Luxembourg, Luxembourg
Luxembourg, Luxembourg

ArcelorMittal S.A. is a multinational steel manufacturing corporation headquartered in Avenue de la Liberté, Luxembourg. It was formed in 2006 from the takeover and merger of Arcelor by Mittal Steel. ArcelorMittal is the world's largest steel producer, with an annual crude steel production of 93.6 million tones as of 2012. It is ranked 91st in the 2013 Fortune Global 500 ranking of the world's biggest corporations. Wikipedia.


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A method for manufacturing a plate, a band, or a coil of hot-rolled steel is provided. The method includes providing an ingot or a slab of steel with a desired composition and a microstructure composed of austenite and 35 to 65% ferrite by volume and hot rolling the ingot or slab at a temperature between 1150 and 1280 C. to obtain a plate, a band or a coil. A method for manufacturing a hot-rolled bar or wire of steel, a steel profile and a forged steel piece are also provided.


Patent
ArcelorMittal | Date: 2017-05-17

The invention relates mainly to a sheet of hot-rolled steel with an elastic limit of more than 680 MPa at least in the direction across the rolling direction, and no higher than 840 MPa, with strength of 780 MPa and 950 MPa, elongation at break higher than 10% and hole expansion ratio (Ac) no lower than 45%, in which the chemical composition consists of, the contents being expressed as weight percentages: 0.04% C 0.08%, 1.2% Mn 1.9%, 0.1 % Si 0.3%, 0.07% Ti 0.125%, 0.05% Mo 0.35%, 0.15% Cr 0.6% when 0.05% Mo 0.11% or 0.10% Cr 0.6% when 0.11 % Mo 0.35%, Nb 0.045%, 0.005% Al 0.1 %, 0.002% N 0.01 %, S 0.004%, P 0.020%, and optionally 0.001% V 0.2%, the remainder consisting of iron and inevitable impurities from the production process, in which the microstructure consists of granular bainite having a surface percentage higher than 70%, and ferrite having a surface percentage lower than 20%, the possible complement consisting of lower bainite, martensite and residual austenite, the sum of the contents of martensite and residual austenite being lower than 5%. The invention also relates to the method for manufacturing such a sheet.


The invention relates to a method for preparing sheets intended for manufacturing a steel welded blank, which comprises the following consecutive steps: providing at least one first (11) and one second (12) pre-coated steel sheets, made up of a steel substrate (25, 26), and a pre-coating (15, 16) made of an intermetallic alloy layer (17, 18) in contact with said steel substrate, mounted on top of a aluminium, aluminium-alloy or aluminium-based metal layer (19, 20), the sheet (11) comprising a main surface (111), an opposing main surface (112), and at least one secondary surface (71), the sheet (12) comprising a main surface (121), an opposing main surface (122), and at least one secondary surface (72); then moving the first (11) and second (12) sheets close together, leaving a clearance (31) of 0.02 to 2 mm between the secondary surfaces (71) and (72) placed facing one another, the fact of moving the first (11) and second sheets (12) together defining a median plane (51) perpendicular to the main surfaces of the sheets (11) and (12); and then simultaneously removing by melting and vaporisation, on the main surface (111) and the main surface (121), the layer of metal alloy (19) in a peripheral area (61) of the sheet (11), and the layer of metal alloy (20) in a peripheral area (62) of the sheet (12), the peripheral areas (61) and (62) being the areas of the main surfaces (111) and (121) that are closest to said median plane (51) located on either side of same. The invention also relates to a welded blank and to a device for manufacturing such welded blanks.


Patent
ArcelorMittal | Date: 2017-02-08

Substrate provided with a plurality of layers, at least one of which includes metal oxides and is topped directly by a metal coating layer that contains at least 8% by weight nickel and at least 10% by weight chromium, the remainder being iron, additional elements and the impurities resulting from the fabrication process, wherein this metal coating layer is topped directly by an anticorrosion coating layer. A corresponding fabrication method is also provided.


The invention relates to a pre-coated blank or metal sheet comprising a steel substrate for heat treatment, at least part of at least one of its main faces being covered by a pre-coating comprising at least one layer of aluminium or aluminium alloy, covered, on at least part of the pre-coating, by a polymerized layer which is between 2 and 30 micrometres thick and is composed of a polymer which contains no silicon and of which the nitrogen content is less than 1 wt.% expressed relative to the layer, the polymerized layer containing carbonated pigments in a quantity of between 3 and 30 wt.%, expressed relative to the layer.


The present invention provides a steel part. The steel part includes a steel precoated with a zinc-based alloy including, the contents being expressed by weight, from 0.5 to 2.5% aluminum and, optionally, one or more elements chosen from the group of: Pb0.003%; Sb0.003%; Bi0.003%; 0.002%.Si0.070%; La<0.05%; and Ce<0.05%. A balance of the precoat includes zinc and inevitable impurities. The steel part also includes a compound formed by at least one heat treatment for alloying between the steel and the precoat. The compound includes over more than 90% of its thickness, 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. A structural or safety part is also provided.


A method for hot-dip coating of a steel strip running in a bath of liquid metal such as zinc, or metal alloy contained in a pan is provided. Dross which are formed during the coating and float at the surface of the bath are moved away from the surface of the strip by at least one inductor. Each inductor produces a sliding electromagnetic field oriented along a given direction and generates a magnetomotive force, and the magnetomotive forces displaced the dross towards a container intended to collect them and/or towards an area of the surfaceof the bath from which they are discharged. For at least one of the inductors, the direction of the respective sliding electromagnetic field is reversed intermittently so as to modify the flows of the dross inside the pan. A hot dip coating facility is also provided.


The invention relates to a method for producing a high strength coated steel sheet having a yield stress YS > 550 MPa, a tensile strength TS > 980 MPa, and improved formability and ductility. The steel contains: 0.15% C 0.25%, 1.2% Si 1.8%, 2% Mn 2.4%, 0.1% Cr 0.25%, Al 0.5%, the balance being Fe and unavoidable impurities. The sheet is annealed at a temperature between TA1 = Ac3 0.45*(Ms QT) and TA2 = 830C for at least 30s then quenched by cooling it to a quenching temperature QT between 180C and 300C, then heated to a partitioning temperature PT between 380C and 480C and maintained at this temperature for a partitioning time Pt between 0 sec and 300 sec, then either hot dip coated and cooled to the room temperature with a cooling rate of at least 25C/s below 300C, or directly cooled to the room temperature with a cooling rate of at least 25C/s and further electro-galvanized, or cooled to the room temperature with a cooling rate of at least 25C/s without coating. The steel according to the invention contains 5% to 25% of intercritical ferrite, at least 50% of partitioned martensite, at least 10% of residual austenite, less than 10% of fresh martensite, and bainite, the sum of partitioned martensite and bainite being at least 60%. It also relates to the obtained coated or non coated sheet.


The invention relates to a rolled steel sheet, for press hardening, the chemical composition of which comprises, the contents being expressed by weight: 0.24% C 0.38%, 0.40% Mn 3%, 0.10% Si 0.70%, 0.015% Al 0.070%, 0% Cr 2%, 0.25% Ni 2%, 0.015% Ti 0.10%, 0 % Nb 0.060%, 0.0005% B 0.0040%, 0.003% N 0.010%, 0.0001% S 0.005%, 0.0001% P 0.025%, it being understood that the titanium and nitrogen contents satisfy: Ti/N > 3.42, and that the carbon, manganese, chromium and silicon contents satisfy: formula (I), the chemical composition optionally comprising one or more of the following elements: 0.05% Mo 0.65%, 0,001% W 0.30%, 0.0005 % Ca 0.005%, the remainder consisting of iron and of unavoidable impurities originating from the production, the sheet containing a nickel content Nisurf at any point of the steel in the region of the surface of said sheet over a depth , such that: Nisurf > Ninom, Ninom denoting the nominal nickel content of the steel, and such that, Nimax denoting the maximum nickel content within : formula (II) and such that: formula (III) the depth being expressed in micrometres, the Nimax and Ninom contents being expressed as weight percentages.


Patent
ArcelorMittal | Date: 2017-06-07

A method for producing a high strength steel piece having desired mechanical properties, obtainable by a reference heat treatment comprising a first reference treatment and a final reference treatment comprising at least an overaging, The method comprising a step of heat treating on an equipment comprising at least an overaging means for which it is possible to set at least one operating point, the final treatment comprising an overaging for which it is possible to calculate two final treatment parameters OAP1 and OAP2 depending on an operating point of the overaging means. A minimum OAP1 min and a maximum OAP2 max final treatment parameters are determined in order to obtain the desired properties, at least one operating points of the overaging section means is determined such that OAP1 OAP1 min and OAP2 OAP2 max. The piece is heat treated accordingly. The parameters are with T(t) the temperature at time t Formula (I)

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