Abstract: The gap between an insertion hole formed in a covering of a ladle and an electrode inserted through the insertion hole is sealed by sealing means. The sealing means has a cap seal longitudinally and slidably fitted over the electrode. A base seal is hermetically disposed between the cap seal and the covering in such a manner that a gap is provided between the electrode and the base seal. The base seal has a gas injection nozzle intended to discharge a gas toward the electrode and another gas injection nozzle intended to discharge the gas downwardly. The use of the base and cap seals enables securing the sealing functions thereof despite any movement of the electrode, thus preventing the pickup of [N] as well as the reoxidation of molten steel. When a gas seal is effected by the formation of a flow of gas rotating around the electrode about the axis thereof, the sealing performance can be more enhanced.

Abstract: A method and an apparatus for removing fine cold shut cracks on a horizontally and continuously cast steel strand, using ejection of a plurality of metal shots, comprises: horizontally and intermittently withdrawing a cast steel strand from a horizontal mold by a plurality of cycles each comprising a pull and a push, cooling the cast steel strand in a cooling zone provided following the horizontal mold on the same horizontal level as that of the horizontal mold, increasing the temperature of the surface portion of the solidified shell of the cast steel strand in a heat-restoring zone provided following the cooling zone on the same horizontal level as that of the cooling zone, to soften the surface portion of the solidified shell of the cast steel strand, and then continuously ejecting a plurality of metal shots from a plurality of shooters in a shooting zone provided following the heat-restoring zone on the same horizontal level as that of the heat-restoring zone onto the cast steel strand, to weld fine cold