Influence of the CO2 content on operational performance of short-circuit GMAW

Liskévych, Olga; Scotti, Américo

doi:10.1007/s40194-014-0196-x

Cited by 19 publications

(5 citation statements)

References 7 publications

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“…where σ tsc is the standard deviation of the average short-circuit time, σ tarcing is the standard deviation of the average arc burning time, t sc is the average short-circuit time, and t arcing is the average arc burning time [23,35]. Furthermore, the IVsc regularity index takes into account both average and standard deviation values so that a lower IVsc value indicates a more regular transition, that is, a more stable metal transfer [40][41][42].…”

Section: Methodsmentioning

confidence: 99%

Effects of Contaminations on Electric Arc Behavior and Occurrence of Defects in Wire Arc Additive Manufacturing of 316L-Si Stainless Steel

Souto,

Lima,

Castro

et al. 2024

Metals

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Additive Manufacturing is a manufacturing process that consists of obtaining a three-dimensional object from the deposition of material layer by layer, unlike conventional subtractive manufacturing methods. Wire Arc Additive Manufacturing stands out for its high productivity among the Additive Manufacturing technologies for manufacturing metal parts. On the other hand, the excessive heat input promotes increased residual stress levels and the occurrence of defects, such as pores, voids, a lack of fusion, and delamination. These defects result in abnormalities during the process, such as disturbances in electrical responses. Therefore, process monitoring and the detection of defects and failures in manufactured items are of fundamental importance to ensure product quality and certify the high productivity characteristic of this process. Thus, this work aimed to characterize the effects of different contaminations on the electric arc behavior of the Wire Arc Additive Manufacturing process and the occurrence of microscopic defects in thin walls manufactured by this process. To investigate the presence of defects in the metal preforms, experimental conditions were used to promote the appearance of defects, such as the insertion of contaminants. To accomplish the electric arc behavior analysis, voltage and current temporal data were represented through histograms and cyclograms, and the arc stability was assessed based on the Vilarinho index for a short circuit. Effectively, the introduction of contaminants caused electric arc disturbances that led to the appearance of manufacturing defects, such as inclusions and porosities, observed through metallographic characterization. The results confirm that the introduction of contaminations could be identified early in the Wire Arc Additive Manufacturing process through electric arc data analysis.

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Section: Methodsmentioning

confidence: 99%

Effects of Contaminations on Electric Arc Behavior and Occurrence of Defects in Wire Arc Additive Manufacturing of 316L-Si Stainless Steel

Souto,

Lima,

Castro

et al. 2024

Metals

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“…A Figura 5a mostra consistência na comparação visual, mas havendo rejeição da hipótese nula. Como sabido [19], CO2 puro como gás de proteção demanda maior tensão para se manter um arco de mesmo comprimento do que uma mistura de CO2 com argônio. Assim, esse resultado pode ser explicado pela diminuição do comprimento do arco (proporcionado pela troca de gás para CO2) e que resultou em um comprimento de arco muito pequeno levando a instabilidades na transferência metálica e maiores picos de reignição.…”

Section: Distribuição Dos Picos De Tensão De Reignição De Arco Para Munclassified

Uma Metodologia para Análise da Distribuição de Contagem dos Picos de Tensão de Reignição para Avaliação da Estabilidade do Processo GMAW Curto-Circuito

et al. 2019

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Resumo A estabilidade do arco tem sido estudada através de análises estatísticas obtidas dos sinais de tensão de arco e corrente de soldagem. Histogramas e cálculo de estatísticas dos parâmetros tempo de arco aberto e tempo de curto circuito são meios de avaliação da estabilidade dos processos de soldagem. Contudo, estudos relacionados aos picos de tensão de reignição do arco elétrico ainda são pouco explorados. Desta forma, este trabalho apresenta uma metodologia de avaliação da distribuição de picos de reignição do arco do processo Gas Metal Arc Welding por curto-circuito (GMAW-CC). Cordões de solda depositados em chapa plana, variando o gás, foram executados a fim de produzir diferentes distribuições de picos de reignição. O teste qui-quadrado foi aplicado para avaliar a distribuição de frequências observadas de picos de tensão e compará-la com a distribuição hipotética. Um cordão padrão foi comparado com sua repetição e testada a hipótese de distribuições iguais. Os resultados mostraram que existem distribuições estatisticamente iguais de picos de tensão entre cordões de solda. Concluiu-se que a metodologia proposta permitiu o estudo da distribuição de picos de reignição. Também foi demonstrada haver potencialmente uma outra forma de avaliar a estabilidade de arcos em soldagem GMAW-CC, através do teste χ2.

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“…Liskevych and Scotti [6] investigated the effect of the CO 2 content in Ar-based shielding gas on the operational performance of short-circuit GMAW. Their results showed that increasing CO 2 content in the shielding gas adversely affected the metal transfer regularity and led to excessive spatter generation and uneven bead appearance.…”

Section: Introductionmentioning

confidence: 99%

Influence of shielding gas on the mechanical and metallurgical properties of DP-GMA-welded 5083-H321 aluminum alloy

Koushki

Goodarzi

Paidar

2016

Int J Miner Metall Mater

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In the present research, 6-mm-thick 5083-H321 aluminum alloy was joined by the double-pulsed gas metal arc welding (DP-GMAW) process. The objective was to investigate the influence of the shielding gas composition on the microstructure and properties of GMA welds. A macrostructural study indicated that the addition of nitrogen and oxygen to the argon shielding gas resulted in better weld penetration. Furthermore, the tensile strength and bending strength of the welds were improved when oxygen and nitrogen (at concentrations as high as approximately 0.1vol%) were added to the shielding gas; however, these properties were adversely affected when the oxygen and nitrogen contents were increased further. This behavior was attributed to the formation of excessive brown and black oxide films on the bead surface, the formation of intermetallic compounds in the weld metal, and the formation of thicker oxide layers on the bead surface with increasing nitrogen and oxygen contents in the argon-based shielding gas. Analysis by energy-dispersive X-ray spectroscopy revealed that most of these compounds are nitrides or oxides.

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Influence of the CO2 content on operational performance of short-circuit GMAW

Cited by 19 publications

References 7 publications

Effects of Contaminations on Electric Arc Behavior and Occurrence of Defects in Wire Arc Additive Manufacturing of 316L-Si Stainless Steel

Effects of Contaminations on Electric Arc Behavior and Occurrence of Defects in Wire Arc Additive Manufacturing of 316L-Si Stainless Steel

Uma Metodologia para Análise da Distribuição de Contagem dos Picos de Tensão de Reignição para Avaliação da Estabilidade do Processo GMAW Curto-Circuito

Influence of shielding gas on the mechanical and metallurgical properties of DP-GMA-welded 5083-H321 aluminum alloy

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