Abstract: Close-coupled atomization systems and methods employing non-axisymmetric gas flow have demonstrated superior efficiency in the production of fine superalloy powder, compared to conventional close-coupled atomization utilizing an axisymmetric annular gas orifice and an axisymmetric melt nozzle. A means has been devised for convening otherwise axisymmetric plenums into non-axisymmetric plenums that produce non-axisymmetric gas flow.

Abstract: A molten steel pouring nozzle having, along the axis thereof, a bore through which molten steel flows. At least part of an inner portion of the molten steel pouring nozzle, which inner portion forms the bore, is formed of a refractory consisting essentially of:zirconia clinker comprising calcium zirconate: from 40 to 64.9 wt. %,where, a content of calcium oxide in the zirconia clinker being within a range of from 8 to 35 weight parts relative to 100 weight parts of the zirconia clinker,graphite: from 10 to 35 wt. %, andcalcium silicate: from 25.1 to 50 wt. %,where, a content of calcium oxide in the calcium silicate being within a range of from 40 to 54 weight parts relative to 100 weight parts of the calcium silicate.

Abstract: An immersion nozzle for continuous casting have an immersion nozzle body, at least one opening hole for receiving the molten metal, a vertical bore, at least one pair of exit ports for introducing the molten metal into the mold through the vertical bore, a slit opening for introducing the molten metal downwardly and a downwardly convex surface of the bottom of the vertical bore.The slit opening is located at a bottom end of the body of said immersion nozzle which is below the exit ports and in parallel to the width direction of the mold.

Abstract: An emergency blank shutting off device for conveying and exchanging pouring tubes sliding along guide-rails (6,7) determining a first trajectory is intended to ensure the immediate and tight stop of a casting operation in case of emergency. It comprises a carrier on which an emergency blank re-fractory plate (8) is set and actuated along a second trajectory which crosses over the first trajectory, from a readiness position (14), off the second trajectory to an alert position (15) on a zone overlapping the two trajectories adjacent to the operating position of a pouring tube (3) in the pouring axis.

Abstract: A reinforced ceramic tube for refractory use comprises a settable slurry cast inside a metal sleeve with longitudinal, compliance. In use the sleeve moves with ceramic under thermal stress to avoid major cracking.

Abstract: An immersion nozzle is employed for discharging material from a vessel to a mold and includes an upper section to be connected to the vessel and a lower section having a region to be immersed in material in the mold. The upper and lower sections have extending therethrough respective discharge channels that communicate and that enable material to be discharged from the vessel to the mold. The discharge channel of the upper section converges downwardly in a first vertical plane to join the discharge channel of the lower section. The discharge channel of the upper section also expands downwardly in a second vertical plane transverse to the first vertical plane to join the discharge channel of the lower section. Each of the upper and lower sections is formed by at least one respective separate member. The members have adjacent ends having mutually facing and fitting surfaces, and each pair of facing and fitting end surfaces has therebetween a seal.

Abstract: The invention is directed to an immersion casting pipe for feeding molten steel from a casting vessel into a mold having wide side walls and narrow side walls for the production of flat products. The immersion casting pipe has a pipe piece which adjoins the casting vessel and expands in cross section in the direction of the narrow side walls of the mold. The pipe piece is provided with a central base member at the lower end which allows for outlet openings for the melt. For the purpose of developing an immersion outlet which allows higher slab withdrawal speed of up to 6 m/min with slabs measuring 50 to 100 mm in thickness and 600 mm to 2000 mm in width, the inner wall of the portion of the immersion casting pipe which widens in cross section forms flow channels in conjunction with the opposite wall parts of the base member. The axes of the flow channels enclose an angle .alpha. between 10.degree. and 22.degree.

Abstract: A fired carbon-bonded, oxide refractory body for use in casting aluminum-killed steel has a metal contacting surface which is resistant to both steel erosion and buildup of alumina. The layer is formed by first firing the pressed body in an oxidizing atmosphere to form a porous oxidized zone on selected steel contacting surfaces. The remaining surface portions of the body are protected against oxidation during firing by a glaze applied prior to firing. A carbon free refractory slip or slurry is infiltrated into the porous oxidized zone to create the erosion and buildup resistant surface layer. A preferred infiltrant material is alumina.

Abstract: A sealing apparatus for shielding air from a path of molten steel in a laddle to a tundish in continuous metal casting facilities to prevent oxidation of the molten metal, the apparatus including a seal box lift mechanism mounted on a tundish body through a bracket and including a drive member and a lift rod member to be vertically moved up and down by the drive member; a seal box including an outer cylinder fixedly mounted on a tundish cover and extending into the tundish, and an inner cylinder telescopically fitted in the outer cylinder and connected to the lift rod member through a lever; a first seal member fixed at the upper end of the inner cylinder and pressed against a nozzle mounting surface of the laddle when the inner cylinder is lifted up by the lift rod member; a second seal member fixed on the outer cylinder to seal gap space between the outer and inner cylinders; and an inert gas inlet provided in the wall of the inner cylinder.

Abstract: A sliding nozzle for a molten steel receiving vessel, which comprises: an upper nozzle (22) made of a refractory inserted vertically into a bottom wall of a molten steel receiving vessel; a fixed plate (23) made of a refractory secured horizontally and stationarily to a lower end of the upper nozzle; a horizontally and reciprocally movable sliding plate (24) made of a refractory arranged below the fixed plate; a lower nozzle (25) made of a refractory secured vertically and stationarily below the sliding plate, the lower nozzle comprising a nozzle body (27) and a metallic frame (28) fitted to a flange (27A) at an upper end of the nozzle body, the lower nozzle having a length sufficient to cause a lower end portion thereof to be immersed into molten steel in a mold; a fitting device (30) for pressing the lower nozzle (25) against the lower end of the upper nozzle (22) through the sliding nozzle (24) and the fixed plate (23); and a driving unit (26) for causing the sliding plate ( 24) to slide horizontally and r

Abstract: A molten steel pouring nozzle which comprises: a nozzle body comprising an alumina-graphite refractory, having, along the axis thereof, a bore through which molten steel flows; and an outer refractory layer arranged on an outside portion of the nozzle body so as to be integral with the nozzle body and to be flush with an outer surface thereof, the outer refractory layer being arranged on a portion of the outside portion of the nozzle body, which portion is in contact, when a lower portion of the molten steel pouring nozzle is immersed into molten steel, with the open air without being immersed into the molten steel, and the outer refractory layer consisting essentially of:______________________________________ alumina (Al.sub.2 O.sub.3) from 40 to 75 wt. %, carbon (C) from 10 to 30 wt. %, silica (SiO.sub.2) from 1 to 30 wt. %, silicon carbide (SiC) from 1 to 20 wt. %, and low-melting glass from 1 to 10 wt. %.

Abstract: A refractory pouring-assembly component for use with a tube changer mechanism, the component having a throughbore for pouring of molten metal during continuous casting from a tundish into a mould and being isostatically pressed from different heat- and wear-resisting reffactories to form a one-piece composite body having at one end a smooth, flat plate surface in which there is defined an aperture, at least the peripheral edge around said aperture being formed of a hard refractory material to provide a cutting edge around the through-bore, whilst the remainder of said body is formed from a thermal shock-resistant material to provide for pouring of melt.

Abstract: Method and apparatus for casting metal strip in which molten metal is introduced between a pair of parallel casting rollers via a tundish and a metal delivery nozzle. Casting rollers are cooled so that shells solidify on the moving roller surfaces and are brought together at the nip between them to produce a solidified strip product at the roller outlet. The delivery nozzle comprises an elongate trough to receive molten metal and an outlet slot extending longitudinally along the bottom of the trough. The floor of the delivery nozzle is formed with an upwardly facing channel extending longitudinally of the trough in side by side relationship with the outlet slot. The channel merges smoothly at one of its sides with a side wall of the trough and rises at the other side above the root of the channel to the outlet slot.

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.

Abstract: An immersion nozzle (2) for metallurgical recipients, in particular for a reservoir arranged upstream of a continuous casting ingot mould, has an interchangeable discharge pipe (2) which can be attached in a leakproof manner on or in a perforated brick (1). To improve the flow conditions and hence the efficiency of the casting, the inlet side of the nozzle comprises an upper elongated section (12) in the form of a tubular shaft (11) which expands conically downward to a given plane and which is narrow in a plane perpendicular to the given plane. A second elongate section (13) ends in an elongated transverse flow section of given dimensions.

Abstract: Molten metal is either poured or injected into the cavity of a permanent mold by way of a bush which comprises a metal sleeve, anchored to the mold itself, a first tubular element of ceramic material lodged internally of the sleeve, and a second tubular element, also ceramic, coaxial with the first. The stream of metal passes from a feeder into the inlet end of the bush, through the first and then the second ceramic element, and enters the cavity ultimately from an outlet end consisting of a metal annular element connected in a precise and effectively fluid-tight fit with the corresponding end of the second tubular element.

Abstract: A molten steel pouring nozzle having, along the axis thereof, a bore through which molten steel flows. At least part of an inner portion of the molten steel pouring nozzle, which inner portion forms the bore, is formed of a refractory consisting essentially of:______________________________________ zirconia clinker comprising calcium from 40 to 89 wt.%, zirconate where, a content of calcium oxide in the zirconia clinker being within a range of from 6 to 35 weight parts relative to 100 weight parts of the zirconia clinker; graphite from 10 to 35 wt.%, and crystal stabilized calcium silicate from 1 to 30 wt.%. comprising dicalcium silicate (2CaO.SiO.sub.2) and tricalcium silicate (3CaO.SiO.sub.

Abstract: A flow-vectored downspout includes a pouring tube and a flow diffuser arranged on an end thereof. The flow diffuser includes horizontal slots disposed toward the faces of an ingot during a continuous casting process with horizontal and angled slots disposed toward the ingot sides. The flow diffuser also includes at its bottom a domed diverter which facilitates transition of vertical molten metal flow through the pouring tube into a substantially horizontal flow pattern for discharge into a mold cavity through the arrangement of horizontal and angled slots. The particular arrangement of slots provides distribution to all areas of the ingot to be cast with minimal turbulence. The flow-vectored downspout is especially adapted for direct chill or electromagnetic casting without the use of a channel bag or the like. A continuous casting method using the downspout is also provided.

Abstract: A refractory pouring-assembly component for use with a tube changer mechanism comprises an elongate tubular body having a throughbore for pouring of molten metal during continuous casting from a tundish into a mould wherein the refractory pouring component is an isostatically pressed, heat- and wear-resisting refractory one-piece composite body which is shaped to provide at one end a smooth, flat plate surface in which there is defined an aperture, the peripheral edge around said aperture being formed of a hard refractory material to provide a cutting edge around the throughbore, whilst the remainder of said body is formed to a tubular shape from a thermal shock-resistant material to provide for pouring of melt. The compositions of said component may be uniform blends of refractory material bonded by silicon nitride or silicon oxy-nitride or an annulus of selected hard materials within a graphite/alumina host body.

Abstract: A method of continuously casting a liquid metal including the steps of providing an upper vessel and a lower vessel, providing a stream protection tube disposed between the upper vessel and the lower vessel, the stream protection tube being connected at an upper end thereof to a tap hole defined in a bottom portion of the upper vessel, the stream protection tube being open at a lower end thereof, at least one aperture being defined in a wall of the tube near the lower end. The method further includes disposing the upper vessel above the lower vessel, lowering the upper vessel until a lower portion of the tube disposed below the aperture is immersed in liquid metal contained in the lower vessel with the aperture being disposed above the liquid metal. Next, the tap hole is opened so that liquid metal disposed in the upper vessel flows into the stream protection tube, air contained in the tube is expelled through the aperture.

Abstract: A method and apparatus are disclosed for inserting a pouring pipe into a mold of a continuous casting machine. The pouring pipe is mounted in a truck, and the truck and pouring pipe combination are then mounted on a conveyor mechanism such that the pouring pipe is set in a substantially horizontal starting position. From this substantially horizontal starting position, the pouring pipe is guided along a pair of guide rails of the conveyor mechanism such that is pivots into a substantially vertical position and is moved into a waiting position wherein its lower end is inserted into the mold. In this waiting position, the pouring pipe is offset laterally from but aligned with a casting opening in the bottom wall of the metallurgical vessel. From this waiting position, the pouring pipe can be forced by a pusher mechanism into a pouring position beneath the casting opening of the metallurgical vessel, such that molten metal can be poured from the metallurgical vessel into the mold via a pouring pipe.

Abstract: An apparatus is disclosed for use in replacing a worn pouring pipe by moving a pouring pipe from a waiting position to a pouring position beneath a discharge opening of a metallurgical vessel, and for use in adjusting flow of molten metal from the metallurgical vessel through the discharge opening. For this purpose, slide rails are provided beneath the metallurgical vessel for supporting head plates of pouring pipe in the waiting position, the pouring position and a discharge position. Also, a linear actuator is provided for pushing the pouring pipe from the waiting position to the pouring position, and can be detachably coupled to the head plate of the pouring pipe so that it can move the pouring pipe in opposing direction to adjust the flow of molten metal through the discharge opening between zero flow and full flow.

Abstract: An assembly includes a discharge member of a metallurgical vessel and a pipe member connected to the discharge member at mutual surfaces thereof defining a seat therebetween. An annular recess is formed in the region of such seat, a seal seals such seat, and gas is supplied to the annular recess. The seal is in the form of a pair of compressible sealing rings positioned between the mutual surfaces of the two members on opposite sides of the annular recess. A pressure indicator is connected to a gas supply line supplying gas to the annular recess to provide an indication of the pressure of gas prevailing in the annular recess, and particularly of changes of such pressure.

Abstract: A sealing device is mounted to slide against the underside of a fixed plate, to allow liquid metal contained in the container to flow out, or to block the casting passage. A fixed reference plate is mounted against the underside of the sealing device, the underside of the reference plate is placed against the upper surface of a bearing plate, and the reference plate comprises a casting opening placed coaxially to the casting channel of the external casting pipe. The whole device is held together by clamping means.

Abstract: An improved metal pouring tube especially adapted for conducting molten metal such as liquid steel, the tube being formed of carbon-impregnated ceramic-bonded refractory material principally comprising alumina, zirconia and silica. Also included is the method of forming the tube.

Abstract: A manipulator is disclosed for manipulating a pouring pipe from a remote position wherein it is oriented substantially horizontally, to a position beneath a metallurgical vessel wherein the pouring pipe is oriented substantially vertically. The manipulator includes a supporting frame which can be transferred on laterally extending track and longitudinally extending tracks from a remote location to a location adjacent the metallurgical vessel. The manipulator is adapted to detachably engage the pouring pipe such that the pouring pipe can be guided along a guide path which preferably includes curved portions. With this arrangement, the manipulator is operable to manipulate the pouring pipe in an accurate manner and without danger to operating personnel into position beneath the metallurgical vessel and into a continuous casting mold, even when space for such manipulation is narrow.

Abstract: A refractory discharge device includes an immersion nozzle formed substantially of carbon-bonded magnesium oxide or carbon-bonded aluminum oxide or fused quartz. The immersion nozzle has therethrough a discharge passage and has an outer surface and an outlet end. An external reinforcement member is formed entirely separately from the immersion nozzle from a zirconium oxide material that is directly bonded without any carbon and by burning at a high temperature. The external reinforcement member is attached to the outer surface of the outer surface of the immersion nozzle at a position such that during use the external reinforcement member will extend above and below a casting powder covering of molten metal into which the refractory discharge device will be immersed.

Abstract: A molten steel pouring nozzle having, along the axis thereof, a bore through which molten steel flows. At least part of an inner portion of the molten steel pouring nozzle, which inner portion forms the bore, is formed of a refractory consisting essentially of:zirconia clinker comprising calcium zirconate: from 40 to 89 wt. %,where, a content of calcium oxide in the zirconia clinker being within a range of from 8 to 35 weight parts relative to 100 weight parts of the zirconia clinker;graphite: from 10 to 35 wt. %; andcalcium silicate: from 1 to 25 wt. %,where, a content of calcium oxide in the calcium silicate being within a range of from 40 to 54 weight parts relative to 100 weight parts of the calcium silicate.

Abstract: A nozzle for use in continuous casting comprising an inner surface region defining the nozzle port for passing a molten steel, said inner surface region being formed from a mixture having a composition containing 50 to 80 wt % of boron nitride (BN) and 20 to 50 wt % of zirconium oxide (ZrO.sub.2), and a sintering assistant composed of silicon carbide (SiC) and boron carbide (B.sub.4 C) mixed at a weight ratio of 1:1, the sintering assistant being added in amount of 5 to 10 wt parts to 100 wt parts of said mixture. The nozzle is produced by a process comprising the steps of: forming a uniform mixture of fine particles of boron nitride (BN), zirconium oxide (ZrO.sub.2), silicon carbide (SiC) and boron carbide (B.sub.4 C); forming the mixture into a cylindrical blank; and fixing the cylindrical blank in the bore of a nozzle member by means of a joint filling material.

Abstract: A sliding nozzle device comprises a metallic case having an opening in the center thereof, a refractory plate secured to the metallic case and having a discharge hole formed in the center thereof for discharging molten metal, a metallic hoop located around the refractory plate, an immersion nozzle projected from the opening of the metallic case and attached to the refractory plate, projecting plates located around the refractory plate, and bolts and nuts used for securing the projecting plates to the metallic case.

Abstract: A three plate non-reversible sliding gate system and tube holder where the plates and tube holder include modified corner configurations so as to preclude reverse loading of the system.

Abstract: A refractory member has therethrough a flow channel for the passage of molten metal. At least an inner wall portion of the refractory member defining the flow channel is at least partially formed of a material that at least partially includes a ceramic material having the properties of being capable of being heated inductively and to being electrically conductive at a temperature at least equal to the liquidus temperature of the molten metal. A primary induction coil, preferably formed of an electrically conductive ceramic material, surrounds the flow channel and inductively heats the material of the inner wall portion to prevent freezing of molten metal within the flow channel and the formation of deposits therein.

Abstract: A transfer tube is produced comprised of a high density ceramic oxide tube having directly bonded to its outer surface wall a low density ceramic oxide shell.

Abstract: A nozzle for discharging molten metal used in a casting device, wherein at least an inner surface portion defining a nozzle bore of the nozzle is made of a refractory, whereby a blockage of the nozzle bore is effectively prevented.

Abstract: A sliding gate valve assembly which has a stationary refractory plate mounted to a mounting plate and secured there by the force pressed against it exerted by another refractory is disclosed. A clamp ring is provided which has extending ears, each of which is bored to ride on a clamp spring assembly. Yieldable means, preferably a coil spring, surrounds the shank of the clamp spring assembly guide shank and engages the underside of the ear and rides in the main frame. When the main frame is closed, pressure is urged on the spring which, in turn, transmits the force to the clamp, the tapered inner edge of which engages the tapered outer edge of the stationary plate. The method of the present invention depends upon utilizing the clamping force of a valve assembly having a main frame and in which yieldable means are provided between the main frame and the mounting plate to urge a continuous clamp ring into engagement with the bandless stationary plate having tapered sidewalls.

Abstract: A nozzle device for discharging molten metal comprising a nozzle having a tapered portion whose outside diameter decreases toward the lower end, a metal holder mounted on the tapered portion and supporting the nozzle, and a ceramic receiving member whose inside surface is parallel with the surface of the tapered portion, the member provided between the tapered portion and the metal holder.

Abstract: An integral transfer tube is produced comprised of a hollow high density ceramic oxide tube having its outer surface wall surrounded by a low density ceramic oxide shell, and having a heating element comprised of a heating wound portion and two end portions wherein the wound portion is intermediate the tube and the shell, and wherein at least a sufficient amount of the end portions are exposed for electrical attachment.

Abstract: A method and apparatus for stirring molten metal as it is poured into a covered metallurgical vessel in a neutral atmosphere. A gas pressurized tube shroud assembly is positioned in an opening in the covered metal vessel and wherein atmosphere is replaced by the injection of inert gas under pressure through the shroud assembly. Molten metal is poured through a portion of the shroud assembly and as it becomes partially submerged within the molten metal forms a bubble field around the shroud protecting it from nonmetallic inclusions and associated erosion normally incurred.

Abstract: An integral transfer tube is produced comprised of a hollow high density ceramic oxide tube having its outer surface wall surrounded by a low density multilayered ceramic oxide shell, and having a heating element comprised of a heating wound portion and two end portions wherein the wound portion is intermediate the tube and the shell, and wherein at least a sufficient amount of the end portions are exposed for electrical attachment.

Abstract: Pouring tubes for use between a ladle and tundish or tundish and mould in continuous casting operations are formed of an inner refractory tube (2) with an outer reinforcing fibrous mat (3) applied around the tube. The fibrous mat may be formed by a helically wound strip and may be impregnated with particulate refractory and optionally a binder to improve the strength and resistance of the composite tube. Metal support means may be attached near one end of the tube.

Abstract: The configuration of a thickened tube holder which flares outwardly at its downstream portion leaving an undercut which is engaged by a rocker arm spring loaded assembly. The pour tube is provided with a collar at its upstream portion, and an undercut mount immediately beneath the collar. Means are provided to induce a vertical force component on the undercut mount in the form of a clamping member which secures the pour tube holder to a depending pour tube mount. In all of the embodiments, compression is induced in the pour tube holder and at the interface between the pour tube and the pour tube holder to inhibit aspiration. Quick disconnect is also provided, and quick makeup for changing pour tubes and pour tube holders.

Abstract: A molten metal stream descends from a ladle through a nozzle and then a shroud into a molten metal bath in a tundish. Structure is provided to contain a ring of inert gas around the nozzle immediately adjacent the junction of the nozzle and the shroud and to prevent outside air from entering the shroud at the junction.

Abstract: An integral transfer tube is produced comprised of a hollow high density ceramic oxide tube having its outer surface wall surrounded by a low density ceramic oxide shell, and having a heating element comprised of a heating wound portion and two end portions wherein the wound portion is intermediate the tube and the shell, and wherein at least a sufficient amount of the end portions are exposed for electrical attachment.

Abstract: A feed system is provided for conveying molten metal to a thin section caster having mold surfaces moving exclusively in the direction of casting. The feed system has a passage of circular cross section adjacent to one end thereof for receiving molten metal and a rectangular cross section at the delivery end thereof adjacent to the caster. The feed system is designed for supplying molten metal to the caster at low pressure for "closed-pool" type caster operation. The point of highest elevation in the metal flow passage of the feed system is on the upper surface of a transition portion where the cross section changes from circular to rectangular adjacent to the nozzle. The level or height of the high point above the centerline of the nozzle exit is selected so as to be less than the pressure of the metal measured in inches at the nozzle exit. This feature enables the maintenance of positive pressure in the metal within the feed system so that ingress of air into the metal is prevented.

Abstract: A movable refractory plate assembly for use in a sliding closure unit for controlling the discharge of molten metal from a metallurgical vessel includes a movable refractory plate having therein at least one aperture and having a sliding surface. A replaceable refractory erosion unit, which may be integral or which may include a separate erosion insert and a separate discharge nozzle, is positioned within the aperture of the movable refractor plate. The erosion unit has therethrough a discharge opening and has a sliding surface aligned with a sliding surface of the movable refractory plate. A frame supports the movable refractory plate for movement, and a support coupling removably mounts the erosion unit with respect to the movable refractory plate.

Abstract: A hot-pressed ceramic composite having good resistance to thermal shock and good erosion/corrosion resistance in molten alloys, and a method for producing said composite which comprises the blending of fused zirconia mullite with boron nitride.

Abstract: An apparatus and method for attaching the submerged nozzle to the lower plate of a sliding gate valve mechanism in a system in which such an assembly is replaceable during a continuous casting operation is disclosed in which the coupling of the lower plate to the submerged nozzle is achieved by way of a bayonet-type attachment between a lower plate container and a submerged nozzle retainer that is uniformly adjustable during operation. The assembly is first tightened snugly in a pre-operative condition, then loaded into an operative position where, after thermal and mechanical forces have acted on the assembly, it is adjusted into a fully tightened operational condition. At all times when the assembly is in (1) the pre-operative snug condition, (2) the operating fully tightened position, and (3) the full range of positions in between, handles are positioned wholely under the lower plate container, whereby unobstructed replacement and adjustment can take place.

Abstract: A nozzle which is submerged in molten metal during steel casting comprises a nozzle body, a nozzle passage provided through the nozzle body such that a molten-metal-and-gas stream can be introduced into the nozzle body at a predetermined point, and at least one discharge port, wherein the discharge port is bordered by a projecting part that presents a surface that is inclined toward the introduction point for the metal/gas stream at a slanting angle, relative to the longitudinal axis of the nozzle body, that is greater than 0.degree.. The nozzle has a substantially prolonged service life.

Abstract: A molten steel pouring nozzle comprising an upper nozzle made of a refractory, an upper end portion of which is to be inserted into a bottom wall of a molten steel receiving vessel; a lower nozzle made of a refractory, having, on an upper end portion thereof, a recess for receiving a lower end portion of the upper nozzle; and an open air shutoff means for preventing an open air from penetrating through an interface between the lower end portion of the upper nozzle and the recess of the lower nozzle.

Abstract: A closure mechanism includes a conical discharge nozzle and a shielding tube fitted over the exterior of the discharge nozzle. A snug conical joint is formed by closely complementary conical surfaces of the discharge nozzle and the shielding tube. At least one ring-shaped seal is provided in such joint to prevent exterior air from entering between the discharge nozzle and the shielding tube into the interior of the shielding tube. The ring-shaped seal comprises an annular recess formed in one of the conical surfaces, thereby defining an annular chamber, and an inert gas filling such chamber.