Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
GTAW COLD WIRE FEED: TRANSITIONAL TRANSFER MODE CHARACTERIZATION
Submission Author:
Anna Louise Voigt , SC
Co-Authors:
Anna Louise Voigt, Tiago Vieira da Cunha, Carlos Enrique Niño
Presenter: Anna Louise Voigt
doi://10.26678/ABCM.COBEM2021.COB2021-0949
Abstract
Regarding the metallic transfer of cold wire applied to the GTAW process, there are basically two transfer modes in the literature: intermittent drop and uninterrupted bridge. Considering an intermittent transfer situation, as the wire-feed speed increases, the droplet frequency is expected to increase until the wire end touches the molten pool, resulting in an uninterrupted bridging transfer. Using a welding current of 100 A, bead-on-plate tests were performed on AISI 304 sheets using a 1.0 mm diameter AWS ER 307Si wire. The wire feed speeds were varied from 0, 3 to 1.0 m/ min, moving from the intermittent drop transfer mode to the uninterrupted bridge condition (1.0 m/min). Through image acquisition and potential difference between wire and tungsten electrode, a transient transfer mode could be characterized, called an “intermittent bridge”. Furthermore, experimental tests of bead on plate were carried out in order to evaluate the influence of the different transfer modes on the weld beads surface aspects. It was observed that the transfer frequency increases as the wire feed speed increases, reaching the maximum point, where the metallic transfer mode starts to assume a transient behavior of intermittent bridge. During the transition, the frequency decreases until it reaches the condition of an uninterrupted bridge.
Keywords
TIG, Metal transfer, Intermittent Bridge, Cold wire, Intermittent Drop
