Estudo comparativo dos processos de soldagem GMAW, FCAW e HLAW na união de peças ferroviárias

Abstract

The productivity of an industry represents its competitive advantage in relation to the market and its own revenue. New materials and technologies applied in manufacturing processes are always on focus of studies on industrial segment. In recent years, the automotive and naval industries have maintained their focus on researching welding processes using lasers, looking for increase welding speeds. Therefore, this Automotive Engineering course completion project aimed to execute comparative tests between the GMAW, FCAW and HLAW welding processes, as well as the 30° and 45° bevel geometries of a welded joint of a railway carriage beam. This joint features a high thickness weathering steel plate, and currently requires a multipass welding process, which is unproductive and has a high heat input. These tests focused on controlling the heat input of the joint, but mainly on gaining productivity, by reducing time, the number of welding passes and increasing the welding speed, presenting its operational and implementation costs. The work methodology stages included the definition of test specimens, determination of welding process parameters and execution of welding procedures stages. Afterwards, samples were prepared for tensile, lateral bending, microhardness, micrography and macrography tests. The results obtained, showed that GMAW and FCAW processes were approved in tensile tests. It also showed that HLAW process was the most productive, with greatest reduction in operational costs, however, the most expensive to implement. Comparing the joint geometries, current 45° bevel proved to be excessive and unnecessary and 30° bevel responded well to the process. [resumo fornecido pelo autor]