Double-sided Hybrid Laser-Arc Welding of 25 mm S690QL High Strength Steel

Abstract

Hybrid Laser-Arc Welding (HLAW) technique is an enabler for the next generation high efficiency we lding, bu t in dustrial ad option ha s be en li mited du e to pr ocess complexity. Previously documented challenges with root cracks posed by incomplete penetration were significant; h owever, t his w ork p resents s uccessful w eld s amples p repared f rom S 690QL steel welded from two sides with a 16 kW disc laser. Weld travel speeds below 500 mm/min and weld line energies between 1.7 and 1.9 kJ/mm gave sound weld samples, evaluated for yield strength, elongation, hardness and Charpy-V toughness according to DS/EN ISO 10025-6:2004+A1. The results shown here indicate a significant i ncrease i n t he overall e fficiency of but t wel ds in high strength steels and further cement the HLAW process for high strength steels. It is shown that the consecutive nature of the weld procedure led to non-negligible interpass temperatures for the second weld.

Effect of Welding Process Parameters on the Strength of Dissimilar Joints of S355 and Strenx 700 Steels Used in the Manufacture of Agricultural Machinery

“…Variations in heat input and cooling rates led to changes in the properties of the heat-affected zone, illustrating the balance required to optimize mechanical properties. Hybrid laser-arc welding for high-strength steels was examined in [8], demonstrating successful weld samples prepared from S690QL steel. The study highlighted the process's potential for high-strength steels but mentioned non-negligible interpass temperatures for the second weld.…”