Product Code: ICAL05_304

Metallurgical Study on Laser - MAG Hybrid Welding of HSLA-590 Steel
Authors:
Muneharu Kutsuna, Nagoya University; Nagoya Japan
Zhong Liu, Nagoya University, School of Engineering ; Nagoya Japan
Presented at ICALEO 2005

The Laser-Arc hybrid welding of HSLA-590 steel has been studied using 2.4kW CO2 laser and 350A MAG welding machine. There are many parameters in hybrid welding process. Each parameter affects the welding results in hybrid welding. The defocusing distance, distance between laser and arc, welding speed, arc torch angle, arrangement of laser and arc, arc welding current and voltage are investigated. Arc leading hybrid welding is better than laser leading hybrid welding from the result of experiments. MAG welding current of 120~180 ampere is the effective arc parameter to get better welds in 2kW CO2 laser hybrid welding. The acceptable distance DLA between Laser and Arc is also important parameter that is decided by observing the welding process and the cross section of welds. Gap tolerance and groove angle are also investigated in the experiments. Hardness and microstructure of weld metal under different hybrid welding conditions are studied. The average grain size was measured. The result shows the hybrid welding is useful to refine the microstructure comparing with Laser welding and MAG welding individually under the same welding speed. The weld metal hardness of hybrid welds is lower than that of Laser welds and MAG welds. The mechanical and formability were investigated.