SLAG-FORMING MIXTURE FOR CONTINUOUS CASTING RAIL STEEL Russian patent published in 2005 - IPC

FIELD: ferrous metallurgy.

SUBSTANCE: slag-forming mixture for continuous casting rail steel comprises the following components, wt.-%: amorphous graphite, 5.5-8.5; dust-like waste in lime manufacturing, 29-35; dust-like waste in ferrosilicon manufacturing, 37-40; dust-like waste in aluminum manufacturing, 20.5-24.4; soda ash, below 1; cryolite, below 1. The mixture has the following composition, wt.-%: carbon, 13.0-18.0; calcium oxide (CaO), 24.0-32.0; silicon dioxide (SiO₂), 31.0-37.5; aluminum oxide (Al₂O₃), 5.5-10.0; fluoride (F), ≥ 4.0; Na⁺, ≥ 0.7; K⁺, ≥ 0.7; iron oxide (FeO), ≤ 2.0; manganese oxide (MnO), ≤ 2.0. The basicity value (CaO/SiO₂) of mixture = 0.6-0.9. Invention provides enhancing quality of steel due to improvement of macrostructure, reducing contamination of steel with nonmetallic inclusions and reducing sorting out continuously casting blanks for surface defects due to improvement of crystallizer lubrication with the melted slag-forming mixture.

EFFECT: improved and valuable properties of mixture.

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