LASER WELDING METHOD FOR PRODUCING A SEMI-FINISHED SHEET METAL PRODUCT MADE OF HARDENABLE STEEL AND COMPRISING A COATING BASED ON ALUMINIUM OR ALUMINIUM-SILICON

摘要

The invention relates to a method for producing a tailored hot-formable semifinished sheet metal product. At least two steel sheets (1, 2') with different degrees of material quality and/or thickness are joined together by a butt joint by means of laser welding. At least one of the sheets is made of a press-hardened steel and has an aluminum- or aluminum-silicon-based metal coating (1.1, 2.1). According to the invention, the steel sheets (1, 2') are welded to each other with a gap (G) which is delimited by the sheet borders to be welded together and which has an average width (b) of at least 0.15 mm. Filler wire (8) material is introduced into the gap (G) to such a degree that the proportion of the filler wire volume introduced into the gap (G) to the volume of the steel sheet material melted by the laser beam is at least 20%. The method according to the invention does not require the coating to be removed from the edges of the sheet borders to be welded together in advance and thus offers substantial cost advantages.