Understanding the influence of different HLAW parameters to increase the welding speed of 8 mm thick structural steel

Abstract

Hybrid Laser Arc Welding (HLAW) integrates laser beam welding (LBW) and gas metal arc welding (GMAW) within a common welding zone, creating synergistic effects. As a result, HLAW achieves high process stability and high-quality joints, requiring careful optimization of multiple welding parameters. The main objective of this paper is to increase the welding speed of this technology for joining 8 mm thick structural S355J2N steel in 1G butt configuration, to improve its productivity. The present study reports the influence of key experimental variables in the HLAW process. The effects of laser power, welding speed, filler wire feed rate, and shielding gas on weld quality were evaluated through visual inspection, metallographic characterization, and microhardness measurements. All joints exhibited full penetration, with fusion zones displaying higher hardness values than the base metal. Mechanical analysis, including tensile, bending, and Charpy testing, was conducted on optimized welds produced at a welding speed of 2.5 m/min, a higher welding rate than those previously reported in this configuration by other authors. The results demonstrated satisfactory mechanical behaviour, with tensile strength comparable to the base metal and excellent toughness, as confirmed by bending and Charpy tests.