Abstract: A tensionless leveller for levelling a metal strip and having an entry and an exit includes n+1 motorized rolls each having a constant radius R. The leveller also includes a lower superposed cassette supporting at least n/2 of the rolls and an upper superposed cassette supporting at least n/2 of the rolls not supported by the lower superposed cassette. The rolls are offset with respect to one another and are placed alternately above and below a path of the strip. An axis of each of the rolls of the lower cassette is separated from an axis of an immediately successive roll of the upper cassette by a center-to-center spacing Ek, in which: for k from 2 to 4, R/Ek=R/E1; for k from n?3 to n, R/Ek=R/En and R/Ec<R/E1; and for k from 5 to n?1, R/En?R/Ek?R/E1, and R/Ek?R/Ek+1.

Abstract: The invention relates to a method for the carboxylation conversion of a metal surface under oxidising conditions in relation to the metal, consisting in bringing the metal into contact with a hydro-organic or aqueous bath containing a mixture of organic acids. The invention is characterised in that; the organic acids comprise saturated linear carboxylic acids having between 10 and 18 carbon atoms; the mixture comprises a binary or ternary mixture of such acids; the respective proportions of said acids are such that (i) for a binary mixture x±5%?y±5%, wherein x and y represent the respective proportions, in molar percentages, of the two acids in a mixture with the composition of the eutectic and (ii) for a ternary mixture x±3%?y±3%?z±3%, wherein x, y and z represent the respective proportions, in molar percentages, of the three acids in a mixture with the composition of the eutectic; and the concentration of the mixture in the bath is greater than or equal to 20 g/l.

Abstract: Plate consisting of a steel substrate (1) and a precoat (2) consisting of a layer of intermetallic alloy (3) in contact with said substrate, topped by a layer of metal alloy (4), characterized in that, on at least one precoated face of said plate, an area (6) situated at the periphery of said plate has said metal alloy layer removed.

Abstract: The invention relates to an appliance for the continuous photocatalytic purification of the air in a room, said appliance preferably being in the form of a wall (1) and comprising an external steel structure, an opening (11) for the admission of the air to be processed, an internal metallic framework (4) to which a plurality of UVA lamps (3) are fixed, a photocatalytic filter (2), and an opening (12) for discharging the purified air. The inventive appliance is characterised in that the photocatalytic filter comprises at least one metal grating (2) covered by a film containing titanium dioxide (TiO2), mainly in an anatase phase, in order to maximise the surface of the photocatalyst illuminated by the UVA light.

Abstract: The invention relates to a hot-rolled steel sheet having a tensile strength of greater than 1200 MPa, an Re/Rm ratio of less than 0.75 and an elongation at break of greater than 10%, the composition of which contains, the contents being expressed by weight: 0.10%?C?0.25%; 1%?Mn?3%; Al?0.015%; Si?1.985%; Mo?0.30%; Cr?1.5%; S?0.015%; P?0.1%; Co?1.5%; B?0.005%; it being understood that 1%?Si+Al?2%; Cr+(3×Mo)?0.3%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the microstructure of the steel consisting of at least 75% bainite, residual austenite in an amount equal to or greater than 5% and martensite in an amount equal to or greater than 2%.

Abstract: The invention relates to a method of detecting surface defects on a continuously-cast crude metallic product, such as a steel slab (4). According to the invention, a sensor (10) is used to detect surface defects by means of eddy currents, said sensor consisting of a matrix comprising at least two rows (22, 24) of at least three adjoining measuring cells (21) which can be controlled by a multiplexing control unit (12). Moreover, each cell can generate eddy currents at the surface of the slab and, alternately, detect eddy currents in said surface. The inventive method comprises a step consisting in controlling a first transmitting cell and a second receiving cell from the same row, but which are separated from one another by at least one inactive cell.

Abstract: The invention relates to a steel part coated with a compound consisting, over more than 90% of its thickness, of at least one Fe/Zn-based phase, the iron weight content of which is equal to 65% or higher and the Fe/Zn ratio of which is between 1.9 and 4, said compound being formed by at least one heat treatment for alloying between said steel and a precoat, said precoat consisting of a zinc alloy comprising, the contents being expressed by weight, between 0.5 and 2.5% aluminum and, optionally, one or more elements chosen from: Pb?0.003%; Sb?0.003%; Bi?0.003%; 0.002%?Si?0.070%; La<0.05%; Ce<0.05%, the balance consisting of zinc and inevitable impurities.

Abstract: The subject of the invention is a process for manufacturing a part made of steel having a multiphase microstructure, said microstructure comprising ferrite and being homogeneous in each of the regions of said part, which process comprises the steps consisting in: cutting a blank from a strip of steel, the composition of which is typical of that of steels having a multiphase microstructure; said blank is heated so as to reach a soak temperature Ts above Ac1 but below Ac3 and held at this soak temperature Ts for a soak time ts adjusted so that the steel, after the blank has been heated, has an austenite content equal to or greater than 25% by area; said heated blank is transferred into a forming tool so as to hot-form said part; and said part is cooled within the tool at a cooling rate V such that the microstructure of the steel, after the part has been cooled, is a multiphase microstructure, said microstructure comprising ferrite and being homogeneous in each of the regions of said part.

Abstract: Steel sheet, the composition of the steel of which comprises, the contents being expressed by weight: 0.08%?C?0.23%, 1%?Mn?2%, 1?Si?2%, Al?0.030%, 0.1%?V?0.25%, Ti?0.010%, S?0.015%, P?0.1%, 0.004%?N?0.012%, and, optionally, one or more elements chosen from: Nb?0.1%, Mo?0.5%, Cr?0.3%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.