Characteristics of Electric Power and Heating of Molten Steel of AC Plasma Torch for Arc Heating of Molten Steel in Tundish

Abstract

The single A. C. plasma arc heating system was adopted in the new No. 4 continuous caster at Kakogawa works in 1989 to keep molten steel temperature constant during casting. By using this system, the effect of atmosphere on plasma arc voltage and the heating characteristics of molten steel were investigated. The obtained results are as follows:
Plasma arc voltage in the case of using molten steel is lower than that of using carbon block because of existence of metallic fume. Plasma arc voltage is affected by the gas composition more than the dust quantity in the tundish and it increases with increasing the content of gas molecules such as O₂ and N₂ gas in the Ar atmosphere. It is possible to keep molten steel temperature constant in the tundish by the suitable plasma arc heating condition.