Effects of weaving laser on scanning laser-MAG hybrid welding characteristics of high-strength steel

Scanning laser-MAG hybrid welding with weaving laser was developed for the bead-on-plate welding of high-strength steel. Weaving laser exerted little effect on the droplet transfer behaviour during the scanning laser-MAG hybrid welding process. In order to achieve the keyhole mode of laser welding, the weaving amplitude should be no more than 2 mm. The weld penetration decreased with the increasing weaving frequency. Compared to laser-MAG hybrid weld, the ratio of arc zone width to laser zone width decreased significantly. Scanning laser-MAG hybrid welding could suppress the porosity defects of weld efficiently. The optimal weaving frequency for the porosity defects suppression was 20 Hz. However, the porosity defects increased sharply with the weaving frequency of laser over 40 Hz. The impact-absorbed energy value of specimen fabricated by scanning laser-MAG hybrid welding was about 46 J, increased by about 31.4% compared to about 35 J of laser-MAG hybrid welding.