Constellium Neuf-brisach

Arcelormittal

Jean-Philippe Masse

Ravi Shahani

Laurent Cervi

Jean-Christophe Hell

Olivier Rebuffet

Lukasz Dolega

Gilles Guiglionda

Petar Ratchev

Christophe Chabriol

Laurent Boissonnet

Stefan Kempa

David Barbier

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=830° C. for at least 30 s then quenched by cooling it to a quenching temperature QT between 180° C. and 300° C., then heated to a partitioning temperature PT between 380° C. and 480° C. 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 25° C./s below 300° C., or directly cooled to the room temperature with a cooling rate of at least 25° C./s and further electro-galvanized, or cooled to the room temperature with a cooling rate of at least 25° C./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.

Method for producing a coated steel sheet having improved strength, ductility and formability

The invention relates to the process for manufacturing a rolled product based on an aluminum alloy, in particular for the automotive industry wherein, successively, a bath of liquid metal made from an aluminum-based alloy. The invention also relates to the products obtained by this process and the use thereof for the manufacture of a motor vehicle.

Process for manufacturing thin sheets made of 7XXX aluminum alloy suitable for shaping and assembly

The invention relates to a process for laser welding monolithic semi-finished products made of aluminium alloy without filler wire, known to a person skilled in the art under the name 'Remote Laser Welding' comprising the following steps:&#x2014;supplying at least two semi-finished products made of aluminium alloy, at least one of which is a laminated plate with the composition (% by weight): Si: 2.5-14; Fe: 0.05-0.8; Cu: 0.25-1.0; Mg: 0.05-0.8; Mn: &#x2264;0.70; Cr: &#x2264;0.35; Ti: 0.02-0.30; Sr up to 500 ppm; Na up to 200 ppm; Sb up to 0.15%, unavoidable impurities &#x3c;0.05 each and &#x3c;0.15 in total, remainder aluminium,&#x2014;laser welding the semi-finished products made of aluminium alloy without filler wire, which process is known to a person skilled in the art under the name 'Remote Laser Welding'. The invention also includes a structural, body-in-white, skin or opening component of a motor vehicle obtained by a process according to the invention.

Aluminium alloy for laser welding without filler wire

The invention relates to a thin sheet metal for a reinforcing or structural part of a car body, consisting of an aluminum alloy. The invention also relates to the method for producing such a sheet metal and to the use of such a sheet metal for producing a reinforcing or structural part for a car body. The sheet metals according to the invention advantageously have a modulus of elasticity of at least 77 GPa.

Highly rigid sheet for car body

The invention relates to a method for the laser welding of monolithic semi-finished products made from aluminium alloy, without filler wire, known to the person skilled in the art as 'remote laser welding', comprising the following steps: supplying at least two aluminium alloy semi-finished products, of which at least one is a rolled sheet of composition (wt.-%): Si: 2.5-14, preferably 2.7-5.0; Fe: 0.05-0.80, preferably 0.15-0.60; Cu: &#x2265;0.20, preferably &#x2265;0.10, also &#x3c;0.05, and even &#x3c;200, also 100 ppm; Mg: 0.05-0.80, preferably 0.20-0.40; Mn: &#x2265;0.70, preferably &#x2265;0.30; Cr: &#x3c;0.35; Ti: 0.02-0.30; Sr up to 500 ppm; Na up to 200 ppm; Sb up to 0.15%, other elements &#x3c;0.05 each and &#x3c;0.15 total, remainder aluminium, on the condition that A: 5.2 Fe+1.95 Si&#x2212;0.5 Cu&#x2212;Mg&#x2265;7.0; and welding semi-finished products made from aluminium alloy, without filler wire, a method known the person skilled in the art as 'remote laser welding'.

Method for the laser welding of monolithic semi-finished products made from aluminium alloy, without filler wire, and corresponding structural component and tailored blank

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Grenoble, France

Jean-Philippe Masse