Per: Alexandre de Freitas gomes de mendonça (Usiminas s.A.), Rodrigo Seara Martins (Usiminas S.A.), Rodrigo Madrona Dias (USIMINAS S.A.), Leonardo José Silva de Oliveira (USIMINAS S.A.)
Abstract:
In continuous casting, the mold powder is responsible for the formation of a liquid slag in the mold which will form a slag film between the copper plate and the solidified shell. The main functions of the film are to lubricate and moderate the thermal flow in the mold. In particular, for steels with a tendency to stick, a slag is proposed to potentiate more intense thermal extraction in relation to the slag applied in steels with tendency to depression. The basicity index of the mold powder is a parameter that affects directly the heat resistance of the slag film and consequently, the thickness of the solidified shell at the outlet of the mold. With the investigative work of the best practices, the basicity index was reduced in 16.8% of the mold powder applied in ultra low carbon steel, and thus it was possible to increase up to 10.1% in the heat flux in the mold. In addition to the increase in the thickness of the solidified skin, this result also influenced the stability of the mold steel level and the slab surface quality.