Product Code: ICAL05_P546

Laser and Hybrid Welding of High Strength Steel. Application to Pressure Vessel Manufacturing
Authors:
Coste Frederic, LALP; Arcueil France
Cyprien Allais, SAIPEM-SA; Montigny le Bretonneux France
Jean Paul Mas, SAIPEM-SA; Montigny le Bretonneux France
Remy Fabbro, LALP; Arcueil France
Presented at ICALEO 2005

The aim of this study is a comparison of the performances obtained with laser Nd:YAG welding (with cold wire) and hybrid welding (laser + MAG ) on a high strength steel. Due to the thickness to be welded (up to 16 mm), multipasses procedure has been developed for both techniques. Parameters optimisation (groove geometry, wire speed, shielding gas) leads to an improvement of 50 % in term of welding speed when using hybrid technique compared to laser alone one. The size of the parts to be welded (up to 48 inches diameter) has lead us to develop a specific work station. In order to manage the thickness variation, the wire speed is controlled during welding in order to achieve a constant filling. For that, a seam tracker system is used to control the welding tool position and to measure the exact volume to be filled. This system is also used to control the focus point and the wire position in accordance with the conventional pipe ovality or out of roundness in such high pipe diameter.