Abstract: Based on the plant trials and thermodynamic calculation，the titanium alloying of ferritic stainless steel containing titanium during the reduction process of VOD，the early stage of LF and the late stage of LF and its influence on the quality of molten steel were investigated. The results showed that the closer the time of titanium alloying is to the end of refining，the higher the titanium yield was. The titanium yield of 409L steel was 62.7 % after VOD reduction，while the yield of titanium alloy was 76 % at the later stage of LF refining. The total oxygen content and the pouring property of steel were also affected by the titanium alloying. The closer it was to the end of refining，the higher the total oxygen content in the steel was and the higher the increase ratio of the plunger position in the casting process was. The oxidizability of molten steel could be reduced and the yield of titanium could be increased by controlling the slag amount from K-OBM-S，weak oxide（Cr₂O₃+MnO+TFe）content in the slag，VOD oxygen blowing and increasing the total aluminum mass fraction in the steel. The mass fraction of total oxygen in molten steel could be reduced and the pouring property of steel was improved when titanium alloying in the early stage of LF refining.

Key words: ferritic stainless steel containing titanium, titanium alloying, titanium yield, refining