Abstract: An apparatus for air-pulverizing high-temperature molten slag by blowing air at high speed through a nozzle into a flow of molten slag that is falling from an inclined container by the intermediary of a turndish. A heat detector is provided for detecting the quantity of heat in the flow of molten slag after being air-pulverized by the high speed air flow, and a feedback control device which is responsive to a detection signal issued from the detector is provided for calculating a desirable inclination angle of the container or the turndish and transmitting a control signal obtained as a result of the calculation to a controller for controlling the inclination of the container or turndish thereby stabilizing the air-pulverizing of the high-temperature molten slag.

Abstract: An Al-killed cold-rolled steel sheet with excellent demagnetization characteristics is provided which is substantially consisted of 0.005% or less C; from 0.05 to 0.50% Mn; 0.010% or less S; from 0.01 to 0.08% Sol.Al; 0.0050% or less N; wherein Mn %/S %.gtoreq.7 and (Sol.Al % - 0.003%)/N %.gtoreq.6; and the remainder iron and inevitable impurities. A shadow mask made of such Al-killed cold-rolled steel sheet and a color television receiver using the same exhibit a very excellent function. A preferred process for producing such an Al-killed cold-rolled steel is also provided, said process being characterized in first obtaining a steel or a specific composition by the use of a vacuum degassing apparatus and then subjecting the steel to sequential steps of hot rolling, cold rolling, decarburization-annealing, and cold rolling.

Abstract: A process for desulfurizing molten steel comprising the steps of: removing converter slag from molten steel; adding a desulfurizing flux onto the molten steel from which the converter slag has been removed; supplying power to electrodes at a predetermined distance from the molten steel so as to generate an electric arc, the desulfurizing flux being melted by arc-heating so as to form the slag; and introducing a gas into the molten steel through a lance submerged into the molten steel to stir the molten steel and the slag which are arc-heated. In the process the desulfurizing flux is melted to a slag consisting essentially of 53 to 62% of CaO, 0 to 15% of SiO.sub.2, and 30 to 45% of Al.sub.2 O.sub.3.

Abstract: The object is to introduce a bottom-blown gas into a molten metal refining furnace so as to minimize the rate of blowing gas flow and increase the control range of the rate of blowing gas flow. There are included a refractory (1) having a plurality of holes (2) having an inner diameter of from 0.5 to 3.0 mm.phi. formed through said refractory and extending its working surface to its back, a metal cover (3) enclosing at least a part of the sides of the refractory (1) and a pressure box (4) formed in the bottom of the refractory (1) so as to communicate with the holes (2) and define a gas reservoir space. The molten metal is prevented from entering the holes (2) when the blowing gas pressure and the rate of blowing gas flow are decreased.

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