Abstract: The invention relates to a process for the continuous casting of metals of the type according to which ultrasonic vibrations are applied to the wall of the ingot mould, characterized in that the vibrations comprise both a component which is oriented parallel to and a component which is oriented perpendicular to the axis of the ingot mould. This method is preferably implemented by applying at least one ultrasound emitter against a surface integral with one of the ends of the ingot mould and with an angle of inclination relative to the axis of the latter. The invention is principally applicable to the continuous casting of steel products of all sizes.

Abstract: An electromagnetic process and apparatus for continuous casting of a thin strip of electrically conductive material on a cooled roll. The free surface of the material in the liquid state in the casting feed injector is subjected to the action of an alternating magnetic field generated by a single phase electrical current. The magnetic field can be generated by means of an inductor from tubular elements within which cooling water circulates.

Abstract: According to this process: the position in respect of height of the "molten metal (2)/liquid slag (3)" interface (M) is continuously determined. Further the position of an isotherm (IS) located at the "liquid slag (3)/powder layer (4)" interface is continuously determined by automatically controlling the position of a thermocouple (8) on this isotherm and by measuring the displacements of this thermocouple.By comparing the position in respect of height of the molten metal/liquid slag interface (M) with the position in respect of height of the isotherm (IS), the thickness and thus the variations in thickness of the liquid slag are continuously deduced.

Abstract: In continuously casting thin metal products such as sheets or strips, molten metal is introduced into the gap between a rotating cooled main cylinder and a counterrotating roller spaced from the cylinder to form a gap corresponding to the thickness of the desired product. The metal, in cooling, forms solidifying skins on the respective rollers. The peripheral speed of the roller exceeds that of the cylinder by 2 to 20%. The resulting product is substantially free of the surface defects characteristic of prior art processes.

Abstract: A process and apparatus for feeding molten metal to the ingot mold (2) of an installation for the continuous casting of thin cogs (3). At least one jet (6) coming from a nozzle (8) connected to a distributor (4) feeds an ingot mold (2) in which the level of metal is regulated. The distributor (4) is movable vertically in order to keep the height of the jet (6) constant and horizontally in the direction of the largest dimension of the ingot mold in order to subject the jet (6) to an alternating lateral movement. The nozzle (8) and the casting tube (10) are protected by a liquified neutral gas circulating between the tube (10) and a sleeve (25) surrounding the tube (10).

Abstract: According to this process and this device:a signal representing the derivative of the intensity of the current in the arc is sensed,the sensed signal is amplified,the amplified signal is directed simultaneously into two band pass filters (6, 7) respectively having a high frequency broad band (6) and having a narrow band centered on a low fundamental frequency (7),the signals emanating from the filters (6, 7) are transmitted to effective value extractors (8, 9),by means of a divider module (11) an energy signal is formulated, which is proportional to the ratio of the effective value of the signal emanating from the broad band filter (6) and the effective value of the signal emanating from the narrow band filter (7),and the proportional energy signal obtained is displayed on a scale (12), where it is expressed as a percentage, this percentage being indicative of the behaviour of the arc, signifying the formulation phase.

Abstract: A closing wall for the lateral end of a casting space of an installation for continuously casting between moving walls which comprises two confronting cooled moving walls (1,2). The closing wall comprises a front part (65) defining a front surface (63) facing toward the casting space and at least one lateral part (66) defining a lateral surface (64) in the extension of the surface of one of the two moving walls and connected to said front surface. The invention is also applicable to the continuous casting of thin metal products between rolls.

Abstract: The apparatus includes a specialized scanning system for sampling the metal includes an annular light source for omindirectionally illuminating the surface, a light regulator, and a matrix camera for forming a grey level image of the surface. The image is histogramed according to grey level. The first four statistical moments are calculated from the histogram. The moments are then used as a feature vector to identify the metal surface. If no match is found within the catalogued metal surfaces, allowing for predetermined tolerances for each moment, then the feature vector is catalogued for future recognition.

Abstract: A method for implanting a tubular probe having a nose in a smelting furnace, the nose of the probe being temporarily closed off by a plug inserted therein, the plug including a substantially cylindrical body force fitted in the probe nose and an internal conduit extending through the plug. The method comprises implanting the probe into the smelting furnace; injecting a gas into the probe; controlling the flow rate of the injected gas until the probe nose has reached a required position; and regulating gas supplying pressure to keep the flow rate between a minimum value, under which furnace gas may penetrate into the probe, and a maximum value, above which the plug may be prematurely ejected. The plug may further include a head axially connected to the cylindrical body designed to cover the probe nose externally, and during the implanting step, the plug is placed on the probe so that an orifice of the internal conduit on an external face of the head is directed downwardly.

Abstract: This process for treating surfaces of products dip-coated in a bath of molten zinc and aluminum, and intended to be phosphated, involves pickling, preceding the phosphating, with a highly alkaline solution of high pH and containing zinc in solution. The process applies chiefly to products whose coating contains a high proportion of aluminum, particularly in the case of galvanized sheet metal, which it makes easier to phosphate. It is used for painted sheet metal for motor vehicles.

Abstract: A plug for a probe nose is produced in one piece having two contiguous parts. The first part is a substantially cylindrical body designed to be inserted in the probe nose such that it ensures tightness between the probe and the plug body. The second part is a substantially conical or semi-spherical head, co-axial to the body and provided at the level of its junction with the latter with a shoulder by which it can abut on the end of the probe. The plug comprises an inner through conduit which connects the surface of the head with the free front face of the body. This conduit authorizes the discharge of a protective gas introduced into the probe, and it is possible by controlling the flow of this gas to assess the difference of pressure exerted on each side of the plug and to adjust accordingly the pressure of the protective gas in order to prevent both the ejection of the plug and the penetration into the probe of hot gases from the furnace.

Abstract: An inductor, used for the inductive reheating of metallurgical products is of the C-shaped magnetic yoke inductor type designed to straddle the product to be reheated. The free ends of the yoke have magnetic poles facing one another. The yoke comprises two polar legs and two intermediate connecting rods joined to one another at one of their ends and each articulated linked respectively to one polar leg by its other end, with the three joints thus formed having parallel axes.This inductor is designed for use in the reheating of products which can have different thicknesses, in particular, for products in motion, for example, as they are being rolled.

Abstract: Typical defects are detected on a product moving relative to detecting means. An alternating magnetic field is generated in order to provoke the circulation of eddy currents on the surface of the product. A signal representative of the variations of the eddy currents is collected by means of a differential sensor and is demodulated by projection along an angle of adjustable phase in order to detect the disturbances introduced by the defects to be detected. This angle of phase is determined so that the projection of the collected signal has a minimum mean value, in order to eliminate disturbances of the collected signal due to repetitive surface irregularities. The component of the collected signal obtained by the projection is converted into digital form, and the digital signal thus obtained is filtered using a digital filter whose characteristics are predetermined as a function of a type of defect to be detected.

Abstract: The tuyere comprises a substantially cylindrical or slightly convergent frusto-conical downstream part, and a divergent frusto-conical upstream part; the plasma torch is placed co-axially to the tuyere at the inlet to the upstream part thereof; the solid materials injection nozzle issues at an angle into the upstream part of the tuyere and the angle of taper of the upstream part of the tuyere substantially corresponds to the angle of natural expansion of the plasma jet, so that said materials are carried with the plasma jet and that part of them are provided onto the inner wall of the tuyere.

Abstract: The device for inductively reheating the verges of a metallurgical product moving down a production line comprises wound pole inductors with C-shaped magnetic yokes, arranged laterally straddling the path followed by the verges. The two arms of the C are trunnioned to open to a greater or lesser extent, providing a variable air gap, controlled by a cylinder.

Abstract: A blast furnace, especially for the production of hot metal for the steel industry and operated with a normal charge above the tuyere blast zone, has its hot metal production increased at least temporarily by a lateral injection of metal oxides into the zone. A supply of the thermal energy requirements for the smelting reduction of these metal oxides by electrically operated plasma torches, and the compensation of a overoxygenation resulting from the oxygen contribution of these metal oxides by the introduction of nitrogen.

Abstract: Process and apparatus for preventing defects in the symmetry of rolled H-beams or I-beams, i.e., a faulty position of their webs (4) in relation to their flanges (5), by correcting such defects in situ. The differential between the torques applied to the upper and lower rolls (1,2) of the rolling stand is determined and compared to a predetermined threshhold value (.delta.). Any excess of the measured value over the threshhold value is eliminated by correction of the elevation of the inlet table of the rolling stand so as to reduce the measured value to below the threshhold value.

Abstract: In a process for forming the bottom of a metallurgical container, especially the bottom of a converter for refining pig iron, of the type which comprises a metallic base, at least one layer of refractory material superimposed on the metallic base, a first layer of refractory bricks superimposed on the layer of refractory material, and a second layer of refractory bricks on said first layer, the steps of placing, spaced from each other, on said first layer a plurality of refractory elements permeable to gas and each enclosed in a metal casing open at the top, circumferentially surrounding the metal casing of each of the elements with bricks of a material which expands during rise of the temperature and thereafter completing the second layer with refractory bricks.

Abstract: A process of pneumatic stirring of a bath of molten metal according to which a stirring fluid is injected through permeable refractory elements arranged at the bottom of a crucible containing the bath, in which the used stirring fluid is, at least temporarily, an organic liquid such as hydrocarbon.The process is advantageously used on a bath of molten pig iron during refining of the same by oxygen, and in which the organic liquid is replaced immediately after decarburization of the bath by an inert gas such as argon or nitrogen.The process thus permits an efficient stirring of the bath of molten metal without the risk of polluting the metal either by hydrogen or nitrogen.

Abstract: An electric furnace for induction heating of metallic products comprises a planar inductor providing a sliding magnetic field, the inductor being incorporated in a pair of transversely spaced walls defining between themselves a space into which the product to be heated is inserted, a layer of refractory material at that side of each wall which borders the space and an independent cooling screen sandwiched between each wall and the respective layer of refractory material, in which the screen is constituted by a plurality of parallel, adjacent metal tubes out of mutual contact with each other to define between themselves electrically insulating spaces, preferably filled with electrically insulating material, and in which the tubes extend normal to the flow of the primary current through the inductor. Preferably at least one of the walls together with the respective refractory layer and screen is movable toward and away from the other wall to accommodate metal products of different widths in the space.