Study On The Mechanical Property And Microstructure Of High Nitrogen Bearing Steels

High nitrogen stainless bearing steel not only has high strength,hardness and good abrasion resistance,but also has corrosion resistance,which is widely used in the manufacture of bearing parts.In order to study the effect of heat treatment process parameters on the organization performance,this paper adopts high steel,nitrogen stainless bearing steel X60 N as test studied including the spheroidizing annealing,quenching temperature,cooling and tempering temperature and tempering heat treatment process parameters such as heat preservation time on the microstructure and mechanical properties of test steel,for the preparation of high nitrogen stainless bearing steel and provide theoretical basis for control of the organization.The main results are as follows:After spheroidizing annealing second phase distribution of carbon nitride particles dispersion,chains and reunion three states,morphology of granular and strip,and long strips of carbide,granular carbon nitrides.The distribution of second phase particles after quenching is mainly agglomeration and dispersion,and the morphology is mainly granular.The higher the quenching temperature,the higher the residual austenite content of high nitrogen stainless bearing steel and the larger the bar martensite size.After quenching,the martensite profile of the test steel presents slender and parallel arrangement.With the increase of tempering temperature,the amount of retained austenite decreased,and the residual austenite was distributed between the strip martensite in two forms of film and block.The tensile fracture of high-nitrogen stainless bearing steel is smooth,and the non-shrinking neck is brittle fracture.However,with the increase of quenching temperature,the number of dimples will increase and the toughness of materials will become better.