Bearings are divided into two types: sliding bearings and rolling bearings. Sliding bearings are cast and do not require heat treatment. Only rolling bearings require heat treatment.

There are three types of rolling bearings, one is general chromium bearing steel, one is carburized bearing steel, and the other is stainless bearing steel. Different types of heat treatment processes are different.

Rolling bearings can be divided into three categories according to their structure, namely inner and outer rings, rolling elements, and brackets. The bracket does not require heat treatment, only the inner and outer rings and rolling elements require heat treatment. Their heat treatment process is:

Since chromium bearing steel has high carbon content and is a super-analytical steel, its high hardness makes it difficult to process, so its preheating treatment is spheroidizing annealing. Reducing hardness facilitates machining. Therefore, spheroidizing annealing should be arranged before processing. If the structure is not good, normalizing should be arranged before spheroidizing annealing to eliminate network carbides. If the structure does not have network carbides, the normalizing process can be omitted.

The final mechanical properties of rolling bearing steel require high hardness and high strength, so its final heat treatment is quenching + low temperature tempering. Since the hardness is high and it is the final heat treatment, it is arranged after the ferrules and rolling elements are processed and formed. conduct.