Abstract: The present invention provides a steel sheet with low aluminum content, which includes: between 0.050 and 0.080% by weight of carbon, between 0.25 and 0.40% by weight of manganese, less than 0.020% by weight of aluminum, and between 0.010 and 0.014% by weight of nitrogen, the remainder being iron and inevitable trace impurities, wherein when in an aged condition the sheet includes a percentage elongation A% satisfying the relationship: (750?Rm)/16.5?A%?(850?Rm)/17.5 where Rm is the maximum rupture strength of the steel, expressed in Mpa. Another embodiment of the invention provides a container, which includes or is made from the above-mentioned steel sheet.

Abstract: The present invention provides a process for manufacturing a steel strip with low aluminum content, which includes: hot-rolling a steel strip which includes between 0.050 and 0.080% by weight of carbon, between 0.25 and 0.40% by weight of manganese, less than 0.020% by weight of aluminum, and between 0.010 and 0.014% by weight of nitrogen, the remainder being iron and inevitable trace impurities, to form a strip; subjecting the strip to a first cold-rolling, to form a cold-rolled strip; annealing the cold-rolled strip, to form an annealed cold-rolled strip; optionally, subjecting the annealed cold-rolled strip to a secondary cold-rolling; wherein the annealing is a continuous annealing which includes: raising the temperature of the strip to a temperature higher than the temperature of onset of pearlitic transformation Ac1, holding the strip above this temperature for a duration of longer than 10 seconds, and rapidly cooling the strip to a temperature below 350° C. at a cooling rate in excess of 100° C.

Abstract: A process is provided for preparation of an aluminum-killed medium-carbon steel sheet containing by weight from 0.040 to 0.080% of carbon, from 0.35 to 0.50% of manganese, from 0.040 to 0.070% of aluminum, from 0.004 to 0.006% of nitrogen, the remainder being iron and the inevitable trace impurities, wherein the steel contains carbon in free state, a grain count per mm2 greater than 20000 and, in the aged condition, has a percentage elongation A % satisfying the relationship: (640-Rm)/10?A %?(700-Rm)/l1 where Rm is the maximum rupture strength.

Abstract: The present invention provides a process for manufacturing a steel strip with low aluminum content, which includes: hot-rolling a steel strip which includes between 0.050 and 0.080% by weight of carbon, between 0.25 and 0.40% by weight of manganese, less than 0.020% by weight of aluminum, and between 0.010 and 0.014% by weight of nitrogen, the remainder being iron and inevitable trace impurities, to form a strip; subjecting the strip to a first cold-rolling, to form a cold-rolled strip; annealing the cold-rolled strip, to form an annealed cold-rolled strip; optionally, subjecting the annealed cold-rolled strip to a secondary cold-rolling; wherein the annealing is a continuous annealing which includes: raising the temperature of the strip to a temperature higher than the temperature of onset of pearlitic transformation Ac1, holding the strip above this temperature for a duration of longer than 10 seconds, and rapidly cooling the strip to a temperature below 350° C. at a cooling rate in excess of 100° C.

Abstract: A process for the continuous dip-coating of a metal strip (1) in a tank (11) containing a liquid metal bath (12), in which process the metal strip (1) is made to run continuously through a duct (13), the lower part of which is immersed in the liquid metal bath (12), in order to define with the surface of the bath a liquid seal (14). In the region where the strip (1) leaves the liquid metal bath (12), the liquid metal is isolated from the surface of the bath in an isolating enclosure (20), and the metal oxide particles and intermetallic compound particles are recovered by the liquid metal flowing from this region into the enclosure (20), and the particles are extracted from this enclosure (20). Also, a plant for implementing the process.

Abstract: The present invention provides a process for manufacturing a steel strip with low aluminum content, which includes: hot-rolling a steel strip including between 0.050 and 0.080% by weight of carbon, between 0.25 and 0.40% by weight of manganese, less than 0.020% by weight of aluminum, and between 0.010 and 0.014% by weight of nitrogen, the remainder being iron and inevitable trace impurities, to form a strip; subjecting the strip to a first cold-rolling, to produce a cold-rolled strip; annealing the cold-rolled strip, to form an annealed cold-rolled strip; optionally, subjecting the annealed cold-rolled strip to a secondary cold-rolling; wherein the annealing is a continuous annealing comprising: raising the temperature of the strip to a temperature higher than the temperature of onset of pearlitic transformation Ac1, holding the strip above this temperature for a duration of longer than 10 seconds, rapidly cooling the strip to a temperature below 100° C. at a cooling rate in excess of 100° C.

Abstract: The subject of the invention is a plant for the continuous dip-coating of a metal strip (1), of the type comprising a tank (11) containing a liquid metal bath (12), a duct (13) through which the metal strip (1) runs and the lower end (13a) of which duct (13) is extended by at least two internal walls (20; 22) each located on one side of the strip (1) and directed towards the surface of the metal bath (12) in order to form at least one compartment (21; 23) for recovering the metal oxide particles and intermetallic compound particles. The duct (13) has a fixed upper part (30) and a movable lower part (31) joined together by a deformable element (32) and means (35) for positioning the movable lower part (31) with respect to the metal strip (1).

Abstract: A process is provided for preparation of an aluminum-killed medium-carbon steel sheet containing by weight from 0.040 to 0.080% of carbon, from 0.35 to 0.50% of manganese, from 0.040 to 0.070% of aluminum, from 0.004 to 0.

Abstract: A method for examining the surface of an unwinding strip to detect a surface fault. The method includes forming at least a digital image of the strip having a set of image elements each with an assigned digital value. The digital image is filtered to detect surface defects. The filter digital image is processed to identify the type of surface fault in the strip. Before the digital image processing step, the digital image is segmented into doubtful zones each containing a surface defect with the image processing step being carried out on the doubtful zones.

Abstract: A process is provided for preparation of an aluminum-killed medium-carbon steel sheet containing by weight from 0.040 to 0.080% of carbon, from 0.35 to 0.50% of manganese, from 0.040 to 0.070% of aluminum, from 0.004 to 0.006% of nitrogen, the remainder being iron and the inevitable trace impurities, wherein the steel contains carbon in free state, a grain count per mm2 greater than 20000 and, in the aged condition, has a percentage elongation A % satisfying the relationship: (640−Rm)/10≦A %≦(700−Rm)/11 where Rm is the maximum rupture strength.

Abstract: A killed and vacuum-degassed very-low-carbon steel containing, by weight, between 0.10 and 0.35% manganese, less than 0.006% nitrogen, less than 0.025% phosphorus, less than 0.020% sulphur, less than 0.020% silicon, at most 0.08% of at least one of the elements copper, nickel and chromium, as well as aluminum. The steel is cast in the form of a slab, the slab is hot rolled in order to obtain a hot-rolled sheet, the hot-rolled sheet is coiled, the hot-rolled sheet is cold rolled in two rolling operations separated by a continuous annealing operation. The steel contains at most 0.006% carbon by weight and 0.010% aluminum and the hot-rolled sheet is coiled at a temperature below 620° C. Preferably, the steel is killed by mixing with a slag containing adjusted amounts of aluminum and of alumina.

Abstract: A process is provided for preparation of an aluminum-killed medium-carbon steel sheet containing by weight from 0.040 to 0.080% of carbon, from 0.35 to 0.50% of manganese, from 0.040 to 0.070% of aluminum, from 0.004 to 0.

Abstract: A method for inspecting a surface of a moving strip to detect surface defects, which includes forming at least one digital picture of at least one face of the strip, in which the digital picture is made up of a set of successive rows of picture elements, each of which is assigned a digital value. The method also includes filtering the at least one digital picture to detect surface irregularities by detecting relative variations in the digital values, and processing the at least one filtered digital picture to identity a type of surface defect corresponding to each detected irregularity. Further, prior to the processing step, an overall characterization of each of the irregularities is performed by determining, a value of predetermined parameters characteristic of surface defects, and a prior classification of the irregularities is performed based on the determined values of the parameters, according to a set of predefined classes.

Abstract: A process for manufacturing carbon-steel strip having a thickness of less than or equal to 10 mm directly from liquid steel, by casting said liquid steel between the lateral surfaces, made of copper or copper alloy, of two internally cooled rotating horizontal rolls.

Abstract: Aluminum-killed medium carbon steel sheets, and the steel sheet stock prepared from it, is useful for manufacturing containers for a variety of food and industrial purposes. High mechanical strength is imparted to steel sheeting when the sheeting is processed through a continuous series of operations including cold-rolling and annealing. Annealing at a temperature maintained above the pearlitic transformation (Ac1) and rapid cooling yields steel sheet of high maximum rupture strength. Improved mechanical properties allows the steel sheet to be used in the manufacture of thin wall containers or containers of novel shape.

Abstract: A method and device for continuously coating at least a metal strip (1) with a crosslinkable polymer fluid film which is free of non-reactive solvent or diluent, and which has a softening temperature higher than 50° C. The method includes the steps of: continuously unwinding the metal strip (1) on at least a back-up roll (30); forming, by forced flow on an applicator roll (20) having a deformable surface, a layer of the crosslinkable polymer; and forming on the applicator roll (20) the crosslinkable polymer film and transferring the film from the applicator roll onto the metal strip. The device implements this method.

Abstract: A method for the continuous coating of at least one metal strip with a fluid, crosslinkable polymer film free from solvent or diluent and having a thickness less than that of the metal strip. The process firs continuously moves the metal strip on at least one support roller, pre-heats the strip, forms by forced flow, on a pinch roller on a lap of the crosslinkable polymer, heats and drives in rotation the pinch roller in the same direction as the support roller, and forms the crosslinkable film by compressing, between the pinch roller and the metal strips, an applicator element with a deformable surface, heated and driven in rotation in the same direction as the support roller to transfer the film from the pinch roller onto the applicator element and from the applicator element onto a metal strip. A coating device for implementing this method is also disclosed.

Abstract: The invention concerns a method for continuously coating at least a metal strip with a crosslikable polymer fluid film free of non-active solvent or diluent and whereof the softening temperature is higher than 50° C. The method consists in continuously unwinding the metal strip (1) on at least a back-up roll (3); forming, on a roll (20) by forced flow, a layer of said crosslinkable polymer in melted state; forming, from said layer (30), said crosslinkable polymer film (31); and transferring entirely in thickness said film onto the metal strip (1) and, between the zone forming the layer (30) on the roll (20) and the zone applying the film (31) on the metal strip, in thermally conditioning the crosslinkable polymer to reduce its viscosity. The invention also concerns a coating device for implementing said method.

Abstract: A procedure for controlling a complex dynamic process. According to the procedure, information is periodically acquired and values of recorded quantities are generated. The condition and the evolution of the process are described by a succession of detected process phenomena. Each process phenomenon that is detected as a function of its own context is judged, which itself is described by other process phenomena. Then, bits of information are directed to operators only when the judgment has determined that they are necessary and timely in the given context to help to maintain or to return the process to its production goals.

Abstract: The invention concerns a steel plate coated with a metal layer based on zinc and a zinc hydroxysulphate layer, whereof the surface density of sulphur is more than 0.5 mg/m2. The invention also concerns a method for obtaining said plate by treating a zinc coated sheet metal: either in a highly alkaline sulphate solution under polarization; or in a sulphate solution containing Zn2+ ions without polarization. The hydroxysulphate deposit brings about a pre-lubricating effect applicable to operations for forming sheet metal.