1. Introduction
GTAW (Gas Tungsten Arc Welding, also known as TIG – Tungsten Inert Gas) is recognized for its high weld quality and precision, and is widely used in applications that require high thermal control and metallurgical integrity (Dutra, 2023). Despite its advantages, one of the main limitations of the conventional GTAW process is the low deposition rate when compared to processes such as GMAW (Gás Metal Arc Welding), which motivates the development of variants that combine the process quality with greater productivity (Da Cunha, dos Santos and Voigt, 2022). Among these innovations is the concept of dynamic wire feeding (TIG AD), in which the filler material is reciprocally introduced into the molten pool, resulting in improved arc stability and metal transfer efficiency (Silva, 2016)(Fronius, 2024)(EWM, 2018)(TipTIG, 2016). This approach makes it possible to combine the intrinsic termal control of the TIG process with an increase of the deposition rate (Pigozzo et al., 2022). It is particularly promising for weld overlaying critical components. The application of orbital welding, as studied by Paes (2016), introduces new welding techniques to increase productivity for pipe welding in the oil and gas sector, demonstrating significant gains in welding speed and penetration.
Among the technological variants of the process, the TOPTIG method stands out, which integrates dynamic wire feeding at a reduced angle close to the tungsten electrode, promoting greater melting efficiency and puddle control (Silva, 2020). Studies carried out by Pigozzo (2024) investigated the advantages of dynamic feeding in the TIG process with a reduced insertion angle, focusing mainly on the metal transfer and their influence on the stability, geometry, and microstructure of the bead. Also in this study, the author developed a procedure synchronizing the moment when the wire makes contact with the weld pool to the elevation of the current until the droplet has separated from the wire. This approach allowed for lower current to be used to maintain the weld pool until the next pulse is administered, possibly reducing overlay material dilution (Pigozzo, Silva and Viviani, 2024).
These improvements are particularly relevant for surface cladding applications with high-performance alloys, such as Inconel 625 (NiCrMo-3), in which controlling the heat input and minimizing dilution are critical factors for ensuring resistance to corrosion and wear in aggressive environments(Riffel et al., 2020).
Continuing previous researches, this work aims to deepen the analysis of metal transfer mechanisms and their effects on the microstructure and stability of the process, with a focus on the application of dynamic wire feeding for cladding on low alloy steel pipes with Inconel 625.
In this context, comparative tests were carried out between three different conditions: constant current with conventional wire feed (CWF-GTAW), constant current with dynamic wire feed (DWF-GTAW) and synchronized current with dynamic wire feed (SWF-GTAW). Thus, this study aims to provide technical support for the selection and optimization of GTAW cladding processes with dynamic wire feeding, contributing to the development of industrial solutions, aligning technological and operational innovation.
Keyword 1: Dynamic Wire Feeding Keyword 2: Overlay Welding Keyword 3: GTAW Keyword 4: Ni-Based Alloy Welding
Referência:
BATISTA, F; ROESLER, E. M.; PIGOZZO, I. O.; VIVIANI, A. B.; SILVA, R. H. G.. Evaluation of the impact of conventional, dynamic and synchronized wire feeding strategies on GTAW welding. Rio Pipeline & Logistics, 2025.