Abstract: Apparatus for pre-heating and conveying a metal charge to a container of a melting plant, comprising at least a conveyor channel along which said metal charge is able to advance so as to be delivered to the container, and in which above said conveyor channel at least a hood is disposed which defines a tunnel inside which at least part of the fumes exiting from said container are able to advance. At least a zone of the hood comprises an expansion chamber located above at least a portion of said metal charge, and able to expand and keep said fumes inside it for a minimum desired time of at least 1.5 seconds before they go into contact with the metal charge.

Abstract: A method and an apparatus for the production and the melting of liquid pig iron or of liquid steel intermediate products in a melt-down gasifier, with the introduction of oxygen-containing gas streams through oxygen nozzles into the solid bed. At least one oxygen nozzle has a single gas supply and introduces at least two gas streams. Using plural gas streams from a nozzle reduces the risk of fluidization of the solid bed because the number of gas raceways in materials in the gasifier is increased.

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 new austenitic stainless steel containing approximately 0.1-1.0 mass % of Si and not more than approximately 0.003 mass % of Al. Nonmetallic inclusions dispersed in a steel matrix are converted to MnO—SiO2—Al2O3 containing not less than approximately 15 mass % of SiO2 and not more than approximately 40 mass % of Al2O3. During steel making, molten steel is covered with basic slag and heavily deoxidized with a Si alloy whose Al content is controlled to not more than approximately 1.0 mass % in a vacuum or non-oxidizing atmosphere. The austenitic stainless steel sheet can be formed to an objective shape without the occurrence of cracking due to its decrease in susceptibility to cracking and its good formability.

Abstract: The invention relates to a method for producing stainless steels, in particular steels containing chromium and chromium-nickel. The method is carried out in a melting device containing a metallurgical vessel, or in a melting device (1) containing at least two vessels (2, 3) for supplying a steel-casting installation, an electric arc furnace process (1) and an air-refining process taking place alternately in the two vessels (2, 3). To improve the efficiency of a method of this type, the aim of the invention is to carry out a reversible treatment of unreduced converter slag in the electric-arc furnace mode. To achieve this, in the first treatment stage, the slag (19) with a high chromium content is melted together with the added charge, the slag is then reduced during the melting process with the silicon and carbon under favorable thermodynamic conditions of the arc, once the slag has reached a minimum temperature of 1,490° C. and the slag is subsequently removed.

Abstract: A process for producing stainless steels, particularly special steels containing chromium and chromium-nickel, in a smelting arrangement having at least two vessels, for supplying a steel foundry. A charge having mostly iron-containing raw scrap materials and partially carbon-containing alloy carriers is melted in a first vessel. At a temperature of 1460° C., the melt is decarburized by the injection of oxygen so as to reduce the carbon content to less than 0.3%. The melt is heated to a tapping temperature of between 1620° C. to 1720° C. and the carbon content is subsequently reduced to 0.1%. A second charge is melted in a second vessel simultaneously with the decarburizing of the first charge in the first vessel.

Abstract: A process for blowing oxygen-containing gas, with and without solid material, on a metal melt in a metallurgical vessel, a process for generating a burner flame and corresponding devices. The inventive process and lance suitable for such process provides, without structural conversion and by a simple design, various different process steps in the treatment of metal melts in a metallurgical vessel while increasing the insertion rates of the individual media. This is accomplished using a multifunctional lance in which the process of blowing oxygen with and without solids, and the generation of a burner flame may be performed independently from one another. The individual supply lines are connected in a corresponding manner depending on the respective process step. In the process for blowing oxygen-containing gas, vibrations are excited in the gas flow in a relatively simple manner.

Abstract: In steel-making, there are conflicting processing requirements at different stages of the process. The method and apparatus of the invention creates different processing conditions at different stages of the process. Molten ferrous material (2) is stirred by bubbling a gas therethrough. A refractory ring (10) is first partially immersed in the molten steel within a substantially slag free portion of the surface of the molten ferrous metal to form a bounded substantially slag-free area. The molten steel is then heated by the introduction of exothermically reacting heating agents such as aluminium and oxygen through an oxygen gas line (7) and an aluminium delivery tube (9), respectively. The refractory ring (10) is then removed from the molten steel when the steel has reached a predetermined temperature and air is then excluded from the volume above the molten steel by placing a hood (16) over the ladle containing the molten steel. Sulphur is then removed from the steel.

Abstract: Method of reducing metal oxide in a rotary hearth furnace (14) to make a feed stock for a refining vessel when manufacturing alloyed iron, alloyed steel or stainless steel. The rotary hearth furnace includes an annular inner refractory wall (32), an annular outer refractory wall (34), an annular refractory platform (33) between the two walls. Stationary fuel burners (36, 40) are mounted to walls (32, 34) at a position just above an upper surface of the platform. A mixture of a metal oxide and a carbonaceous reductant is placed onto the upper surface of the platform and rotated past the burners. The oxide is heated by an oxidizing flame. Thereafter, a second layer of a reductant is charged over the hot first layer, and both layers are heated for an additional period of time to a temperature of at least 1300.degree. C. to reduce the metal oxide. The metal oxide may be chromium ore, chromium ore concentrate, nickel ore, nickel ore concentrate and stainless steel flue dust. The reductant may be coal or coke.

Abstract: A method for desulfurizing molten pig-iron involving injecting a gas-evolving desulfurization agent which includes a calcium compound and a gas forming material comprising of a gas-producing compound, a slag-forming agent and magnesium.

Abstract: In secondary steel refining, in addition to the process gas oxygen, the gases nitrogen and argon are employed as treatment gases in the bottom blowing converter. Oxygen and argon can be partially replaced by inexpensive CO.sub.2. The invention provides a process which makes it possible to completely replace nitrogen and argon by CO.sub.2.

Abstract: The invention encompasses a pneumatic steelmaking vessle and a method for the production of steel from hot carbon-bearing metallized raw materials such as direct reduced iron. The vessle is a refractory-lined ladle, having an eccentric ladle cover with an opening on one side. Opposite the opening in the ladle cover is at least one downwardly directed oxygen lance or tuyere. The vessel is mounted on trunnions for rotation about its central axis to a generally horizontal position. The bottom of the vessel has a porous plug, and a hot metal outlet controlled by a sliding gate closure member or other convenient type closure. The vessel is used in connection with a method of steelmaking by serving as the means for transporting molten metal to melting, refining, ladle metallurgy, and teeming operations.