Abstract: Ultrasonic probes containing a plurality of gas delivery channels are disclosed, as well as ultrasonic probes containing recessed areas near the tip of the probe. Ultrasonic devices containing these probes, and methods for molten metal degassing using these ultrasonic devices, also are disclosed.

Abstract: A method of decarburizing a molten alloy may generally comprise injecting a first gas comprising at least one of argon, carbon dioxide, and oxygen through a first fluid-conducting portion of a tuyere into the molten alloy below the surface of the molten alloy, and injecting a second gas comprising at least one of argon and carbon dioxide through a second fluid-conducting portion of the tuyere into the molten alloy below the surface of the molten alloy. The tuyere may comprise an inner portion concentrically aligned within an outer portion to define an annulus therebetween. The first gas may be injected through the inner portion, and the second gas may be injected through the annulus.

Abstract: A method of manufacturing a ferritic stainless steel containing an ultra low level of carbon concentration in molten steel within time shorter than existing technology by controlling content, appropriate composition, and liquid-state fraction, etc., of Cr2 O3 in slag to maximize vacuum decarburization refining efficiency, the method comprising: tapping molten steel to a ladle in a non-deoxidized state after pre-decarburization and denitrification in an ARGON OXYGEN DECARBURIZATION refining furnace and then removing non-deoxidized slag; placing the ladle in a vacuum furnace, reducing pressure and then blowing-in oxygen gas from the upper of the molten steel through a lance; creating Al2 O3 by injecting Al at point of time of beginning of oxygen blowing; forming CaO—Al2 O3 —Cr2 O3 —MgO-based slag by injecting calcium oxide at point of time of completion of the oxygen blowing; and supplying inert gas through a porous plug on a bottom of the ladle.

Abstract: A method of producing steel for a steel pipe excellent in sour-resistance performance comprises controlling the amount of Ca addition charged into a molten steel in a ladle according to a N content in the molten steel prior to Ca addition. Non-metallic inclusions in the steel are mainly composed of Ca, Al, 0 and S, and a CaO content in the inclusions is in the range of 30 to 80%, the ratio of the N content in the steel to the CaO content in the inclusions satisfying equation (1), and a CaS content in the inclusions satisfies equation (2), 0.28?[N]/(% CaO)?2.0??(1) (% CaS)?25%??(2) where [N] represents the mass content (ppm) of N in the steel, (% CaO) represents the mass content (%) of CaO in the inclusions, and (% CaS) represents the mass content (%) of CaS in the inclusions.

Abstract: A method of producing steel pipe excellent in sour-resistance performance, uses comprises controlling the amount of Ca addition charged into molten steel in a ladle according to a N content in the molten steel prior to Ca addition. As a result of the controlling step, a CaO content in the inclusions is in the range of 30 to 80%, the ratio of the N content in the steel to the CaO content in the inclusions satisfies the relation expressed by equation (1), and a CaS content in the inclusions satisfies the relation expressed by equation (2). 0.28?[N]/(% CaO)?2.0??(1) (% CaS)?25%??(2) where [N] represents the mass content (ppm) of N in the steel, (% CaO) represents the mass content (%) of CaO in the inclusions, and (% CaS) represents the mass content (%) of CaS in the inclusions.

Abstract: For the production of stainless steel of the ferritic AISI 4xx group of steels, particularly the AISI 430 group of steels, based on liquid pig iron and FeCr solids, the invention proposes the use of the AOD (Argon Oxygen Decarburization) process in which oxygen and inert gas (inactive gas) together are blown into the bath through nozzles and top-blown onto the surface of the bath by a blowing lance. The aim of the treatment is to conclude a smelting charge within an optimal time period, to achieve the intended tapping temperature and composition, and to minimize chromium losses. This is achieved by a correspondingly applied technology and by means of a metallurgic process model which observes, prognosticates and controls the treatment of the smelting charge.

Abstract: A process and apparatus for supplying solid feed materials for a direct smelting process to solids injection lances of a direct smelting vessel is disclosed. The feed materials supply apparatus includes a supply line (L) for conveying iron-containing material and solid carbonaceous material under pressure to solids injection lances (7), and the supply line includes a main feeder line section (15) and a plurality of branch line sections (17) extending from the main feeder line section. Each branch line section is connected to one solids injection lance for supplying iron-containing material and carbonaceous material to that lance. The apparatus further includes an assembly for dispensing iron-containing material under pressure into the main feeder line section of the supply line and an assembly for dispensing carbonaceous material under pressure into the main feeder line section of the supply line.

Abstract: A steel charge and slag forming material is heated in a ladle to form molten steel covered by a slag containing silicon, manganese and calcium oxides. The steel is stirred by injection of an inert gas such as argon or nitrogen to cause silicon/manganese-deoxidation and desulphurization to produce a silicon/manganese killed molten steel. Stirring of the molten steel by the inert gas injection while in contact with slag high in calcium oxide generates low free oxygen levels in the steel and desulphurization to sulphur levels below 0.009%. The slag may subsequently be thickened by lime addition to prevent reversion of sulphur back into the steel and oxygen may be injected into the steel to increase its free oxygen content to produce a steel that is readily castable in a twin roll caster.

Abstract: A procedure for starting up a direct smelting process for producing iron from a metalliferous feed material in a metallurgical vessel is disclosed. The vessel is of the type which includes a plurality of feed material injection lances/tuyeres (11, 13). The start-up procedure includes the steps of: (a) preheating the vessel; (b) supplying a charge of molten iron to the vessel and forming a molten bath in the vessel, (c) supplying carbonaceous material and flux to the molten bath and injecting oxygen-containing gas through one or more than one feed material injection lance/tuyere and combusting carbon and bath derived gas (if present) and thereby heating the molten bath and generating slag; and (d) suppling metalliferous feed material to the vessel while continuing supply of carbonaceous material and flux and injection of oxygen-containing gas and smelting metalliferous feed material and producing molten iron and thereby completing the start-up procedure.

Abstract: The invention is directed to a method for operating a steelmaking furnace including the steps of charging steelmaking materials into the steelmaking furnace, blowing oxygen into the steelmaking furnace, discontinuing the oxygen blow when the charged steelmaking materials are reduced to a liquid steel product, determining the temperature of the finished liquid steel product, blowing a nitrogen gas coolant into the steelmaking furnace to reduce the temperature of the finished liquid steel product to an aim tapping temperature, discontinuing the nitrogen gas coolant blow when the finished liquid steel product temperature is lowered to the aim tapping temperature, and tapping the finished liquid steel product at the aim tapping temperature for downstream processing.

Abstract: A process for stirring molten steel in a container. In this process, argon gas is introduced into the container at a flow rate of from about 0.005 to about 0.2 cubic feet of argon per ton of molten steel per minute, the extent to which said container is caused to vibrate is measured, analog signals are produced corresponding to the rate of flow of argon gas into said container, the analog signals are sampled at a rate of at least 800 times per second, the analog signals are converted to digital signals, the digital signals are transformed by subjecting them to fast Fourier transformation, and the transformed digital signals are evaluated.

Abstract: Offgas recycling processes, including an argon degassing embodiment which cyclically regenerates one treatment flow path while the other treatment flow path is treating the offgas. The system is changed into a second mode to regenerate the previously treating portion of the system while the offgas is being treated by the previously regenerated treatment device. A second embodiment oxidizes a copper chloride bed to release chlorine, which is injected into the melt. The offgas contains chlorine and HCl, which react with a second bed, containing oxides of copper, forming copper chloride. Water vapor and nitrogen are exhausted to the environment. Before the beds are fully reacted, the flow of gas through the beds is reversed, oxidizing the CuCl bed and reducing the copper oxides.

Abstract: A process is described for producing amorphous metal alloys wherein impure ferrophosphorus slag, a by-product from a phosphorus-producing electric furnace, is used to supply phosphorus, chromium, vanadium and iron values to such alloys by treating the ferrophosphorus slag to a separation step to recover a purified molten ferrophos, mixing it with iron and any other desired metalloid and/or elements to form a molten mixture and rapidly cooling the molten mixture to below its vitrification temperature to form a solid amorphous metal alloy.

Abstract: The present invention pertains to a gas purging plug with integrated electrode for use in electric-arc furnaces.

Abstract: A lance intended for injecting oxygen and/or an inert gas into liquid steel comprises a metal supply tube which opens into a distributor from which issue a plurality of injection tubes arranged parallel and concentrically with respect to the longitudinal axis of the lance, these injection tubes being embedded in a sheath of refractory material. Preferably, the distributor comprises two chambers which are separate from each other, the first chamber communicating with the supply tube for a first gas and with a plurality of first injection tubes, and the second chamber communicating with a second supply pipe for another gas and with a plurality of second injection tubes.

Abstract: A lime-based injection powder for use in steel-refining, having excellent waterproofing and desulphurization effects, consists of (a) more than 65% by weight of calcium oxide, (b) less than 30% by weight of fluorite, and 5-10% by weight of Al powder, 5%-7% by weight of the calcium oxide being converted into CaCO3 by reacting the calcium oxide with carbon dioxide in a multi-stage fluidized bed reactor.

Abstract: The present invention relates to a process for producing steel in a ladle furnace in which the molten steel is stirred by injection of an inert gas in the lower part of the furnace. According to the invention, the stirring of the bath of steel is effected by the injection of gaseous argon so as to distribute in a homogeneous manner the additives added and the metal temperature in the course of the treatment, while there is simultaneously injected liquid argon above the surface of the bath in the region of intumescence. In this way, substantially any increase in the concentration of nitrogen of the bath of steel in the course of the treatment is avoided. In some cases, and in particular when wires of the type filled with silico-calcium are employed, a reduction in the concentration of nitrogen in the bath of steel is found.

Abstract: A process for the in-ladle treatment of liquid steels by injecting gas through the ladle bottom. The process comprises injecting at least one inert gas from locations which are distributed over the ladle bottom in such a way as to form at the surface of the liquid steel an annular swelling, the outside edge of which is close to the inside edge of the lining of the wall of the ladle. An oxidizing gas may be mixed with the inert gas for decarburization. The process is applied in particular to the treatment of carbon steels.