MACROSTRUCTURAL COMPARISON OF GTAW (COLD WIRE) WELDING WITH CONTINUOUS AND DYNAMIC FEEDING IN STRUCTURAL STEEL

Abstract

The GTAW (Gas Tungsten Arc Welding) process stands out for its high metallurgical quality and precise control of heat input. With advancements in filler metal feeding systems, variations such as continuous feeding (C-GTAW) and dynamic feeding (GTAW-DWF – Dynamic Wire Feed) have emerged, the latter characterized by controlled and variable wire feeding. This study is based on the work of Neves (2022), which analyzed the influence of dynamic feeding frequency in the automated GTAW process, highlighting relevant differences between continuous and dynamic feeding modes. In this context, the present study presents a technical comparison between both processes, focusing on the macrostructural analysis of the fusion zone and the heat-affected zone. Aspects such as bead geometry, penetration, dilution, and process stability are evaluated. The results indicate that the GTAW-DWF process provides better geometric control, improved heat input control, and enhanced weld bead uniformity.