Abstract: Process for measuring distances by optical means on a specular or quasi-specular strip (1) of bright metal, characterised by the following steps: an incident light beam is emitted by a source (7) incorporated into a measurement head (10), said source projecting a pattern (11) in the form of a plurality of points, preferably a line, arranged along an axis that is essentially perpendicular to the motion direction of the metal surface, in an incidence direction upon a fixed part (5), preferably non-specular, of the installation; firstly, said beam is partially reflected by said fixed part (5) essentially along the same path as the incident beam and in the opposite direction towards a detector (8) belonging to said measurement head (10) and located in the immediate vicinity of said source (7); secondly, said beam is partially reflected towards said metal strip (1), from where it is further reflected in the direction of said detector (8).

Abstract: In a process for the inspection of the surface of a cylindrical body and more especially that of a mill roll, at least one zone of the surface is observed by means of an inspection device having an optical axis oriented towards this zone of the surface with a view to determining the state of the surface. To this end, at least one image of the zone supplied by the inspection device is captured, at least one of the images captured is analysed, the analysis of the image or images captured is compared with the analysis of a reference image, the differences between the analysis of the image or images captured and the analysis of the reference image are detected, and at least the orientation of the optical axis is adjusted so as at least to reduce and preferably to eliminate the differences found. The device can include mechanical and/or optical means of adjusting the orientation of the optical axis.

Abstract: The invention concerns an apparatus for inspecting a surface, in particular the surface of a mill roll, comprising a housing wherein are arranged means for transmitting and receiving a light beam, and an optical coupling device arranged on the outer surface of a front wall of the housing. The optical coupling device comprises: (a) a component (5), called fluid dispenser, (b) a hollow cylindrical nozzle (11), and (c) a mobile tubular component (16), successively traversed by the light beam. The mobile tubular component (18) is arranged partly inside the cylindrical nozzle (11), so as to be able to slide inside said cylindrical nozzle, and partly exits therefrom in the extension thereof, towards the surface to be inspected (2). Different cross-sections (shoulders 14, 19) are provided in the cylindrical nozzle (11) and in the mobile tubular component (16), in particular for limiting said sliding movement.

Abstract: The invention concerns a nozzle mainly consisting, when viewed in vertical position and in a forward movement of the liquid steel from the top downwards, of a vertical conduit (5) comprising in its upper part a distributing member, arranged substantially at the intake of said conduit and including a dome (6) for deflecting the metal penetrating into the nozzle, which is also provided with means for injecting a gaseous, liquid or solid finely divided material beneath said dome (6) into an inner zone (11). The dome (6) of said distributing member is provided with means for separating liquid steel into two jets (B, C), one jet (B) flowing into the inner zone (11) and penetrating into the ingot mould (1) through a first orifice (9) at the lower base of said conduit (5) and the other jet (C) flowing into an outer zone (12) and penetrating into the ingot mould (1) through lateral orifices (8) located in the vertical wall of said conduit (5).

Abstract: The invention concerns a method for making a multiphase hot-rolled steel strip comprising an ultra-fast cooling operations, which consists in carrying out said ultra-fast cooling operation after controlled slow cooling of the strip on a conventional slow cooling table of the rolling mill. The controlled cooling constitutes a first slow cooling, at the output of the finishing mill, from an end-of-roll temperature to an intermediate temperature of about 750° C. to 500° C.; said first cooling determines the fraction of the first phase (ferrite) in the steel. The ultra-fast cooling (>150° C./s), which solidifies the resulting structure, lowers the temperature of the strip down to a coiling temperature, ranging between about 600° C. and room temperature, at which a second slow cooling is performed which results if the formation of the second phase (bainite or martensite).

Abstract: A method for making a low carbon and low manganese cold rolled steel strip for deep-drawing whereby a steel strip hot rolled in the austenistic region coiled at the end of the high temperature hot rolling process (680° C.<T<750° C.) is subjected to a cold rolling process with a reduction rate between 65 and 80 %, and finally subjected to an annealing and overageing heat treatment. The method consists in heating the steel strip at a heating rate Vh ranging between 150° C./s and 1000° C. up to the annealing temperature Ta ranging between 650° C. and 750° C., and in maintaining it at said annealing temperature for a time interval between 1 and 20 seconds, then in cooling it at cooling rate Vc between 100° C./s and 500° C./s up to an overageing temperature Toa ranging between 150° C. and 450° C.

Abstract: The mold comprises a tubular metal component (4), made of copper or a copper alloy, cooled by water circulation against its external wall and intended to ensure that the cast metal undergoes peripheral solidification on contact with its internal wall, and an uncooled feed head (9) made of a thermally insulating refractory, intended to contain cast metal in the liquid state and sitting on top of the cooled metal component (4) and defining with it a continuous sizing passage for the cast metal. A horizontal metal annulus (16) cooled by internal circulation is added between the feed head (9) and the tubular component (4) and aligned with the internal wall of the latter.

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: An installation for manufacturing an ultrathin foil by electrolytic deposition onto a moving cathode with eventual separation of the deposited material from the cathode is disclosed. The installation includes at least one anode having a plate perforated by a first series of orifices supplied with means of feed of electrolyte. The plate is also perforated by a second series of orifices which are suppled with means of evacuation of electrolyte. The installation of manufacturing includes the moving cathode which is comprised of a metallic belt extended taut between two parallel rolls, which are preferably horizontal. At least one of the rolls is motorized so as to cause the belt to rotate around the two rolls. A first set of the anodes is disposed facing a portion of the length of a first longitudinal run of the belt. Means of electrical connection are provided from the plate of each anode of the first set to the positive terminal of a source of continuous D.C. current.

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.