Study on the Process of Adding TiO₂ and VC Superfine Particle to Molten Industrial Pure Iron

Ingot specimens were obtained by the process of adding individual 80 nm TiO₂ and 1.5 μm VC superfine particles to molten industrial pure iron.Nonmetallic inclusions were extracted from industrial pure iron ingot sample by the electrolytic method in the nonaqueous solution.Morphology, existent state and components of inclusions were investigated by SEM and EDS.The results showed that additive TiO₂ and VC particles usually combine with microelements and molten inclusion form complex inclusions, and existed in the interior of complex inclusions.There were a lot of white punctate and ribbon MnS inclusions at some surface of VC complex inclusions.Stability of additive TiO₂ and VC superfine particles in molten is also investigated by thermodynamic calculation.