A spatter reduction process in pulsed CO2 gas shielded arc welding has been studied by focusing on the rectangular pulsed wave form control and the chemical compositions of welding wire.
The spatter in pulsed CO2 arc welding is mainly caused by the reason that a molten droplet on the welding wire is blown off by arc repulsion force at the peak current duration. The droplet blow off depends on a up-slope of peak current, and the rapid-up-slope induces the increase of a large spatter.
Furthermore, the droplet blow off is influenced by the deoxidizing elements. The increase of deoxidizing elements (Al, Ti, Si) in the chemical composition of welding wire greatly reduces the spatter from molten pool and droplet necking. However, surplus content of deoxidizing elements spoils the stability of 1 pulse 1 drop transfer, and a molten droplet is blown off at the peak current duration.
With the optimization in wave form control and content of deoxidizing elements in the wire, the amount of spatter decreases to 1/6 in comparizon of that the conventional CO2 arc welding.
