Modified dual-beam method for welding galvanized steel sheets in lap configuration

Abstract

The dual laser beams method to lap weld galvanized steel sheets is being discussed, modeled, and analyzed, involving a precursor beam and a higher-power actual beam used in tandem and generated independently or otherwise split from the same source (Nd:yttrium-aluminum-garnet or CO2 laser). The first beam cuts a slot, thus making an exit path for the zinc vapors, while the second beam welds as required. The article also presents and discusses some experiments performed in laboratory using this method, along with the metallurgical analysis results from laboratory showing total absence of zinc in the weld area.

Role of side assisting gas on plasma and energy transmission during CO2 laser welding

“…However, due to the low boiling point (960 • C) of zinc, the zinc vapor generated during the welding process can easily lead to defects such as porosity, incomplete fusion and cracks, which makes the laser welding of galvanized steel very challenging. Gualini et al (2006) discussed, modeled, and analyzed the dual laser beams method to lap weld galvanized steel sheets. The leading laser beam cuts a slot as the exit path for the zinc vapor while another following higher-power laser beam welds the sheets.…”