Carburized bearing steel is also called semi-hardenable steel, which is soft inside and hard outside. The material has a certain degree of "elasticity" for impact resistance. It needs to be carburized and quenched, and the process is more complicated.

G20Cr2Ni4A

Features and uses: used in impact-resistant occasions, medium and large bearings, and can be deeply carburized.

Technical characteristics: The effective carburizing layer can be deeper than 2.5mm, and the surface quenching and tempering hardness is HRC58~63.

Bearing parts made of this type of steel have high hardness (hardness ≥ HRC58), certain wear resistance and high contact fatigue resistance after heat treatment processes such as carburization, quenching and tempering, and guarantee The heart has good toughness (hardness HRC33-48). This surface hardened core has the characteristics of toughness, making the carburized bearing steel particularly suitable for stable operation under conditions of large impact loads.

After carburizing and quenching, the surface retains the state of compressive stress and has good fatigue resistance. It has strong ability to bear impact load, and the surface hardened layer has micro cracks and it is not easy to expand to the inside. The surface has a higher hardness and the core hardness is lower. Compared with high carbon chromium bearing steel, it has better core impact toughness. The depth and concentration of carburization can be adjusted as required.

However, the cost of bearings made of G20CrNi4A is relatively high, and in the use of small and medium-sized bearings, their life will not be greatly improved compared with bearing steel. Therefore, only carburized steel is used for medium and large bearings.