The paper presents studies showing the effectiveness of the use of wire with SiCa filler in the out-of-furnace processing of steels. The efficiency of use was evaluated by calculating the contamination with non-metallic inclusions, as well as by determining the phase composition of non-metallic inclusions at the stages of out-of-furnace processing and casting. (installation bucket furnace→vacuum cleaner→continuous casting). The study found that the adjustment of the content of aluminum before casting leads to the formation of refractory inclusions of corundum - (AlO), spinels - (AlO·MgO), which are deposited on the walls of the steel filling path and worsen the spillability of steel. The use of SK30prov with SiCa filler at the final stages of extra-furnace processing (after the introduction of aluminum), leads to the modification of refractory inclusions in low-melting calcium aluminates of the type (CaO·AlO). The presence of low-melting inclusions is more preferable, since this type of inclusions is not deposited on the walls of the filling cup and does not have a negative effect on the contamination of the continuously cast billet and products obtained from them with inclusions.