Effect of shielding gas on the metal transfer and weld morphology in pulsed current MAG welding of carbon steel

2018 ◽  
Vol 262 ◽  
pp. 382-391 ◽  
Author(s):  
Yong Zhao ◽  
Xiaojian Shi ◽  
Keng Yan ◽  
Guoqiang Wang ◽  
Zhanjun Jia ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Metal Transfer ◽  
Mag Welding ◽  
Pulsed Current ◽  
Shielding Gas

scholarly journals Effects of active gases on droplet transfer and weld morphology in pulsed-current NG-GMAW of mild steel

2020 ◽  
Author(s):  
Guoqiang Liu ◽  
Xinhua Tang ◽  
Qi Xu ◽  
Fenggui Lu ◽  
Haichao Cui
Keyword(s):  
Mild Steel ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Metal Transfer ◽  
Pulsed Current ◽  
Shielding Gas ◽  
Droplet Transfer ◽  
Spray Transfer ◽  
Pure Argon

Abstract Small amount of active gases CO 2 and O 2 were added into pure argon inert shielding gas to improve the weld formation of pulsed-current narrow-gap gas metal arc welding (NG-GMAW) of mild steel. Their effects on droplet transfer and arc behavior were investigated. A high-speed visual sensing system was utilized to observe the metal transfer process and arc morphology. When the proportion of CO 2 , being added into the pure argon shielding gas, changes from 5% to 5%, the metal transfer mode changes from pulsed spray streaming transfer to pulsed projected spray transfer, while it remains the pulsed spray streaming transfer when 2% to 10% O 2 is added. Both CO 2 and O 2 are favorable to stabilizing arc and welding process. O 2 is even more effective than CO 2 . However, O 2 is more likely to cause the inclusion defects in the weld, while CO 2 can improve the weld appearance in some sense. The weld surface concavity, which is sensitive to the formation of lack-of-fusion defect in NG-GMAW, is greatly influenced by the addition of active gas, but the weld width and weld penetration almost keep constant.

scholarly journals Influence of Metal Transfer Stability and Shielding Gas Composition on CO and CO2 Emissions during Short-circuiting MIG/MAG Welding

2016 ◽  
Vol 21 (3) ◽  
pp. 253-268
Author(s):  
Valter Alves de Meneses ◽  
Valdemar Silva Leal ◽  
Américo Scotti
Keyword(s):  
Short Circuit ◽  
Metal Transfer ◽  
Mag Welding ◽  
Gas Composition ◽  
Breathing Zone ◽  
Shielding Gas ◽  
Residual Concentration ◽  
Average Current ◽  
High Level ◽  
Welding Processes

Abstract: Several studies have demonstrated the influence of parameters and shielding gas on metal transfer stability or on the generation of fumes in MIG/MAG welding, but little or nothing has been discussed regarding the emission of toxic and asphyxiating gases, particularly as it pertains to parameterization of the process. The purpose of this study was to analyze and evaluate the effect of manufacturing aspects of welding processes (short-circuit metal transfer stability and shielding gas composition) on the gas emission levels during MIG/MAG welding (occupational health and environmental aspects). Using mixtures of Argon with CO2 and O2 and maintaining the same average current and the same weld bead volume, short-circuit welding was performed with carbon steel welding wire in open (welder’s breathing zone) and confined environments. The welding voltage was adjusted to gradually vary the transfer stability. It was found that the richer the composition of the shielding gas is in CO2, the more CO and CO2 are generated by the arc. However, unlike fume emission, voltage and transfer stability had no effect on the generation of these gases. It was also found that despite the large quantity of CO and CO2 emitted by the arc, especially when using pure CO2 shielding gas, there was no high level residual concentration of CO and CO2 in or near the worker’s breathing zone, even in confined work cells.

UNIFLUX 70

Alloy Digest ◽  
1978 ◽  
Vol 27 (9) ◽  
Keyword(s):  
Carbon Dioxide ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Carbon Steel ◽  
Physical Properties ◽  
Heat Treating ◽  
Shielding Gas ◽  
Electrode Wire ◽  
Welding Electrode

Abstract UNIFLUX 70 is a continuous flux-cored welding electrode (wire) for welding in carbon dioxide shielding gas in the flat groove and horizontal fillet positions. It is used widely in shipbuilding and other fabricating industries to weld carbon steel and provides around 82,000 psi tensile strength and around 50 foot-pounds Charpy V-notch impact at 0 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: CS-74. Producer or source: Unicore Inc., United Nuclear Corporation.

FRACTAL ANALYSIS OF METAL TRANSFER IN MIG∕MAG WELDING

2009 ◽  
Author(s):  
A. P. Vieira ◽  
H. H. M. Vasconcelos ◽  
L. L. Gonçalves ◽  
H. C. de Miranda ◽  
Donald O. Thompson ◽  
...  
Keyword(s):  
Fractal Analysis ◽  
Metal Transfer ◽  
Mag Welding

Research on the Use of Robotized Tandem MAG Welding in Steel Plates Destined for the Manufacture of Pipelines

2016 ◽  
Vol 1138 ◽  
pp. 133-138 ◽  
Author(s):  
Daniela Maria Iovanas ◽  
Cosmin Toma ◽  
Radu Iovanas
Keyword(s):  
Welded Joints ◽  
Steel Plates ◽  
Mag Welding ◽  
Welding Parameters ◽  
Filler Materials ◽  
Shielding Gas ◽  
Complete Replacement ◽  
Positive Effects ◽  
Welding Head ◽  
Welding Procedure

The performed research focuses on the complete replacement of the pipeline manufacturing process consisting in welding on SAW+MIG / MAG generators with the robotized Tandem MIG / MAG welding procedure, with low energy consumption.The Tandem MAG procedure was experimented on X52 MS steel plates destined for the manufacture of pipelines, measuring 400x150x12 mm, with Y-joints (30o).The welded joints were executed horizontally and unilaterally, with flux bed support, 3 welding seams, using for filler material two wires of the same quality, EN ISO 14341: G 42 4 M G3Si1 (Filcord C), measuring 1.2 mm in diameter, and shielding gas EN ISO 14175 (CORGON 18).The entire technological welding process was carried out in fully robotized, laboratory conditions, using the QIROX -315 welding robot, fitted with Tandem MIG/MAG welding equipment, type QUINTO-GLC 603.The welding seams were executed with the same Tandem MAG welding head, with two wires, taking advantage of the possibility to rotate the welding head so as to obtain welding seams with the wires either positioned one after the other (tandem), or transversally (perpendicular to the welding direction), obtaining, by correlation with the welding speed, optimal linear energies, implicitly, seams of various widths and penetrations.The results of the tests concerning the characterization of the obtained welded joints corresponded to the mechanical – metallographic tests, falling within the ranges provided by the applicable standards.The welding parameters used in the robotized Tandem MAG procedure may lead to remarkable advantages concerning the use of energy and filler metal. Thus, linear energies are about 40% - 45% smaller than in the case of the classical SAW+MIG / MAG process, with positive effects on the mechanical and metallographic characteristics of the welded joints, leading to significant reductions in energy consumption. Furthermore, the use of filler materials (wire, shielding gas) decreases by 10% - 15% as compared to the classical SAW+MIG / MAG process, leading, implicitly, to lower costs.As a consequence of the obtained results, MAG Tandem welding procedure may become an alternative to SAW submerged arc welding and combined SAW and MIG / MAG welding and a classical reference method for the manufacture of pipelines

Effect of Shielding Gas Mixture on Gas Metal Arc Welding (GMAW) of Low Carbon Steel (LR Grade A)

2016 ◽  
Vol 705 ◽  
pp. 250-254 ◽  
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
M. Wirawan Pu ◽  
Fandi Alfarizi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Steel ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Shielding Gas ◽  
Weld Metals ◽  
Metal Arc Welding

The aimed of this research is to determine the feasibility and effect of the mixture of the shielding gas in the physical and mechanical properties. Low carbon steel LR grade A in a thickness 12 mm were joined in butt joint types using GMAW (Gas Metal Arc Welding) with groove’s gap 5 mm and groove angle’s 400 with variation of shielding gas composition. The composition of shielding gas that used were 100% Ar, 100 % CO2 and 50% Ar + 50 % CO2. The measured of mechanical properties with regard to strength, hardness and toughness using, tensile test, bending test, Vickers hardness Test, and Charpy impact test respectively. The physical properties examined with optical microscope. Results show that tensile strength of welding metals are higher than raw materials. Welds metal with mixing Ar + CO shielding gas has the highest tensile strength. Hardness of weld metals with the shielding gas 100% Ar, 100 % CO2 and 50% Ar + 50 % CO2 are 244.9; 209.4; and 209.4 VHN respectively. The temperature of Charpy test was varied to find the transition temperature of the materials. The temperature that used were –60°C, -40°C, -20°C, 0°C, 20°C , and room temperature. Weld metals with various shielding gas have similar trends of toughness flux that was corellated with the microstructure of weld .

Effect of shielding gas and transfer mode on the application of 625 alloy in carbon steel

2011 ◽  
Vol 25 (12) ◽  
pp. 903-909 ◽  
Author(s):  
Carlos Eduardo Iconomos Baixo ◽  
Jair Carlos Dutra
Keyword(s):  
Carbon Steel ◽  
Shielding Gas ◽  
Transfer Mode
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