NEWS

Linhai Baiai Metal Forgings Co., Ltd.

26

2021

-

07

Bearing material

Author:


The rings and rolling elements of rolling bearings bear high contact pressure repeatedly while making rolling contact with sliding. The cage is in sliding contact with the two sides of the ring and the rolling element or one of the sides, and the other side bears the tensile force and the compressive force. Therefore, the main requirements for the materials and performance of bearing rings, rolling elements and cages are as follows:

  (1) The required properties of ferrule and rolling element materials: high rolling fatigue strength, high hardness, and high wear resistance;

  (2) The required performance of the cage material: good dimensional stability and high mechanical strength.

  (3) Good processability is required. Depending on the application, it is also required to have good impact resistance, heat resistance, and corrosion resistance.

  Material of rings and rolling elements

  Rings and rolling elements usually use high-carbon chromium bearing steel. Most of the bearings use SUJ2 in the JIS steel grade. SUJ3 is used for large bearings. The chemical composition of SUJ2 has been standardized as a bearing material in various countries around the world. For example: AISL52100 (USA), DIN100Cr6 (West Germany), BS535A99 (UK), etc. are all of the same kind of steel.

  When further impact resistance is required, chromium steel, chromium molybdenum steel, nickel chromium molybdenum steel, and carburizing and quenching are used as bearing materials to make the steel have a hardened layer from the surface to an appropriate depth. Carburized bearings with proper hardening depth, fine structure, proper hardness of surface and core hardness have better impact resistance than bearings using bearing steel, and the chemical composition of general carburized bearing steel. NSK and DKF have implemented vacuum degassing treatment, so the materials used have high purity, low oxygen content and good quality.

  Furthermore, proper heat treatment is adopted to significantly increase the rolling fatigue life of the bearing. In addition to the above-mentioned steel grades, high-speed steel with excellent heat resistance and stainless steel with good corrosion resistance are also used for special purposes.

  Cage material

  The material of the stamping cage is low-carbon steel. Depending on the application, brass plates and stainless steel plates are also used. The material for cutting the cage is made of high-strength brass, carbon steel, and synthetic resin.