Avaliação do Uso do Tecimento na Soldagem a Arco Submerso

Abstract

Este é um artigo publicado em acesso aberto (Open Access) sob a licença Creative Commons Attribution Non-Commercial, que permite uso, distribuição e reprodução em qualquer meio, sem restrições desde que sem fins comerciais e que o trabalho original seja corretamente citado.Recebido: 08 Dez., 2017 Aceito: 04 Abr., 2018 E-mails: t.cunha@ufsc.br (TVC), hormeu@ifsc.edu.br (HOR)Resumo: Apesar de muito comum em diversos processos de soldagem, não se encontra nas aplicações industriais, tampouco na literatura especializada, qualquer referência ao uso do movimento de oscilação transversal do eletrodo na soldagem a arco submerso. Em vista disso, neste trabalho foi realizada uma investigação quanto ao emprego da técnica de tecimento no processo SAW. Para tanto, foram realizados ensaios de soldagem com amplitudes de tecimento (triangular) entre 0 e 30 mm para três níveis diferentes de energia de soldagem e avaliadas a penetração, largura, reforço, área do reforço e da área fundida dos cordões de solda obtidos, além da estabilidade do processo. Como resultado, verificou-se que, além de perfeitamente viável, a aplicação da citada técnica no processo SAW resultou em maior eficiência de fusão no processo, sem, entretanto, acarretar em instabilidades no processo ou problemas relacionados à inclusão de escória.Palavras-chave: Oscilação transversal; SAW; Eficiência de fusão; Morfologia dos cordões. Evaluation of Oscillation Movement in Submerged Arc WeldingAbstract: Although very common in many welding processes, there is no reference in the industrial applications, nor in the specialized literature, to the use of transverse oscillation movement of the electrode in submerged arc welding. In view of this, in this work an investigation was made regarding the use of the weaving technique in the SAW process. Therefore, welding tests with amplitudes of weaving (triangular) between 0 and 30 mm were carried out for three different levels of welding energy and the penetration, width, reinforcement, reinforcement area and melt area of the weld beads obtained were evaluated, besides the stability of the process. As a result, it was found that, in addition to being perfectly feasible, the application of cited technique in the SAW resulted in higher process melt efficiency, without, however, process instabilities or problems related to the inclusion of slag. Key-words:Transverse oscillation; SAW; Fusion efficiency; Weld bead morphology. IntroduçãoO emprego do processo de soldagem a arco submerso (SAW) na construção pesada como em estaleiros, mineradoras, siderúrgicas, fábricas de perfis e estruturas metálicas é algo recorrente. Isto se deve, sobretudo, a capacidade deste processo em atender a uma demanda comum destas empresas, que consiste na união de chapas de maior espessura.Uma característica marcante do processo SAW está no seu elevado rendimento de deposição e de fusão. Isto se deve, fundamentalmente, à inexistência de perdas de material por projeções ou respingos e à menor perda de calor para o meio, o que faz com que o processo aprese...

Universal Submerged Arc Welding (USAW): High Weaving Amplitudes as a New Possibilities to Saw Process

“…With this, voltaic arcs established at higher welding currents (higher weaving amplitudes) naturally have a more considerable ability to promote the fusion of the base metal. Similar results were obtained by Cunha and Riberio [11], who observed an increase in the molten area with the increase of the weaving amplitude using the same welding energy.…”

“…In both situations, the authors attributed the discontinuities to the lack of material deposition. On the other hand, when Cunha and Ribeiro [11] increased the welding energy by reducing the welding speed (Vx), they did not obtain a weld bead of satisfactory geometry, reinforcing the hypothesis that there is a minimum amount of material to be deposited. Thus, the mass of material deposited on the weld beads was quanti ed for each weaving amplitude used in the Group I tests (Table 1).…”

“…The authors observed an increase in dilution with the introduction of transverse oscillation, resulting in values close to 70% for the higher welding energy condition in contrast to the 65% dilution for welding without weaving. However, despite the increase in dilution, Cunha and Ribeiro [11] observed that, for the 20 mm amplitude, the molten area increased up to 78% relative to the weld bead without weaving, indicating a higher melting yield of the process with the use of weaving. However, for the 30 mm weaving amplitude condition, the material feed rate used by the authors did not prove su cient to obtain a discontinuity-free weld bead, given that it presented a lacking deposition.…”

“…However, except for two recent studies [10][11] published by the research group of which the authors of the present study are part, there is no reference in the specialized literature or the productive sector regarding the application of the weaving technique in the SAW process. [11] evaluated the weaving technique in the SAW process by promoting the transverse movement of the workpiece with weaving amplitudes from 0 mm to 30 mm, while the welding torch remained static. The authors kept the oscillation frequency at 1 Hz and performed experimental tests with three different welding energy levels.…”

“…Still regarding the GMAW process with weaving, the literature brings a considerable number of studies that address its effects on the weld bead. However, except for two recent studies [10][11] published by the research group of which the authors of the present study are part, there is no reference in the specialized literature or the productive sector regarding the application of the weaving technique in the SAW process. [11] evaluated the weaving technique in the SAW process by promoting the transverse movement of the workpiece with weaving amplitudes from 0 mm to 30 mm, while the welding torch remained static.…”