scholarly journals Formation of Particles in Welding Fume Plasmas: Numerical Modeling and Experiment

2019 ◽  
Vol 64 (5) ◽  
pp. 392
Author(s):  
V. I. Vishnyakov ◽  
S. A. Kiro ◽  
M. V. Oprya ◽  
O. D. Chursina ◽  
A. A. Ennan
Keyword(s):  
Numerical Modeling ◽  
Gas Metal Arc Welding ◽  
Welding Fume ◽  
Liquid Droplets ◽  
Breathing Zone ◽  
Shielding Gas ◽  
Gas Temperature ◽  
Gas Plasma ◽  
Metal Arc Welding ◽  
Primary Particles

Formation of particles in a fume plasma obtained from the gas metal arc welding is investigated by the numerical modeling of the plasma evolution. The model of welding fume plasma evolution includes the following processes: vapor emission from the arc zone and mixing with a shielding gas, plasma formation, nucleation, nucleus growth via the material condensation and coalescence, solidification of liquid droplets into primary particles, and coagulation of primary particles into inhalable particles in the breathing zone. The computed results are compared with experimental data on the specific surface area, chemical composition, and dependence of the particle sizes on the shielding gas temperature.

scholarly journals Influence of the CO2 Content in Shielding Gas on the Temperature of the Shielding Gas Nozzle during GMAW Welding

2020 ◽  
Vol 4 (4) ◽  
pp. 113
Author(s):  
Martin Lohse ◽  
Marcus Trautmann ◽  
Uwe Füssel ◽  
Sascha Rose
Keyword(s):  
Carrying Capacity ◽  
Gas Metal Arc Welding ◽  
Welding Current ◽  
Shielding Gases ◽  
Shielding Gas ◽  
Metal Arc Welding ◽  
Average Current ◽  
Gas Nozzle ◽  
Wire Feed ◽  
Gmaw Welding

Gas metal arc welding torches are commonly chosen based on their current-carrying capacity. It is known that the current-carrying capacity of welding torches under CO2 is usually higher than under argon dominated shielding gases. In this publication, the extent to which this can be attributed to the shielding gas dependent arc radiation is investigated. For this purpose, the influence of the shielding gas on the thermal load of the shielding gas nozzle of a GMAW torch was calorimetrically measured. These experiments were carried out for four different shielding gases (argon, CO2, and two argon/CO2 mixtures). The measurements were all performed at an average current of 300 A. The welding current was set by adjusting the wire feed rate or the voltage correction. For each case, a separate set of experiments was done. It is shown that the changed arc radiation resulting from the different shielding gases has an influence on the heat input into the gas nozzle, and thus into the torch. For the same shielding gas, this influence largely correlates with the welding voltage.

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 .

scholarly journals Visualisation and optimisation of shielding gas coverage during gas metal arc welding

2018 ◽  
Vol 255 ◽  
pp. 451-462 ◽  
Author(s):  
I. Bitharas ◽  
N.A. McPherson ◽  
W. McGhie ◽  
D. Roy ◽  
A.J. Moore
Keyword(s):  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Shielding Gas ◽  
Metal Arc Welding

SHIELDING GAS AND HEAT INPUT EFFECTS ON THE MECHANICAL AND METALLURGICAL CHARACTERIZATION OF GAS METAL ARC WELDING OF SUPER MARTENSITIC STAINLESS STEEL (12Cr5Ni2Mo) JOINTS

2016 ◽  
Vol 24 (05) ◽  
pp. 1750069
Author(s):  
T. PRABAKARAN ◽  
M. PRABHAKAR ◽  
P. SATHIYA
Keyword(s):  
Stainless Steel ◽  
Heat Input ◽  
Arc Welding ◽  
Martensitic Stainless Steel ◽  
Gas Metal Arc Welding ◽  
Microstructural Analysis ◽  
Tensile Tests ◽  
Shielding Gas ◽  
Metal Arc Welding ◽  
Super Martensitic Stainless Steel

This paper deals with the effects of shielding gas mixtures (100% CO2, 100% Ar and 80 % Ar [Formula: see text] 20% CO[Formula: see text] and heat input (3.00, 3.65 and 4.33[Formula: see text]kJ/mm) on the mechanical and metallurgical characteristics of AISI 410[Formula: see text]S (American Iron and Steel Institute) super martensitic stainless steel (SMSS) by gas metal arc welding (GMAW) process. AISI 410[Formula: see text]S SMSS with 1.2[Formula: see text]mm diameter of a 410 filler wire was used in this study. A detailed microstructural analysis of the weld region as well as the mechanical properties (impact, microhardness and tensile tests at room temperature and 800[Formula: see text]C) was carried out. The tensile and impact fracture surfaces were further analyzed through scanning electron microscope (SEM). 100% Ar shielded welds have a higher amount of [Formula: see text] ferrite content and due to this fact the tensile strength of the joints is superior to the other two shielded welds.

Study the Shielding Gas Effect on the Metal Transfer and Weld Pool Dynamics in GMAW

2009 ◽  
Author(s):  
Z. H. Rao ◽  
J. Hu ◽  
S. M. Liao ◽  
H. L. Tsai
Keyword(s):  
Weld Pool ◽  
Gas Metal Arc Welding ◽  
Droplet Formation ◽  
Shielding Gas ◽  
Bead Width ◽  
Droplet Shape ◽  
Helium Content ◽  
Mixing Ratios ◽  
Metal Arc Welding ◽  
Dependent Processes

This paper studied the influences of shielding gas compositions on the transport phenomena in the metal domain during gas metal arc welding (GMAW). A comprehensive model was developed to simulate the time-dependent processes of the electrode melting; the droplet formation, detachment, transfer and impingement onto the workpiece; the weld pool dynamics and bead formation and their transient coupling with the arc plasma. The transient melt-flow velocity and temperature distributions in the metal shielded by pure argon and argon-helium mixtures with various mixing ratios are presented. It is predicted that the increase of helium content and the resulting arc contraction induce an upward electromagnetic force at the bottom of the droplet to sustain the droplet at the electrode tip. As a result, the more oblate droplet and the longer droplet formation time are produced. The behaviors of the predicted droplet shape and detachment frequency are in agreement with the published results. It is also found that, under the identical energy input, the weld bead has a shallower penetration depth and broader bead width when helium content increases.

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