Abstract: A method of making a steel with low carbon less than 0.035% by weight including steps of preparing a heat of molten steel composition in a steelmaking furnace to a tapping temperature as desired for desulfurization at a VTD, tapping open into a ladle the molten steel composition with an oxygen level between about 600 and 1120 ppm, providing slag forming compound to the ladle to form a slag cover over the molten steel composition in the ladle, transporting the molten steel composition in the ladle to a VTD, decarburizing the molten steel composition at the VTD by drawing a vacuum of less than 650 millibars, after decarburizing, adding one or more deoxidizers to the molten steel composition and deoxidizing the molten steel composition, after deoxidizing, adding one or more flux compounds to desulfurize the molten steel composition, and casting the molten steel composition to form a steel with low carbon less than 0.035% by weight.

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: The present invention relates to a method for manufacturing an amorphous alloy by using liquid pig iron. The exemplary embodiment of the present invention provides a method for manufacturing an amorphous alloy, including providing liquid pig iron, adding an alloy material to the liquid pig iron, and solidifying the liquid pig iron.

Abstract: The disclosure relates to improvements of technology for producing metallic iron by thermally reducing an iron source such as iron ore with a carbonaceous reductant such as coke by including efficiently reducing iron oxides into metallic iron at a lower operation temperature while conducting carburization, and efficiently separating the generated metallic iron from slag-forming components such as gangue components contained in raw material ore whereby metallic iron with controlled carbon concentrations can be produced in high yield.

Abstract: A direct smelting process for producing molten metal from a metalliferous feed material in a direct smelting vessel is disclosed. The process includes using a stream of off-gas from the vessel as a fuel gas in (i) stoves for generating a hot blast of air or oxygen-enriched air for the process and (ii) a waste heat recovery apparatus for generating steam for the process. The process also includes controlling pressure in the vessel by controlling pressure in the off-gas stream while the process is producing molten metal.

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: A method of cold starting a molten bath-based direct smelting process for producing molten iron in a vessel (3) is disclosed. The method includes a step of preheating the vessel before supplying solid feed materials into the vessel. The method also includes a subsequent step of supplying an oxygen-containing gas and solid feed materials including material for forming slag, iron-containing feed material, and carbonaceous material into the vessel and generating heat and forming a bath of molten material that includes molten iron and molten slag in the vessel. This step includes supplying feed materials to promote formation of molten slag over molten iron in an early stage of developing the molten bath.

Abstract: Molten steel is refined in an electric furnace by using iron scrap as a main iron source, and is tapped into a separate refining vessel. Thereafter, metallic-Al containing material and CaO are added onto a bath surface of the molten steel, and an oxygen containing gas is supplied to the molten steel. Thereby, a nitrogen-removal reaction utilizing an AlN formation reaction is caused to proceed. Consequently, even in the case of molten steel having a low carbon content, a low-nitrogen steel can be refined and produced at low costs.

Abstract: A direct smelting vessel (3) for operating a molten bath-based direct smelting process under pressure conditions in the vessel is disclosed. The vessel includes a forehearth (67) for tapping molten metal continuously from the vessel. The forehearth includes an open connection (97) that extends through a side wall of the vessel into the interior of the vessel. The open connection is formed to dampen the impact of sudden changes in pressure in the vessel on molten metal flow in the forehearth that could result in an undesirable surge of molten metal from the forehearth. The open connection is also formed so that molten metal does not freeze in the connection for at least 6 hours when molten metal is not being discharged from the vessel into the forehearth via the open connection.

Abstract: A process for producing steel and for obtaining slag having a high content of additional elements such as vanadium in a two-step process. Liquid pig iron is initially blown onto a high-grade slag at a lower temperature, the slag being further processed separately after tapping, while the pig iron is supplied to at least one additional converter in which it is blown at a higher temperature to form steel. A high-grade slag is generated while shortening the steel production process using the process in that the intermediate metal product that is tapped from the first converter is subjected to a heating and/or holding phase before being supplied to the second converter.

Abstract: A method of injecting oxygen into a melt located within a metallurgical furnace having a heated furnace atmosphere in which oxygen and fuel is injected into 1 or more nozzles having passageways of converging-diverging configuration under choked flow conditions to produce supersonic jet or jets discharged from the passageways. Fuel is injected into internal circumferential locations of the passageways so as to impart a structure to the jets being discharged that have an outer circumferential region containing a mixture of fuel and oxygen and a central region containing essentially oxygen. Such a structured jet upon discharge interacts with the furnace atmosphere to create an outer shear-mixing zone in which the outer circumferential layer mixes with the heated furnace atmosphere and auto-ignites to produce a flame envelope surrounding a supersonic jet of oxygen. The jet of oxygen and flame envelope can be directed against a melt contained within the metallurgical furnace for injection of oxygen into the melt.

Abstract: A direct smelting process and a fixed, ie non-rotatable, metallurgical vessel for producing metal from a metalliferous feed material is disclosed. The process is a molten bath-based process which includes injecting solid feed materials with a carrier gas into the molten bath via one or more downwardly extending lance/tuyere (11) and causing gas flow from the molten bath at a flow rate of at least 0.30 Nm3/s/m2 at the interface between the metal layer (15) and the slag layer (16) of the molten bath (under quiescent conditions).

Abstract: The invention concerns a method which consists in injecting into a molten metal bath to be treated, jointly but separately into the same bath zone, oxygen and carbon in a form capable of being blown (powder carbon preferably) so as to generate locally in the bath CO bubbles from those two elements, which will then be loaded in denitriding nitrogen. A stoichiometric adjustment of the carbon and oxygen inputs enable a constant carbon denitriding in the bath. The method is preferably applicable to the production of low-carbon steel grades, in particular in an electric oven.

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 direct smelting process and a fixed, i.e. non-rotatable, metallurgical vessel for producing metal from a metalliferous feed material is disclosed. The process is a molten bath-based process which includes injecting solid feed materials with a carrier gas into the molten bath via one or more downwardly extending lance/tuyere (11) and causing gas flow from the molten bath at:a flow rate of at least 0.30 Nm3/s/m2 at the interface between the metal layer (15) and the slag layer (16) of the molten bath (under quiescent conditions).

Abstract: A method for making steel in an electric furnace, wherein a predetermined amount of liquid melt is fed into the electric furnace. The method comprises the steps of (a) continuously feeding a controlled flow of liquid melt into the furnace without interrupting the heating from the electric arc, (b) continuously injecting a refining gas into the furnace before the C and/or Si content of the metal bath reaches a predetermined value, until the end of the feeding process, and (c) pursuing the injection of refining gas after the predetermined amount of melt has been fed into the furnace, until the target value for the C and/or Si content of the metal bath has been reached.

Abstract: In a process for supplying unit (9) that consumes a gas at several pressures, the gas is produced at the highest pressure and is sent to the unit. When the consumption of the unit falls, at least one portion of the high pressure gas is stored in an accumulator (5).

Abstract: A method of supplying both an oxygen steelmaking process and an ironmaking process with oxygen. The oxygen is separated from air by rectification of the air. A first stream of oxygen from the rectification to the steelmaking process. A second stream of oxygen is also supplied from the rectification to the ironmaking process. The first and second streams of oxygen are both withdrawn from essentially the same stage of the rectification and both contain from about 97 to about 98% by volume of oxygen and less than about 100 parts per million of nitrogen.

Abstract: A steelmaking furnace is cleaned and maintained using a lance which includes an elongated lance body including at least one first nozzle opening proximal to an end that extends into the furnace and at least one other second nozzle opening spaced upwardly from the first nozzle opening. Structure defines at least one passageway extending through the body to the first nozzle opening and to the second nozzle opening. Gas supply means selectively introduces different gases into the passageway. The lance apparatus can be operated to emit either different gases or the same gas from the first and second nozzle openings at the same time. The gases emitted include an oxygen-containing gas and a gas that includes an inert gas.

Abstract: Improvements in metallurgical conversion in accordance with the present intion consist in the preparation of a semifinished item (a charge stock) in the form of a pig by forming thereof in a molding box of a casting machine from a solid filler, for the most part an oxidizing agent, and a liquid pig iron followed by cooling, provided said solid filler and said liquid pig iron undergo, in the process of forming, an action which prevents the floating up of the solid filler in the liquid pig iron. Such an action is effected both by applying a mechanical force, in particular by providing a casting machine with a cantilever (8) having a hollow roller (9) which rests on a molding box (2) and a weighting material (10), and by choosing relative dimensions of the solid filler pieces and selecting a rate of pig casting. Optimal conditions for using such semifinished item for metallurgical conversion which in accordance with the present invention is carried out in oxygen converters and arc furnaces are described.

Abstract: The invention relates to a method of manufacturing stainless steel, by treating a raw high-carbon steel in a first stage with a gaseous mixture that contains oxygen and inert gas, therewith lowering the carbon content of the raw steel to a value of 0.2-0.1%. The steel bath is then treated in a second stage with solely an inert gas, until the carbon content has fallen to the desired value. The invention is characterized in that the steel bath is treated in the first stage alternately with an oxygen-rich gas and with an inert gas, until the carbon content of the steel has fallen to the desired value.

Abstract: The disclosure describes a method of direct steel making wherein liquid iron is produced in a melter gasifier system using a solid fuel reductant, preferably petroleum coke, and low silica containing iron ore, preferably less than 2.0% by weight, and the liquid iron is transferred directly to an oxygen blown steel making reactor for steel production and refining.

Abstract: In the production of stainless steel it is aimed at to depress the highest temperature reaching during refining the molten steel with keeping the necessary tapping temperature so as to prolong the life of refractory materials of the refining furnace. After carrying out decarburization treatment under atmospheric pressure in a refining furnace by blowing an oxygen-containing gas into molten steel, further decarburization of the molten steel and reduction of chromium oxides is carried out under stirring by blowing a non-oxidizing gas under a reduced pressure, and then, reducing agent is charged into the furnace to reduce chromium oxides under keeping the reduced pressure.

Abstract: A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.

Abstract: In the operation of a top-blowing steelmaking converter having at least one blowing lance, the distance of said lance from the surface of the molten metal bath is controlled in dependence on the sound levels of the blowing noise measured through the slag at selected frequencies. In order to minimize the risk of slopping, the actual values of the sound levels measured at predetermined frequencies are combined to form a resultant value, the difference between said resultant value and a predetermined reference value, which is associated with a sound level and indicates that slopping is likely to occur, is determined, and said difference is used as an indication of the probability of an occurrence of slopping and is compared with at least one predetermined probability limit, the distance of the blowing lance and optionally also the oxygen supply rate is corrected when said difference exceeds said probability limit.

Abstract: A method and apparatus for the forced production of exceptionally clean steel wherein a metallurgical vessel is insulated and sealed to maintain a neutral environment into which steel is tapped and cleaned by use of gas injection and impurity precipitation and removal.

Abstract: A method for making steel in an electric furnace, wherein a predetermined amount of liquid melt is fed into the electric furnace. The method comprises the steps of (a) continuously feeding a controlled flow of liquid melt into the furnace without interrupting the heating from the electric arc, (b) continuously injecting a refining gas into the furnace before the C and/or Si content of the metal bath reaches a predetermined value, until the end of the feeding process, and (c) pursuing the injection of refining gas after the predetermined amount of melt has been fed into the furnace, until the target value for the C and/or Si content of the metal bath has been reached.