Reduction of the welding fume emission rate of gas-shielded cored wires by the MAG pulse welding process variant

Abstract

The aim of the study is to reduce welding fume emissions from flux-cored wires using pulse technology. Low-alloyed cored wires of the rutile, basic, and metal powder types were selected for this purpose. The analyses were carried out on a DIN EN ISO 15011–1:2010 compliant test rig. In addition, high-speed recordings of the material transition mode and metallographic cross-sections were made to interpret the results. Using characteristic curves developed in pre-tests, the influence of pulse time, pulse frequency, and trigger current on the welding fume emission potential of the rutile cored wire was first determined. Short pulses, medium trigger current, and medium pulse frequency were found to have a positive influence on the emission rate.Finally, the welding fume emissions of the conventional characteristic are compared with the emission-optimized pulse characteristic. For all three filling types, emission reductions of up to 41% were found when using the pulse technology. When considering the ratio of fume generated to the mass of the weld metal produced, with the associated greatly reduced economy of the process, it became apparent that pulse welding is not suitable for welding cored wires without restrictions.In summary, the suitability of pulse GMAW technology for reducing welding fume emissions can also be confirmed for flux-cored wires.