Effect of isothermal annealing on Spheroidization of carbides in GCr15 steel

The spheroidizing effect of GCr15 steel was studied and the microstructure was analyzed by SEM under different isothermal annealing. The results show that: the carbide particles become smaller and smaller which is easy to form and grow into lamellar carbide with the increase of the temperature, and when the heating temperature is increased to 800 degrees C; The carbide particles can grow into spherical shape independently, and even some of the particles begin to grow up with the increasing of the heating time; The optimum process of GCr15 steel is heating temperature 780 degrees C, heating time 5h, isothermal temperature of 700 degrees C, isothermal time 3h.