A method for preparing zinc-coated metal sheets to be joined by laser welding

摘要

In order to prepare a first zinc-coated metal sheet for joining to a second zinc-coated metal sheet by laser welding, surface knurling is formed in a zinc-coated interface surface of the first sheet. The knurling defines escape paths for the zinc vapour generated in the subsequent laser welding step. The knurling is carried out in a step subsequent to the shaping of the sheet, by a forming tool separate from the drawing die which shaped the first sheet.