Abstract: A refractory block for continuous casting comprising: a unitary assembly comprising: a plate brick having a top, a bottom, sides and a passageway therethrough, and a submerged nozzle having a top, a bottom, sides and a passageway therethrough, the sides of the submerged nozzle having a shoulder portion, the bottom of the plate brick joining the top of the submerged nozzle; a metal casing surrounding the unitary assembly such that the metal casing surrounds and supports a portion of the sides of the plate brick, a portion of the bottom of the plate brick and a portion of the sides of the submerged nozzle including the shoulder portion, and an air cooling jacket surrounding the metal casing.

Abstract: A refractory block for continuous casting is disclosed comprising a unitary assembly including a plate brick having a top, bottom, sides and a passageway therethrough; a gas permeable porous brick having a top, bottom, sides and a passageway therethrough, where the top of the porous brick is attached to the bottom of the plate brick, a gas pool for containing gas surrounds the sides of the porous brick, and a submerged nozzle having a top, bottom and sides, where the sides have shoulder portions, has the top of the submerged nozzle attached to the bottom of the porous brick. A metal casing surrounds the unitary assembly so that the metal casing surrounds and supports a portion of the sides of the plate brick, a portion of the bottom of the plate brick, the sides of porous brick, and a portion of the sides of the submerged nozzle, including the shoulder portions. The metal casing further includes gas feed and discharge pipes therethrough in communication with the gas pool.

Abstract: The nozzle for continuous casting has a plurality of steps in the molten steel pouring hole of the nozzle. The dimension of the inside diameters of the steps to the inside diameter d of the main pipe is d.sub.1 >d.sub.2 >d or d.sub.1 >d.sub.2 d.sub.3 >d, the inside diameter d.sub.2 or d.sub.3 immediately above the molten steel pouring outlet is d+10 mm.gtoreq.d.sub.2 or d.sub.3, and the material of the inner peripheral wall near the pouring outlet is boron nitride-carbon.