Bearing steel is used to make balls, rollers and bearing rings. Bearing steel has high and uniform hardness, wear resistance and high elastic limit. The requirements for the uniformity of chemical composition, the content and distribution of non-metallic inclusions, and the distribution of carbides of bearing steel are very strict. It is one of the most stringent steel grades in all steel production. In 1976, ISO, the International Organization for Standardization, incorporated some general bearing steel grades into the international standard, and divided the bearing steel into four categories: fully hardened bearing steel, surface hardened bearing steel, stainless bearing steel, and high-temperature bearing steel, totaling 17 steel grades.
Bearing steel is also called high carbon chromium steel. The carbon content Wc is about 1%, and the chromium content Wcr is 0.5% - 1.65%. Bearing steel is divided into high carbon chromium bearing steel, chromium free bearing steel, carburized bearing steel, stainless bearing steel, medium and high temperature bearing steel and antimagnetic bearing steel.
High carbon chromium bearing steel GCr15 is the largest bearing steel produced in the world. Its carbon content is about 1% and chromium content is about 1.5%. Since its birth in 1901, the main composition has not changed for more than 100 years. With the progress of science and technology, research work continues and product quality is also improving.
