Arcelormittal France

Sollac

Arceloemittal France

Arcelormittl France

Pascal Verrier

Wolfram Ehling

Rene Vierstraete

Aurelien Pic

Bernd Thommes

Jean-Francois Canourgues

Gilles Peru

Hugues Oberle

Jean-Marc Krzys

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 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.

Steel part

A plate is provided. The plate includes a steel substrate and a precoat having a layer of intermetallic alloy in contact with the substrate, topped by a layer of aluminum alloy. On at least one precoated face of the plate, an area situated at the periphery of the plate has the aluminum alloy layer removed. A part and a welded blank are also provided. Methods are also provided.

Welded blank and part

A method of fabricating a precoated steel plate is provided. The method includes coating a steel plate by dipping the steel plate in a molten bath to obtain a precoat upon the steel plate. The precoat consists of an intermetallic alloy layer and a metal alloy layer, the intermetallic alloy layer is topped by the metal alloy layer. On at least one face of the plate, the metal alloy layer is removed in an area at a periphery of the plate using a laser beam, while at least part of the intermetallic alloy layer is left in the area. The step of removing includes measuring a characteristic of the laser or an area where the metal alloy area is to be removed to obtain a measured value, comparing the measured value with a reference value and stopping a removal operation to leave the at least part of the intermetallic alloy in place as function of the comparing step. Additional methods are also provided.

Methods of fabricating a precoated steel plate

A method of forming a steel part is provided. The method includes the steps of coating a first steel plate to obtain a first precoat upon the first steel plate so as to define a first base, a first intermetallic alloy layer on the first base and a first metal alloy layer on the first intermetallic alloy layer. On a first face of the first steel plate the first metal alloy layer is removed in a first area of the first steel plate, while at least part of the first intermetallic alloy layer in the first area remains. A second steel plate is coated to obtain a second precoat upon the second steel plate so as to define a second base, a second intermetallic alloy layer on the second base and a second metal alloy layer on the second intermetallic alloy layer. On a second face of the second steel plate, the second metal alloy layer is removed in a second area of the second metal plate, while at least part of the second intermetallic alloy layer in the second area remains. After removal of the first and second metal alloy layers, the first steel plate is butt-welded to the second steel plate at the first and second areas to form a welded blank. A heat treatment is performed on the welded blank. The welded blank is shaped after the heat treatment into the steel part. A steel part is also provided.

Method of forming a steel part and steel part

A method of fabricating a precoated steel plate, the method including coating a steel plate by dipping the steel plate in a molten bath to obtain a precoat upon the steel plate, wherein the precoat includes an intermetallic alloy layer and a metal alloy layer. The intermetallic alloy layer is topped by the metal alloy layer. On at least one face of the plate, the metal alloy layer is removed in an area at a periphery of the plate using a laser beam, while leaving at least part of the intermetallic alloy layer in the area. The at least part of the intermetallic layer in the area has a thickness between 3 and 10 micrometers thick.

Precoated steel plate, welded blank, part and methods

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

Method for manufacturing a welded component with very high mechanical characteristics from a coated lamination sheet

A method of butt-welding steel plates is provided. The method includes the steps of coating a first steel plate by dipping the first steel plate in a molten bath to obtain a first precoat upon the first steel plate. The first precoat includes a first intermetallic alloy layer and a first metal alloy layer, the first intermetallic alloy layer is topped by the first metal alloy layer. On a first face of the first steel plate, the first metal alloy layer is removed in a first area at a first periphery of the first steel plate, while at least part of the first intermetallic alloy layer in the first area remains. A second steel plate is coated by dipping the second steel plate in the molten bath or a further molten bath to obtain a second precoat upon the second steel plate. The second precoat includes a second intermetallic alloy layer and a second metal alloy layer, the second intermetallic alloy layer is topped by the second metal alloy layer. On a second face of the second steel plate, the second metal alloy layer is removed in a second area at a second periphery of the second metal plate. While at least part of the second intermetallic alloy layer in the second area remains. After removal of the first and second metal alloy layers, the first periphery of the first steel plate is butt-welded to the second periphery of the second steel plate to form a welded blank.

Method of butt-welding a coated steel plate

Plate

Process for butt welding two metal blanks(1,2) of which the first blank is of steel and the second blank is of a metal having a melting temperature lower by more than 400.degree. C. than the melting temperature of the steel. The process includes positioning the two metal blanks (1,2) so that they contact each other in the region of their lateral faces to be butted together, maintaining the two metal blanks in contact, directing onto one of the principal faces of the metal blank (1) a high energy density bean (5) which passes through the first metal blank (1) and of which the focusing point is situated at a given distance from the joint plane (3) so as to generate in the region of the joint plane (3) a temperature equal to the melting temperature of the second metal blank (2) to within 10%, and displacing the high energy density beam (5). This process is applicable to the welding of two metal blanks of which one is of steel and the other is of aluminium or aluminium alloy for producing a motor vehicle part, in particular a body and structural part.

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Lumbres, France

Pascal Verrier