Cleanliness of GCr15 Bearing Steel During Steelmaking Process

T[O] and inclusions during EAF→LF→VD→Purging→CC process were investigated on GCr15 bearing steel.Through controlling carbon content at EAF tapping from 0.2% to 0.4%, adding aluminum and flux during tapping for deoxidation and pre-refining, making high basicity slag with little(TFe+Mn O) content during LF refing, stirring the steel in VD and preventing steel reoxidation in tundish, bearing steel with w(T[O]) = 8 × 10-6can be produced. Inclusions changed in order of Al2O3→Mg O·Al2O3→Ca O-Mg O-Al2O3 during the secondary refining process. The average size of inclusions decreased after ladle refining, while picked up after vacuum treatment, and continously decreased during purging and in tundish. Inclusion number can be reduced by 74% through VD process.