Resumo:
This work has the aim to analyse and optimise the influence of welding parameters on
the geometric characteristics and production of a weld bead applied in a Flux Cored Arc
Welding – FCAW- process. The process parameters investigated were welding voltage, wire
feed rate, nozzle-to-plate distance, shielding gas, torch angle, and welding speed. As
responses the penetration, convexity weld bead index and dilution were evaluated as the main
geometric characteristics and the deposition rate and efficiency of the welding as production
characteristics of the process. For this purpose statistical techniques were used to design the
experiments runs and process the analysis. In the first phase, a Fractional Factorial was
designed to select the most significant parameters influencing the process and in the second
phase, a Full Factorial Design followed by a Response Surface Methodology in order to
delineate the mathematical models and the influence of the main parameters on the response
of the process. The results showed that wire feed rate had the most significant effect in the
responses, followed by the welding voltage and the nozzle-to-plate distance. The welding
speed was, among the parameters assessed, the least significative.
