GMA-laser Hybrid Welding of High-strength Fine-grain Structural Steel with an Inductive Preheating

Abstract

The industrial use of GMA-laser hybrid welding has increased in the last 10 years, due to the brilliant quality of the laser beam radiation, and higher laser output powers. GMA-laser hybrid welding processes operate in a common molten pool. The combination of the laser beam and the arc results in improved welding speed, penetration depth, heat affected zone and gap bridgeability. Single-layer, GMA-laser hybrid welding processes have been developed for high-strength fine-grain structural steels with a grade of S690QL and a thickness of 15 mm and 20 mm. In addition, the welding process is assisted by an integrated, inductive preheating process to improve the mechanical properties of the welding seam. By using the determined parameters regarding the energy per unit length, and the preheating temperature, welding seams with high quality can be achieved.

Hybrid Welding (Laser–Electric Arc MAG) of High Yield Point Steel S960QL

“…An increase in hardness in the aforesaid area could be ascribed to the rate of heat propagation and the hardening of the joint. A similar distribution of hardness in hybrid-welded joints made of fine-grained high-strength steel was observed by Lahdo et al (2014) [ 30 ]. The authors stated that the weld–HAZ interface underwent hardening, which was connected with the rate at which the above-named area was cooled.…”

Innovative Technologies and Materials for the Production of Mechanical, Thermal and Corrosion Wear-Resistant Surface Layers and Coatings

“…An increase in hardness in the aforesaid area could be ascribed to the rate of heat propagation and the hardening of the joint. A similar distribution of hardness in hybrid-welded joints made of fine-grained high-strength steel was observed by Lahdo et al (2014) [30]. The authors stated that the weld-HAZ interface underwent hardening, which was connected with the rate at which the above-named area was cooled.…”

Advances in macro-scale laser processing

“…This kind of laser source can be used for several processes in the field of laser material processing such as e.g. high power welding processes [22,23,236] and laser-arc hybrid welding processes [131,233,234]. The high beam quality described by a small beam parameter product (BPP ~ 2 mm•mrad for TruDisk 2000 with an output power of 2 kW [265]), allows for the usage of an optical waveguide with a minimal diameter of 50 µm and thus a beam focus diameter on the work piece in the same size.…”