What is Bearing Steel?

Bearing steel, also known as high-carbon chromium steel, has a carbon content of about 1% and a chromium content of Wcr of 0.5%-1.65%. Bearing steel is divided into six categories: high-carbon chromium bearing steel, chromium-free bearing steel, carburizing bearing steel, stainless bearing steel, medium and high temperature bearing steel and anti-magnetic bearing steel. Bearing steel is used to make balls, rollers and bearing rings. Bearing steel has high and uniform hardness and wear resistance, as well as high elastic limits. The requirements for the uniformity of chemical composition of bearing steel, the content and distribution of non-metallic inclusions, and the distribution of carbides are very strict, which is one of the most demanding steel types in all iron and steel production. In 1976, ISO of the International Organization for Standardization incorporated some general bearing steel numbers into international standards, dividing bearing steel into four categories: fully quenched bearing steel, surface hardened bearing steel, stainless bearing steel, high-temperature bearing steel and a total of 17 steel numbers.

● Performance requirements of bearing steel

In order to meet the above requirements for the performance of dynamic bearings, the following basic performance requirements are put forward for bearing steel materials:

1. High contact fatigue intensity,

2. After heat treatment, it should have high hardness or hardness that can meet the requirements of bearing performance.

3. High wear resistance and low friction coefficient.

4. High elastic limit.

5. Good impact toughness and fracture toughness.

6. Good dimensional stability.

7. Good rust resistance.

8. Good cold and hot machining performance.

● Bearing steel manufacturing requirements

The content of impurities is closely related to the oxygen content in steel. The higher the oxygen content, the more inclusions and the shorter the service life. The larger the particle size, uneven distribution and shorter the service life of impurities and carbides, and their size and distribution are closely related to the smelting process and quality used. The main processes for producing bearing steel are continuous casting and electric furnace smelting and slag remelting, and a small number of vacuum induction plus vacuum self-consumption. Double vacuum or multiple vacuum self-consumption processes to improve the quality of bearing steel. The smelting quality of bearing steel is very demanding, and it is necessary to strictly control the content of sulfur, phosphorus, hydrogen, as well as the quantity, size and distribution of non-metallic impurities and carbides, because the quantity, size and distribution of non-metallic impurities and carbides have a great impact on the service life of bearing steel, and often the failure of bearings is in large clips. Microcracks around impurities or carbides propagate.

● Bearing steel classification

1. High-carbon chromium bearing steel, brand number: GCR6, GCR9, GCR95siM.

2. Carburizing chromium bearing steel, brand number: G20CrMo, G20CrNiMo, G20CrNi2Mo.

3. High-carbon chromium stainless steel bearing steel, brand number: Cr4Mo4F, 9Cr18Mo.

4. High-temperature bearing steel, brand number: Cr14Mo, 16Cr14Mo.

5. Chromium-free bearing steel, brand number: GSIMnV, GSMVRE, GSIMnMoV, can replace chromium-containing bearing steel.

The author of this article is Shaanxi Gainhui Heavy Industries Co., Ltd., which is a professional bearing manufacturer and distributor in China. The company supplies many types of the bearings, such as single row angular contact ball bearings, single row deep groove ball bearings with snap ring, etc. With high quality and competitive bearing products, we sincerely provide services to customers all over the world.

Contact us for more details:

E-mail: emily@gainhui.com

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