scholarly journals Comparative study of solidification behaviors of weld pool through modelling of heat transfer and fluid flow during single- and multiplelayer deposits of 2319-aluminum alloy based on variable polarity gas tungsten arc welding

2020 ◽  
Vol 38 (2) ◽  
pp. 112s-115s
Author(s):  
DU Jun ◽  
GENG Ruwei ◽  
WEI Zhengying ◽  
Ninshu Ma
Keyword(s):  
Heat Transfer ◽  
Aluminum Alloy ◽  
Fluid Flow ◽  
Comparative Study ◽  
Weld Pool ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Gas Tungsten Arc ◽  
Variable Polarity ◽  
Gas Tungsten

Heat Transfer Modelling and Investigation of the Effect of Pulse Frequency and Current in Pulsed Current Gas Tungsten Arc Welding

2014 ◽  
Vol 592-594 ◽  
pp. 395-399
Author(s):  
A. Prabakaran ◽  
R. Sellamuthu ◽  
Sanjivi Arul
Keyword(s):  
Heat Transfer ◽  
Weld Pool ◽  
Arc Welding ◽  
Gta Welding ◽  
Gas Tungsten Arc Welding ◽  
Transfer Model ◽  
Pulsed Current ◽  
Current Frequency ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

Gas Tungsten Arc Welding (GTAW) involves several process parameters. In Pulsed Current GTAW frequency of pulse and pulse to time ratio differentiates the characteristics of weld pool geometry of from GTAW. In the present work a simple heat transfer model for Pulsed Current GTA welding was developed and the weld pool dimensions were experimentally verified with AISI 1020 steel. Relationship between speed and pulsed current frequency on weld pool dimension was studied. Weld pool dimension of pulsed and non-pulsed GTAW is studied.

Numerical simulation of heat transfer and fluid flow in a double-sided gas-tungsten arc welding process

2003 ◽  
Vol 217 (1) ◽  
pp. 87-97 ◽  
Author(s):  
H Dong ◽  
H Gao ◽  
L Wu
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Arc Welding ◽  
Welding Process ◽  
Gas Tungsten Arc Welding ◽  
Experimental Results ◽  
Staggered Grid ◽  
Gas Tungsten Arc ◽  
Gas Tungsten ◽  
Arc Welding Process

Double-sided arc welding powered by a single power supply is a new type of welding process developed recently at the University of Kentucky. Experiments show that this process has advantages over conventional single-sided arc welding in enhancing penetration, minimizing distortion, improving solidification structure and welding aluminium without the necessity of using filler metal for cracking prevention. In this paper, a three-dimensional transient numerical model is developed for the heat transfer and fluid flow in double-sided gas-tungsten arc welding, including flat-position welding and vertical-up position welding. Based on a non-uniform staggered grid system, the governing equations are solved numerically using the SIMPLEC algorithm. The roles of the surface tension gradient, electromagnetic force and buoyancy force in determining the fluid flow and weld penetration are analysed and compared with those in the conventional arc welding process. The computed weld geometry is compared with experimental results and it is found that the computational results agree with the experimental results with reasonable accuracy.

Real-time observation of cathodic cleaning during variable-polarity gas tungsten arc welding of aluminium alloy

2009 ◽  
Vol 223 (9) ◽  
pp. 1143-1157 ◽  
Author(s):  
R Sarrafi ◽  
D Lin ◽  
R Kovacevic
Keyword(s):  
Real Time ◽  
Process Parameters ◽  
Arc Welding ◽  
Molten Pool ◽  
Gas Tungsten Arc Welding ◽  
Process Conditions ◽  
Current Electrode ◽  
Gas Tungsten Arc ◽  
Variable Polarity ◽  
Gas Tungsten

Online observation is expected to provide a better understanding of the cathodic cleaning of oxides from the molten pool during variable-polarity gas tungsten arc welding (VP GTAW) of aluminium alloys. In this paper, a machine-vision system with appropriate illumination and filtering is used to monitor in real time the effect of different process parameters on the cleaning of oxides from the molten pool during VP GTAW of Al 6061. Based on the observations, the process conditions under which a clean molten pool can be achieved are determined. In addition, the control of the welding process to maintain the consistency of cathodic cleaning is discussed. The results showed that in order to have an oxide-free molten pool, the solid surface in front of the molten pool should be cleaned from oxides by the electric arc. The choice of process parameters to satisfy this condition has been discussed. It was found that the percentage of direct current electrode positive (DCEP) polarity in the cycle of current has the highest impact on the cathodic cleaning, with the arc current having less influence, and the welding speed showing the least effect. Furthermore, in order to keep the consistency of oxide cleaning, process parameters should be set or controlled to maintain the cleaned zone larger than the molten pool.

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