Improvement of weld quality with beam-weavinglaser welding

Abstract

This paper describes a way to improve the weld quality through suppressing the porosity formation and restraining the growth of columnar grains with weaving-beam laser welding. A beam weaving system is set up to perform bead-on-plate welding with a 3kW CO2 laser. The influence of beam-weaving laser welding on reduction of nitrogen and argon porosity is investigated with low carbon steel. The experimental results indicate that beam-weaving laser welding can remarkably reduce N2 porosity with weaving frequency increasing, and porosity can be eliminated when weaving amplitude is only 0.5mm. Beam-weaving laser welding can also effectively reduce Ar porosity. The Ar porosity in the weld metal is decreased with increasing weaving frequency and amplitude.A kind of ultra-fine grained steel is used as base metal to study the influence of beam-weaving laser welding on the growth of columnar grains and mechanical properties of weld metal. The experimental results show that beam weaving with appropriate amplitude and frequency can restrain the growth of columnar grain of weld and improve the tensile strength of the laser weld.This paper describes a way to improve the weld quality through suppressing the porosity formation and restraining the growth of columnar grains with weaving-beam laser welding. A beam weaving system is set up to perform bead-on-plate welding with a 3kW CO2 laser. The influence of beam-weaving laser welding on reduction of nitrogen and argon porosity is investigated with low carbon steel. The experimental results indicate that beam-weaving laser welding can remarkably reduce N2 porosity with weaving frequency increasing, and porosity can be eliminated when weaving amplitude is only 0.5mm. Beam-weaving laser welding can also effectively reduce Ar porosity. The Ar porosity in the weld metal is decreased with increasing weaving frequency and amplitude.A kind of ultra-fine grained steel is used as base metal to study the influence of beam-weaving laser welding on the growth of columnar grains and mechanical properties of weld metal. The experimental results show that beam weaving with appropriate amplitude and...