Research on behavior of non-metallic inclusions of bearing steel in refining process

This paper analyzes the transformation of non-metallic inclusions of bearing steel GCr15 in the refining stage with the process of EAF-LF-VD-CC in an electric furnace factory.The main source of non-metallic inclusions was ascertained using the methods of optical microscopy and SEM.The results showed that the inclusions in LF procedure were mainly lump Al2O3,ametabolic dotlike inclusions and sulfides;after procedure of VD,the amount of ametabolic dotlike inclusions reduced sharply,whereas complicated inclusions with CaO,MgO,Al2O3 and sulfides increased to a certain extent.No ametabolic dotlike inclusions were found in the samples of finished steel.There were only a bit of small sized Al2O3 and sulfides in the inclusions observed.