Carbide uniformity is one of the main factors affecting the fatigue performance of bearings.The crushing test steel balls made of GCr15 raw materials produced by different processes in steel mills is carried out

and the crushed steel balls are analyzed by carbide network and banded structure test.The experimental results show the crushing load increases with the prolongation of the high temperature diffusion time

and the crushing load increases more significantly with the controlled rolling and cooling on this basis.When the carbide particles are between2.5 and 6 μm

the larger the carbide particles are

the smaller the crushing load value is.The average crushing load of the steel ball is the highest which peach to 251.581 kN. While the high temperature diffusion temperature of the billet is 1220- 1240 ℃

the time is 16 h

and the final rolling temperature of the coil is 750-800 ℃

and the cooling speed is 4-5 ℃/s.