Patent ID: 6646225
Filing Date: 2003-11-11
Classification: B23K

Abstract:
A method of welding a steel sheet metal part having a zinc galvanized coating to a second sheet metal part where said parts are held together in overlapping configuration and zinc coating material is present at a welding interface of said overlapping parts, said method comprising:directing a first laser beam on a surface of said steel part and advancing said first laser along said surface to cut a slot through said steel part, at least to the depth of said steel part's interface with said second part, in a path for a welding seam, the energy of said first laser and the depth and width of said slot being sufficient to evaporate zinc from said interface through said slot; directing a second laser beam along said slot following said first laser beam, said second laser beam having sufficient energy to melt ferrous metal into said slot for said weld; and cooling the molten metal to complete said weld.