Abstract: The subject of the invention is a method of lubricating a mold (1) for the continuous casting of a metal product (16), of the type including a vigorously-cooled vertically-oscillating metal tubular element (2) defining a passage (4) for the cast metal and intended to cause, in contact with its wall (3) in said passage, the solidification of said metal product, in which a lubricant in the liquid state is injected through said metal tubular element toward said metal product being solidified, wherein said injection is carried out at points distributed annularly at a single level of said tubular element, said level lying at a distance greater than 20 cm from the lowest level at which solidification of said product is able to be initiated, and in that the flow rate of said lubricant is sufficient to cause a fraction of said lubricant to rise up along said wall to the level at which solidification of said product is effectively initiated.

Abstract: A method and apparatus for continuously treating a strip of hot dip-galvanized steel. The method comprises the steps of rapidly reheating the strip to a predetermined temperature between 460.degree. C. and 600.degree. C., with a heating flux greater than 180 kWatts per meter squared based for each face of the strip; maintaining the strip at a substantially constant temperature for a predetermined period of time lasting between 10 and 30 seconds; and subsequently cooling the strip rapidly to a temperature below 420.degree. C., using a cooling flux of a magnitude greater than 100 kWatts per meter squared for each face of the strip. The step of rapidly reheating is performed following a drying operation conducted on the strip as it exits from a zinc bath.

Abstract: A steel product having a coating based on a hypereutectic zinc-aluminium alloy made by passing it through a zinc bath containing aluminium and silicon wherein the aluminium content is approximately 55% by weight, the silicon content is 1% to 2% by weight, and the bath further includes strontium in a quantity in the range 0.0001% to 0.2% by weight and at least one other element selected from among vanadium in a quantity in the range of 0.02% to 0.2% by weight and chromium in a quantity in the range of 0.005% to 0.2% by weight. The addition of strontium and chromium and/or vanadium stabilizes the structure of the coating and reduces the formation of acicular precipitates of silicon. The coating has an improved adherence and ductility which permits it to be formed without cracking, while retaining an excellent resistance to corrosion. The resulting crystallization pattern of the coating is also finer and more regular and is independent of the substrate.

Abstract: A process for continuous dip coating of a steel strip by passing it through a zinc bath containing aluminum and silicon wherein the aluminum content is approximately 55% by weight, the silicon content is 1% to 2% by weight, and the bath further includes strontium in a quantity in the range of 0.0001% to 0.2% by weight and at least one other element selected from among vanadium in a quantity in the range of 0.02% to 0.2% by weight and chromium in the range of 0.005% to 0.2% by weight. The addition of strontium and chromium and/or vanadium stabilizes the structure of the coating and reduces the formation of acicular precipitates of silicon. The coating has an improved adherence and ductility which permits it to be formed without cracking, while retaining an excellent resistance to corrosion. The resulting crystallization pattern of the coating is also finer and more regular and is independent of the substrate.

Abstract: A continuous electrolytic deposit of constant thickness is formed on a moving substrate (2) constituting a cathode passing in adjacent spaced relation to an anode (3) to provide a narrow electrolysis gap therebetween. The anode consists of a plurality of anode modules (3) which are supported mechanically independent of each other. The electrical and hydraulic circuits respectively feeding the anode modules include flexible sealing members (8, 11, 12, 14) between the fixed sources of current and electrolyte respectively and the anode modules. The anode modules are provided with supports (4, 9, 10) whereby they are supported on the cathode (2) or on a surface (1) directly linked to the cathode. The support for at least one anode module (3) may be adjustable for adjusting the distance between the anode module and the cathode. The supports (4) are shoes or rollers, for example, which may be mounted at the ends of arms (9, 10) supporting the anode modules.

Abstract: A metal product, such as cold rolled steel sheet, has a surface comprising a plurality of flat, smooth facets which are preferably 50 to 200 .mu.m across and which make up at least 30% of the area of said surface. The facets may be formed either by pressing a network of valleys in a flat, smooth surface or by flattening the peaks of a rough surface.

Abstract: A cooling apparatus for a cylindrical member in linear motion comprises a tubular conduit through which the cylindrical member passes axially, an envelope surrounding the tubular conduit and forming therewith an annular chamber therebetween closed at its ends by an upstream wall and a downstream wall, respectively, cooling agent being introduced into the annular chamber. The tubular conduit is pierced radially by a plurality of a straight passages providing communication between the annular chamber and the internal space in the tubular conduit. These passages are located in planes perpendicular to and axially spaced along the longitudinal axis of the tubular conduit and are equally circumferentially spaced within each plane and angularly displaced with respect to the passages in the adjacent planes. Cooling agent passes through the passages radially inwardly and is drained from the internal space of the tubular conduit.

Abstract: A lubricant is introduced through at least one orifice extending through the peripheral wall of a continuous casting mold. The lubricant melts and spreads between the peripheral wall and metal cast in the mold. The lubricant may be pre-heated.

Abstract: A metal product, such as cold rolled steel sheet, has a surface comprising a plurality of flat, smooth facets which are preferably 50 to 100 .mu.m across and which make up at least 30% of the area of the surface. The facets may be formed either by pressing a network of valleys in a flat, smooth surface or by flattening the peaks of a rough surface.

Abstract: A laser beam focussed on a moving surface, e.g. of a rolling mill, is modulated by means of a rotating disk with through-orifices. The radial lateral faces of the orifices have, relative to the axis of the laser beam, angles of inclination which are different from each other; this difference in inclination is such that the laser beam deviated by one of the radial lateral faces is then reflected by the opposite radial lateral face towards the zone of the surface which is struck by the laser beam passing, without being deviated, through the orifice. The difference in inclination may be between 15.degree. and 30.degree.. The lateral faces of the through-orifices may be lined with a reflective material.

Abstract: A device for casting a metal in the pasty phase in a continuous casting mold comprises a vertical conduit disposed upstream of the mold and provided externally with cooling means a distributor member disposed substantially at the inlet of the conduit to deflect the metal flowing from a casting nozzle towards the inner surface of the vertical conduit which may be extended by a tubular element penetrating into the mold and an inlet section for the conduit at least the inner surface of which is formed by refractory material, the distributor member being disposed in the inlet section. The device may have an injector for injecting a gaseous agent into the vertical conduit below the distributor member, and a further device for causing the metal to rotate in the inlet section.

Abstract: The surface of a rolling mill roll is coated with a coating comprising a metallic substance and is then marked by means of an intermittent laser beam. As a result, micro-craters are formed which penetrate the roll and which have rims containing components from the roll and the coating. The longevity of the roughness of the roll can thereby be enhanced.

Abstract: A process for surface treatment of a rolling mill roll coated with a coating of metal wherein the coated roll is surface heated, e.g. by a continuous laser beam in a helical path to melt the coating and a thin superficial layer of the roll thereby forming an uninterrupted molten alloy layer comprising at least a part of the coating and of the superficial layer of the roll, cooling the alloy layer, and marking the roller by an intermittent laser beam, e.g. following the same helical path with a given delay to produce local fusion of the alloy layer and of the roll surface beneath the alloy layer and form micro-craters having bases and rims integrated, after solidification, with the alloy layer.

Abstract: Starting from a temperature at or above the A.sub.3 transformation point of the steel of the rail, the head of the rail is cooled to a temperature not lower than the Ms point at a rate lower than the critical quenching rate so that the head acquires a fine perlitic structure. Simultaneously the web is superficially cooled to the Ms point or below, at a rate greater than the head, so as to obtain a surface layer of martensite and/or bainite, and the surface cooling is controlled so that, at the end of controlled cooling, internal portions of the web not transformed to martensite and/or bainite retain sufficient heat to temper the surface layer during subsequent cooling to ambient temperature. At the same time the flange of the rail is cooled at a rate ensuring straightness of the rail.

Abstract: A light beam, e.g. from a laser, is transmitted onto the surface of a cold-rolled product such as steel strip. The light beam has a wavelength at least equal to the maximum roughness of the product surface. The reflected light energy is measured, preferably in the specular direction with respect to the incident beam; the surface roughness is deduced from that measurement. The light beam may be interrupted to provide two beams alternately incident on the same spot at different angles.

Abstract: In a secondary cooling zone below a continuous casting mold there is provided one or more chambers having an anterior wall with apertures facing the continuously cast metal product at a given distance from the surface of the product. Pressurized cooling liquid is supplied to the apertures to form a continuous layer of pressurized cooling liquid flowing in the direction of travel of the product.

Abstract: A method wherein the levels of a plurality of points on the surface of a moving rolled strip are determined in relation to a horizontal reference plane by optical triangulation and planarity, or flatness, indices of the strip are deduced therefrom. The position of at least one of the side edges of the strip is detected with respect to a predetermined fixed reference in a cross-section of the strip containing at least plurality of points. The real, or true, position of the point with respect to the fixed reference is deduced and the orientation of the emitted beam and of the re-transmitted, or reflected, beam used in the triangulation is modified to compensate for the real, or true, position of the point.

Abstract: An upper transverse chamber and a lower transverse chamber have apertures for the passage of cooling agent to a product passing between them. At least the upper chamber is divided into a central compartment corresponding to the central zone of the product, and two lateral compartments, corresponding respectively to the two edge zones of the product. The division into compartments is achieved by partitions which are perpendicular to the bottom of the upper chamber. The partitions form, inside of the upper chamber, a channel converging in the direction of motion of the product.

Abstract: A metal product having at least one plane surface, e.g. steel strip, is cooled by means of an aqueous fluid as it moves along a predetermined path by apparatus comprising a wall disposed opposite the plane surface of the product and substantially parallel thereto so as to form a chamber of substantially constant thickness between the plane surface and the wall, at least one aperture in the wall communicating with the chamber for the passage of the aqueous fluid connected to the aperture through the wall. The aperture is connected to a source of the aqueous fluid. The rate of flow of the aqueous fluid and the spacing between the wall and the plane surface are both adjustable.

Abstract: In the production of medium carbon steel wire rod, upon leaving the hot rolling mill, the rod is cooled in two phases. The first phase is operative as the rod moves at end-of-rolling speed along a cooling line disposed between the finishing block and feed rollers disposed at the entry of a head for placing the rod in overlapping turns on a conveyor, the cooling line being continuous--i.e. being devoid of air cooling breaks between consecutive intensive cooling sections, the length and capacity of the cooling line being such that the surface temperature of the rod at the end of the first phase is between, on the one hand, the start-of-martensitic-transformation temperature for the particular steel concerned and, on the other hand, the latter temperature plus 200.degree. C.