Laser build-up welding technique using automatic wire feeding

摘要

By the experiment of laser build-up welding technology on 45steel using high-power CO_2 laser beam and wire feeder, the paper investigated the effect of laser build-up welding technology on structure and properties of surfacing layer. This experiment showed that the optimized processing parameters were as follows: laser specific energy (E_s) was 100-130 J/mm~2 and wire feed rate should be faster than laser scanning speed (ΔV = 1.5-2.5 mm/s). Compared with argon arc welding, the structure of laser build-up welding layer was evidently refined and its hardness was increased by 70%, and the transition zone was narrower. The experiment also proved that the microstructure of laser build-up welding layer got coarser with the increasing of E_s. At the same time, overheated structure easily appeared at heat-affected zone. Laser build-up welding had shown good wear resistance, which was increased by 42.6% than that of high-speed steel.