Abstract: The present invention relates to a method for producing a blade or blade arrangement of a turbomachine, which features the following steps: producing a blade (4) from at least one blade material, machining the blade in at least one region of the blade by a surface machining process, cleaning the surface of the blade depositing an erosion protection coating (10) of at least two layers of different hardness by physical vapor deposition in the at least one region, machining the erosion protection coating (10) by a coating smoothing process in order to establish a defined surface roughness. Furthermore, the invention relates to correspondingly produced blades or blade arrangements.

Abstract: In a molten iron refining method by charging molten iron and a cold iron source into a converter type refining vessel, supplying a material containing CaO with an oxygen source dissolving the cold iron source and conducting molten iron desiliconization, removing at least a part of the produced slag as an intermediate slag removal, and supplying a slag-forming agent and an oxygen source to the molten iron for dephosphorization, a silicon-containing material or a combination of it and carbonaceous material is added in the desiliconization then carried out under conditions such that the slag basicity (mass % CaO/mass % SiO2) in the desiliconization completion is more than 0.5 but less than 1.5 and a molten iron temperature in the desiliconization completion is more than 1280° C. but less than 1350° C. and more than 30 mass % of the slag produced in the desiliconization is removed from the vessel in the intermediate slag removal.

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: Methods for degassing and for removing impurities from molten metals are disclosed. These methods can include operating an ultrasonic device in a molten metal bath, and adding a purging gas into the molten metal bath through the tip of the ultrasonic device.

Abstract: A method of refining a ferroalloy includes the step of blowing molecular oxygen or a gas mixture including molecular oxygen into a melt of the ferroalloy. A metallurgically acceptable particulate material is introduced from above into the melt. The particulate material is carried into the melt in a first supersonic gas jet which travels to the melt shrouded by a second gas jet.

Abstract: An object of the present invention is to provide a method for producing molten iron, the method being capable of minimizing the generation of converter dust and increasing the thermal degree of freedom in the converter process. In addition, the present invention provides a method for improving a converter operation method in the production of steels. The present invention relates to a method for producing molten iron including the steps of: 1) supplying carbon-containing molten pig iron to a converter, 2) continuously supplying iron oxide into the converter, and 3) blowing a mixed gas comprising a fuel gas and a combustion-supporting gas at a speed equal to or faster than the speed of sound to the molten pig iron to cause a combustion reaction, thereby heating the molten pig iron by heat of the combustion reaction.

Abstract: A method of recovering metallic iron from iron-bearing metallurgical waste in steelmaking comprising steps of providing an iron-bearing metallurgical waste containing more than 55% by weight FeO and FeO equivalent and a particle size of at least 80% less than 10 mesh, mixing the iron-bearing metallurgical waste with a carbonaceous material to form a reducible mixture where the carbonaceous material is between 80 and 110% of the stoichiometric amount needed to reduce the iron-bearing waste to metallic iron, and as needed additions to provide a silica content between 0.8 and 8% by weight and a ratio of CaO/SiO2 between 1.4 and 1.8, forming agglomerates of the reducible mixture over a hearth material layer to protect the hearth, heating the agglomerates to a higher temperature above the melting point of iron to form nodules of metallic iron and slag material from the agglomerates by melting.

Abstract: A method and apparatus for forming internally shrouded supersonic coherent jets comprising an inert gas, such as pure argon and argon/oxygen mixtures. This method and apparatus can be employed to produce low-carbon steels with a top lance in basic oxygen steelmaking.

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 method and apparatus for preparing and delivering various types of carbon and microalloy steel, free of oxygen with abundance of nuclei, when cast producing ultra fine grain steel free of internal defeats with excellent quality. A horizontal sealed table caster has a chamber, containing a suitable atmosphere for casting, with a tube connecting to a tundish so as to allow a liquid to flow into the chamber. The liquid metal is captured on a cooling belt along the bottom of the chamber and is maintained as a specific width and depth. The cooling belt serves as a heat sink causing the liquid metal to solidify from the bottom up, allowing inclusions to migrate to the surface of the steel. A layer of liquid metal is maintained on top of the solidifying steel until the solidification reaches the surface. The belt moves the solid metal toward the exit of the chamber.

Abstract: Apparatus and process for producing metal products, in which a metal-containing charge material is melted in a melting unit, and a working gas, in particular an at least partially reducing working gas, is additionally produced in the melting unit. The working gas produced is extracted and if appropriate after cleaning, is used as a carrier gas, at least in part for—preferably pneumatic—transport of an at least partially reduced metal-containing material in the form of fine particles.

Abstract: A method of applying flux to molten metal. A heat insulating shell comprises a porous ceramic fibrous refractory material. The shell includes an opening therein. A fluxing material is poured into the shell through the opening and is bonded thereto. The shell with the fluxing material therein is then exposed to molten metal in a casting mold. Only the portion of the fluxing material closest to the opening is exposed to the molten metal. The remainder of the interior fluxing material is thermally insulated from the heat of the exterior molten metal. That portion of the fluxing material that is exposed to the molten metal melts and escapes into the molten metal. Thus, the method provides for applying flux to molten metal in a controlled time release manner.

Abstract: A method is for feeding a gas into a metallurgical vessel having a condensable and/or evaporable component entrained by the gas. The gas is fed to the metallurgical vessel via one or more gas supply means. According to the method, if there are a number of the gas supply means, in a first section, the gas velocity is continuously increased, in a turbulence zone, the gas is intimately mixed with the condensable and/or evaporable component, in an exit section, the gas velocity is kept substantially constant, and the gas which has been intimately mixed with the entrained component is blown into the metallurgical vessel. A gas supply device for carrying out the method is also disclosed. The method and apparatus according t the invention make it possible to prevent or reduce nozzle damage.

Abstract: Fume dust is prevented when molten metal is poured into a vessel, and water spray of water mist is introduced into the vessel or onto the molten metal, creating a reduced level of oxygen concentration of about 12% by volume, preferably about 8% by volume, inside the vessel or at the molten metal surface.

Abstract: Equipment for the treatment of a liquid such as a metal melt has one or more rotors (5) for the supply of gas and/or particulate material to the liquid in a reaction chamber (1). The reaction chamber (1) is closed and has an inlet (3) and an outlet (13) and is designed to be placed under a vacuum. The outlet (13) communicates with another chamber or outlet passage (2). The equipment may have several reaction chambers (1, 2) arranged in series. The first reaction chamber (1) then communicates with the second reaction chamber (2), the second reaction chamber with a third, etc. via an opening (16).

Abstract: Upward variations of a molten metal level in a container for melting metallic material shall be carried out by detecting variations of a liquid level inside a detector connected to a gas-pipeline, wherein a rise in the pipeline pressure causes the liquid level to move down. Communication is established by means of a gas-pipeline 13 for inert gas between that portion of a container for melting metallic material which is above a molten metal surface 15a and that portion of a detector 16 comprising a transparent tubular container 18 which is above a liquid surface 17a. Variations of the liquid level 17a inside the detector 16 due to a rise in the pressure inside the above-mentioned gas-pipeline 13 are detected as upward variations of the level of the molten metal surface.

Abstract: An apparatus for treating, in particular purifying or degassing, molten metal (40), comprising a component (10) exposable to molten metal to be treated and means (13) for imparting a rotary motion to the molten metal (40) about a substantially vertical axis. The apparatus is so arranged that during use at least part of a wear-exposed surface of the component (10) is temporarily or permanently in contact with molten metal (40), the contacting molten metal being in motion relative to the wear-exposed surface. The wear-exposed surface is coated with a slurry-applied protective coating (18A,18B) of refractory material in a heat stable binder, in particular an inorganic colloidal and/or polymeric binder, protecting the wear-exposed surface against erosion, oxidation and corrosion.

Abstract: An apparatus is provided for the treatment of molten metal, e.g. aluminum, with a particulate treatment agent and a gas. This includes a vessel for holding molten metal, a rotary device for breaking up particulate treatment agent and gas within the molten metal and for dispersing particulate treatment agent and gas within the molten metal contained in the vessel and means for supplying the particulate treatment agent and gas to the rotary device. The rotary device includes a hollow shaft having a rotor with an axial opening fixed to the discharge end of the shaft, this rotor being in the form of an annular plate with a plurality of radially mounted upwardly directed blades projecting from the top face of the annular plate and a plurality of radially mounted downwardly directed blades projecting from the bottom face of the annular plate.

Abstract: The present invention provides a process for efficiently dephosphorizing, dephosphorizing and decarbonizing, or desulfurizing, dephosphorizing and decarbonizing a hot metal in a converter. The amount of flux to be charged and the amount of bottom-blown gas are adjusted so that the bottom-blowing agitation power and the CaO/SiO.sub.2 ratio subsequent to the treatment become at least 0.1 kW/ton and from 0.7 to 2.5, respectively and the hot metal temperature at the treatment end point becomes from 1,200.degree. to 1,450.degree. C. Furthermore, the operation of the process is controlled so that the sum of a T.Fe concentration and a MnO concentration in the slag subsequent to the treatment becomes from 10 to 35% by weight by adjusting the top-blown oxygen feed rate, the flow rate of bottom-blown gas or the top-blowing lance height.

Abstract: A method and apparatus are disclosed for injecting vaporizable material, such as a vaporizable waste, into a molten bath. A gas is injected into the molten bath at a rate which is sufficient to cause the gas and the molten bath to form a gaseous dispersion. The gas component of the gaseous dispersion occupies a sufficient fraction of said dispersion to cause a significant portion of the vaporizable material, at a rate at which the vaporizable material is injected into the molten bath, to volatilize, combust or decompose during exposure to said gas component. A vaporizable material, such as a particulate solid or hazardous liquid waste, is injected into the gaseous dispersion at a rate which cases a significant portion of the vaporizable material to volatilize, combust or decompose during exposure of said vaporizable material to the gas component of said gaseous dispersion.

Abstract: A method and apparatus for purging air from the interior of a container in which purge gas is supplied to the interior of the container from one or more injectors in a turbulent jet flow having a modified Reynolds number Re' of less than 14,000 and the purge gas is supplied at a flow rate to produce a positive pressure within the container of at least 2.times.10.sup.-8 atm above the ambient pressure.

Abstract: A method and apparatus are disclosed for injecting liquids into a molten bath. The method includes forming a suitable liquid dispersion of a liquid phase disposed in a gas phase. The liquid phase has a ratio of surface area to volume which is sufficient to cause an accumulated amount of the liquid phase in the molten bath to be significantly less than that which would occur by injection of a continuous stream of the liquid into the molten bath. The liquid dispersion is directed into the molten metal bath, whereby the liquid volatilizes or decomposes. The rate at which the liquid dispersion is injected into the molten bath is sufficient to cause the liquid of the liquid phase to volatilize or decompose at a rate which is sufficient to cause the accumulation of the liquid phase in the bath to be significantly less than that which would occur by injection of a continuous stream of the liquid into the molten bath. The apparatus includes an atomizer which is disposed at a reactor containing the molten bath.

Abstract: A method of steelmaking in an at least partially refractory lined furnace. The process includes the steps of retaining a portion of a hot liquid slag from a previous heat, and altering the retained slag with basic slag forming material to increase its basicity, melting temperature, and viscosity, and to reduce its melting temperature below the melting point. The altering step is performed before charging ferrous materials for a new heat. Altered slag is then positioned on the bottom of the furnace, or on the furnace walls, or both, using a slag coating technique. Ferrous metal is then charged, after which a second charge of basic slag forming materials may be added prior to and/or during the first controllable oxygen blow. A slagging off step is conducted after less than one-half of the oxygen is introduced into the heat and when the mass of oxygen already introduced is sufficient to oxidize approximately all of the silicon introduced with hot liquid metal charged into the furnace.

Abstract: A steel making process is disclosed that utilizes solid ferrous metallic material as a substantial part of the metallic charge and uses heat released by combustion of two different types of carbonaceous materials and steel scrap that have been strategically charged inside of at least a partially refractory lined steel making vessel. One of the carbonaceous materials contains a high content of volatile hydrocarbons and is primarily responsible for early preheating and partial melting of the solid ferrous material. The second carbonaceous material contains a low content of volatile hydrocarbons and is primarily responsible for providing a reducing capability to the slag, for carburizing the melt and for providing additional heat generated by combustion which is used to enhance heating and melting of solid ferrous materials.

Abstract: An elongate lance (4) is raised or lowered by means of a carnage (7) which is guided by vertical channels (8). The lance has lateral projections (18) whereby it is supported in a cradle (17) mounted to carriage (7) via springs (29). The apparatus permits the lance lower end (12) to be submerged in bath (3) and permits restricted lateral movement of the lance lower end.

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 a process for the production of a metal melt in a metallurgical vessel, the filter dusts incurring in producing the metal melt are to be processed to charging substances without causing a load on the environment and without great expenditures.This is achieved in that the filter dusts are introduced into the metallurgical vessel by aid of a gaseous conveying medium composed of natural gas or a mixed gas primarily containing natural gas, the filter dusts being supplied to the metallurgical vessel in a closed system and reduced by the carrier gas.

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: The proposed method is characterized in that the liquid bath is constituted by the melt of low carbon steel and molten slag. Oxidation and reducing zones are created through which, along a closed path on the surface of the molten low-carbon steel, is circulated the molten slag, into which are blown powder slag materials which are melted with the heat of a fuel oxygen torch immersed into the melt. The melting is carried out in a melting reservoir shaped as a closed annular chamber (1) provided with partitions (11) hermetically dividing the gas space above the molten slag into oxidation (6) and reducing (7) zones.

Abstract: A refining method of decarburizing a molten steel containing a large quantity of chromium, which can be completed in a shorter period, and therefore, with reduced consumption of Ar gas, and with safety of operation. A mixed gas of O.sub.2 and Ar is blown into a molten steel in a refining vessel through a tuyere at the bottom of the vessel under atmospheric pressure, and when the C-concentration becomes to such a low level as 0.15% (by weight) or less, vacuum suction is applied to reduce the pressure to 150-200 Torr, and only Ar gas is blown. At the change of the refining conditions from atmospheric to vacuum or during the vacuum refining a reducing agent such as ferrosilicon is added to the molten steel to reduce Cr-oxides for recovery. Even if the amount of the reducing agent is less than that necessary for reducing all the Cr oxides, majority of Cr can be recovered. If an excess amount is used, a steel of low nitrogen in addition to low carbon is obtained.Whole or a portion of Ar can be replaced with N.sub.

Abstract: An improved impeller head is provided for treating molten metals and other liquid systems with a gas. A multiple-vaned impeller head is adapted for mounting on a hollow impeller shaft for rotation within the liquid The edges of the impeller vanes are extended by an axial groove which intercepts the hub and the vanes of the impeller head. Extension of the trailing edge of the vanes creates greater turbulence in the liquid as the impeller is rotated in the liquid and increases the impeller's efficiency. The impeller vanes may also have canted leading surfaces which create an upward axial flow of liquid to discourage formation of a surface vortex. Multiple impellers may also be mounted on a shaft in the vessel and the gas may be introduced remotely.

Abstract: Disclosed is a method of refining of a high purity steel capable of effectively lowering impurities in molten steel into respective ultra-low ranges. In secondary refining for molten steel after a molten iron prerefining process and a converting process, a reducing agent and a flux are added on the bath surface within a ladle containing the molten steel decarburized in a converter so that the composition of slag on the bath surface is adjusted in such a manner that the total concentration of FeO and MnO becomes 5 wt % or less, and subsequently, impurities in the molten steel are effectively lowered into respective ultra-low ranges using a RH vacuum degassing unit.

Abstract: For the procedure a gas, heated to at least 1000 degrees Celsius, preferably even beyond the liquid temperature of the melt, is blown into the discharge opening (26). In this manner freezing problems and deposits in the discharge opening can be largely prevented. The pouring sleeve (20) according to the invention has a gas supply line (21), leading into a gas permeable insert (23) surrounding the opening (26), which is led for a certain length along the upper range of the sleeve (20) which is in contact with the melt, for the purpose of heating the gas.

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: 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.