Suppression of porosity in beam weaving laser welding

The present paper describes a beam weaving laser welding technique to suppress argon or nitrogen porosity, which may appear during laser welding of low carbon steel Bead on plate welding was performed using a 3 kW CO2 laser. The weaving frequency was varied within 0-30 Hz and the weaving amplitude within 0-2 mm during welding. The experimental results show that under 2.4 kW laser power and 1.0 m min(-1) welding speed, the nitrogen porosity decreases remarkably with increasing frequency, and it can be eliminated for a weaving frequency of 22 Hz with 0.5 min weaving amplitude. Under 2.4 kW laser power and 1.5 m min(-1) welding speed, beam weaving laser welding can also effectively reduce argon porosity at a weaving frequency of 22 Hz and amplitude of 1.0-1.5 mm.