When designing and manufacturing bearing steel balls, bearing materials are generally selected according to the following principles.
1. Choose according to the working conditions of the bearing
a. Working temperature
Bearings working at room temperature use chromium bearing steel. When the working temperature is higher than 150 ℃ and lower than 250 ℃, chromium bearing steel is also used, but it needs special heat treatment (200 ℃ or 300 ℃ tempering is required).
b, the size of the impact load
Bearings that bear strong impact loads generally do not use chromium bearing steel, and most use high-quality carburized structural steel, impact-resistant tool steel or quenched and tempered structural steel.
c. Contact medium
Bearings used in corrosive media must be made of corrosion-resistant steel or alloy steel with good corrosion resistance.
2. Choose according to the fatigue life and reliability requirements of bearing steel balls
The fatigue life and reliability of bearing steel balls depend to a certain extent on the purity and uniformity of the steel. For general use occasions, ordinary bearing steel smelted in acidic open furnace or alkaline electric furnace is mostly used. With the continuous improvement of smelting methods, new smelting methods such as current remelting, vacuum smelting, and electron beam furnace smelting have been produced. The life of bearings made of bearing steel smelted in the above manner has also increased accordingly. It is suitable for bearing steel balls with special requirements on fatigue life and reliability.