Arcelormittal France

Arcelormittal

Arcelormittal Investigacion Y Desarrollo, S.l.

Arceloemittal France

Arcelormittl France

Wolfram Ehling

Rene Vierstraete

Pascal Verrier

Aurelien Pic

Bernd Thommes

Jean-Francois Canourgues

Francis Schmit

Qingdong Yin

Laurent Cretteur

René Vierstraete

Niko Van Der Borght

A method for the preparation of steel sheets for fabricating a welded steel blank is provided. The method includes a step of removing at least part of the first and second metal alloy layers in first and second peripheral zones of pre-coated steel first and second sheets, respectively, by simultaneously ablating the first and second precoatings in the first and second peripheral zones of the pre-coated steel first and second sheets to define first and second ablation zones, the first and second peripheral zones being zones of the first and second principal faces closest to the median plane and located on either side of the median plane.

Methods for preparation of sheets to be used for fabrication of a welded steel blank and fabricating a welded blank

A welded steel part with a very high mechanical strength is provided. The welded steel part is obtained by heating followed by hot forming, then cooling of at least one welded blank obtained by butt welding of at least one first and one second sheet. The at least one first and second sheets including, at least in part, a steel substrate and a pre-coating which includes an intermetallic alloy layer in contact with the steel substrate, topped by a metal alloy layer of aluminum or aluminum-based alloy. A method for the fabrication of a welded steel part and the fabrication of structural or safety parts for automotive vehicles are also provided.

Hot-formed previously welded steel part with very high mechanical resistance and production method

A method for creating a welded steel part includes providing a first steel plate having a first base, a first intermetallic alloy layer on the first base and a first metal alloy layer on the first intermetallic alloy layer; providing a second steel plate having a second base, a second intermetallic alloy layer on the second base and a second metal alloy layer on the second intermetallic alloy layer; butt welding the first and second steel plates at a weld so as to melt material from at least the first base, the first intermetallic alloy layer, the second base and the second intermetallic layer to form a molten weld material; austenizing the welded steel plates at a temperature between Ac1 and Ac3+100 degrees C. for a time greater than or equal to 20 seconds; and cooling the welded steel plates so as to render a uniform microstructure to the weld.

Method for creating a welded steel part with uniform microstructure

A method for the preparation of steel sheets for fabricating a welded steel blank is provided. The method includes procuring at least two pre-coated steel sheets, each having a pre-coating of an intermetallic alloy layer, topped by a layer of aluminum metal or aluminum alloy or aluminum-based alloy. The sheets have a principal face, an opposite principal face, and at least one secondary face. The sheets are positioned so a gap between 0.02 and 2 mm exists between the secondary faces. The secondary faces face each other. The positioning of the first and second sheets defines a median plane perpendicular to the principal faces. Layers of metal alloy are removed by melting and vaporization simultaneously on the principal faces, in a peripheral zone of the sheets, the peripheral zones being the zones of the principal faces closest in relation to the median plane.

Method for the preparation of aluminized steel sheets to be welded and then press hardened

The invention relates principally to a welded steel part with a very high mechanical strength characteristics obtained by heating followed by hot forming, then cooling of at least one welded blank obtained by butt welding of at least one first and one second sheet consisting at least in part of a steel substrate and a pre-coating which is constituted by an intermetallic alloy layer in contact with the steel substrate, topped by a metal alloy layer of aluminum or aluminum-based alloy. This welded steel part claimed by the invention is essentially characterized in that the metal alloy layer () has been removed from the edges () in direct proximity to the weld metal zone (), while the intermetallic alloy layer () has been left in place, and in that over at least a portion of the length of the weld metal zone (), the ratio between the carbon content of the weld metal zone () and the carbon content of the substrate () of either the first or the second sheet () having the higher carbon content (Cmax) is between 1.27 and 1.59. The invention likewise relates to a method for the fabrication of a welded steel part as well as the use of this welded steel part for the fabrication of structural or safety parts for automotive vehicles.

A welded blank includes a first pre-coated steel sheet, a second pre-coated steel sheet the first pre-coated steel sheet including a principal first face and an opposite principal first face, the first layer being removed by melting and vaporization in a first peripheral zone of the first pre-coated steel sheet, and the second pre-coated steel sheet including a second principal face and an opposite second principal face, the second layer being removed by melting and vaporization in a second peripheral zone of the second pre-coated steel sheet. At least one welded joint defining a median plane perpendicular to the first and second principal faces. The welded joint area has at least one advantageous characteristic such as a sum of the widths of the first and second peripheral zones of the first and second pre-coated steel sheets varying by less than 10% along the welded joint, the first and second solidification ripples being aligned at the welded joint with respect to the median plane, morphologies of the first and second solidification ripples at the welded joint being identical and symmetrical, and/or an aluminum content in the welded joint being below 0.3%.

Welded blanks made from aluminized steel sheets and having advantageous welded joint characteristics

The present invention provides a method for the preparation of steel sheets to be fabricated into a welded steel blank. The method includes procuring at least one pre-coated first steel sheet and one pre-coated second steel sheet, made up of a steel substrate and a pre-coating made up of an intermetallic alloy layer in contact with the steel substrate, topped by a layer of aluminum metal or aluminum alloy or aluminum-based alloy, the first sheet having a principal face, an opposite principal face, and at least one secondary face, the second sheet having a principal face, an opposite principal face and at least one secondary face, positioning the first and second sheets, leaving a gap of between 0.02 and 2 mm between the secondary faces and facing each other, the mating of the first and second sheets defining a median plane perpendicular to the principal faces of the first sheet and the second sheet, then removing the layers of metal alloy by melting and vaporization simultaneously on the principal faces, in a peripheral zone of the sheets, the peripheral zones being the zones of the principal faces closest in relation to the median plane located one on either side of it.

Method and device for preparing aluminum-coated steel sheets intended for being welded and then hardened under a press; corresponding welded blank

A formed steel part includes a first steel plate having a first base, a first intermetallic alloy layer on the first base and a first metal alloy layer on the first intermetallic alloy layer, the first steel part having a first area without the first metal alloy layer and having at least part of the first intermetallic alloy layer; and a second steel plate having a second base, a second intermetallic alloy layer on the second base and a second metal alloy layer on the second intermetallic alloy layer, the second steel part having a second area without the second metal alloy layer and having at least part of the second intermetallic alloy layer in the second area. The first and second steel plates are joined together. The formed steel part may also include a butt-weld joining the first and second steel plates.

Growing community of inventors

Ghent, Belgium

Wolfram Ehling