Product Code: ICA13_902

Induction Assisted Gma-Laser Hybrid Welding of High-Strength Fine-Grain Structural Steels
Authors:
Rabi Lahdo, Laser Zentrum Hannover e.V.; Braunschweig USA
Oliver Seffer, Laser Zentrum Hannover E.V.; Hannover Germany
Andre Springer, Laser Zentrum Hannover E.V.; Hannover Germany
Stefan Kaierle, Laser Zentrum Hannover E.V.; Hannover Germany
Ludger Overmeyer, Laser Zentrum Hannover E.V.; Hanover Germany
Mareike Collmann, Institut FüR Stahlbau; Hannover Germany
Peter Schaumann, Institut FüR Stahlbau; Hannover Germany
JöRg Neumeyer, Institut FüR Elektroprozesstechnik; Hannover Germany
Holger Schulbe, Institut FüR Elektroprozesstechnik; Hannover Germany
Bernard Nacke, Institut FüR Elektroprozesstechnik; Hannover
Presented at ICALEO 2013

The huge range of using high-strength fine-grain structural steels increases because of
advantages regarding to the mechanical properties and the suitability for welding. Thick sheets up
to 10 mm are used e.g. for offshore applications, mobile crane-, concrete pump-, pipeline- and
shipbuilding. Conventionally, the fine-grain structural steels are joined with arc welding methods in
multi-layer processes and with a comparatively low welding structural speed. The preparation time
regarding the edge pretreatment and the high consumption of additional materials is typical for arc
welding methods.
The induction assisted GMA-laser hybrid welding is suitable because of the advantages in terms of
the high welding speed, a reduction of the edge pretreatment with lower flank angles and a lower
heat affected zone. In this research a process is developed for a single-layer joint of fine-grain
structural steels with the grades S700MC, X70 and S690QL in a thickness range from 10 to
15 mm. For this configuration a reproducible process was achieved. The high quality welding
seams are characterized by metallographic analyses, tensile tests, notched-bar impact tests and
hardness tests. In addition, the use of the inductive preheating causes advantages regarding the
process and the metallurgy. It is possible to increase the welding speed and to obtain
homogeneous mechanical properties in the vicinity of the welding seam. A simulation model is
developed for the preheating process and the GMA-laser hybrid welding process to accompany the
experimental research.