Estudo da viabilidade de alteração de processo de soldagem de FCAW para GMAW para possível redução de custos em indústrias de estruturas metálicas

Abstract

The welding process in the metal structures industry is one of the most important, as it is fundamental for the safety of the structures and for the final cost. Because it is a processes with several alternatives in the market and has many variables involved companies not always choose the best methodology for each application. The most used processes are GMAW and FCAW, because of their high productivity, easy deployment of equipment at the company, among other factors. The industry in wich this research was carried out, uses the FCAW process for welding overlapping joints of metallic pillars made from ASTM A572GR42 steel. In order to analyze the feasibility of changing the process, two alternative conditions were studied: welding with the solid wire ER70S-6 and CO2 as shield gás, using the short circuit transfer and welding with the same wire, but using the Ar + 4%CO2 as shield gas. After conducting some tests and taking some prices of the consumables, it was found that even the FCAW process uses a more expensive wire, it still more economically viable for this application, since the gas used in the condition that allowed a competitive speed of welding is much more expensive than the CO2.