关键词: GCr15轴承钢, 夹杂物, 塑性, VD低碱度渣

Abstract:  In order to reduce the harm of B-type and D-type inclusions in Al deoxidized GCr15 bearing steel， a comparative industrial experimental study was conducted on refining VD low alkalinity slag and normal alkalinity slag. The results showed that when refining slag alkalinity was reduced from 9.34 to 1.96， the proportion of plastic inclusions in the steel increased from 14.81 % to 40.65 %. As the same time， the content of total oxygen （T. O） decreased from 7.7 × 10^-6 to 4.9 × 10^-6； the content of total aluminum （T. Al） and acid-soluble aluminum （Al_S） decreased from 279 × 10^-6 and 210 × 10^-6 respectively to 80 × 10^-6 and 75 × 10^-6. Thermodynamic calculation shows that the increase of ［Si］ activity in the liquid steel causes the decrease of Al₂O₃（inc） content in the composite inclusion， and the acid soluble aluminum （Al_S） content in the steel falls within the range of equal aluminum concetration lines corresponding to plastic inclusions， the theoretical calculations are consistent with experimental results. The VD refining with low basicity slag is beneficial for achieving control over the plasticization of inclusions in bearing steel.

Key words:  , GCr15 Bearing Steel； Inclusions； Plasticity； VD Low Basicity Slag