Impact of inter-sheet gaps on laser overlap welding performance for galvanised steel

For overlap joints with different galvanised sheet combinations, the inter-sheet gap size and range control under different conditions were experimentally studied, and the factors affecting the inter-sheet gap range were examined. The application of a delta control method to laser welding of car door parts was explored. The results indicate that the formation and strength of weld joints initially improve and then worsen as the inter-sheet gap increases. The inter-sheet gap for different types of sheet combinations has a specific range, the value of which is related to the sheet thickness, weld pool width, welding speed, and laser beam parameters. Further, the consistency of the size of delta along the entire welding bead can be maintained by using a,subsection welding method. Application of the conditions identified here, in combination with optimal technological parameters, can facilitate the high-quality welding of auto-body parts. (C) 2015 Elsevier B.V. All rights reserved.