During welding of zinc-coated materials, zinc trapped in the overlap of a lap joint expands violently because of vaporization, and therefore disturbs the laser keyhole. Laser twin-spot welding is a new approach for welding of thin sheet C-Mn steel. The dual beam principle creates a larger and more stabilized weld pool. Therefore welding of galvanized zero gap lap joints becomes possible. This opens a new joining approach for automotive and other industries to perform high speed laser welding. The possibility to laser weld steels with 20 μm zinc coating thickness with high speed and high quality is a technical breakthrough
Godkänd; 2011; Bibliografisk uppgift: 1 CD-ROM; 20110406 (andbra)