What is the relative fatigue strength of bearings

What is the relative fatigue strength of bearings

Fatigue strength refers to the maximum stress that a metal material can withstand without failure under infinite alternating loads, which is called fatigue strength 

or fatigue limit

During the working process, each operation of the bearing causes damage to the bearing, and the fatigue strength is continuously decreasing. For the convenience 

and simplicity of calculation, a reliable value is used to determine the life of the damaged rolling bearing and the allowable equivalent dynamic load to calculate the 

fatigue strength, which is the relative fatigue strength of the bearing.

The relative fatigue strength of a bearing refers to the gradual attenuation of its fatigue strength under the continuous action of alternating loads during operation. 

For the convenience and simplicity of calculation, a reliable value is usually used to determine the life of the damaged rolling bearing and the allowable equivalent 

dynamic load to calculate the fatigue strength, which is the relative fatigue strength of the bearing.

Definition and influencing factors of bearing fatigue strength

Fatigue strength refers to the maximum stress that a metal material can withstand without failure under infinite alternating loads, known as fatigue strength or 

fatigue limit.

The fatigue strength of bearings is mainly affected by the following factors:

Microstructure and purity of materials: The microstructure and purity of materials have a decisive impact on fatigue strength. By adopting advanced smelting 

technology and strict material inspection procedures, impurities and defects inside the material can be reduced, thereby improving the fatigue strength of the 

material.

Hardness: The hardness of bearing steel in use generally needs to reach HRC61~65 in order for the bearing to achieve high contact fatigue strength and wear 

resistance.

Chemical composition: By adjusting the chemical composition of the material, such as adding alloying elements such as chromium and molybdenum, the wear 

resistance and fatigue strength of the material can be strengthened.Selection and maintenance of bearing materials

The selection of bearing materials has a significant impact on the performance of bearings, mainly including the following aspects:Load bearing capacity: The

hardness and strength of the material directly affect the load-bearing capacity of the bearing. High hardness materials can resist deformation caused by external 

forces, while good plasticity and toughness can protect bearings in the event of sudden impacts.Wear resistance: Through fine surface treatment techniques and 

reasonable heat treatment processes such as grinding, polishing, quenching, tempering, etc., the wear resistance of materials can be improved.

Thermal stability: In environments with high temperatures or frequent temperature fluctuations, the thermal stability of materials can maintain their original 

physical properties.In summary, the relative fatigue strength of bearings is an important indicator for measuring their ability to work under alternating loads, 

and its influencing factors include the microstructure, hardness, chemical composition, etc. of the material. Choosing appropriate bearing materials and 

maintenance methods is crucial for extending the service life of bearings.