Bearing steel is used to make balls, rollers and bearing rings. Bearings are under great pressure and friction when working, so bearing steel is required to have high and uniform hardness and wear resistance, as well as high elastic limit. The requirements on the uniformity of the chemical composition of bearing steel, the content and distribution of non-metallic inclusions, the distribution of carbide and so on are very strict, is one of the most strict requirements in all steel production.

 

Bearing steel is divided into: chromium bearing steel, carburized bearing steel, special purpose bearing steel

 

Metallographic microstructure inspection items of chromium bearing steel: grading of nonmetallic inclusions, grading of carbide mesh and liquid out and spheroidized annealing microstructure, quenching and tempering microstructure, fracture and bainite microstructure

 

Metallographic microstructure inspection of carburized bearing Steel: Metallographic microstructure inspection of carburized bearing steel and rolling bearing parts of semi-finished and finished products. Strip rating of nonmetallic inclusions and carbides in steel

 

Domestic Metallographic inspection standard for bearing steel:

GB/T 3086-2008 high carbon chromium stainless bearing steel

GB/T 18254-2002 high carbon chromium bearing steel

Technical conditions for heat treatment of JB/T 1255-2001 high carbon chromium bearing steel rolling bearing parts

Technical conditions for heat treatment of JB/T 1460-2002 high carbon chromium stainless steel rolling bearing parts

Technical conditions for heat treatment of JB/T 2850-2007 Cr4Mo4V high temperature bearing steel parts

JB/T 6366-1992 Technical conditions for heat treatment of 55SiMoVA steel rolling bearing parts

JB/T 7362-1994 Test method for decarbonization layer of rolling bearing parts

JB/T 8881-2001 rolling bearing parts carburizing heat treatment technical conditions

Technical specification for YB 9-68 chrome bearing steel

 

A small bearing, ball will affect the operation of a piece of equipment, a qualified bearing is required to carry out strict testing, only qualified products, will ensure the operation of a piece of equipment, the implementation of a project. It is necessary to detect the metallographic structure of bearing steel with high precision and high quality metallographic microscope and metallographic sampling equipment