According to the national standard and the bearing use requirement, currently used in rolling bearing ring and body material has high carbon chromium bearing steel, carburized bearing steel, such as the material according to their different characteristics and is used for different occasions.
It is not to say that the bearing with high value of carburizing steel is more suitable than bearing steel bearing.
. High carbon chromium bearing steel is also called all-harden-hardened steel, which is consistent with the internal and external hardness of steel. It is applied to ordinary occasions, with the largest amount of the material, accounting for more than 80% of the total amount of the material.
 
1. GCr15
Features and USES: used for common occasions, maximum dosage, suitable for martensite and bainite quenching.
Technical characteristics: the effective wall thickness is below 26mm, the light narrow range is below 16mm, and the hardness of quenching is HRC57~ 62.
2. GCr15SiMn
Features and USES: used in ordinary occasions for large bearings, only for martensite quenching.
Technical characteristics: the effective wall thickness is above 26mm, the light narrow series is over 16mm, and the hardness of quenching is HRC57~ 62.
GCr15 and GCr15SiMn is the most commonly used brand, can be seen from the above introduction of the two steel performance is basically the same, because GCr15SiMn steel hardenability is better than GCr15 steel, so for large size bearing parts, appropriate USES GCr15SiMn steel.
GCr15SiMn bearing steel is mainly used to make wall thick bearings, such as various large and special bearings, which can be used in heavy duty machine and rolling machine without heavy impact load.
Due to the large crack sensitivity of GCr15SiMn steel, the impact toughness difference is not sufficient to meet the requirement of the heavy wall bearing with impact load.
3. GCr18Mo
Features and USES: bainite is used for steel and wear-resisting and is only suitable for bainite quenching.
Technical characteristics: the effective wall thickness is between 26~ 48mm, and the light narrow range is below 16mm, and the hardness of quenching is HRC57~ 62.
The lower bainite resistance is better than martensitic body and is suitable for wear-resisting.
. Carburizing bearing steel is also known as semi-hardenable steel, which has a certain "elasticity" in the performance of the material, which can be used for impact resistance. It needs to be hardened by carburizing, and the process is more complicated.
 
G20Cr2Ni4A
Features and USES: used for impact, medium and large bearings, deep carburizing.
Technical characteristics: effective carburizing depth can be greater than 2.5 mm, surface quenching hardness HRC58~ 63.
Made of this kind of steel bearing parts, after carburizing, quenching and tempering heat treatment process, has the very high surface hardness, hardness HRC58 or higher) and certain abrasion resistance and contact fatigue strength is higher, and ensure its core has good toughness, hardness HRC33-48).
This kind of surface hardened core has the characteristics of toughness, which makes the cementing bearing steel especially suitable for stable work under the conditions of heavy impact load.