What are the requirements for bearing materials, and what are the commonly used materials for bearings?

Since rolling bearings are usually used to bear large loads with a very small contact surface and rotate at a certain speed (otherwise there is no need for bearings), the material of bearing is a crucial factor. Usually, fatigue resistance, wear resistance, high hardness, good rigidity and non- deformation are the most basic requirements for rolling elements and rings. In some special situations, some special bearing materials are required.

What are the commonly used materials for bearings?

1. GCr15 (ie 52100) high carbon chromium bearing steel. It is a special steel for bearings that has been treated with electroslag remelting. It has many advantages such as high base purity, high density, uniform carburization, fatigue resistance, and is widely used. For large bearings or large-section bearings, heavy metal elements such as manganese or molybdenum are also added to improve hardenability and rigidity.

2. SUS440C (ie 9Cr18) stainless steel. Stainless steel bearings are often used in some humid and polluted environments, and stainless steel often has higher precision, so it is widely used in medical equipment, printing machinery, food processing and other humid and corrosive environments.

3. Low carbon steel. The main advantage of low carbon steel bearings is that they are relatively inexpensive and suitable for low speed, light load applications (such as trolleys, casters, sliding doors, manual machinery, etc.).

4. Ceramics. Ceramic bearings can be used in extremely harsh environments and special working conditions. They have a wide operating temperature range, good wear resistance, corrosion resistance, insulation, oil-free self-lubrication, high speed and other characteristics. Ceramic bearings usually have three types: zirconium oxide (ZrO2), silicon nitride (Si3N4), and silicon carbide (Sic).

5. Carburized bearing steel. There are two ways of carburizing, one is surface carburizing and the other is through carburizing. For details, please refer to the article "What is the difference between surface hardening and through hardening of bearings?" .

6. Heat-resistant bearing steel. For example, metal smelting machinery, which handles high temperature for a long time, needs to use heat-resistant bearing steel with small softening and dimensional change during operation. This type of bearing steel uses molybdenum or tungsten materials.

7. Thermoplastic plastic bearings. Plastics will not rust, and because of their ductility, plastic bearings have strong vibration absorption and no noise. Because of their physiological inertness, they are suitable for contact with food and are often used in food processing machinery.

8. Others. In addition to the commonly used materials mentioned above, there are also bearings made of other materials, such as copper, aluminum, silver, etc., which have different application fields.