Research on key influence factors of laser overlap welding of automobile body galvanized steel

In views of structure characteristics of the auto-body parts, the influences of the beam incident angle and joint gap on the performance of laser overlap welded joints were investigated. The experimental results indicate that there were the critical values of beam incident angle and joint gap during laser overlap welding of galvanized steel. The thickness of sheet and the width of joint had a certain influence on the critical beam incident angle and the limit joint gap. With regard to thicker sheet, the limit joint gap can increase appropriately, but the critical beam incident angle should not be too big. With narrow weld width, the laser beam incident angle can increase appropriately, but the joint gap should not be bigger. Additionally, the critical beam incident angle and the limit joint gap were varied with the thickness of the upper sheet. The tensile-shear tests show that the maximum tensile-shear strength of the joint can be obtained with an optimized beam incident angle and joint gap. (C) 2012 Published by Elsevier Ltd.