A practical approach for increasing penetration in hybrid laser-arc welding of steel

Hybrid laser-arc welding of thick-section steel requires high power lasers, appropriate process parameters, and alternative techniques for obtaining deeper penetration. Conventional techniques for increasing penetration/efficiency include groove beveling, preheating, and the use of pre-set gap, but they are costly and inconvenient. Therefore, investigating alternative approaches for increasing process efficiency is of great importance. Recent studies on laser welding of steel reveal that the edge surface roughness, geometry, and preparation method of the joint can influence the penetration in a butt joint configuration. In this study, a number of experiments were carried out on 25 mm steel plates using current industrial procedures. Common industrial preparation methods such as standard quality machining and pre-set gap were compared with alternative methods providing different edge surface roughness values and roughness patterns. The results showed that the preparation of edge surface quality should be considered as an alternative approach for increasing process efficiency. (C) 2016 The Authors. Published by Elsevier B.V.