Determination of Maximal Gap for Laser Welding

Abstract

Nowadays laser welding is widely used in industrial applications. Often, steel sheets are welded without welding material by using this process. The research aims to determine the maximal gap size and the related welding parameters for the laser welding of a 3 mm thick steel sheet of S235J2 steel grade. During welding, a joint gap may occur due to inadequate edge preparation, which must be considered during the design of the technology. The result of the experiments is that using the Trumpf TLF 5000 turbo-type carbon dioxide laser of 4.5 kW power, 3000 mm/min welding speed, with a focus the maximal gap size is 0.10 mm, while at 2000 (mm/min) welding speed, with 5 mm above focus the maximal gap size is 0.27 mm which can be welded with acceptable seam quality.