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: 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 liquefied neutral gas circulating between the tube (10) and a sleeve (25) surrounding the tube (10).

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 subject of the invention is a process for improving the corrosion resistance of a metallic material, characterized in that the metallic material is subjected cold to a surface treatment by a low-temperature plasma, at a pressure of 1 to 10.sup.3 Pa in an atmosphere comprising at least one gas chosen from the following; oxygen, ozone, nitrogen, hydrogen, air, carbon dioxide, carbon monoxide, the oxides of nitrogen, water, combustion gases and mixtures of these with a neutral gas.

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: Process for the continuous casting of a fine metal wire, in which a jet of liquid metal is quenched and solidified in a layer of cooling liquid deposited on a surface in motion. The dispersal of the turbulence of the cooling liquid is accelerated upstream of the point of impact of the jet of metal on the liquid. The apparatus for carrying out the process comprises a grating arranged across the layer of cooling liquid between the outlet of the pipe feeding the cooling liquid onto the surface in motion and the point of penetration of the jet of metal into the cooling liquid.

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: The device for protecting the poles of an electromagnetic inductor comprises a heat exchanger formed by one or more co-planar metal tubes (6) designed to allow the circulation of a cooling fluid therein and of such an arrangement that there is at most one electrical junction between any two tubes or tube elements. The exchanger is fastened to a rigid electrically insulating support plate (5) coated with refractory concrete (10) and covers the entire polar surface as far as the cowls (3). The exchanger can be shaped in the form of a series of alternating hairpins or in the form of a spiral with one or more branches. The device serves especially for protecting the poles of inductors used for the induction heating of metal products.

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: The bench for supporting and introducing an elongated rectilinear probe in a blast furnace comprises probe supporting and guiding means and probe driving means, constituted by a carriage guided according to a translatory movement on rails. The probe is held in position on the carriage at the level of the rails so that the thrusting force exerted by the carriage on the probe in order to cause its penetration into the furnace, is applied in the axis of said probe. The means for guiding the probe comprise articulated arms which are retractable in order to clear the path followed by the carriage when the latter is moved toward the furnace.

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: A magnetic field is produced by way of an emitter placed close to the surface of a product to be controlled and a receiver separate from the emitter is placed, with respect to said emitter, on the one hand, in such a way as to be aligned with the emitter in a direction corresponding to the general orientation of the defects to be detected on the surface of the product, and on the other hand, so as to avoid any substantial direct influence from the eddy currents generated by the emitter when the product surface is defect-free, so that a significant signal is only picked up by the receiver in the case of a deviation of said eddy currents in its direction due to a discontinuity in the surface of the product. The invention finds an application in the detection of surface defects in semi-finished metallurgical products and in particular continuously cast steel products.

Abstract: For improving permeability of a metallurgical vessel bottom provided with permeable refractory elements for controlled injection of a stirring fluid into a molten metal bath, the metallurgical vessel is emptied of its contents, a castable composed of a refractory material compatible with the refractory material of the bottom is deposited in the bottom and spread over the latter, and the castable is left to dry and set, while maintaining in the permeable refractory elements a sufficient pressure to provide a permanent flow of a stirring fluid. A hydraulic magnesian refractory castable used in this method has a content of water of substantially between 8 and 10% by weight.