Research on Controlling Titanium Content in Bearing Steel during Secondary Refining

Based on the production process characteristics and quality requirements of bearing steel,industrial test and actual production data had been compared to analyze the main metallurgy process which can bring titanium uptaking in the steel.According to thermodynamic calculation the effects of oxygen activity in steel,acid-soluble aluminum and the composition of slag on the titanium content had been investigated.LF refining stage was thought as the main process causing titanium uptaking during steelmaking process.After BOF tapping,the content of titanium can be reduced effectively by using weak deoxidization,reducing the basicity of the refining slag and decreasing the soluble aluminum content in the steel.When the content of oxygen is above 20 × 10^-6 after BOF,the titanium content could be controlled below 20 ×10^-6.When the soluble aluminum content is below 0.018%,the content of SiO₂ in slag is above 6.5%,it is beneficial to control titanium uptaking.