scholarly journals Silicate Island Formation in Gas Metal Arc Welding

2021 ◽  
Vol 100 (01) ◽  
pp. 13-26
Author(s):  
RICHARD DERRIEN ◽  
◽  
ETHAN MICHAEL SULLIVAN ◽  
STEPHEN LIU ◽  
ELODIE MOINE ◽  
...  
Keyword(s):  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Formation Rate ◽  
Welding Process ◽  
Electromagnetic Levitation ◽  
Welding Parameters ◽  
Silicate Formation ◽  
Metal Arc Welding ◽  
Initial Melting

Because formation of silicate islands during gas metal arc welding is undesirable due to decreased productivity and decreased quality of welds, it is important to understand the mechanism of the formation of these silicate islands to mitigate their presence in the weld. The effects of welding parameters on the silicate formation rate were studied. Results showed that the applied voltage and oxidizing potential of the shielding gas were the parameters that most strongly influenced the amount of silicates formed on the surface of the weld bead. High-speed video was used to observe the formation of silicate islands during the welding process, which showed that the silicates were present at each stage of the welding process, including the initial melting of the wire electrode, and grew by coalescence. A flow pattern of the silicate islands was also proposed based on video analysis. An electromagnetic levitation system was used to study the growth kinetics of the silicate islands. Silicate coverage rate was found to increase with increasing oxidizing time, increasing oxidizing potential of the atmosphere, and increasing content of alloying elements except for Ti.

Effect of the Heat Input in the Transformation of Retained Austenite in Advanced Steels of Transformation Induced Plasticity (TRIP) Welded with Gas Metal Arc Welding

2013 ◽  
Vol 339 ◽  
pp. 700-705 ◽  
Author(s):  
Victor Lopez ◽  
Arturo Reyes ◽  
Patricia Zambrano
Keyword(s):  
Heat Input ◽  
Arc Welding ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Residual Austenite ◽  
Welding Parameters ◽  
Transformation Induced Plasticity ◽  
Metal Arc Welding

The effect of heat input on the transformation of retained austenite steels transformation induced plasticity (TRIP) was investigated in the heat affected zone (HAZ) of the Gas Metal Arc Welding GMAW process. The determination of retained austenite of the HAZ is important in optimizing the welding parameters when welding TRIP steels, because this will greatly influence the mechanical properties of the welding joint due to the transformation of residual austenite into martensite due to work hardening. Coupons were welded with high and low heat input for investigating the austenite transformation of the base metal due to heat applied by the welding process and was evaluated by optical microscopy and the method of X-Ray Diffraction (XRD). Data analyzed shows that the volume fraction of retained austenite in the HAZ increases with the heat input applied by the welding process, being greater as the heat input increase and decrease the cooling rate, this due to variation in the travel speed of the weld path.

An Evaluation System of Pulsed GMAW Process

2013 ◽  
Vol 483 ◽  
pp. 599-602
Author(s):  
Ying Gao ◽  
Jing Hua Han ◽  
Li Yan Lou ◽  
Huan Li
Keyword(s):  
Arc Welding ◽  
Evaluation System ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Electric Signal ◽  
Characteristic Parameters ◽  
Display Module ◽  
Metal Arc Welding ◽  
Labview Platform

A process evaluation system for pulsed gas metal arc welding (GMAW-P) based on the LabVIEW platform has been developed. This system is comprised of two modules, a simultaneous display module and a data analysis module. Using these modules, the system can not only provide a comprehensive direct viewing display of the welding electric signal and high speed camera photo, but also can analyze the characteristic parameters of the welding process. The results show that the system works properly.

Arc Interruptions in Tandem Pulsed Gas Metal Arc Welding

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Ruham Pablo Reis ◽  
Daniel Souza ◽  
Demostenes Ferreira Filho
Keyword(s):  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Electrical Current ◽  
Gas Tungsten Arc ◽  
Metal Arc Welding ◽  
Two Factors ◽  
Single Arc ◽  
Mean Current

In addition to electromagnetic attraction between the arcs in Tandem Pulsed gas metal arc welding (GMAW), arc interruptions, mostly in the trailing arc at low mean current levels, may also occur, which is a phenomenon not widely discussed in the welding field. These arc interruptions must be avoided, since they also represent interruptions in metal fusion and deposition during the welding process, leading to lack of fusion/penetration and/or deposition flaws, adding cost for repairing operations. To improve the understanding on arc interruptions in Tandem Pulsed GMAW and how the current pulsing synchronism between the arcs relates to this phenomenon, this work proposes to evaluate the influence of parameters of adjacent arcs (Tandem Pulsed GMAW) and also of a single arc (GTAW—gas tungsten arc welding), but similarly subjected to magnetic deflection, on the occurrence of arc interruptions/extinctions. High-speed filming was used to help understand the interruption/extinction mechanism. In the case of Tandem Pulsed GMAW, the pulses of current of the leading and trailing arcs need to be almost-in-phase to prevent interruptions in the trailing arc. The distance of 10 mm between the adjacent arcs helped reduce the incidence of trailing arc interruptions, yet keeping a sound weld visual quality. In the case of GTAW, the higher the electrical current flowing through the arcs and the shorter their lengths, the more they resist to the extinction. The trailing arc interruptions in Tandem Pulsed GMAW seem to be determined by the deflection and heat in this arc, and their prevention can be achieved by a balance between these two factors, which is reached by synchronized pulsing currents.

Effect of Gas Metal Arc Welding Parameters on Mechanical Properties for Carbon Steel ASTM A285 Grade A

2011 ◽  
Vol 341-342 ◽  
pp. 16-20
Author(s):  
Mongkol Chaisri ◽  
Prachya Peasura
Keyword(s):  
Carbon Dioxide ◽  
Tensile Strength ◽  
Carbon Steel ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Welding Parameters ◽  
Shielding Gas ◽  
Metal Arc Welding ◽  
Arc Welding Process

The research was study the effect of gas metal arc welding process parameters on mechanical property. The specimen was carbon steel ASTM A285 grade A which thickness of 6 mm. The experiments with full factorial design. The factors used in this study are shielding gas and voltage. The welded specimens were tested by tensile strength testing and hardness testing according to ASME boiler and pressure vessel code section IX 2007. The result showed that both of shielding gas and voltage had interaction on tensile strength and hardness at 95% confidential (P value < 0.05). Factors affecting the tensile strength are the most carbon dioxide and 27 voltage were tensile strength 213.43 MPa. And hardness maximum of 170.60 HV can be used carbon dioxide and 24 voltage. This research can be used as data in the following appropriate parameters to gas metal arc welding process.

Modeling of Weld Dilution in Gas Metal Arc Welding Process Using Taguchi's Design of Experiments

2011 ◽  
Vol 110-116 ◽  
pp. 2963-2968 ◽  
Author(s):  
Masood Aghakhani ◽  
Ehsan Mehrdad ◽  
Ehsan Hayati ◽  
Maziar Mahdipour Jalilian ◽  
Arash Karbasian
Keyword(s):  
Mathematical Model ◽  
Arc Welding ◽  
Gas Flow ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Welding Parameters ◽  
Gas Flow Rate ◽  
Metal Arc Welding ◽  
Wire Feed ◽  
Plate Distance

Gas metal arc welding is a fusion welding process which has got wide applications in industry. In order to obtain a good quality weld, it is therefore, necessary to control the input welding parameters. In other words proper selection of input welding parameters in this process contribute to weld productivity. One of the important welding output parameters in this process is weld dilution affecting the quality and productivity of weldment. In this research paper using Taguchi method of design of experiments a mathematical model was developed using parameters such as, wire feed rate (W), welding voltage (V), nozzle-to-plate distance (N), welding speed (S) and gas flow rate (G) on weld dilution. After collecting data, signal-to-noise ratios (S/N) were calculated and used in order to obtain the optimum levels for every input parameter. Subsequently, using analysis of variance the significant coefficients for each input factor on the weld dilution were determined and validated. Finally a mathematical model based on regression analysis for predicting the weld dilution was obtained. Results show that wire feed rate (W),arc voltage (V) have increasing effect while Nozzle-to-plate distance (N) and welding speed (S) have decreasing effect on the dilution whereas gas Flow rate alone has almost no effect on dilution but its interaction with other parameters makes it quite significant in increasing the weld dilution

Contributions to the Environmental Impact of the Process of Welding Work in the Environment of Protective Gases

2016 ◽  
Vol 1138 ◽  
pp. 101-106
Author(s):  
Gheorghe Amza ◽  
Gabriel Iacobescu ◽  
Dan Florin Niţoi ◽  
Cătălin Gheorghe Amza ◽  
Zoia Apostolescu
Keyword(s):  
Environmental Impact ◽  
Chemical Reactions ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Working Environment ◽  
Welding Parameters ◽  
Metal Arc Welding ◽  
The Impact

Paper presents the main pollutants that appear Gas metal arc welding, the main chemical reactions take place in the melting bath where results the pollutants, determining the impact on the working environment by calculating the coefficient of pollution. The optimization of welding process gives a coefficient of minimum pollution and determines the influence of welding parameters of the system on the appearance of major pollutants elements.

scholarly journals Application of Cold Wire Gas Metal Arc Welding for Narrow Gap Welding (NGW) of High Strength Low Alloy Steel

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 335 ◽  
Author(s):  
Rafael Ribeiro ◽  
Paulo Assunção ◽  
Emanuel Dos Santos ◽  
Ademir Filho ◽  
Eduardo Braga ◽  
...  
Keyword(s):  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Parameters ◽  
Narrow Gap ◽  
Dynamic Features ◽  
Narrow Gap Welding ◽  
Cold Wire ◽  
Metal Arc Welding ◽  
Welding Processes

Narrow gap welding is a prevalent technique used to decrease the volume of molten metal and heat required to fill a joint. Consequently, deleterious effects such as distortion and residual stresses may be reduced. One of the fields where narrow groove welding is most employed is pipeline welding where misalignment, productivity and mechanical properties are critical to a successful final assemblage of pipes. This work reports the feasibility of joining pipe sections with 4 mm-wide narrow gaps machined from API X80 linepipe using cold wire gas metal arc welding. Joints were manufactured using the standard gas metal arc welding and the cold wire gas metal arc welding processes, where high speed imaging, and voltage and current monitoring were used to study the arc dynamic features. Standard metallographic procedures were used to study sidewall penetration, and the evolution of the heat affected zone during welding. It was found that cold wire injection stabilizes the arc wandering, decreasing sidewall penetration while almost doubling deposition. However, this also decreases penetration, and incomplete penetration was found in the cold wire specimens as a drawback. However, adjusting the groove geometry or changing the welding parameters would resolve this penetration issue.

scholarly journals Influence of Gravity on Molten Pool Behavior and Analysis of Microstructure on Various Welding Positions in Pulsed Gas Metal Arc Welding

2019 ◽  
Vol 9 (21) ◽  
pp. 4626 ◽  
Author(s):  
Jin-Hyeong Park ◽  
Sung-Hwan Kim ◽  
Hyeong-Soon Moon ◽  
Myung-Hyun Kim
Keyword(s):  
Weld Metal ◽  
Arc Welding ◽  
Molten Pool ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
High Speed Camera ◽  
Shielding Gas ◽  
Metal Arc Welding ◽  
The One

This study performed welding on various welding positions in the flat, overhead, and vertical down positions using a pulsed gas metal arc welding (P-GMAW) process. Despite the same amount of heat input on various welding positions, the welding characteristics varied depending on the welding positions. The effect of gravity on the welding process determined the different formation of the weld bead, and the influence of molten pool behavior on various welding positions changed the microstructure in the weld metal. The current and voltage signals were synchronized with a high-speed camera using a data acquisition (DAQ) system. To induce the one pulse one drop (OPOD) process of metal transfer, the shielding gas was used 95% Ar+5% CO2. The microstructure of the weld metal was analyzed in relation to molten pool behavior.

Welding Phenomena in Hybrid Laser-Rotating Arc Welding Process

2007 ◽  
Vol 539-543 ◽  
pp. 4093-4098 ◽  
Author(s):  
Hyun Byung Chae ◽  
Cheol Hee Kim ◽  
Jeong Han Kim ◽  
Se Hun Rhee
Keyword(s):  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Laser Illumination ◽  
Metal Arc Welding ◽  
Rotating Arc ◽  
Arc Welding Process ◽  
Conventional Laser

Hybrid laser-rotating arc welding (HLRAW) process was designed by combining the laser beam welding (LBW) process with the rotating gas metal arc welding (RGMAW) process. In this study, comparing with conventional HLAW, weld bead characteristics as a function of the various process parameters were evaluated for HLRAW. Moreover, welding phenomena were analyzed by high speed monitoring with laser illumination. The arc rotation enhances the weld pool motion, therefore it reduces the undercut formation which is one of most critical weld defects in the conventional laser-arc hybrid welding.

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