CONTINUOUS CASTING METHOD OF NITROGENNCONTAINING STEEL

摘要

PURPOSE:To accurately restore the amount of nitrogen in steel having been decreased in vacuum degassing process by regulating the nitrogen partial pressure in non-oxidizing atmosphere gas, in continuously casting the ntirogen-contg. refined steel having undergone vacuum-degassing treatment. CONSTITUTION:A sealing box 2 is disposed between a ladle 1 and a tundish 5, and non-oxidizing atmosphere gas is introduced through a conduit 8. The ladle influent flow 3 of the nitrogen-contg. refined steel having undergone vacuum degassing treatment forms vortexes in an ingate and enters a mold 7 by way of a submerged nozzle 6. At this time, it is equally well to shield the tundish 5 and the mold 7 by gas simulatneously or in place of this. Nitrogen is added in the atomsphere gas to be introduced at the time of performing this continuous casting or the nitrogen partial pressure in the atmosphere is regulated by using the atmosphere gas mainly composed of nitrogen in the steel owing ot the vacuum degassing process to assure the content of nitrogen.