GCr15 steel used in GCr15 stainless steel ball is a high carbon chromium bearing steel with less alloy content, good performance and wide application. After quenching and tempering treatment, it has high and uniform hardness, good wear resistance and strong contact fatigue performance.
The contact fatigue life of GCr15 stainless steel balls is particularly sensitive to the non-uniformity of the microstructure and properties of the steel. Therefore, the organization and the original organization in the state of use have put forward a series of requirements. The structure of the bearing steel in use should be tempered martensite substantially uniformly distributed with fine-grained carbides, such a structure can impart the desired properties to the bearing steel.
In general, the requirements for the original structure of GCr15 stainless steel ball mainly include two aspects: one is pure, which means that the content of impurity elements and inclusions in steel is less; the other is uniform organization, which refers to non-metallic inclusions in steel. The material and carbide should be finely dispersed and evenly distributed. In other words, the purity and uniformity of steel are two important indicators for measuring the metallurgical quality of bearing steel.