2018 Volume 58 Issue 12 Pages 2262-2270
The reduction of ferroalloy consumption used in the steel making is an important approach to high-performance and low-cost steel manufacture. In this paper, the effect of size of ferrotitanium on the yield in the refining of interstitial free steel by RH de-gasser was investigated. Motion trajectory of ferrotitanium after the addition into molten steel in RH de-gasser was investigated through water model experiment. The effect of size of ferrotitanium on the melting time was investigated by numerical simulation. Combining water model experiment with numerical simulation, the loss mechanism and effect of size on the yield of ferrotitanium were discussed. It was found that the size of ferrotitanium larger than a certain value has a great opportunity of floating up to the interface of molten steel and slag in ladle and being oxidized there. Results of industrial experiment verified the mechanism. As for a 300 tons RH de-gasser, Fe-70%Ti alloy whose size was larger than 43 mm had a low yield because of oxidation by the ladle slag.