whole, bearing steel tube is developing towards high quality, high performance and variety. Bearing steel according to the characteristics and application environment can be divided into: high carbon chromium bearing steel tube, carburized bearing steel tube, high temperature bearing steel tube, stainless bearing steel tube and special bearing materials.
In order to meet the requirements of high temperature, high speed, high load, corrosion resistance and radiation resistance, a series of new bearing steel tubes with special properties need to be developed. In order to reduce the oxygen content of bearing steel tube, vacuum smelting, electroslag remelting and electron beam remelting were developed. The smelting of large quantities of bearing steel tube was developed from electric arc furnace to various types of primary smelting furnace and external refining.
At present, the bearing steel tube is produced by LF/VD or RH+ continuous casting + continuous rolling process with a capacity of more than 60 tons, in order to achieve high quality, high efficiency and low energy consumption. In terms of heat treatment technology, the continuous controllable atmosphere annealing furnace has been developed from car bottom furnace and hood furnace. At present, the longest type of continuous heat treatment furnace is 150m, the spheroidized structure of bearing steel tube is stable and uniform, the decarburization layer is small, and the energy consumption is low.