METHOD OF SECONDARY TREATMENT OF STEEL IN LADLE (VERSIONS) Russian patent published in 2009 - IPC C21C7/00 C21C7/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy, namely to methods of secondary treatment of the steel in the ladle. The method involves tapping of the steel from the steel-melting unit into the ladle, supplying of deoxidiser or slag-forming materials in the ladle at the time of steel tapping. Calcium carbide is used as the deoxidiser with the size 0.1-25 mm and consumption of 0.5-3.0 kg/t of steel which is determined depending on specific consumption of the calcium carbide at the time of steel tapping in the ladle and oxygen concentration in the steel before tapping by a certain dependence. As one of the versions of the method, after supplying calcium carbide into the steel during tapping and after tapping the steel into the ladle refining slag is delivered into the ladle with consumption 13-16 kg/t of steel then again calcium carbide is charged into the ladle with consumption of 1.0-3.0 kg/t of steel. After the second charge of calcium carbide, the steel in the ladle is blown with argon with consumption of 0.5-5.0 l/min for at least 5.0 min. According to another version, after supplying calcium carbide, the steel ladle is put under the ladle-furnace, the steel is heated, supply refining slag into the ladle with consumption of 13-26 kg/t of steel and again supply calcium carbide into the ladle. After the repeated charge of calcium carbide, the steel in the ladle is blown with argon with consumption of 0.5-5.0 l/min for at least 5 min.

EFFECT: reduced saturation of the treated steel with gases and reduced content of nonmetallic impurities.

9 cl, 3 tbl, 15 ex