Arcelormittal

René Vierstraete

Wolfram Ehling

Francis Schmit

Qingdong Yin

A method for butt laser welding two metal sheets includes providing a first metal sheet and a second metal sheet and butt welding the metal sheets along a direction of welding. The butt welding step includes simultaneously generating a first front keyhole in the first metal sheet, generating a second front keyhole in the second metal sheet, and generating a back keyhole in the first and second metal sheets. The first and second front laser beams and the back laser beam are configured in such a manner that at each moment in time, a solid phase region and/or a liquid phase region of the metal sheets remains between the first front keyhole and the back keyhole and between the second front keyhole and the back keyhole.

Method for butt laser welding two metal sheets

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.

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Maisons-Laffitte, France

René Vierstraete